Creatures like sea stars, jellyfish, sea urchins and sea anemones don't have brains, yet they can capture prey, sense danger and react to their surroundings.

So does that mean brainless animals can think?

"Brainless does not necessarily mean neuron-less," Simon Sprecher, a professor of neurobiology at the University of Fribourg in Switzerland, told Live Science in an email. Apart from marine sponges and the blob-like placozoans, all animals have neurons, he said.

Creatures like jellyfish, sea anemones and hydras possess diffuse nerve nets — webs of interconnected neurons distributed throughout the body and tentacles, said Tamar Lotan, head of the Cnidarian Developmental Biology and Molecular Ecology Lab at the University of Haifa in Israel.

"The nerve net can process sensory input and generate organized motor responses (e.g., swimming, contraction, feeding, and stinging), effectively performing information integration without a brain," she told Live Science in an email.

This simple setup can support surprisingly advanced behavior. Sprecher's team showed that the starlet sea anemone (Nematostella vectensis) can form associative memories — learning to link two unrelated stimuli. In the experiment, the researchers trained sea anemones to associate a harmless flash of light with a mild shock. Eventually, the light alone made them retract.

Another experiment showed that sea anemones can learn to recognize genetically identical neighbors after repeated encounters and curb their usual territorial aggression. The fact that anemones change their behavior toward genetically identical neighbors suggests they can distinguish between "self" and "non-self".

A study led by Jan Bielecki, a neurobiologist at Kiel University in Germany, showed that box jellyfish can associate visual cues with the physical sensation of bumping into objects, helping them navigate around obstacles more effectively.

"It is my core belief that learning can be achieved by single neurons," Bielecki told Live Science in an email.

So if animals with nerve nets instead of brains can remember and learn from experience, does that mean they can think?

"This is a tricky question to answer," Sprecher said. The definition of 'thinking' depends on the field. Psychologists, biologists and neuroscientists define 'thinking' differently, Bielecki noted.

Additionally, "thinking is too vague a concept," Bielecki said. Scientists study things like decision-making, pattern recognition, associative learning, memory formation and inductive reasoning. Each has their own, much narrower definition.

Ken Cheng, a professor of animal behavior at Macquarie University in Australia, noted that scientists tend to use the word "cognition" instead of "thinking."

"Scientists shy away from the term 'thinking' because thinking, to most of us, means something running through the head, and we don't have a good way to verify that in another animal or nonanimal species," Cheng told Live Science. Even "cognition" does not have an agreed-upon definition, he said, but "in the broadest sense, cognition is information processing — using information from the world, including the world inside an organism, to do things."

If thinking is that broad sense of cognition, then all life-forms think, Cheng said. This includes animals like marine sponges and placozoans, which process information about their surroundings to keep themselves alive. But when it comes to "advanced cognition," which goes beyond basic learning, however, scientists aren't sure whether brainless animals can think, Cheng said.

Basic cognition can be regarded as any change in behavior that goes beyond reflexes, Sprecher said. By that definition, brainless animals do show cognition. "However, more advanced types of cognitive abilities might require consciousness or self-awareness," he said.

Lotan pointed out that cnidarians (an animal family that includes jellyfish, sea anemones and many other marine invertebrates), which evolved more than 700 million years ago, continue to thrive while many animals with brains have long disappeared.

"This resilience suggests that they possess a unique adaptive system enabling them to endure and flourish through extreme environmental changes over geological timescales — despite lacking a brain," she said. Their neurons allow them to sense and interpret their surroundings, "perhaps representing a rudimentary form of thinking."

Brain quiz: Test your knowledge of the most complex organ in the body

A rocket-like jellyfish, a majestic Komodo dragon and a dangerous surfing encounter are just a few of the stunning photographs captured by the finalists for the Ocean Photographer of the Year 2025 competition. The competition includes categories such as Impact and Hope, which have solicited breathtaking photographs that capture diverse forms of marine life and human interaction with the ocean.

The overall and category winners of the contest, hosted by Oceanographic Magazine and watch company Blancpain, will be announced in September. But all of the finalists' photos emphasize the need to protect the planet.

"In the midst of a deepening climate and biodiversity crisis on our blue planet, ocean photography has never been more important," Will Harrison, director of Ocean Photographer of the Year, said in a statement from the organization. "These images are far more than just beautiful; they are powerful visual testaments to what we stand to lose, and they remind us of the urgent need for protection."

Here are some of the gorgeous photos.

Synchronized swimmers

Photographer Yuka Takahashi, a finalist in the "Young" category of the competition, captured a pair of synchronized humpback whales in French Polynesia swimming through rays of sun. "These two humpback whales are always seen together, and I was fortunate to capture this rare moment of synchronicity," Takahashi said. "To me, this photo reflects the strong bond between them while also revealing their playful and curious personalities."

Warm bath

In this image, snapped by "Wildlife" category finalist and photographer Suliman Alatiqi, a Komodo dragon (Varanus komodoensis) looms over an Indonesian shore. Because Komodo dragons are cold-blooded, they rely on cold water or mud to regulate their body temperature in the summer. They also travel across seabeds to search for food and mates.

Related: Ocean Photographer of the Year 2024: See stunning photos of hungry whale, surfing seagull, freaky fish babies, land-loving eel and adorable toxic octopus

Collateral damage

Photographer Natnattcha Chaturapitamorn snapped this image of fishers unloading their catches at a Bangladeshi harbor during sunrise, which is a finalist in the "Impact" category.

"Amidst this industrious energy, the presence of an endangered species serves as a reminder of the urgent need to protect marine biodiversity," Chaturapitamorn said. "As global fish stocks decline, safeguarding threatened species like this is vital, not only for ecological balance but for the long-term sustainability of fishing communities that depend on the ocean’s bounty."

Stranded

On July 1, wildlife veterinarians received a call about a humpback whale stranded on an Australian beach, and photographer Craig Parry documented the harrowing scene from above. For 15 hours, rescue teams and other members of the community worked to save the whale but were unsuccessful.

"While the outcome was heartbreaking, witnessing the collaboration and compassion shown by multiple agencies and volunteers was incredibly moving — a powerful reminder of what can be achieved when people come together with a shared purpose," said Parry, whose photo is a finalist in the "Human Connection" category.

School of fish

This mesmerizing image, taken in Indonesia by photographer Kim Hyeon Min, captures a school of juvenile fish circling around a tower of coral and is a finalist in the "Hope" category. The vibrancy of the coral suggests it has been unaffected by bleaching and is still able to host a miniature ecosystem for surrounding creatures. "In a time when marine ecosystems are rapidly disappearing, this image is a reminder of what we still have — and a hopeful glimpse of what we must protect for the future," Hyeon Min said.

Otherworldly jellyfish

Jellyfish are often described as alien-like, and this ethereal image captured in Spain by photographer Toni Bertran Regàs takes that comparison to new heights with this finalist in the "Fine Art" category.

"I've always been fascinated by the resemblance between jellyfish and space rockets," Bertran Regàs said. "I was looking for a photograph that conveyed that connection: a rocket leaving Earth. To do this, I used a fisheye lens and took the photo just as the sun was rising. Snell's Window" — an underwater optical phenomenon — "helped me create the Earth, the particles were the stars, and the sun luckily appeared behind it."

Monster waves

Photographer Ben Thouard, a finalist in the "Adventure" category, captured a day of rough seas in Nazaré, Portugal. Though the water was too dangerous for many surfers, two gave it a go. Despite the difficulty of photographing between huge waves and through salt water in the air, Thouard eventually shot this moment.

A mysterious oceanic barrier is stopping some deep-sea jellyfish in the Arctic from reaching the Atlantic Ocean, a new study has found.

The animals, members of the jellyfish subspecies Botrynema brucei ellinorae, inhabit depths between 3,300 and 6,600 feet (1,000 to 2,000 meters) and can be divided into two groups based on whether individual specimens have a knob on their umbrella-like bell structure.

"This jellyfish [...] has two different shapes depending on which area it occurs in — one with a distinctive knob at the top and one without," study lead author Javier Montenegro, a biologist at the University of Western Australia, said in a statement.

The sea creature’s anatomy somehow influences its worldwide distribution: jellyfish with the distinctive knob live across all oceans and latitudes, while those without a knob have only ever been documented in the Arctic and sub-Arctic, Montenegro said.

For the study, Montenegro and his colleagues examined observational and photographic records of B. brucei ellinorae going back more than 120 years. The researchers then mapped the distribution of the jellyfish subspecies by combining these records with genetic analyses. They published their results in the online version of the journal Deep Sea Research on July 3.

Related: Jellyfish Lake: Palau's saltwater pool with a toxic bottom and surface waters brimming with millions of jellyfish

Genetic data indicated that specimens of B. brucei ellinorae with and without knobs in the Arctic and sub-Arctic were almost identical to specimens with knobs in the western Atlantic. This suggested that, despite strong genetic similarities, knobless jellyfish were unable to leave the frigid waters.

So how does the animal’s shape determine its distribution? It appears that access to the Atlantic is blocked by a barrier — not a physical obstacle, but a biological one, or one determined by local geography.

"The differences in shape, despite strong genetic similarities across specimens, above and below 47 degrees north, hint at the existence of an unknown deep-sea bio-geographic barrier in the Atlantic Ocean," Montenegro said.

This barrier is located within the North Atlantic Drift, a warm ocean current that extends northward from the Gulf Stream, but it's unclear if the current itself is the obstacle for knobless jellyfish. A possible explanation could be that there are predators lurking beyond the North Atlantic Drift that knobless jellies aren't equipped to escape — but why having a knob may be advantageous remains unclear.

The barrier "could keep specimens without a knob confined to the north while allowing the free transit of specimens with a knob further south," Montenegro said.

No such barrier is required to keep knobless B. brucei ellinorae in Arctic waters on the Pacific Ocean side, because the Bering Strait already blocks most deep-sea creatures from moving south, according to the study. The strait is only 165 feet (50 m) deep, so deep-sea jellyfish like B. brucei ellinorae can't cross it.

The discovery of a potential oceanic barrier associated with the North Atlantic Drift is important, as it could help scientists better understand evolutionary relationships and dispersal patterns. "The presence of two specimens with distinctive shapes within a single genetic lineage highlights the need to study more about the biodiversity of gelatinous marine animals," Montenegro said.

A NASA astronaut has captured an electrifying image of Earth from space, featuring a gigantic, jellyfish-shaped "sprite" of red lightning shooting upwards above a thunderstorm in North America. The rare phenomenon is still poorly understood, despite being studied for more than 30 years.

Nichole Ayers, the pilot of SpaceX's Crew-10 mission and member of International Space Station (ISS) expeditions 72 and 73, snapped the striking photo on Thursday (July 3) as the space station passed above a large thunderstorm hanging over parts of Mexico and the southern U.S., including California and Texas.

"Just. Wow. As we went over Mexico and the U.S. this morning, I caught this sprite," Ayers wrote on the social platform X. "Sprites are TLEs or Transient Luminous Events, that happen above the clouds and are triggered by intense electrical activity in the thunderstorms below," she added.

TLEs are a range of visual phenomena that occur in the upper atmosphere during thunderstorms, including upward-shooting blue jets and UFO-like rings of light, known as ELVES. However, the most common TLEs are sprites, like the one photographed by Ayers.

Sprites are sometimes referred to as jellyfish because they contain multiple branches of light that spread out like tentacles, while others call them "carrots" because they can be accompanied by fainter tendrils that trail behind them in the opposite direction like plant roots. They are often associated with large thunderstorms, including those produced by hurricanes.

Related: Electrifying time-lapse image captures 100 lightning bolts torching the sky

Sprites can range in size and shape, with the largest reaching up to 50 miles (80 kilometers) above Earth's surface. They have a red color because they interact with nitrogen in the upper atmosphere, according to NASA's Earth Observatory.

Sprites were first properly observed in the 1950s by airline passengers but were not photographed until 1989. The red jellyfish have also been spotted in the atmosphere of Jupiter, and they are thought to occur on Saturn and Venus, according to Live Science's sister site Space.com.

But despite years of research, researchers are still unsure why some lightning strikes cause sprites and others don't, according to FOX Weather.

TLEs from space

Sprites and other TLEs can be photographed from Earth's surface if the conditions are right. However, ISS astronauts are uniquely well-positioned to see TLEs and frequently see the flashes of lightning strikes at the same time, providing useful data to help researchers figure out how these phenomena work.

"We have a great view above the clouds, so scientists can use these types of pictures to better understand the formation, characteristics, and relationship of TLEs to thunderstorms," Ayers wrote.

One of the most recent examples of this was in March, when an unnamed ISS astronaut snapped faint red sprites glowing at the end of a "gigantic jet" of lightning shooting upward above New Orleans.

Another excellent example was an eerie red jellyfish that seemed to float independently in Earth's atmosphere, high above a flash of lightning in June 2024, Space.com previously reported.

Astronomers have discovered what seems to be a new "jellyfish" galaxy about 12 billion light-years away from Earth using high-resolution imaging from the James Webb Space Telescope (JWST).

The galaxy appears to have tentacle-like trails of gas and stars jutting off from one side, likely making it a jellyfish galaxy — a class of galaxies that drip tendrils of star-forming material as they swim through space. Though more analysis is needed to confirm whether the newfound galaxy truly falls into this category, all signs so far indicate that it does.

Ian Roberts, an astronomer at Waterloo University, found the unique galaxy while sifting through images taken by JWST. His team's research is available to read on the preprint server arXiv, but has not yet been peer reviewed.

"The fact that an interesting galaxy such as this one could be found in such a cursory way suggested that there would be real value in doing a truly systematic search for these sorts of objects," Roberts told Live Science in an email.

Jellyfish galaxies

Jellyfish galaxies develop their tentacles as they undergo a phenomenon called ram pressure stripping, which happens when a galaxy moves through the dense medium between other closeby galaxies within a galaxy cluster. This movement eventually pushes some gas and stars out of the roaming galaxy, leaving them to trail behind. These tentacles sometimes trigger a large number of stars to form.

Though astronomers don't believe this kind of pressure stripping to be rare in nearby space, the jellyfish stage is short on the cosmic timescale, so it's unusual to capture these aquatic forms before they disappear, Roberts said.

Related: 'Previously unimaginable': James Webb telescope breaks its own record again, discovering farthest known galaxy in the universe

Farther out in the universe, though, where JWST observed this new jellyfish galaxy, "we really have no idea" how common they are, Roberts said.

Jellyfish galaxies provide a way to study galaxy evolution and star formation. Some galaxies in dense environments form many fewer new stars than others, and understanding the reasons why is fundamental to our understanding of how galaxies change over time.

Stars are also affected by ram pressure stripping. Though a surge of new stars may form in the trail behind a jellyfish galaxy, the loss of gas in the center of the galaxy could prevent formation there, according to Roberts.

While ram pressure stripping is the best explanation for the new observations, there may be other possible reasons that the galaxy looks the way it does, and they can't yet be ruled out. The jelly's appendages could be an illusion; parts of the image that show the tentacles were taken using a method that creates blurring, introducing some uncertainty, Roberts said.

Next steps

With the limited existing data about jellyfish galaxies, it's not clear to astronomers whether a jellyfish galaxy so far out in space is rare or not. "We don't know the answer yet, but the more galaxies like this that are discovered the more clues that we get," Roberts said.

The research team is hoping to sharpen their image by gathering data from other telescopes, which would allow them to determine whether or not what they've observed is indeed a jellyfish galaxy.

James Webb Space Telescope quiz: How well do you know the world's most powerful telescope?

Jellyfish Lake is a pool of saltwater on Eil Malk island in Palau that is brimming with golden jellyfish — a subspecies not found anywhere else on Earth. The lake typically houses around 5 million jellyfish, according to the Coral Reef Research Foundation (CRRF) — although there have been years, including 2005, when the number of jellies exceeded 30 million.

Jellyfish Lake is highly stratified, meaning it is separated into distinct layers. Golden jellyfish inhabit the top layer, which extends from the surface down to about 43 feet (13 meters) deep. Between 43 and 50 feet (13 to 15 m) deep, the lake contains pink bacteria that prevents light and oxygen from reaching the bottom layer of the lake, which sits between 50 and 100 feet (15 to 30 m) deep.

The lake is connected to the ocean through small cracks in Eil Malk's limestone rock, but it is nevertheless considered an isolated ecosystem, according to CRRF learning resources. Jellyfish Lake formed toward the end of the last ice age, roughly 12,000 years ago, due to ice melt and sea level rise. Sea water filled depressions in Palau's islands and elsewhere, creating three types of lakes: stratified lakes, such as Jellyfish Lake; mixed lakes, which are connected to the ocean via large tunnels; and transitional lakes, which are also connected to the ocean, but via smaller tunnels.

Related: 'A challenge and an opportunity for evolution': The extreme, hidden life thriving in Earth's most acidic and alkaline lakes

Jellyfish Lake's pink layer exists because the conditions in that layer suit a type of bacteria that are pink in color. These bacteria create a barrier between the lake's oxygenated top layer and its oxygen-free bottom layer. This barrier bobs up and down depending on density changes in the water.

The lack of oxygen beneath the pink layer is deadly for most life. What's more, plant and animal decomposition at the bottom of Jellyfish Lake releases poisonous hydrogen sulfide gas, which means only certain microbes can survive there, according to the CRRF.

Jellyfish Lake's endemic golden jellyfish (Mastigias papua etpisoni) population likely evolved from a handful of spotted jellyfish (Mastigias papua) that became trapped when sea levels dropped following the lake's formation. Unique conditions inside the lake forced the jellies to adapt, leading to a new subspecies, which is named after Palau's former president, Ngiratkel Etpison.

Golden jellyfish have a symbiotic relationship with single-celled, photosynthetic algae that give them nutrients in exchange for a place to live. The jellyfish follow an unusual migration pattern that involves swimming towards the sun as it rises and sets, always avoiding the lake's edges where jellyfish-eating sea anemones (Entacmaea medusivora) lurk. These predatory anemones prefer the shadows, so golden jellyfish have evolved to stay in sunlit waters. Every morning, the jellies crowd along the lake's eastern shadow line, and visitors may occasionally see a "wall" of jellyfish forming underwater, according to the CRRF.

While golden jellyfish have stinging cells, the sting is so mild that humans can't feel it. Visitors can safely swim in Jellyfish Lake, but people should take care not to accidentally introduce non-native species to the lake, as these can, and already do, endanger the fragile ecosystem, according to the CRRF.

Discover more incredible places, where we highlight the fantastic history and science behind some of the most dramatic landscapes on Earth.

Rubbery blue sea creatures are washing up on California beaches by the thousands.

The translucent blobs, known as by-the-wind sailors (Velella velella), began piling up Sunday (March 30) along several beaches in the San Francisco Bay Area. Although the animals look like jellyfish, they're more closely related to the Portuguese man o' war (Physalia physalis).

Each creature, which can grow up to 4 inches (10 centimeters) long, is actually a colony of hundreds of smaller organisms with specialized functions. The velellas' S-shaped sails crest the surface of the ocean, carrying them through the warm waters they call home, while their short tentacles hang below the water to catch their prey.

By-the-wind sailors' stings are relatively mild compared with those of their more dangerous cousins, though experts recommend that you avoid touching your face or eyes after coming into contact with one.

Related: The weirdest creatures to wash ashore

These blobs have turned up en masse on beaches around the world before, usually in the spring and early summer. The creatures typically live in the open ocean, but large storms blowing in over the coast can propel them onto shore.

"This time of year the ocean along the west coast transitions into upwelling season," Jennifer Stock, an education specialist at Greater Farallones National Marine Sanctuary in California, told SFGate. Upwelling occurs when cold, nutrient-rich water rises from deep in the ocean.

"The true start/end of that season shifts every year based on a wide set of variables, but the presence of velellas indicates a shift in winds and currents, and the velellas, which are propelled by wind/current alone, get directed to the beaches," Stock said.

Because the velellas can't steer themselves, they get stranded on the beach until either the tide carries them back out to sea or they die. Recent northward winds and storms have carried the animals to the Bay Area over the past week — and experts predict more could wash up in the coming days.

"I would say if we get a nice high pressure system, which is generally associated with nice clear skies, but also upwelling, it's going to really concentrate them just offshore," Raphael Kudela, an oceanographer at the University of California, Santa Cruz, told KQED. "And then all we need is a break in that — a low [pressure system] coming through or the high weakening — and then we would probably see a nice big raft of them come washing into the beaches."

"It's kind of cool to see," Kudela added. "They're really beautiful."

Name: Giant phantom jelly (Stygiomedusa gigantea)

Where it lives: Every ocean except the Arctic Ocean

What it eats: Plankton and small fish

Why it's awesome: Earth's oceans are home to many secretive and unusual creatures that humans rarely see — including giant phantom jellies. These elusive deep-sea creatures have a 3.3-foot-wide (1 meter) bell and four ribbon-like arms that grow up to 33 feet (10 m) long, making them among the largest invertebrate predators in the ocean.

The first giant phantom jelly specimen was collected in 1899 and described in 1910. The species has only been spotted around 120 times since. This is because these jellies generally live in deep waters, down as far as 22,000 feet (6,700 m) below the surface.

They have compressible, squashable bodies, which help them to survive the incredibly high pressures they experience at these depths.

In 2022, researchers observed giant phantom jellies on three separate occasions during submersible expeditions in Antarctica, with videos and images showing the creatures swimming at relatively shallow depths of between 260 and 920 feet (80 to 280 m). In a study reporting the sightings, researchers said it's likely the jellies live closer to the surface in high southern latitudes because seasonal variations in sunlight may drive prey closer to the surface.

Unlike other jellyfish, giant phantom jellies don't have stinging tentacles to catch prey. Instead, they wrap their arms around their food — usually plankton or small fish — and hoist them into their mouths.

Related: Newly discovered jellyfish is a 24-eyed weirdo related to the world's most venomous marine creature

Giant phantom jellies also differ from other jellyfish by being viviparous, meaning they give birth to live young. The young develop inside the mother before detaching from inside the hood and swimming out of their mother's mouth.

When there is visible light, giant phantom jellies emit a slight orange-red light via bioluminescence — meaning they produce light through natural chemical reactions. It's not known exactly why they glow, but researchers believe it could be to communicate, confuse predators, lure prey or attract potential mates. However, because these jellies live in the deep ocean — where red light cannot penetrate very far — their glow is very faint, which likely helps to keep them hidden.

These jellyfish are solo explorers, but they also appear to help to protect smaller sea creatures. During an expedition in the Gulf of California, researchers from the Monterey Bay Aquarium Research Institute spotted small fish, pelagic brotula (Thalassobathia pelagica) sheltering underneath a giant phantom jelly. In return, the fish aided the jelly by removing parasites.

Venom is one of the animal kingdom's oldest and most effective weapons, providing creatures with an effective means of attack or defense. Spider venom, for example, is thought to have evolved from a single protein 375 million years ago, while snake venom first appeared 60 to 80 million years ago. Scientists have even identified a dinosaur from the early Cretaceous period (145 to 66 million years ago) that used venom to place its prey in a "rapid state of shock," according to a study published in 2009.

Unlike poisonous animals, which have toxins that victims inhale, absorb or swallow, , venom is injected into the target.

Venom has evolved multiple times across all animal groups, except birds, with its potency developing through a chemical arms race alongside the target's resistance to the venom. An estimated 15% of animals are venomous, from jellyfish the size of your fingernail through to giant lizards and snakes. Here are 32 of the most venomous animals on Earth.

Irukandji box jellyfish  

The Irukandji box jellyfish (Carukia barnesi) is a tiny species, growing to just 0.8 inch (2 centimeters) in diameter, yet its stinging tentacles, which can stretch up to 3.2 feet (1 meter), can pack a very nasty punch. Its venom — which causes Irukandji syndrome — attacks the nervous system and can paralyze the lungs and heart. The jellyfish attack using the specialized stinging cells that line their four tentacles, firing venom-filled barbs at their target, according to the Australian Museum. Their venom is the Irukandji's defense system against would-be predators.

Platypus

Adult male platypus (Ornithorhynchus anatinus) have hollow spurs on their hind legs that are linked to glands that produce venom. Their venom production peaks during mating season, leading scientists to believe it is used as a weapon to compete with other males for access to females, according to the Australian Platypus Conservancy.

They inject venom by wrapping their legs around the victim and driving the spurs into their rival's flesh, according to a blog written by Bianca op den Brouw, a toxicologist at the University of Melbourne in Australia. Platypus venom is not lethal to humans (or other platypuses), but it can cause swelling and severe pain.

Black mamba 

Black mambas (Dendroaspis polylepis) are the longest venomous snakes in Africa, reaching around 8 feet (2.5 m) in length. They are also one of the fastest snakes on Earth, hitting speeds of around 12.5 mph (20 km/h), according to National Geographic.

If untreated, a bite from a black mamba is almost always fatal. Each fang of an adult black mamba contains between 12 and 20 drops of venom, and it only takes two drops to kill a human, wrote Ryan Blumenthal, a forensic pathologist at the University of Pretoria, for The Conversation.

Geography cone snail 

Geography cone snails (Conus geographus), found in reefs of the Indo-Pacific, grow up to 6 inches (15 cm) long and are the most venomous of the 500 known cone snails. There are more than 10,000 active compounds in their venom, which is delivered through a tooth that is propelled from a flexible and extendable appendage called a proboscis, according to National Geographic.

There is no antivenom for a cone snail sting, and treatment involves keeping the victim alive until the toxins wear off. Around 15 people have died from cone snail stings in the last 30 years, according to a 2016 study published in the International Journal of Clinical Pharmacology and Therapeutics.

Bullet ant 

Bullet ants (Paraponera clavata) deliver one of the world's most excruciating ant stings — often likened to being shot with a bullet — and the pain can last unabated for up to 24 hours. These creatures, which are just 0.8 inches (2 cm) in length, pack a powerful sting in their tiny bodies. Bullet ants inject venom that targets nerve cells involved in pain perception, causing paralysis at the site of the sting and uncontrollable shaking. While their venom paralyzes and kills small organisms, stings are not fatal to humans.

Komodo dragon 

The largest lizards on Earth, Komodo dragons (Varanus komodoensis) can grow up to 10 feet (3 m) in length. Along with huge, serrated teeth they use to shred prey and bacteria-filled saliva, Komodo dragons also use venom produced in glands in their lower jaws to take down prey.

This venom causes shock and prevents blood from clotting, according to a study published in 2009, ultimately finishing a victim off and allowing the dragons to feast at a leisurely pace.

Komodo dragons are closely related to Megalania (Varanus priscus), an enormous, extinct monitor lizard that could reach up to 23 feet (7 m) in length — making it the largest venomous animal to have ever lived, according to the study.

Bruno's casque-headed frog 

Bruno's casque-headed frogs (Aparasphenodon brunoi) — unlike their poisonous relatives that deliver toxins through skin secretions — are venomous. These little frogs inject their deadly venom through spikes on their heads, according to a study published in 2015.

Their venom is stored in skin glands around their heads, ready to be delivered through the bony spines that line their skulls. The venom of Bruno's casque-headed frogs is an estimated 25 times stronger than that of a pit viper. Just 0.03 ounces (1 gram) of venom from this species could kill 80 people, according to New Scientist.

Blue-ringed octopus 

There are four species of blue-ringed octopus: the greater blue-ringed octopus (Hapalochlaena lunulata), the southern blue-ringed octopus (Hapalochlaena maculosa), the blue-lined octopus (Hapalochlaena fasciata) and the common blue-ringed octopus (Hapalochlaena nierstraszi). They are all small enough to fit in the palm of your hand and contain a powerful neurotoxin that can paralyze and kill humans within minutes. There's also no known antidote for their venom.

They are named for the colorful rings that appear when the octopus feels threatened or is getting ready to dispense venom.

Russell's viper 

One of the world's deadliest snake species, the Russell's viper (Daboia russelii) is responsible for the majority of the 58,000 snake bite deaths in India every year, according to a study published in 2021. The viper kills so many because it combines potent venom with close proximity to humans — snakes often rest in paddy fields and cross paths with farmers during harvest season.

Their venom can lead to a wide range of symptoms, including severe bleeding, organ damage and kidney failure, according to a 2014 report. Antivenom is available, but people bitten are often in rural areas without quick access to care, while many still rely on traditional healers instead of medical professionals.

Sydney funnel-web spider 

Sydney funnel-web spiders (Atrax robustus) are found across coastal areas of eastern Australia. Females can reach up to 3.14 inches (8 cm) across, while the largest male recorded was 3.1 inches (7.9 cm) across — about the size of an Olympic gold medal. The venom produced by males contains a neurotoxin that can be deadly for humans.

A bite from a Sydney funnel-web spider can kill in as little as 15 minutes, although no deaths have been recorded since antivenom was introduced almost 50 years ago.

Saddleback caterpillar 

Saddleback caterpillars (Acharia stimulea) are the larvae of slug moths. They are brightly colored and possess venomous spines that protrude from its body. They are found across the eastern United States, from Florida up to New York and as far west as Texas.

The spines are pointed and hollow and embed deeply into the tissue of a victim before breaking off. The venom can cause a range of symptoms, from hives to anaphylactic shock, blood clots and hemorrhaging, according to the University of Florida.

Brazilian wandering spiders 

All Brazilian wandering spiders are venomous and their cocktail of toxins affects the neuromuscular system. Humans experience a burning pain at the site of a bite, along with sweating and goosebumps. Around 30 minutes after a bite, victims can experience convulsions, blurred vision, a fast or slow heart rate and hypothermia, along with other symptoms — including painful and long-lasting erections.

Fatalities are rare, however. Fifteen deaths have been attributed to these spiders in Brazil since 1903, according to a study published in 2000.

Deathstalker scorpion 

The deathstalker scorpion (Leiurus quinquestriatus) is one of the deadliest scorpion species in the world.Its sting causes pain and paralysis, according to Arizona State University. These scorpions live in desert and scrublands from North Africa to the Middle East and hide under rocks as they wait for prey to pass. It is a large species, reaching almost 4 inches (10 cm) long, and can strike at incredible speeds of up to 51 inches (130 cm) per second.

While very painful, the venom is rarely fatal to healthy adults. It is also being investigated for its potential role in cancer treatments.

Slow loris 

Slow lorises (genus Nycticebus) are the world's only venomous primate. These furry little animals, native to South and Southeast Asia, have a unique delivery system for their venom. They secrete toxic oil from glands on their upper arms, and when they feel threatened, they raise their arms and lick these glands, combining the oil with their saliva to produce a venomous bite.

This venom-packed bite causes flesh to rot. It can also result in anaphylactic shock and, in rare cases, death.

King cobra 

King cobras (Ophiophagus hannah) are the longest venomous snake on Earth, measuring up to 18 feet (5.5 m), according to the Natural History Museum in London. If they feel threatened, they lift their heads off the ground and flare out the skin around their heads. While their venom is not the most potent, the snake can deliver huge quantities in each bite — and they tend to strike several times during each attack. A single bite can kill a human in around 15 minutes, Sean B. Carroll, molecular biologist at the University of Maryland, wrote in The New York Times.

Red imported fire ant 

Red imported fire ants (Solenopsis invicta) are native to South America, but they have gained a foothold as an invasive species in the United States and Australia. Worker fire ants attach to the skin using their mandibles and then inject the venom into their victims with their stinger, according to the University of Florida.

Stings are painful and can trigger allergic reactions, including anaphylactic shock, which in rare cases, can be fatal. Around 1% of the population is hypersensitive to the venom and are at risk of experiencing lethal allergic reactions, according to Texas A&M University.

Inland taipan 

Native to central and eastern Australia, inland taipans (Oxyuranus microlepidotus) are one of the most venomous species of snake in the world. Their venom is one of the most potent ever discovered, according to a study published in 2007. A single bite contains enough venom to kill 100 humans, according to the Australia Zoo.

Symptoms of an inland taipan bite include headache, nausea, abdominal pain and paralysis. Coupled with its extreme potency, their venom also contains a special enzyme that helps increase the rate of absorption.

Luckily, inland taipans rarely come into contact with humans, meaning few bites are ever recorded.

Common vampire bat 

With a wingspan of just 7 inches (18 cm), common vampire bats (Desmodus rotundus) are venomous mammals that use their toxic bite to help them feed on blood. They normally target large animals like cattle, horses, pigs and sheep while they are sleeping. Vampire bats will use their sharp incisors to puncture their victim's skin before delivering venom from the sides of its tongue as it sucks up the blood via ducts on either side of its tongue.

The bite is described as painless, and their venom has anticoagulant properties that delays blood clotting, allowing the bat to feed for as long as it needs.

Stonefish 

Stonefish (Synanceia) are a group of fish consisting of five species, all of which can deliver a potentially fatal venomous sting. These fish, found in coastal reefs in the Indian and Pacific oceans, sit completely still on the seafloor, waiting for unsuspecting prey to swim by.

Their venom is designed for defense, rather than to subdue their next meal. Their dorsal spines contain venom that is released under pressure — if stood on, for example. A sting from a stonefish can cause extreme pain and swelling at the site, which can spread to the rest of the leg or arm within minutes, according to Mount Sinai. Fatalities are extremely rare, but can happen.

Southern black widow spider 

Southern black widow spiders (Latrodectus mactans) are a small species found throughout the southeastern U.S. that pack a nasty bite. Their venom is a highly potent neurotoxin, according to the Centers for Disease Control and Prevention. It causes pain at the bite area, which then spreads to the chest, abdomen and potentially the entire body.

Bites are rarely fatal, but they can kill children and older adults, with severe symptoms including seizures and difficulty breathing, according to Mount Sinai.

Portuguese men-of-war 

Portuguese men-of-war (Physalia physalis) are venomous siphonophores that resemble jellyfish. These creatures actually form up a colony of genetically identical individuals with different forms and functions, which work together as one. They float along the surface of the ocean, leaving long strands of tentacles trailing in the water, sometimes reaching lengths of 100 feet (30 m), according to the National Oceanic and Atmospheric Administration (NOAA). Their tentacles contain barbed tubes that paralyze and kill their prey. While their sting is rarely fatal to humans, it is extremely painful.

Eastern brown snake 

Australia's deadliest snake, the eastern brown snake (Pseudonaja textilis), has highly potent venom that can cause internal bleeding and paralysis, according to the Australian Museum. The initial bite is often painless and difficult to detect, meaning a person won't immediately realize they are in danger. Eastern brown snakes are often found in city suburbs and large towns, as well as agricultural land, bringing them in close contact with people regularly. Many bites result from people trying to kill the snakes.

Red lionfish 

Red lionfish (Pterois volitans) are beautiful but deadly fish that have venom glands within the grooves of its spine. This venom causes excruciating pain, respiratory distress and paralysis, according to NOAA. Red lionfish are native to the Indian and South Pacific oceans, but they have become an invasive species in the Caribbean and along the southeastern coast of the U.S., where their population has exploded.

Redback spider 

Redback spiders (Latrodectus hasselti), also known as Australian black widows, tend to live in areas where humans are around and often find shelter in junk piles, sheds and toilets. They can live pretty much anywhere there is food for them. Bites from this venomous spider are common, with more than 250 of the bites requiring treatment with antivenom each year, according to the Australian Museum. Bites can be fatal, and the venom acts on the nerves to cause pain, muscle weakness, nausea and vomiting.

Gila monster  

Gila monsters (Heloderma suspectum) are venomous lizards found across the U.S. Southwes, and their bites cause agonizing pain. Gila monsters are black with a pink or orange pattern, and reach up to 22 inches (56 cm) long. They have large, grooved teeth in their lower jaws, which release venom as the monsters chew, according to the Smithsonian's National Zoo & Conservation Biology Institute. Their venom is similar in toxicity to a western diamondback rattlesnake (Crotalus atrox), and in humans, causes burning pain, nausea and high blood pressure, among other symptoms. In extreme cases, it can cause death.

Asian giant hornet 

Also known as "murder hornets" because of their intensely painful sting, Asian giant hornets (Vespa mandarinia) can grow up to 2 inches (5 cm) long and their stinger can release large quantities of venom. Just a couple of these huge hornets can kill an entire bee hive in 2 hours. While their venom is less toxic than other hornet species, they can inject more in each sting. Their stinger is long enough to break through thick clothing, according to the Natural History Museum in London. They can also sting multiple times, making them dangerous to young children and people with certain health conditions.

Flower urchin 

Flower urchins (Toxopneustes pileolus) are considered one of the world's most venomous species of sea urchin — Toxopneustes means "toxic breath." They deliver their venom through claw-shaped flower-like appendages, which clasp shut when prey approaches and keeps it trapped. A sting from a flower urchin causes pain, respiratory problems and muscular paralysis, according to Medscape. Deaths from sea urchins have been reported, including a pearl diver who was supposedly stung by a flower urchin and drowned after falling unconscious from the venom.

Crown-of-thorns starfish 

Reaching up to 18 inches (46 cm) wide, crown-of-thorns starfish (Acanthaster planci) are carnivorous predators that feed by extruding their stomachs out through their mouths. They then wrap their stomachs around corals to digest the tissues. They have up to 21 arms and are covered in toxic spikes that can deliver nasty stings to humans. The venom causes pain, vomiting and swelling — and the pain can persist, because they normally leave spines in their victims that have to be surgically removed.

Common krait  

The common krait is one of the "big four" species of snake in India that cause the most deaths. The venom of common kraits (Bungarus caeruleus) causes muscular paralysis that can prevent the diaphragm from moving. This stops air from entering the lungs, causing the victim to suffocate. The snake is nocturnal and lives close to humans. The snakes often bite people sleeping on the floor at night — often victims don't know they've been bitten. Respiratory failure happens in about half of all cases.

Giant silk moth 

The larvae of the giant silk moth (Lonomia obliqua), a species native to South America, are covered in spikes that can easily puncture human flesh and inject extremely potent venom, according to The Ohio State University. The caterpillars tend to group together on low tree trunks in the daytime, meaning a victim can be stung by many at once. Their toxic venom causes internal bleeding, and between 1989 and 2001, 21 people died in the south of Brazil as a result of their stings.

Amazonian giant centipede  

This 12-inch (30 cm) giant centipede (Scolopendra gigantea) from South America is the largest in the world and is capable of eating toads, mice and lizards. Its venom is delivered through claws containing a poison gland. It uses its venom to capture prey and to defend itself. Bites to humans are painful, but very rarely fatal, and children are at greater risk of death. In 2000, doctors recorded a case of a newborn being bitten by an Amazonian giant centipede and suffering from pain, blood clots, hyperthermia and edema.

Australian box jellyfish 

Australian box jellyfish (Chironex fleckeri) are found along Australia's northern coast and are considered the most venomous marine animals in the world. They have a large, transparent box-shaped bell with up to 60 tentacles at the base, according to the Australian Museum. The tentacles can grow up to 10 feet (3 m) long, with each strand having millions of tiny hooks filled with venom. Their venom is deadly to humans and can be fatal within just minutes of being stung. Each jellyfish has enough venom to kill over 60 people.

An estimated 40 people die from boxy jellyfish stings each year, according to Science magazine.

Eerie new footage captures a rare, otherworldly scene: a giant jellyfish with a tiny isopod swimming around in its bag-like body. In the video, the translucent blob contracts its veiny membrane as it floats in the twilight zone with the bright-orange isopod, a type of crustacean, inside its bell.

Scientists with the Schmidt Ocean Institute spotted the elusive creature at a depth of 2,766 feet (843 meters) during an expedition to the Atacama Trench off the coast of Chile. They identified the jellyfish as belonging to the genus Deepstaria. These jellyfish lack long, stinging tentacles, so they capture their dinner by enveloping prey within their bodies, according to an Instagram post from the institute. The isopod in the video, however, isn't prey: Rather, it is a permanent resident.

Deepstaria jellyfish were first discovered off the California coast in 1966 and were named after Deepstar 4000, the submersible that spotted them. Since then, Deepstaria sightings have been extraordinarily rare.

There are currently two recognized species within this genus: Deepstaria enigmatica and Deepstaria reticulum.

Their exact distribution remains unknown but both species have been found in the Gulf of Mexico, off the coast of California, Caribbean and Central Atlantic Ocean. D. enigmatica has also been observed in the Southern Ocean near the Antarctic. All observations were recorded at depths of around 2,000 to 5,700 feet (600 to 1,750 m), according to a 2018 study.

Related: Alien-like giant phantom jellyfish spotted in frigid waters off Antarctica

Deepstaria jellyfish use their membranous bell to engulf small crustaceans, fish and even other jellyfish, closing their bell to keep prey trapped inside. This motion allows isopods to enter the body of the jellyfish.

The footage reveals the veiny network of the gastrovascular system on its body, which is important for digesting and delivering food to the stomach at the top of the animal's bell, according to the post.

"We are seeing a large scyphozoan jellyfish called Deepstaria enigmatica which belongs to the family Ulmaridae, the same family as the common moon jellyfish," said Allen Collins, curator of Porifera, Medusozoa and Ctenophora at the Smithsonian's National Museum of Natural History, who was not on the expedition.

"On the underside of the subumbrella (up inside the bell) we can see an isopod, Anuropus bathypelagicus that is often (always perhaps) associated with this jelly," Collins told Live Science in an email.

A. bathypelagicus is a large, blind isopod that can grow to more than 3 inches (8 centimeters) long. Researchers have spotted Anuropus living in both species of Deepstaria and using hooked appendages to grip onto their bodies.

In 1969, a study using the Deepstar submersible reported observations of D. enigmatica with abnormal, almost motionless swimming movements. As the submersible moved, the wave of water flipped the jellyfish on its side, revealing a small Anuropus isopod clinging to its body.

When examined, the jellyfish was missing body parts, including its stomach and the lining of its body, which explained its flaccid behavior and led to suspicions that the isopod might be feeding on the jellyfish. Jellyfish remains have also been found in the stomach contents of A. bathypelagicus, which further supports the notion that the isopod eats its Deepstaria host, Collins said.

However, this could also suggest that the isopod feeds on the captured prey within the Deepstaria.

"Just a handful of papers have mentioned it and no one specifically has traced the isopod actually eating the Deepstaria host," Collins explained.

As the jellyfish floats in the water column, the isopod may benefit by using the giant blob as a vehicle and protection from predators. "The isopod is blind and likely benefits by getting a ride on the jellyfish and perhaps a safer place to hide," Collins said. What, if anything, Deepstaria gets out of the relationship is unclear.

A heartbreaking photograph highlights the exploitation of a captive orangutan as it waits for a photo shoot with tourists after a show at a Bangkok zoo. 

The image, titled "See No Evil," was taken by photographer Aaron Gekoski and is the winner of the 2024 Environmental Photography Award competition, which is run by the Prince Albert II of Monaco Foundation. 

Orangutans at Safari World Bangkok take part in daily shows, where they dance in bikinis, ride bicycles and fight one another, Gekoski said in a statement emailed to Live Science. "After the shows, they stoically wait for tourists to take photos with them," he said. 

Gekoski said his winning image highlights abuses within the wildlife tourism industry. "Young orangutans are captured in the wild and their mothers are killed," he said. "They are trained using cruel methods, including physical violence and starvation. When they become too old, they are locked up in cages for the rest of their lives."

Related: Bornean clouded leopard family filmed in wild for 1st time ever

There are three orangutan species living today: Bornean (Pongo pygmaeus), Sumatran (Pongo abelii) and Tapanuli (Pongo tapanuliensis). All are critically endangered, according to the International Union for Conservation of Nature's Red List. They face multiple threats, including deforestation, poaching and the illegal pet trade. Which species is in Gekoski's image is unknown.

Gekoski's image was chosen from more than 11,000 entries from 2,600 photographers.

"It captures one of the world's most intelligent animal species in a graphic composition that is emotionally charged to the point of obsession," Alex Mustard, chairman of the jury, said in the statement. "This photograph will live long in the minds of all who see it.".

In addition to being chosen as the overall winner, Gekoski's image won the Humanity versus Nature category of the competition. The runner-up was Alvaro Herrero López-Beltrán's photograph of a humpback whale (Megaptera novaeangliae) whose tail was deformed as a result of getting entangled in fishing gear off the coast of Mexico.

Daniel Valverde Fernández's image of a polar bear (Ursus maritimus) caught in a blizzard in Canada in 2022 won the Polar Wonders category, while an image of an argonaut (Argonauta hians) attached to a jellyfish taken by Magnus Lundgren won the Ocean Worlds category. 

This striking photo shows an extremely unusual thunderstorm cloud in the shape of a jellyfish floating above western Africa.

The oddly shaped cloud, which was roughly 185 miles (300 kilometers) long, was spotted above central Mali by the Suomi NPP weather satellite, which is co-run by NASA and the National Oceanic and Atmospheric Administration (NOAA). The "bell" of the jellyfish is located above the city of Mopti, while the "tentacles" stretch into Burkina Faso, according to NASA's Earth Observatory.

The bizarre cloud was the result of a meteorological phenomenon known as an outflow boundary, which is essentially a shock wave of fast-moving air that radiates from thunderstorm clouds. Outflow boundaries, also known as gust fronts, are triggered when cold air from the clouds descends to the surface, according to NOAA. When this movement, known as a downdraft, happens, cold air then starts to rapidly expand outward like ripples in a pond, forcing warmer air upward.

"The arc-shape line of clouds is caused by less dense air being lifted up and over the boundary," Joseph Munchak, a meteorologist at NASA's Goddard Space Flight Center, told Earth Observatory. 

Related: 12 amazing images of Earth from space

Normally, this creates a large disk of elevated clouds, known as shelf or roll clouds, which often looks like an anvil when viewed from the ground. But in this case, only part of the disk formed because the outflow boundary was partially disrupted by wind shear, Munchak said.

In dry regions, outflow boundaries can sweep up dust and sand from the surrounding landscape, creating short-lived walls of particulates known as haboobs, according to Earth Observatory. These dust storms, which usually last just a few minutes, often appear as if from nowhere after thunderstorms and can majorly reduce visibility and air quality, according to the National Weather Service.

Outflow boundaries can also sweep up other objects, including insects, seeds and even birds. When this happens, the wave of debris can sometimes show up as dense rings in radar images captured by weather satellites, The Washington Post reported.

A strange,never-before-seen jellyfish with a distinctive stomach that looks like a red cross has been discovered inside a volcanic structure off the coast of Japan.

Researchers spotted the jellyfish, which has been named the St. George's cross medusa (Santjordia pagesi), 2,664 feet (812 meters) below the Pacific Ocean's surface near Japan's Ogasawara Islands. It was floating around the Sumisu caldera, a 6.2-mile-wide (10 kilometers) hydrothermally active volcano that sits on a volcanic arc, or chain of volcanoes, known as the Ring of Fire.

The umbrella-shaped jellyfish has a diameter of around 4 inches (10 centimeters) and is transparent, except for a bright red cross, which is visible when the creature is viewed from above.

The jellyfish is so rare it has only ever been spotted twice. It was first seen in 2002 by a remotely operated vehicle (ROV) during a dive in the Sumisu caldera. However, researchers could not describe a newfound species based on a single specimen, as it could have been a mutated individual belonging to an already-known species, according to a statement from the Japan Agency for Marine-Earth Science and Technology (JAMSTEC).

Related: City-size seamount triple the height of world's tallest building discovered via gravitational anomalies

In 2020, scientists revisited the region and spotted the mysterious jellyfish again. While they were unable to collect a sample, they filmed the jellyfish swimming around.

This second encounter enabled them to describe the jellyfish as a unique species. The team reported its findings in a study published Nov. 20, 2023, in the journal Zootaxa.

The unusual cross shape at the center of S. pagesi is the jellyfish's stomach. The color helps to disguise the jellyfish and the food it consumes from predators in its dark, deep-sea home. Much of the creature's diet consists of bioluminescent organisms that glow in the dark — having a red stomach diminishes the light they emit, protecting the jellyfish from predators after it has eaten its meal.

S. pagesi differs a great deal to its closest relatives, which include large, deep-sea jellyfish such as Tiburonia granrojo and the giant phantom jelly Stygiomedusa gigantea, according to the statement. The newfound species is much smaller and, unlike its relatives, has tentacles as well as arms, which it uses for feeding. Because of its unusual traits, researchers believe S. pagesi may have a never-before-seen type of venom that could be used in genetic research, for example, in medicines.

The caldera where the jellyfish lives is rich in minerals and could potentially be commercially developed for deep-sea mining. The researchers published information about the jellyfish to try to protect the area and its marine life.

"Maybe it holds secrets more valuable than all the mineral wealth that could be extracted from that place. All this with the advantage of keeping the species and the site intact," André Morandini, a professor of zoology at the University of São Paulo's Institute of Biosciences and part of the research team, said in a statement.

A jellyfish "elevator" carrying a hitchhiking fish up from the ocean depths has been captured in a photo documenting one of the largest migrations in the world — one that takes place every night. 

Tom Shlesinger, a marine ecologist at Tel Aviv University, took the photo, titled "Nightly Elevator," off the coast of Florida's Palm Beach. It won the Behavior category at this year's Royal Society Publishing Photography Competition.

Shlesinger's photo captures the vertical journey of billions of marine creatures that live in the twilight zone — between 660 and 3,280 feet (200 to 1,000 meters) beneath the ocean surface — as they travel up to the surface. In the photo, an unidentified jellyfish species carries a hitchhiking yellow fish as it ascends from the depths.

According to a statement from the Royal Society, many small or young animals hitch a ride up to the surface on jellyfishes, providing them with a "unique elevator." 

"Not only that these juveniles can peacefully rest while the jellyfish transports them above, but they also get some protection," representatives wrote. "With their stinging cells, the jellies protect their hitchhikers from predators that will avoid getting too close."

Researchers think the nightly migration — known as the diel vertical migration (DVM) — is related to feeding behaviors, enabling smaller creatures to feed in the food-rich surface waters under the cover of darkness, which helps protect them from predators. Before dawn, they descend back to the safety of the twilight zone.

Related: Alien-like comb jellies have a nervous system like nothing ever seen before

The overall winner of the photography competition was Irina Petrova Adamatzky, whose image "Martian landscape" depicted the slime mold Lamproderma scintillans growing on a fallen leaf in the U.K. 

Other category winners included an image of a starfish on a coral reef, also taken by Shlesinger, and "A crack in time," by Chia-Hsin Tsai, which shows a fault in an outcrop in the Corinth Canal in Greece that was exposed during excavation work in 2022. 

Two fishers from Australia were recently airlifted to hospital after being stung by one of the most venomous jellyfish in the world while they were far out on the ocean. 

The two unnamed men were on a boat around 12 miles (19 kilometers) off the coast of Dundee Beach in Australia's Northern Territory when they were stung by an Irukandji jellyfish on Oct. 10, Australian news site 7News reported.

There are 16 known species of Irukandji jellyfish, which are all endemic to the deep seas around northern Australia. The venom of each of these tiny box jellyfish can trigger Irukandji syndrome — an extremely painful and potentially deadly set of reactions. 

It is unclear which species stung the two fishers, but most cases of Irukandji syndrome are caused by Carukia barnesi, according to the National Center for Biotechnology Information (NCBI). The species is only around 0.8 inch (2 centimeters) long but is one of the most venomous marine creatures on Earth.

The two men were airlifted to hospital from their boat and were discharged 48 hours later. Both are expected to make a full recovery, 7News reported.

Related: What's the difference between poison and venom? 

C. barnesi administer their toxins using specialized stinging cells, known as nematocysts, which line their four tentacles and fire venom-filled barbs into their prey or as a defense mechanism against predators, according to the Australian Museum. Due to their small size, most people are unaware of the jellyfish until they have been stung.

Irukandji venom works in a similar way to tetrodotoxin, one of the world's most potent venoms that is administered by animals such as pufferfish and blue-ringed octopuses, according to NCBI. Both toxins stop nerves from properly signaling to muscles by blocking sodium ion channels. 

The symptoms of Irukandji syndrome include shooting pains in muscles, backache, headache, nausea, vomiting, anxiety, hypertension, breathing problems and cardiac arrest, according to NCBI. Although most people make a full recovery, there are cases of people continuing to experience pain up to a year later. Symptoms can begin as soon as five minutes after being stung, according to the Queensland Ambulance Service (QAS).  

Like with tetrodotoxin, there is no known antivenom for Irukandji venom, and treatment is only supportive, according to NCBI. Experts recommend immediately dousing the sting area with vinegar because its acidic properties can prevent the barbs from releasing their venom, according to QAS.

On average, there are between 50 and 100 cases of Irukandji syndrome in Australia every year, according to NCBI. Most cases occur in the summer when warmer waters and high winds push the jellyfish to the surface and toward land, but cases have been documented in every calendar month. Two people — an American scientist and a British tourist — are known to have died from Irukandji syndrome, Scientific American previously reported. 

Another two people, both French tourists, are suspected of being killed by Irukandji stings in a single snorkelling incident, Australian news site ABC News previously reported. But they were both elderly and had underlying health conditions, which made it hard to determine an exact cause of death.

Australia is also home to several of the world's most venomous sea creatures, including other box jellyfish, stonefish and blue-ringed octopuses, each of which have killed multiple people.

An astronomer recently captured one of the most detailed-ever shots of a rare type of upward-shooting red lightning, known as a sprite, which briefly hovered in the air like a gigantic jellyfish during a thunderstorm over central Europe. 

Stanislav Kaniansky, an astronomer at the Banská Bystrica Observatory in Slovakia, snapped the sprite near his home in Látky, Slovakia, on Aug. 14, Spaceweather.com reported. The luminous, zig-zagging structure measured more than 31 miles (50 kilometers) across and lasted for just a few fractions of a second before disappearing.

Sprites, or stratospheric perturbations resulting from intense thunderstorm electrification, are created when electrical discharges from lightning shoot upward, often in addition to their normal downward trajectory. These discharges create long strands of plasma, or ionized gas, in the ionosphere — the ionized part of Earth's atmosphere that starts at around 50 miles (80 km) above Earth's surface, according to NASA.

Sprites are very hard to photograph because they are fleeting and often obscured by thick clouds. But Kaniansky's orientation enabled him to get a great look at the phenomenon. "The thunderstorm was about 320 km [200 miles] away, giving me a good view of the atmosphere just above the cloud tops," he told Spaceweather.com. 

The image is "one of the most detailed pictures ever of a sprite," according to Spaceweather.com.

Related: Electrifying time-lapse image captures 100 lightning bolts torching the sky over Turkey

Sprites were officially discovered in the early 1990s when NASA's space shuttles captured the first clear images of the phenomenon. But the red lightning has proved hard to study because it is so short-lived.

Scientists now believe that sprites may be partly triggered by disturbances in atmospheric plasma caused by tiny objects like meteors, but the exact mechanism behind the phenomenon is still unclear.

On Aug. 20, sprites were also photographed above lightning strikes from Hurricane Franklin as it passed Puerto Rico. 

Sprites are part of a group of phenomena known as transient luminous events (TLE) that are all tied to lightning. Other TLEs include blue jets, which are more powerful and energetic versions of sprites, and elves, or emission of light and very low-frequency perturbations due to electromagnetic pulse sources, which are fleeting rings of red light created when electromagnetic pulses (EMPs) from lightning hit the ionosphere.

Other TLEs are also very rare but are becoming easier to photograph thanks to advancements in technology. In 2019, instruments aboard the International Space Station captured images of a gigantic blue jet from space. The phenomenon was also seen alongside a 2018 lightning bolt in Oklahoma, which is suspected of being the most powerful of its kind ever recorded. And in April this year, a photographer in Italy captured an eerie photo of a ring-shaped elve, which appeared to hang above a town like a UFO.

It's an iconic scene: A beachgoer is stung by a jellyfish and is writhing in pain. Desperate, the victim allows someone to do the unthinkable — pee on them.

Urinating on a jellyfish sting to relieve the pain is infamous thanks to TV shows like "Friends." But does pee really help relieve the ache of a jellyfish sting? It turns out, urine is likely to make the sting worse, not better.

Experts agree that peeing on a jellyfish sting doesn't offer any real benefit. The myth likely started because urine contains ammonia and urea, giving it a slightly basic pH, Jessica Colla, director of education at the Maui Ocean Center in Hawaii, told Live Science in an email.

Jellyfish are gelatinous marine creatures that sting in response to pressure that activates venom cells lining the animal's tentacles. These venom cells, called nematocysts, deploy tiny, harpoon-like structures to inject their venom into the skin and then continue to hang on like a prickly burr. What the injured person does next is critical, because pouring the wrong liquid on the injury — something with a drastically different pH or salt balance — can cause the nematocysts on the skin to discharge more venom.

Related: Do bees really die if they sting you?

The urine-jellyfish myth is based on the idea that pee with its basic pH "could be more indicative of seawater," the nematocysts' natural environment, Richard Clark, medical director of the San Diego division of California Poison Control System, told Live Science. The rationale is that urine could rinse away the nematocysts without stimulating them, he said. But that's not what happens.

Since urine is often diluted, it can resemble fresh water more than seawater. And you never want to rinse a sting with fresh water, because it makes the pain worse. The dramatic difference in dissolved salt between fresh and seawater causes the nematocysts to release more venom. The same is true for urine. If it's too dilute, it will cause the nematocysts to keep firing.

The far better option is to just use seawater, Clark told Live Science. Studies have also shown vinegar (5% acetic acid) can neutralize nematocysts from some jellyfish species.

True jellyfish first aid can be surprisingly simple. Here are some better — and less disgusting — ways to manage discomfort after a jellyfish encounter, according to Colla.

1. 1. Rinse with sea water or vinegar: Copious amounts of sea water is the best way to rinse the sting. Vinegar is also a reliable option for stings by most jellyfish species, helping to inactivate nematocysts and prevent further venom release. However, If the type of jellyfish is unknown, it's best to stick with sea water, Colla said.
2. 2. Remove the tentacles: Removing tentacles and nematocysts is important to prevent further envenomation and pain. Do not try to scrape off the tentacles with your hands. Instead, carefully remove them with tweezers, then remove the nematocysts with the edge of something flat and stiff, like a credit card.
3. 3. Seek medical attention: Some jellyfish stings can be severe or fatal. If you experience "swelling, nausea, confusion, body aches or difficulty breathing — see a doctor right away," Colla said. A sting from a box jellyfish (endemic to the Indo-Pacific region and Australia) may require antivenom medication.

This article is for informational purposes only, and is not meant to offer medical advice.

Scientists in Hong Kong have discovered tiny, cube-shaped box jellyfish in a brackish shrimp pond that are completely unknown to science.

The diminutive jellies have a completely transparent and colorless body, or bell, as well as 12 tentacles ending in small, paddle-like structures that enable the critters to speed through water faster than most other jellyfish species. 

Like other box jellies — a group of Cnidarians that includes the Australian box jellyfish (Chironex fleckeri), the world’s most venomous marine animal, according to the National Ocean Service — the newly described jellies have 24 eyes arranged in clusters of six around its cubic bell.

"This box jellyfish connects the base of its tentacles and its bell with a flat base that looks like a boat paddle, making it distinct from other common jellyfish," Qiu Jianwen, a professor in the Department of Biology at Hong Kong Baptist University who led the research, said in a video. "Another feature of the box jellyfish is that it has six eyes located on each side of its body." 

Researchers named the newfound species Tripedalia maipoensis after Mai Po Nature Reserve in Hong Kong, where they found it. They describe its features and relationship to other box jellies in a study published March 20 in the journal Zoological Studies.

Related: Alien-like giant phantom jellyfish spotted in frigid waters off Antarctica 

T. maipoensis is the first-ever box jelly to be found in Chinese waters. It is unclear whether the half-inch-long (1.5 centimeters) animal can sting humans, but it may be venomous enough to stun tiny shrimp called Artemia. "It seemed to paralyze Artemia offered in the lab," Qiu told Live Science in an email. "But we did not touch the animal to feel the sting."

The researchers first noticed the unusual creatures in samples collected from an intertidal shrimp pond, known as a "gei wai" locally, during the summers of 2020 to 2022. The jellyfish were "quite abundant," Qiu told Live Science, numbering "up to 400 individuals in an area of the pond." A tidal channel from the brackish pool means that the species could also be present in the adjacent waters of the Pearl River estuary, but no work has been done yet to confirm this, the researchers wrote in the study.

Box jellyfish, which are also known as sea wasps, move by allowing water to enter canals that run along a muscular membrane on the underside of their bodies and then expelling it. The researchers found that, unlike closely related species, T. maipoensis has forked canals separating into multiple branches. The newly discovered species is the third known member of a group of box jellies characterized by tentacles ending in flat, paddle-like structures, called Tripedalia. 

The scientists also noted that each cluster of six eyes on the jellies' cubic bell includes a pair of eyes with lenses that enable image-forming, as well as four eyes that can only sense light.

The species probably feeds on small crustaceans called copepods, which were abundant in the samples taken from the shrimp pond, Qiu told Live Science.

"We are thrilled with this discovery," Qiu said in the video. "Finding a new species in Mai Po, where extensive research has been conducted, highlights the potential for more marine life discovery in the Hong Kong and even the Chinese coastal waters."

Often, a discovery isn't so much about gathering new information as it is about looking at something from a new perspective. That's not always simple — except in the case of a newly described fossil sea anemone, when it was as simple as turning a presumed jellyfish fossil upside down.

The fossil, first described in 1971, is famous in both scientific and amateur paleontology circles for being such an easy to find fossil, despite totally lacking a skeleton. But it turns out, the story of the creature was a bizarre case of mistaken identity, scientists reported in a study published March 8 in the journal Papers in Paleontology. 

The Mazon Creek fossil beds in Illinois, which formed 309 million years ago, capture a glimpse of water-dwelling species that lived during the warm, wet Carboniferous period (358.9 million to 298.9 million years ago). At that time, the area was an estuary, where silty fresh water from a river flowed into an ocean that covered much of modern-day North America. When plants and animals died in this estuary, often they would be quickly covered in sediment, which led to the impeccable fossilization of not only animal skeletons but also soft-bodied animals, like jellyfish, that typically don't fossilize well. 

That's why Mazon Creek is so remarkable. "These fossils are better preserved than Twinkies after an apocalypse," study co-author James Hagadorn, an expert on unusual fossil preservation at the Denver Museum of Nature and Science, said in a statement. "In part that's because many of them burrowed into the seafloor as they were being buried by a stormy avalanche of mud." The most common fossil found at Mazon Creek is that of a bizarre jellyfish called Essexella asherae but more casually referred to as "the blobs" by the amateur fossil hunters who have historically collected them as souvenirs.

But in 2016, Roy Plotnick, a professor emeritus of invertebrate paleobiology and paleontology at the University of Illinois Chicago, noticed that something seemed off about E. asherae.

Related: 520-million-year-old sea monster had 18 mouth tentacles

"I've always looked at these jellyfish fossils and I've thought, 'That doesn't look right to me,'" Plotnick, lead author of the new study, told Live Science. That lingering hunch led Plotnick to invite Hagadorn and Graham Young, curator of geology and paleontology at the Manitoba Museum in Canada, to reexamine the thousands of E. asherae fossils held at the Field Museum in Chicago as well as other museums and private collections. 

Plotnick told Live Science that Young and Hagadorn are experts in jellyfish fossils and their preservation, so if anybody had a chance of making sense of these creatures, it would likely be them. 

E. asherae looks downright bizarre compared with a stereotypical jellyfish, or medusa, which many envision as a mushroom-like cap that looks to be molded out of petroleum jelly with trailing, party-streamer-like tentacles. But not E. asherae. Fossils suggest that instead of sporting delicate tentacles underneath the cap, E. asherae rocked a membranous skirt, which would make it unique, especially among modern jellyfish, all of which swim around unskirted. 

E. asherae's true nature was revealed when Plotnick and colleagues noticed that the cap didn't look like a cap at all. Instead, it resembled the muscular foot that many sea anemones use to burrow into the sea floor.

"I said, 'Wait a minute; that looks like the foot of a sea anemone,'" Plotnick said. When he flipped the specimen over, he had an epiphany: E. asherae wasn't a jellyfish at all. It was a bulbous sea anemone that anchored itself to the seafloor with its muscular foot. At the risk of oversimplification, anemones are relatives of jellyfish that filter-feed in the water column as opposed to swimming through it.

Further examination revealed that the "skirt" was actually the anemone's barrel-shaped body, with a hole at the top to allow it to suck in water for feeding. Moreover, tiny snails that had fossilized with E. asherae were not the ancestors of modern jellyfish parasites but  rather scavengers that were buried while feeding on E. asherae corpses, further separating E. asherae from the jellyfish it was thought to be. 

The team's analysis showed that paleontologists hadn't just identified the specimen as the wrong species — they'd also placed it in the completely wrong taxonomic order, the broad grouping above family and species.  This means taking the animal out of the order Semaeostomeae, which contains jellyfish, and into the sea anemone order, Actiniaria. It's a big shift that has literally turned our understanding of this common fossil on its head.

Editor's note: Updated at 12:47 p.m. EDT on March 16 to correct Roy Plotnick's title. He is at the University of Illinois Chicago, not the University of Chicago. 

Rare sightings of giant phantom jellyfish — deep-sea creatures that look like UFO spaceships with thick ribbons streaming from their undersides — have been reported by cruise liner passengers who spotted the otherworldly animals off the coast of Antarctica, a new study finds. 

The giant phantom jellyfish (Stygiomedusa gigantea), one of the deep sea's largest invertebrate predators, met the guests while they were riding in a submersible deployed by cruise line operator Viking in early 2022. Researchers estimated that the jellyfish were longer than 16 feet (5 meters), with one stretching to at least 33 feet (10 m) in length, according to a study published Jan. 30 in the journal Polar Research. 

Study first author Daniel Moore first realized guests had encountered the giant phantom when he saw a picture of one on a guest's camera. "I instantly recognised it for what it was and, given the rarity of sightings, was flooded with excitement," Moore, one of Viking's chief scientists, told Live Science in an email. 

Related: Largest crown jellyfish ever discovered is a blood red, saucer-like weirdo

Giant Phantom jellyfish live in every ocean except for the Arctic Ocean. However, because these cryptic creatures typically swim deep below the surface, they are scarcely seen by humans. The new study describes direct observations of three different jellyfish made during submersible dives off the Antarctic Peninsula.

"On every sighting the jellyfish appears to be swimming slowly, gently pulsing its bell for propulsion," Moore said. "They don't appear to have shown any inclination towards the lights of the submersible or reaction to our presence."

The jellyfish were spotted at depths of 260 feet (80 m), 285 feet (87 m) and 920 feet (280 m). Giant phantom jellyfish primarily occupy depths of below 3,280 feet (1,000 m), but they are encountered higher up in the Southern Ocean, or Antarctic Ocean. It's not yet known why they hang out in relatively shallow waters around Antarctica.

Moore noted that one potential explanation is that the jellyfish swim higher up to expose themselves to ultraviolet radiation, which will rid them of parasites. Another hypothesis put forward by Moore is that the upwelling deep water found around the Antarctic continent simply carries them upward. Moore hopes that their observations will lead to a better understanding of giant phantom jellyfishes' lives. 

The practice of cruise lines taking passengers to Antarctica has attracted some controversy. The U.S. Coast Guard announced on Feb. 2 that it has joined international partners to investigate four deaths and other casualties involving U.S. citizens on Antarctic passenger vessels between Nov. 15 and Dec. 1, 2022. This includes one death on the Viking Polaris, operated by Viking, after a large wave hit the ship.

The U.S. Coast Guard describes the Antarctic as a "unique high-risk" environment and aims to improve marine safety and prevent similar incidents in the future. The waters around Antarctica can be treacherous and the continent has a history claiming intrepid explorers in famous expeditions. 

Over 500 million years ago, sea-dwelling invertebrates pioneered a new evolutionary experiment: skeletons. But while those durable, tube-like structures stood the test of time as fossils, the animals' soft bodies decayed and vanished, erasing all evidence of what these ancient animals may have looked like. Now, a recent re-examination of those ancient skeletal tubes has finally unveiled the identity of one of these mysterious organisms.

These early calcium-reenforced "skeleton"  tubes date to a period known as the Cambrian explosion (541 million to 510 million years ago) and seem to have been an effective survival strategy, as they cropped up in multiple groups across a relatively short span of geologic time (about 50 million years). During this period, everything from the segmented ancestors of earthworms to the bizarre ancient relatives of tardigrades created tube-like protective structures. 

However, tracing the evolutionary history of these early exoskeletons has proved tricky. "Soft tissues tend to decay away," Xiaoya Ma, an invertebrate paleontologist at Yunnan University in China and co-author of a study describing the findings, told Live Science. For this reason, identifying fossil Cambrian tubes has been a little like trying to guess the contents of an empty, unlabeled can based on the shape of the tin alone — most could just as easily have held chicken soup as creamed corn.

But scientists are shedding light on these enigmatic skeleton makers. In the new study, published Nov. 2 in the journal Proceedings of the Royal Society B, an international team of researchers described four incredibly well-preserved Cambrian specimens from China's Yunnan province. These 514 million-year-old fossils of the tube-dwelling creature Gangtoucunia aspera include soft tissue impressions left behind by the animals' bodies. By studying these impressions closely, the scientists determined that the tubes belonged to, of all things, an ancient skeleton-making jellyfish.

Soft-bodied invertebrates are hard to find in the fossil record, and jellyfish in particular are almost never preserved. "This fossil was a double whammy in terms of rarity," Luke Parry, a paleobiologist at the University of Oxford and co-author of the study, told Live Science in an email.

Related: Ancient armored 'worm' is the Cambrian ancestor to three major animal groups

Normally, when a marine organism dies, scavengers and bacteria make quick work of its soft tissues. But very occasionally, a wave of fine sediment covers the remains quickly enough to prevent aerobic bacteria from settling in. This is how the famous North American Burgess Shale fossil deposit formed, according to the Smithsonian National Museum of Natural History in Washington, D.C., and it is likely how the Yunnan site formed, as well. 

The newfound fossils, which were discovered by lead study author Guangxu Zhang, Ma's graduate student at Yunnan University, were preserved in such detail that the paleontologists could even make out the animals' internal organs. The creatures' mouths were surrounded by a ring of tentacles, each measuring about 0.2 inch (5 millimeters) long. And they had a saclike gut with just one opening (unlike the separate mouth and anus that vertebrates are blessed with).

These characteristics led the team to conclude that G. aspera likely belonged to the phylum Cnidaria, which includes modern-day jellyfish, corals and sea anemones. It also laid to rest an older theory that the creature was an annelid worm, which is defined by its segmented body and gut with two openings.

G. aspera likely hung out in ancient oceans with one end of its tube anchored to other members of its species or to mobile creatures such as trilobites, retracting into its shell when predators swam by. It probably fed much like modern jellyfish polyps do, extending its stinging tentacles when prey was near.

Only the larvae of one jellyfish group, Scyphozoa, create exoskeletons today. Some other cnidarians, such as corals, retain their skeletons into adulthood. However, today's corals build their skeletons from calcium carbonate; in contrast, G. aspera crafted its tubes out of calcium phosphate, the same tough compound that makes up our tooth enamel and bones. 

Why modern cnidarians switched from calcium phosphate to calcium carbonate exoskeletons remains a mystery. "One potential reason is that the environment before our current time was phosphorus rich," Ma said. But the answer could be found in cnidarian genetics as well. Ma and her team hope to answer this and other questions as their research continues. "Hopefully, we'll have more for everyone in the near future," she said.

The longest-living animals are equipped with traits to hold off, and sometimes even stop or reverse, the aging process. While humans may have an "absolute limit" of 150 years, this is just a blink of an eye compared with the centuries and millennia that some animals live through.

The true age champions live in water, often at great depths where conditions are stable and consistent. Scientists can't record the birth and death of every member of a species, so they typically estimate maximum life spans based on what is known about a species' biology. From old to oldest, here are 13 of the longest-living animals in the world today.

13. Saltwater crocodiles: 120+ years old

If they survive to adulthood, saltwater crocodiles (Crocodylus porosus) normally live for over 70 years. Accurate information on their maximum lifespan is largely lacking. However, records of two especially long-lived crocs suggest they can live to over 120 years.

Cassius — the world's largest captive crocodile — is believed to be up to 120 years old. He was captured in 1984 on a cattle ranch southwest of Darwin, Australia, and has been kept at the Marineland Crocodile Park on Green Island ever since. He was 16 feet, 10 inches (5.13 meters) at the time, leading experts to estimate he was between 30 and 80 years old. As of 2023, he was thought to be up to 120 years old. Cassius is also still growing, providing scientists with "serious knowledge on longevity," Toody Scott, a crocodile keeper who looks after Cassius previously told Live Science.

Related: The secrets to extreme longevity may be hiding with nuns... and jellyfish

Another long-lived saltwater crocodile is Mr Freshie, who lived between 120 and 140 years, experts estimate. The crocodile was caught in North Queensland by Steve Irwin and his father in 1970 and moved to the Australia Zoo, where he lived for 40 years until his death in 2010. He was estimated to have been around 100 when he was captured, according to the Courier Mail.

12. Seychelles giant tortoise: 190+ years old

Tortoises are famed for their longevity. The oldest living land animal is a 190-year-old Seychelles giant tortoise (Aldabrachelys gigantea hololissa) named Jonathan. The tortoise lives on the island of St. Helena in the South Atlantic Ocean after having been brought there by people from the Seychelles in 1882. Jonathan's age is an estimate, but a photograph of him taken between 1882 and 1886 shows he was fully mature — at least 50 years old — in the late 19th century, Live Science previously reported.    

On Jan. 12, 2022, Guinness World Records announced that Jonathan was the oldest tortoise ever. "He is a local icon, symbolic of persistence in the face of change," Joe Hollins, Jonathan's veterinarian, told Guinness World Records at the time. 

Giant tortoises need to live a long time so they can breed repeatedly and produce plenty of eggs, because many of their eggs are eaten by predators. Their ability to quickly kill off damaged cells that normally deteriorate with age may help tortoises live so long, Live Science previously reported.  

Related: Tiny white tortoise baby is the 'first of its kind' 

11. Red sea urchins: 200 years old

Red sea urchins (Strongylocentrotus franciscanus) are small, round invertebrates covered in spines. They live in shallow coastal waters off North America from California to Alaska, where they feed on marine plants, according to Oregon State University. Researchers used to assume that red sea urchins grew quickly and had modest life spans of up to about 10 years, but as scientists studied the species in more detail, they realized these urchins continue to grow very slowly and, in some locations, will survive for centuries if they can avoid predators, disease and fishers.  

The red sea urchins found off Washington and Alaska probably live more than 100 years, and the longest-living individuals in British Columbia, Canada, may be around 200 years old, according to a 2003 study published in the journal Fishery Bulletin. 

Related: Mysterious 'blue goo' at the bottom of the sea stumps scientists

10. Bowhead whale: potentially 200+ years old

Bowhead whales (Balaena mysticetus) are the longest-living mammals. The Arctic and sub-Arctic whales' exact life span is unknown, but stone harpoon tips found in some harvested individuals prove that they comfortably live over 100 years and may live more than 200 years, according to the National Oceanic and Atmospheric Administration (NOAA).

The whales have mutations in a gene called ERCC1, which is involved with repairing damaged DNA, that may help protect the whales from cancer, a potential cause of death. Furthermore, another gene, called PCNA, has a section that has been duplicated. This gene is involved in cell growth and repair, and the duplication could slow aging, Live Science previously reported. 

Studying these long-lived whales could provide hints about how to prolong human life. "My own view is that different long-lived species use different tricks to evolve long life spans, and there aren't many genes in common," João Pedro de Magalhães, an expert in aging science at the University of Birmingham in the U.K., previously told Live Science. "But you do find some common pathways, so there may be common patterns." 

Related: Natural rates of aging are fixed, study suggests

9. Rougheye rockfish: 200+ years old

The rougheye rockfish (Sebastes aleutianus) is one of the longest-living fish, with a maximum life span of at least 205 years, according to the Washington Department of Fish and Wildlife. These pink or brownish fish live in the Pacific Ocean from California to Japan. They grow up to 38 inches (97 centimeters) long and eat other animals, such as shrimp and smaller fish, according to the Committee on the Status of Endangered Wildlife in Canada, an independent advisory panel that assesses the statuses of species threatened with extinction in Canada. 

A 2021 study published in the journal Science looked at the genomes of 88 rockfish species, including rougheye rockfish, and found genetic calling cards for longevity, including DNA repair pathways that may help ward off cancers. A longer life span allows the rockfish to grow larger and produce more young. 

Related: Is fish caught off Alaska 200 years old?

8. Freshwater pearl mussel: 250+ years old

Freshwater pearl mussels (Margaritifera margaritifera) are bivalves that filter particles of food from the water. They live mainly in rivers and streams and can be found in Europe and North America. The oldest known freshwater pearl mussel was 280 years old, according to the World Wildlife Fund for Nature. These invertebrates have long life spans thanks to their low metabolism.

Freshwater pearl mussels are an endangered species. Their population is declining due to a variety of human-related factors, including damage and changes to the river habitats they depend on, according to the International Union for Conservation of Nature.

Related: Seattle mussels test positive for opioids

7. Greenland shark: 272+ years old

Greenland sharks (Somniosus microcephalus) live deep in the Arctic and North Atlantic oceans. They can grow to be 24 feet (7.3 meters) long and have a diet that includes a variety of other animals, including fish and marine mammals such as seals, according to the St. Lawrence Shark Observatory in Canada.

A 2016 study of Greenland shark eye tissue, published in the journal Science, estimated that these sharks can have a maximum life span of at least 272 years. The biggest shark in that study was estimated to be about 392 years old, and the researchers suggested that the sharks could have been up to 512 years old, Live Science previously reported. The age estimates came with a degree of uncertainty, but even the lowest estimate of 272 years still makes these sharks the longest-living vertebrates on Earth, Julius Nielsen, a researcher at Greenland Institute of Natural Resources, previously told Live Science.  

Related: 100-year-old Greenland shark that washed up on UK beach had brain infection, autopsy finds

6. Tubeworm: 300+ years old

Tube worms are invertebrates that live on the ocean floor. Bacteria in their tubes create sugars from chemicals, which they absorb as food, according to the Woods Hole Oceanographic Institution's Dive and Discover website. Some tube worms live around hydrothermal vents, but the longest-living species are found in colder, more stable environments called cold seeps, where chemicals spew from cracks or fissures in the seafloor, according to the Exploring Our Fluid Earth website hosted by the University of Hawaii. 

A 2017 study published in the journal The Science of Nature found that Escarpia laminata, a cold-seep species of tube worm in the Gulf of Mexico, regularly lives up to 200 years, and some specimens survive for more than 300 years. Tube worms have a slow metabolism and few natural threats (such as predators), which has helped these creatures evolve such long life spans. 

Related: Wonderland of iridescent worms and hydrothermal vents found off Mexican coast

5. Ocean quahog clam: 500+ years old

Ocean quahog clams (Arctica islandica) inhabit the North Atlantic Ocean. This saltwater species can live even longer than the other bivalve on this list, the freshwater pearl mussel. One ocean quahog clam found off the coast of Iceland in 2006 was 507 years old, according to National Museum Wales in the U.K. The ancient clam was nicknamed Ming because it was born in 1499, when the Ming dynasty ruled China (from 1368 to 1644). 

"In the colder waters surrounding Iceland the Ocean Quahog has a slower metabolism and so grows slowly and may even live for longer than 507 — scientists just haven't found an older one yet!" Anna Holmes, curator of invertebrate biodiversity (bivalves) at National Museum Wales, wrote on the museum's website in 2020. 

Related: 1 billion sea creatures cooked to death in Pacific Northwest

4. Black coral: 4,000+ years old

Corals look like colorful, underwater rocks and plants, but they are actually made up of the exoskeletons of invertebrates called polyps. These polyps continually multiply and replace themselves by creating a genetically identical copy, which over time causes the coral exoskeleton structure to grow bigger and bigger. Corals are therefore made up of multiple identical organisms rather than being a single organism, so a coral's life span is more of a team effort. 

Deep-water black corals are among the longest-living corals. Black coral specimens found off the coast of Hawaii have been radiocarbon dated to be 4,265 years old, Live Science previously reported. 

Related: We finally know why Florida's coral reefs are dying, and it's not just climate change

3. Glass sponge: 10,000+ years old

Sponges are made up of colonies of animals, similar to corals, and can also live for thousands of years. Glass sponges are among the longest-living sponges on Earth. Members of this group are often found in the deep ocean and have skeletons that resemble glass, hence their name, according to NOAA. 

A 2012 study published in the journal Chemical Geology estimated that a glass sponge belonging to the species Monorhaphis chuni was about 11,000 years old. Other sponge species may be able to live even longer. 

Related: 300-year-old Arctic sponges feast on the corpses of their decaying, extinct neighbors

2. Turritopsis dohrnii: potentially immortal

Turritopsis dohrnii is called the immortal jellyfish because it can potentially live forever. Jellyfish start life as larvae before establishing themselves on the seafloor and transforming into polyps. These polyps then produce free-swimming medusas, or jellyfish. Mature T. dohrnii are special in that they can turn back into polyps if they are physically damaged or starving, according to the American Museum of Natural History, and then later return to their jellyfish state.

The jellyfish, which are native to the Mediterranean Sea, can repeat this feat of reversing their life cycle multiple times and therefore may never die of old age under the right conditions, according to the Natural History Museum in London. T. dohrnii are tiny — less than 0.2 inch (4.5 millimeters) across — and are eaten by other animals, such as fish, or may die by other means, thus preventing them from actually achieving immortality.

Related: Thousands of jellyfish swarm near Israel, mesmerizing images reveal

1. Hydra: potentially immortal

Hydra is a group of small invertebrates with soft bodies that slightly resemble jellyfish and, like T. dohrnii, have the potential to live forever. These invertebrates are largely made up of stem cells, which continually regenerate through duplication or cloning, so these animals don't deteriorate as they get older. They do die under natural conditions because of threats such as predators and disease, but without these external dangers, they could keep regenerating forever. 

"They don't seem to age, so potentially, they are immortal," Daniel Martínez, a biology professor at Pomona College in Claremont, California, who discovered the hydra's lack of aging, previously told Live Science. 

Related:  Here's the secret to how 'immortal' hydras regrow severed heads

Originally published on Live Science Aug. 16, 2021, and republished Oct. 28, 2022.

Thousands of globular cannonball jellyfish (Stomolophus meleagris) have washed ashore along a stretch of North Carolina coastline in what is being dubbed a "jellyfish jamboree."

Park rangers from the Cape Hatteras National Seashore, part of the National Park Service (NPS), snapped photos of the spectacle on Friday (Oct. 14) and shared it in a Facebook post.

The "large swarm" washed up along the northern edge of Ocracoke Island, one in a chain of islands that makes up the Outer Banks. The sudden influx of these squishy, stinger-less blobs coincides with the presence of red drum (Sciaenops ocellatus), a species of saltwater fish that's currently in the midst of spawning season — the fish’s larvae also happen to be the preferred snack for the jellyfish, according to the post.

Similar to actual cannonballs in both shape and size — the jellies weigh about 1 pound (450 grams) on average and measure 10 inches (24 centimeters) in diameter — the species is one of the most common types of jellyfish along the southeastern coast, according to the Georgia Department of Natural Resources.

So why did they wash up now?

"Jellyfish rely on winds and currents to help them swim. Colder water temperatures, winds and currents can all play a role in them washing ashore," the post read.

Related: Thousands of jellyfish swarm near Israel, mesmerizing images reveal

And the stars lined up particularly well this year: a red drum spawning event combined with colder water temperatures to create a huge seafood buffet for the voracious blobs, according to Newsweek.

"Why blooms occur in some years and not in others, or why sometimes blooms are larger in some years compared to others is all tied to environmental factors, but not well understood," Cheryl Lewis Ames, an associate professor of applied marine biology at the Graduate School of Agricultural Science, Tohoku University in Japan, told Newsweek. "In my several decades of jellyfish research I have found that few jellyfish species will reliably show up just when you expect them."

Jellyfish are swarming in massive numbers in the Mediterranean Sea, close to the port city of Haifa in northern Israel. The sea was "bedazzled with thousands of white dots," according to The Jerusalem Post, which also reported that the swarm extended below the surface to depths of several hundred meters.  

Officials with Israel’s Nature and Parks Authority (NPA) captured footage of the swarming nomad jellyfish (Rhopilema nomadica) in Haifa Bay on July 20 using aerial drones, and they shared the footage on the agency's website. The NPA also advised people against swimming in the area, due to the risk of painful jellyfish stings.

This unusually high concentration of jellyfish individuals, also known as a bloom, likely stems from human activities that may include pollution and climate change , NPA representatives said in a statement (translated from Hebrew).  

The explosion in jellyfish numbers this summer could have catastrophic consequences for the marine ecosystem near coastal Haifa, and could even affect industry and tourism, Ruthy Yahel, an NPA marine ecologist, said in the statement.

"We see great damage from it in many areas, such as ecological competition with the fish for food, economic damage, clogging of desalination plant pumps, cooling of power plants, damage to fishermen, and the public keeping their feet off the beaches because of the burning [from jellyfish stings]," Yahel said. (Remember: Despite the urban legend, don't treat jellyfish stings with pee, which can cause the jellyfish's stinging cells to release more venom. Instead, remove the tentacles with a tool — not your bare fingers — and splash something acidic, such as vinegar, on the wound, Live Science previously reported.)

Related: Scientists inserted disco 'strobe lights' into jellyfish to see how they function without brains

Jellyfish are a common sight off the coast of Israel during the summer, and large blooms were reported in 2015 and 2017, The Jerusalem Post reported. The University of Haifa maintains a website that tracks jellyfish swarms using reports from open water swimmers, divers, boaters, fishers, surfers, paddlers and kayakers. Its interactive map helps both fishing boats and beachgoers avoid areas of the ocean and beaches where jellyfish swarms have been spotted. 

Nomad jellyfish, currently the most common jellyfish species in waters near Haifa, are an invasive species that originated in tropical waters of the Indian and Pacific Oceans. Scientists suspect that the jellyfish invaded the Mediterranean from the Indian Ocean by using the Suez Canal — the artificial waterway in Egypt that connects the Mediterranean to the Red Sea through the Isthmus of Suez — CNN reported in 2015.

One possible cause for jellyfish blooms such as the recently-observed event, could be pollution; jellyfish may have flocked to this region in record numbers to escape sewage and dispersing solid waste that's pumped into the ocean, according to the NPA statement. Overfishing and population reduction in ocean animals that compete with jellyfish, such as sunfish, or that prey on them, such as sea turtles, could also explain why jellyfish are especially numerous this year, NPA representatives said.

Changing climate could also be playing a part in driving Haifa's jellyfish bonanza, Dror Angel, a marine ecologist in the University of Haifa’s Department of Maritime Civilizations, told The Jerusalem Post. "The past winter has been very rainy and cold at times. This may have affected the intensity of the blooms and their life cycle," Angel said. "We know for sure if there’s heavy rain, then lots of nutrients get washed into the sea. So there's more algae, plankton and more food for the jellyfish to eat."

Originally published on Live Science.

A bizarre, tentacled creature that lived in the deep ocean 560 million years ago resembled a goblet crammed full of wriggling fingers. It may be an ancient relative of modern jellyfish and the earliest known predator in the animal kingdom, analysis of a newly described fossil suggests. 

More than a decade ago, scientists uncovered a fossil of the purported jellyfish relative in an outcrop of volcanic and sedimentary rocks called the Bradgate Formation in Leicestershire, England. Located in Charnwood Forest, the outcrop formed about 557 million to 562 million years ago, during the Ediacaran period (635 million to 541 million years ago). 

This means that the newly identified fossil predates the Cambrian explosion, a 55-million-year episode  in which life on Earth rapidly diversified. During the Cambrian period (541 million to 485.4 million years ago), many animal forms evolved, including arthropod ancestors of insects, spiders and crustaceans; clamlike and hard-shelled brachiopods; and chordates — creatures with a spinal nerve cord. 

It's almost unheard of for Precambrian fossils to resemble forms seen in animals alive today, so the discovery of an Ediacaran animal resembling a jellyfish is exceptional, said Philip Donoghue, a professor of palaeobiology at the University of Bristol in England, who was not involved in the study. "They found an animal, a member of a modern group of animals, in the Precambrian, where they're classically not meant to be found," Donoghue told Live Science.  (Although not involved in the new work, Donoghue was formerly the doctoral advisor to several authors on the paper.)

Related: Largest crown jellyfish ever discovered is a blood red, saucer-like weirdo

To date, the vast majority of Ediacaran fossils don't share structural features with any living animals, so they're generally thought to belong to extinct animal groups, Donoghue said. "This fossil's probably the oldest one recognized, with quite convincing evidence, to be a member of one of the living phyla," or large groups of related animals, Donoghue said.

The researchers named the newly identified creature Auroralumina attenboroughii and described the animal in a new study, published Monday (July 25) in the journal Nature Ecology & Evolution. The genus name, Auroralumina, translates to "dawn lantern" in Latin and references the fossil's old age and its torch-like shape. The species name honors broadcaster and biologist Sir David Attenborough for "his work raising awareness of the Ediacaran fossils of Charnwood Forest," the authors wrote in their report. 

The world's oldest known predator? 

The research team uncovered A. attenboroughii during a 2007 expedition in Charnwood Forest, but the first major fossil discoveries there date to the 1950s, when two children, first Tina Negus and then Roger Mason, stumbled upon a fern-shaped fossil in a quarry, according to the University of Reading in England. That organism, named Charnia masoni, was the first fossil that could be confidently dated to the Ediacaran period, and since its discovery, many paleontologists have traveled to Charnwood to hunt for similar snapshots of Precambrian life.

On their 2007 expedition, the scientists focused their search on a rockface that rose from the forest floor at a 45-degree angle and wore a thick coat of lichen and dirt. The team dug into the rockface while dangling from ropes, using toothbrushes, toothpicks and high-pressure water jets to expose any fossils hidden under the muck. 

"As soon as we cleaned off all the dirt, all of sudden, rather than just a couple scrappy fossils there were a thousand fossils on this surface," said paleobiologist Philip Wilby, a team leader for Palaeontology at the British Geological Survey and senior author of the study. The fossils, which likely represent 20 to 30 different species, were preserved as impressions in the rock; excluding A. attenboroughii, many of the fossils resembled the frond-like creatures previously found in Precambrian rocks. 

"Beautifully preserved — some of them absolutely stunning," Wilby told Live Science.

The team made rubber casts of the fossil-filled rockface and transported the casts back to the lab. Such impressions can be difficult to work with "because they're all squidged, flattened," which makes the animals' internal anatomy and body shapes challenging to interpret, Donoghue said. To create 3D models of their flat fossil casts, the researchers used a technique that involved illuminating the casts from different angles and snapping lots of photos; these photos were then compiled into a virtual 3D model that could be manipulated digitally.   

Related: Coral reefs have 'halos,' and they can be seen from the heavens

These reconstructions revealed that one of the fossil creatures resembled a simple candelabra, with two goblet-like structures branching off from a single node. "They seem to have actually budded off from one another," Wilby said. The tips of short tentacles could be seen poking over the edge of each goblet, like stubby fingers reaching from the center of a cup. Ridges that ran up the sides of the fossil suggest that these "goblets" were supported by a stiff skeleton.

"This is the first creature, the first animal that we're aware of that actually grew a skeleton," Wilby said. Its tentacle structure hints that A. attenboroughii likely fed on plankton and protists, which would make it the earliest known predator in the animal kingdom.

A. attenboroughii shares many core characteristics with Cambrian fossils of Medusozoa, a group that includes modern jellyfish and other animals that transform into free-swimming, bell-shaped creatures for part of their life cycle. "That's what leads us to believe that it is a Medusozoan," Wilby said. While the fossil might not look like a jellyfish at first glance, it's important to note that, for part of their life cycle, neither do Medusozoans. For a chapter of their lives, the animals anchor themselves to the seafloor to reproduce asexually. During this life stage they resemble anemones — and A. attenboroughii.

If A. attenboroughii is indeed a member of Medusozoa, it would belong to a broader group of organisms known as the cnidarians, which also includes corals, sea pens and sea anemones. Prior to the new study, fossil evidence suggested that the basic "blueprint" for cnidarians didn't emerge until the Cambrian period. However, "what we're able to show here is that, at least 20 million years before that, the blueprint for cnidarians was actually set," Wilby said. 

This not only pushes back the evolutionary history of cnidarians but also provides hints about what animals must have come before them, Donoghue said. Prior research suggests that cnidarians and bilaterians — a group of animals that includes humans — split off from a common ancestor. If A. attenboroughii existed 560 million years ago, it’s possible that the split already occurred and the earliest bilaterians were already roaming the planet.

"The fossil's not just important for showing us, clearly, cnidarians are here — by implication, their sibling lineage must have also evolved by this time," Donoghue said.

Originally published on Live Science.

Scientists have discovered a new species of crown jellyfish that looks like a scarlet alien saucer in the sunless "midnight zone" of California's Monterey Bay.

The newly described species, Atolla reynoldsi, measures about 5 inches (13 centimeters) in diameter and can have anywhere from 26 to 39 tentacles, researchers with the Monterey Bay Aquarium Research Institute (MBARI) said in a statement. Like the 10 other known species of the Atolla genus, A. reynoldsi sports a deep groove running around its central bell, giving its body the appearance of a domed head wearing a frilly red crown.

Though it's not much wider than a dollar bill, A. reynoldsi seems to be the largest of the known species of Atolla jellies, the researchers said. However, what really sets this jelly apart from its cousins is what's missing; unlike all other currently known species of crown jellyfish, A. reynoldsi lacks a single elongate tentacle — one long, thin tentacle that trails behind its body, measuring up to six times the diameter of the jelly's bell.

According to the researchers, a crown jelly uses this extended appendage to help snag prey, which can include crustaceans, siphonophores (rope-like gelatinous animals) and other small creatures that pass through the ocean's midnight zone — the deep, sunless region of the ocean that extends from 3,300 to 13,100 feet (1,000 to 4,000 m) below the water's surface.

While analyzing thousands of hours of footage taken in the Monterey Bay's midnight zone between April 2006 and June 2021, MBARI researchers occasionally spotted crown jellies that lacked the signature trailing tentacle. The team suspected that they had discovered three new crown jelly species in the Bay, but sightings were too rare to prove it.

Now, in a new study published March 16 in the journal Animals, the researchers have conclusively identified one of the unknown jellies as the new species A. reynoldsi. The team studied 10 specimens of the mysterious crown jelly, including both physical specimens and sightings from archival footage, to conclude that the species is "molecularly and morphologically distinct" from all other known species in the genus — that is, it looks different both physically and genetically from its cousins.

A. reynoldsi has so far only been spotted in the Monterey Bay, swimming at depths of 3,323 to 10,463 feet (1,013 to 3,189 m).

"These remarkable new jellies underscore how much we still have to learn about the deep sea," lead study author George Matsumoto, a senior education and research specialist at MBARI, said in the statement. "On just about every dive into the depths of Monterey Bay, we learn something new."

MBARI researchers have identified more than 225 new species over the past 34 years, according to the institute. The two other crown jelly species observed without trailing tentacles may well end up being classified as new Atolla species in the future, the researchers added — however, more observations are still required.

Originally published on Live Science.

If you're looking for bizarre creatures that defy explanation, there is no better place to look than the deep sea. Every year, researchers capture incredible footage of alien-looking animals and strange new species lurking in the deep, and this year was no different. Here is our list of the top 10 weirdest deep-sea creatures seen in 2021.

Blood-red jellyfish

In August, researchers with the National Oceanic and Atmospheric Administration (NOAA) announced the discovery of a brand-new and unnamed species of blood-red jellyfish. The dark red jelly likely belongs to the genus Poralia, according to the researchers.

They first spotted the new jelly on July 28 using a remotely operated vehicle (ROV) at a depth of around 2,300 feet (700 meters) just off the coast of Newport, Rhode Island. Other animals, including other cnidarians (jellyfish & corals), ctenophores (comb jellies), crustaceans and Actinopterygii (ray-finned fishes), were also seen on the dive.

Lots of deep-sea creatures have evolved a similar red color because red wavelengths of light do not penetrate into the deep ocean. This means that red animals appear black because there is no red light to reflect back toward potential predators. 

Read more: Mysterious blood-red jellyfish may be rare species unknown to science, researchers say

Elusive glass octopus

Also in August, researchers from the Schmidt Ocean Institute (SOI) released footage of an elusive glass octopus (Vitreledonella richardi) off the coast of the remote Phoenix Islands, an archipelago located more than 3,200 miles (5,100 km) northeast of Sydney, Australia.

The translucent cephalopod was originally discovered during a 34-day expedition of the Central Pacific Ocean onboard the SOI's research vessel Falkor. Onboard scientists  spotted the creature using the ROV SuBastian, which spent a total of 182 hours scanning the seafloor during the expedition.

Like other "glass" creatures, such as glass frogs and certain comb jellies, glass octopuses are almost completely transparent, with only their cylindrical eyes, optic nerve and digestive tract appearing opaque.

Read more: Elusive glass octopus spotted in the remote Pacific Ocean (Video)

Shape-shifting whalefish

The Monterey Bay Aquarium Research Institute (MBARI) released footage in August showing a bright orange, female whalefish (of the order Cetomimiformes) around 6,600 feet (2,013 m) deep offshore of Monterey Bay, California.

Very little is known about this bizarre fish because of the three drastically different appearances of the juveniles (tapetails), males (bignoses) and females (whalefish). The three forms look so different that scientists originally thought they were three different species. The shape-shifting transformation from juvenile to mature females is believed to be one of the most extreme among any vertebrates.

"Whalefish have rarely been seen alive in the deep, so many mysteries remain regarding these remarkable fish," the Monterey Bay Aquarium Research Institute tweeted. 

Read more: Shape-shifting fish that confounded scientists for 100 years spotted off California coast

'Emperor Dumbo'

In May, researchers reported the discovery of a brand new species of Dumbo octopus (Grimpteuthis imperator), nicknamed "Emperor Dumbo" by the researchers. 

Researchers discovered the adorable creature in 2016 when they accidentally dragged it to the surface in a net while aboard the German research vessel Sonne during an expedition of the Aleutian Islands in the Bering Sea. Dumbo octopus species can be identified by the umbrella-like webbing joining their tentacles and their cartoonishly ear-like fins that resemble the oversized ears on Disney's famous elephant.

"It was a really lucky find," Alexander Ziegler, a researcher at Friedrich Wilhelm University in Bonn, Germany, and chief scientist onboard the research vessel, told Live Science, "because we weren't really looking for it. Plus, the whole animal came to the surface intact."

Read more: All hail 'Emperor Dumbo,' the newest species of deep-dwelling octopus

Real-life SpongeBob and Patrick

In August, NOAA released a comical photo of the real-life counterparts of the cartoon best friends SpongeBob Squarepants and Patrick Star side-by-side on the seafloor.

The image of the square(ish) yellow sponge and five-pointed pink sea star were taken by an ROV on July 27, at a depth of 6,184 feet (1,885 m) during an expedition of the Retriever Seamount off the coast of New England. 

"The sponge is [in] the genus Hertwigia and the sea star is [in] the genus Chondraster," Christopher Mah, a marine biologist at Smithsonian's National Museum of Natural History who first made the comparison on Twitter, told Live Science. The exact species is unclear, and they could even be brand new to science, he added.

Read more: Real-life SpongeBob and Patrick found side by side on seafloor. But they likely don't get along.

Alien-like spindly squid

In November, NOAA scientists spotted a rare bigfin squid (of the genus Magnapinna) with an ROV during an expedition in the Gulf of Mexico. 

The ghostly squid has a very odd body plan with huge, iridescent fins and bizarre elbow-like bends in its tentacles. "All of their arms and tentacles have this long, spaghetti-like extension," Mike Vecchione, a research zoologist with the NOAA Fisheries National Systematics Laboratory, can be heard saying in the NOAA video footage. "It's really difficult to tell the arms from the tentacles, which is very unusual for a squid."

To date, there have been fewer than 20 confirmed sightings of this deep-sea cephalopod since it was first discovered in 1998. 

Read more: Eerie video captures elusive, alien-like squid gliding in the Gulf of Mexico

Giant phantom jellyfish

In November, MBARI released rare video footage of a giant phantom jellyfish (Stygiomedusa gigantea). Scientists operating an ROV at a depth of 3,200 feet (975 m) in Monterey Bay, California, spotted the massive jelly, with its 3.3-foot-wide (1 m) bell and 33-foot-long (10 m) ribbon-like arms.

Not much is known about phantom jellyfish, but scientists think it uses its arms, which stream like loose scarves in its wake, to ensnare unfortunate prey and winch them up to its mouth. The creature also propels itself through the pitch-black depths with periodic pulses from its faintly glowing bell.

"The giant phantom jelly was first collected in 1899. Since then, scientists have only encountered this animal about 100 times," MBARI said in a statement. Although it is rarely spotted, the jelly has been found in the depths of every major ocean in the world, except for the Arctic Ocean.

Read more: Giant 'phantom jellyfish' that eats with mouth-arms spotted off California coast

Photobombing squid

In October, researchers trying to map the seafloor of the Gulf of Aqaba in the Red Sea were shocked when they discovered a recent shipwreck from 2011. While trying to film the remains of the vessel, the team's ROV was continuously photobombed by a purpleback flying squid (Sthenoteuthis oualaniensis).

The shipwreck and squid were found at a depth of around 2,788 feet (850 m). The scientists from OceanX think it was a solitary squid, but it may have been more than one as it was hard to identify the cephalopod as it zoomed across the screen. The researchers also said the squid had a total body length of about 6 feet (2 m), which would be near the maximum size for the species. 

"It was just so spectacular for me," Mattie Rodrigue, science program lead at OceanX, told Live Science. "We had absolutely no idea that we were going to encounter such a magnificent and large animal."

Read more: Giant purpleblack flying squid photobombs crew investigating shipwreck

Sponge tracks on the seafloor

In April, a new study revealed the first evidence of deep-sea sponges crawling around on the seafloor, after researchers snapped photos of bizarre brown tracks left behind by the surprisingly mobile creatures in the Arctic.

The sponge trails were first photographed in 2016 by towed cameras behind a research vessel at Langseth Ridge — a poorly studied region of the Arctic Ocean that's permanently covered in sea ice — at a depth of between 2,300 and 3,300 feet (700 to 1,000 meters).

"The trails are made up of the spicules, or spines, which the sponge can grow," study co-author Autun Purser, a deep-sea ecologist at the Alfred Wegener Institute at the Helmholtz Center for Polar and Marine Research in Germany, told Live Science. "The sponge seems to expand along these spines, then contract to the new, moved position. During this process, some spines break off, forming the trails."

Read more: Arctic sponges crawl around the seafloor and leave bizarre brown trails to prove it

A see through skull

In December, MBARI researchers caught a rare glimpse of a barreleye fish (Macropinna microstoma). This bizarre fish has a translucent forehead, which it actually looks through using a pair of bulbous green eyes inside its head.

An ROV filmed the strange creature while cruising at a depth of about 2,132 feet (650 m) in the Monterey Submarine Canyon, one of the deepest submarine canyons on the Pacific coast. Extraordinarily, MBARI scientists have only ever spotted the species nine times previously, despite having completed more than 5,600 dives in the fish's habitat.

"The barreleye first appeared very small out in the blue distance, but I immediately knew what I was looking at. It couldn't be mistaken for anything else," Thomas Knowles, a senior aquarist at the Monterey Bay Aquarium, told Live Science.

Read more: New footage shows bizarre deep-sea fish that sees through its forehead

Originally published on Live Science.

Beaches across the globe saw their share of weird blobs wash ashore. Sometimes this shoreline debris was small and weird, like a tangled rope coral that found its way onto a beach in Texas, or the tar balls that dotted Israel's Mediterranean coastline in February. Other times, the organisms numbered in the millions, such as the by-the-wind sailor jellyfish whose corpses stranded across shores; and in other instances, the beached animal itself was a behemoth, such as the rotting body of a nearly 10-foot-long (3 meters) "river monster" spotted near the Gulf of Mexico this year. Here's a look at the wild and strange "things" that washed ashore in 2021. 

Millions of 'sailor' jellyfish

Every year, millions of by-the-wind sailor jellyfish (Velella velella) wash up and die on beaches around the world. These jellies float near the top of the ocean, and have a little sail on their backs that catches wind and pushes them from one feeding ground to the next. When wind patterns change with the seasons, huge colonies of the jellies can end up stranded on the shore. Sometimes, those colonies include thousands of individual jellies; other times, they include millions.

Why are some Velella stranding events so much more massive than others? A study published in March 2021 found that the biggest stranding events occurred in years with record high ocean surface temperatures, driven by a phenomenon known as "the blob." The blob warms surface waters in the Pacific Ocean, fostering larger colonies of Velella at sea; when the winds change, those massive colonies end up on shore, littering beaches with millions of jelly carcasses. This trend of mass die-offs will likely continue as global warming escalates over the coming decades.

Read more: Millions of dead jellyfish are washing up around the world. 'The blob' could be to blame.

Young killer whale strands on Scottish beach

A juvenile killer whale was heroically rescued in January after getting stranded on a Scottish beach. A group of trained medics from the British Divers Marine Life Rescue (BDMLR) and helpful locals carried out the rescue on Sanday, an island off the coast of Scotland. After determining the animal was healthy and old enough to survive on its own, they managed to get it off its side and onto a special dolphin stretcher. It took eight people to lift the 11-foot-long (3.4 meter) orca into deeper water. Then, it suddenly headed off and was never seen again.

The entire rescue took just over an hour, but BDMLR area coordinator Neave-Webb, who led the rescue, believes it was only possible because of the team's newly acquired dolphin stretcher and the help of the locals. "It was a lucky animal to strand on an island with people who knew what they were doing and had the equipment to save it," she told Live Science. "It definitely chose the right place to throw itself on the beach."

Read more: Young killer whale rescued after stranding on Scottish beach

A truck-size basking shark

A male basking shark measuring 26 feet (8 meters) long washed up on the coast of Bremen, Maine in January, stunning local fishermen with its pickup-truck-sized body. Basking sharks live in warm waters across the world, and are the second largest fish in the sea; Only the elusive whale shark, which measures up to 60 feet (18 m), is longer. Despite their formidable size, basking sharks are harmless to humans. They mainly prefer to cruise through the water with mouths open, filtering tasty zooplankton and tiny invertebrates through their complex gills. As for the Bremen shark's cause of death? Marine researchers still aren't sure.

Read more: A truck-size shark washed up on a Maine beach. How did it die?

Twisted 'rope pile' on a Texas beach

It might look like a tangled snarl of yellow rope, but this knotty pile that washed up on a beach in Texas is really a type of coral known as a colorful sea whip (Leptogorgia virgulata). Colonies of soft-bodied coral polyps lend sea whips their vibrant colors, in shades of yellow, red, orange, purple, lavender and violet. After a National Park Service (NPS) guide found the partly-buried "rope ball" at the Padre Island National Seashore near the Gulf of Mexico, she shared the image on Facebook. Several commenters remarked that they had seen colorful sea whips on the beach before, but had always assumed that the creatures were trash, such as discarded cord or part of a fishing net. 

Read more: 'Pile of rope' on a Texas beach is a weird, real-life sea creature

40 refloated whales in New Zealand

Hundreds of people assembled on a remote beach in New Zealand when 49 long-finned pilot whales stranded there on a February morning. Nine of the whales died during the stranding, but conservation rangers, locals and volunteers from the marine rescue group Project Jonah tended to the surviving whales throughout the day, keeping their skin cool and moist and preventing their fins from being crushed beneath their beached bodies. High tide rolled in by evening, allowing the group to guide the whales back into deeper water. The volunteers herded the whales back into a pod and then formed a barrier to usher them away from shore; once the animals reached deep enough water, boats began patrolling the shoreline to keep the whales away from the beach.

Read more: 40 beached whales 'refloated' in New Zealand

Toxic tar balls wash up on Israel's coastline

In February, strange balls of tar began to wash up along Israel's Mediterranean coastline. Over 100 miles (160 kilometers) were affected by the tar balls which were the result of an oil spill 31 miles (50 km) off the coast. Normally, oil spills form a slick across the sea's surface and washes up on beaches in a more liquid form. The Israel spill, however, turned into tar balls because rough sea conditions from a storm broke up the slick and mixed it into the seawater for several days creating small concentrated blobs of congealed oil. It was described by officials as "one of the most serious ecological disasters" the country had ever seen. Beaches also had to be closed to the public after several cleanup volunteers had to be taken to hospital after inhaling toxic fumes given off by the tar balls.

Read more: Mysterious oil spill covers Israel's coastline in toxic tar balls

Amazon 'river monster' turns up dead in Florida

When Florida locals found the rotting body of a dead Amazon "river monster" near the Gulf of Mexico, many worried that this beast might become the state's latest invasive species. But this so-called monster, the arapaima (Arapaima gigas), faces many hurdles before it can call Florida home. 

The arapaima is one of the world's largest freshwater fish, and can grow to be 10 feet (3 meters) long and up to 440 lbs. (200 kilograms). But it has a few quirks: It breeds only in nests on flood plains, spends valuable time and energy caring for its young, and doesn't reach sexual maturity until it's about 5 feet (1.5 m) long and at least 3 to 5 years old, Solomon David, an aquatic ecologist at Nicholls State University in Louisiana who wasn't involved with the recent arapaima sighting, told Live Science.

What's more, it would take many arapaimas to set up a viable population in Florida, and just one dead arapaima has been found so far, David noted. But wildlife officials should still be on the lookout just in case these fish get a foothold in the Sunshine State, he said. 

Read more: Amazon 'river monster' turns up dead in Florida

Majestic moofish surprises Oregon beachgoers

The dazzling remains of a 100-pound (45 kilograms) moonfish washed up on an Oregon beach in July, where it surprised beachgoers with its girth and glistening hue. The 3.5-foot-long (1 meter) fish (also called an opah) showed off a mix of silvery and bright reddish-orange scales with scattered white dots covering its flattened body. And it sported golden eyes.

Even more surprising than its appearance was finding the fish hundreds of miles from home. These pelagic, or open ocean, fish are typically found off the coast of California and near Hawaii, so finding one so far north is extremely rare. As for why the hefty fish had meandered so far north, global warming could be the culprit; as ocean temperatures heat up, opah are leaving their too-balmy homes for once-colder dwellings. "We are seeing some marine organisms moving northward as ocean temperatures increase," Heidi Dewar, a research biologist with NOAA Fisheries who was not involved in the recovery, told The Washington Post.

And the fish's "life" wasn't over quite yet: Scientists at the Seaside Aquarium in Oregon froze the beached opah so that students this year could dissect its scaly remains. 

Read more: Majestic 100-pound moonfish washes up on Oregon beach

A fish inside a jellyfish 

Dead jellyfish dotting the shoreline are typically nothing to stop and look at. But in August, a peculiar blob caused beachgoers in the U.K. to take notice. This cnidarian had an undigested fish in its translucent bell for all to see. The juvenile fish must have been consumed right before the hungry compass jellyfish (Chrysaora hysoscella) — named for its brown, V-shaped markings that are reminiscent of a compass — met its end as well. 

The unfortunate fish could have been hiding out in the jelly's tentacles, a known behavior, when its protector struck. The jellyfish likely stung the fish to death and would have continued to slowly digest the snack in its rudimentary stomach had it not washed ashore and met its doom, Live Science reported. 

A local photographer who spotted the beached jelly while walking his dog near Padstow in Cornwall on Aug. 4, said "It's not something you see every day," according to The Daily Mail.

Read more: Translucent jellyfish, with fish trapped inside it, washes up on UK beach

Record-breaking sawfish 'mom' a boon to science

This toothy invertebrate never got to bask in the glory of breaking a world record for largest smalltooth sawfish ever recorded. That's because the animal was dead when scientists found (and measured) it in the Florida Keys in April. Perhaps on the bright side, the 16-foot-long (4.9 meters) specimen was a boon to science. The fish had softball-size eggs in her reproductive tract, meaning scientists could study the carcass to learn more about this individual's age and reproductive past, as well as that for her species, 

"Although it's a sad occurrence when a big animal like that dies, from a scientific standpoint we knew we could learn a lot from it," said Gregg Poulakis, a fish biologist at the Florida Fish and Wildlife Conservation Commission. "That makes us feel a little bit better about having lost such a big female." 

The fish could also be one of the oldest of its kind ever recorded. "We're excited to see how old the 16-footer that we got this week is," Poulakis said. "My guess is that she is older than [14]," which would mean she would be tied with the current record-holder for the oldest sawfish Poulakis' team had ever caught.

Read more: Largest recorded smalltooth sawfish washes up dead in Florida

'Death in a dumpster' washes up in Plymouth

Some beached animals garner attention for their looks, while others just smell really, really bad. That was the case for a minke whale found dead in Plymouth, Massachusetts, in July, which locals said had such a bad odor it was "like death in a dumpster," according to news reports at the time. 

Typically, a whale carcass like this one would be left on the beach to naturally decompose, where it could serve as a buffet for scavengers before the nutrients seep back into the ecosystem. But this 21-foot-long (6.4 meters) carcass was way too smelly and way too close to town.

"I live up the hill over on the other side, and there are days when you walk outside hoping to smell sea air and all you can smell is dead whale," local resident Lynn Holdsworth told NBC Boston in July. "And it's like death in a dumpster. It's horrible."

NOAA Northeast/Mid-Atlantic worked with the nearby homeowner's association (HOA) that was responsible for the beach to figure out a disposal plan. The HOA then got heavy equipment to haul the whale to the nearby Bourne landfill. 

Read more: Stranded minke whale stinks so bad it's like 'death in a dumpster'

Originally published on Live Science.

Jellyfish may be brainless, yet they can do surprisingly complex things with their simplistic nervous systems. Now, by fiddling with the genes of jellyfish, researchers have devised a way to spy on the animals' inner workings. 

In the new study, the researchers created a model using the jellyfish species Clytia hemisphaerica, a transparent, umbrella-shaped jellyfish with a tube-like mouth at its center. The teeny jellyfish grows to be only 0.4 inches (1 centimeter) in diameter, meaning the team could place the whole jellyfish under the microscope and observe its entire nervous system at once.

While the human brain serves as a centralized control center for the body, jellyfish have no such structure in their nervous systems. Instead, many jellyfish carry a diffuse "net" of nerves that radiates symmetrically from the center of their bodies; in addition, they have a nerve ring that runs around the bottom of the bell — the half-moon-shaped portion of the jellyfish. Some jellyfish lack nerve nets and have only nerve rings, according to a 2013 report in the journal Current Biology, but C. hemisphaerica has both of these structures. 

The big question is, with no centralized control over their movements, how do these teensy jellyfish perform coordinated behaviors? For instance, how do the blobby critters snatch shrimp from the water column and then fold in half to pull the snacks toward their tubular mouths?

Related: From dino brains to thought control — 10 fascinating brain findings 

To answer this question, the team raised a batch of C. hemisphaerica with a genetic modification that coded for a protein called GCaMP, which glows green when it comes into contact with calcium. 

The special glowing protein was inserted into a location in the jellyfish genome so that it only lit up in active neurons, said first author Brandon Weissbourd, a postdoctoral scholar in biology and biological engineering at the California Institute of Technology. "When neurons are active, the amount of calcium [inside the neurons] goes up, so GCaMP becomes more fluorescent. This means that neural activity looks like flashing," Weissbourd told Live Science in an email. 

But jellyfish are naturally luminescent. So to see their engineered flashing more clearly, the team used CRISPR to snip out a specific gene that makes a different fluorescent protein, one that kept outshining the GCaMP they had inserted, he said.

With their jellyfish thus transformed into miniature light shows, the team ran a number of experiments to see which neurons lit up during their typical feeding behaviors. They found that, when the jellyfish latched onto a brine shrimp, or came into contact with a "shrimp extract" made by the team, a group of neurons physically near the shrimp suddenly lit up. 

Related: Weird animal facts

This activation didn't ripple through the entire jellyfish, like how a stone plopped in a puddle would send ripples across its entire surface. Rather, only neurons within a well-defined, wedge-shaped region of the bell lit up in response to the shrimpy snack. This wedge of active neurons was shaped like  like a single pizza slice within a circular pie, according to a statement. The neurons that were closest to the shrimp lit up first, the team found, and then a slew of strobe lights would illuminate the rest of the slice.

So for example, if a shrimp was placed at the far edge of the pizza slice, onto its "crust," the crust would light up first, followed by the rest of the slice. This ripple effect coincided with the jellyfish folding up in the corner of its bell, in order to bring the shrimp to its mouth. 

The team didn't expect to observe this level of organization within the seemingly unstructured nerve net, Weissbourd said. "The finding of an intrinsic structure within the network was certainly surprising," he said. 

Looking forward, the team plans to investigate how jellyfish exert control over all their behaviors, not just feeding, and they plan to study different species of jellyfish, which perform different behaviors to C. hemisphaerica, Weissbourd said. For instance, while some jellyfish perform a similar food-passing behavior as C. hemisphaerica, others instead use long-reaching mouthparts to pluck food from their tentacles. "Given the diversity of jellyfish, and that so many of them are small and transparent, I think they could provide an exciting platform in the future for understanding how nervous systems evolve."

These studies of strobing jellyfish could also shed light on basic principles that govern all nervous systems, from the most simplistic to the most complex. "The idea is to develop experimental and theoretical approaches towards understanding how simpler nervous systems work as a step towards understanding the human brain, which is orders of magnitude more complex," Weissbourd told Live Science.

The team published their findings Nov. 24 in the journal Cell. 

Originally published on Live Science.

Scientists piloting a remote submarine have filmed mesmerizing footage of a giant phantom predator lurking in the deep waters of Monterey Bay, California.

The giant phantom jellyfish (Stygiomedusa gigantea) was captured as it was serenely floating — its long, velvety "mouth-arms" trailing around it — at a depth of 3,200 feet (975 meters) by marine biologists from the Monterey Bay Aquarium Research Institute (MBARI). This is one of only nine times that MBARI scientists have spotted the elusive creature across the institute’s many thousands of submarine dives.

"The giant phantom jelly was first collected in 1899. Since then, scientists have only encountered this animal about 100 times," MBARI said in a statement. 

Related: In photos: Spooky deep-sea creatures

The giant phantom, which is among the largest jellyfish on the planet, has been spotted in the deepest parts of all the world’s oceans except for the Arctic. Even so, MBARI says that sightings of the creature are still rare, as it usually lives too far down for humans or remote submarines to access.

The sunhat shaped-bell of the deep-sea dweller is more than 3.3 feet (1 meter) wide, and it's ribbon-like mouth-arms can grow to more than 33 feet (10 m) in length, MBARI said.

Not much is known about phantom jellyfish, but scientists think it uses its mouth-arms, which stream like loose scarves in its wake, to ensnare unfortunate prey and winch them up to its mouth. The creature propels itself through the pitch-black depths of the ocean with periodic pulses from its faintly-glowing orange head.

Before the deployment of remote controlled submarines like the one used for this expedition, scientists often used trawl nets to capture deep-sea creatures. This was ideal for studying some creatures, but not deep-sea jellyfish, MBARI said.

"These nets can be useful for researching robust creatures like fish, crustaceans and squids," MBARI said. "But jellies disintegrate into gelatinous goo in trawl nets."

Jellyfish are some of the most common creatures to be found in the deep sea, the compressible, squidgy jelly of their bodies enabling them to survive incredibly high pressures. However, much about the brainless creatures remains to be discovered. It was once assumed that jellyfish were largely unimportant in deep-sea ecology, but a 2017 study by MBARI researchers showed that these cnidarians are actually among the most important predators in the dark depths, competing with cephalopods like squid, as well as fish and even blue whales for food.

Originally published on Live Science.

A clever photographer has used some camera trickery to capture a stunning shot of what appear to be around a dozen "dancing" jellyfish in a Spanish lake. But there's a twist: There are only two jellyfish. 

Spanish photographer Angel Fitor snapped the photo, titled "Medusa Ballet" (named for the free-floating life stage of jellyfish) at Mar Menor, Europe's largest saltwater lagoon. The mesmerizing image features 11 Mediterranean jellyfish (Cotylorhiza tuberculata), also known as fried egg jellyfish, whose translucent orange bells perfectly match the setting sun behind a far-off mountain on the horizon. The shot was voted the overall winner at the European Wildlife Photographer of the Year 2021 competition on Oct. 28.

However, if you look closely at the floating cnidarians, you'll realize that they look remarkably alike. That's because there are actually only two jellyfish in the shot. But this isn't a case of copy and paste; instead, Fitor used multiple flashes to capture the pair as the jellies moved across the water's surface on a gentle current. 

Related: Photos: Stunning shots of the natural world and wildlife

"For more than six years, I tried to realize this image idea, and I had to put up with countless failed attempts," Fitor said in a statement. "Which is not surprising considering the unpredictability of the factors that were prerequisite for success."

The award-winning photo was originally taken in 2014, shortly before the first of several mass die-offs of marine life in Mar Menor over the last five years that have decimated the ecosystem. The most recent die-off in August was the worst yet and led to tons of dead fish washing ashore, according to the BBC. 

Environmentalists blame persistent agricultural pollution that has degraded the water quality in the lagoon and caused frequent algal blooms. Dubbed "the green soup" by locals, these blooms of algae suck up the oxygen in the water and suffocate the creatures below the surface.

Fitor described his photo as "an ode to the unique natural heritage Mar Menor once was."

The contest judges said a combination of the photographer's skill and the subject's environmental significance helped the photo win the award.

"The powerful image spoke strongly to us jury members on many levels," competition judge Jim Brandenburg said in the statement. "After the ecological catastrophe that occurred only a short time later at the place where it was taken, it also speaks about the massive environmental problems of this region."

Originally published on Live Science.

The gelatinous, transparent bodies of bizarre jellylike sea creatures — illuminated by the twinkling of an internal light, and some with a recent meal still visible in their bellies — tumble and drift in hypnotic footage that was captured below the Antarctic ice.

Edited into a "trippy video composition," as filmmaker and scientist Emiliano Cimoli described the film in a statement, the footage presents close-up views of jellyfish, comb jellies and other soft-bodied, see-through ocean life in the Ross Sea, a deep body of water in the Southern Ocean at McMurdo Sound. 

The exceptional detail in the video enabled researchers to spot a dozen species of gelatinous animals, of which two species of jellyfish and three comb jelly species are as yet unknown to science, according to a new study.

Related: Image gallery: Jellyfish rule!

Cimoli, co-author of the study and a postgraduate researcher at the University of Tasmania in Hobart, Australia, shot the footage when he visited Antarctica to conduct research in 2018 and 2019. But he wasn't there to study jellyfish or comb jellies; rather, he was testing sensing equipment to monitor algae that live under sea ice, Cimoli wrote in a video description on YouTube.

"Ice algae play a crucial role in polar marine food webs and ecosystems," Cimoli said. "The research theme of the expeditions was to investigate their abundance and physiology under changing light conditions," such as those caused by climate change, he explained on YouTube. 

Inside the researchers' field tent, there was a sizable viewing hole cut into the sea ice. Cimoli, an amateur wildlife videographer and photographer, saw this as an opportunity to send cameras under the ice — some tethered to the surface, and some attached to diving robots — to seek out elusive marine life that's often difficult to observe in its natural habitat.

This opened a window into a rarely-glimpsed ocean ecosystem, "kind of like a magic portal to another world," Cimoli said in the statement.

In some of the footage, surface ice is visible overhead. Other clips show the sea bottom sprinkled liberally with pink starfish. But the most dramatic scenes are the ones in which jellies drift and undulate through inky water. In an astonishing shot, a Diplulmaris antarctica jellyfish's body gently pulses and ripples; a number of small orange globes — small parasitic crustaceans called hyperiid amphipods — cluster around its bell. And engulfed inside the jellyfish is a recent meal: a comb jelly in the Beroe genus.

Cimoli edited the video during COVID-19 lockdown, and he posted it on YouTube and Vimeo in March 2020. Gerlien Verhaegen, a postdoctoral researcher at the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) in Kanagawa, Japan, and lead author of the study, recognized that the footage was a gold mine for biologists studying jellies. Delicate structures in jellyfishes' and comb jellies' squishy bodies are very hard to preserve when the animal is removed from the water, so the study authors identified species in the video by comparing them to naturalists' illustrations and descriptions, many of which date to the early 20th century, Verhaegen said in the statement.

"Our study constitutes the first optics-based survey of gelatinous zooplankton in the Ross Sea," the study authors reported. This is also the first study to use observations of living jellies in their Southern Ocean habitats to describe species and document some of the behaviors in jellyfish and comb jellies.

The scientists reported sightings of 12 species of these gelatinous animals — but not all of them matched descriptions in scientific literature, and five individuals could be undescribed species. Images from the footage will also be used to train computer algorithms to identify jellyfish species, a feat that is only possible when training databases contain high-quality photos or video that the computer can learn from, according to the study.

And after peering into otherworldly marine environments under sea ice, people may wish to learn more about mysterious, remote habitats such as this one, Cimoli wrote on YouTube.

"When curiosity is triggered, it engages one to get deeply involved and become knowledgeable about something," Cimoli said.

The findings were published Aug. 16 in the Biodiversity Data Journal.

Originally published on Live Science.

Researchers with the National Oceanic and Atmospheric Administration (NOAA) may have discovered a previously unknown jellyfish, bobbing along almost 2,300 feet (700 meters) underwater.

Like a floating beret fringed with thin tassels, the jelly in question has a blood-red body and appears to belong to the genus Poralia, the researchers said in a statement. Only one other Poralia species has been described so far — Poralia rufescens, which has a bell-shaped body, 30 tentacles and lives in deep water across the world's oceans.

The NOAA team spotted the as-yet-unnamed jellyfish in footage from a deep-water dive conducted on July 28, off the coast of Newport, Rhode Island. The agency's remotely operated vehicle (ROV) Deep Discoverer dove to a maximum depth of about 3,000 feet (915 m) into the North Atlantic Ocean, filming any creatures that it passed.

Quinn Girasek, a NOAA intern studying biology at Juniata College in Pennsylvania, first saw the jellyfish while annotating footage from the dive.

"Overall, a variety of animals were seen, like ctenophores [also called comb jellies], cnidarians, crustaceans and Actinopterygii (ray-finned fishes)," Girasek said in the statement. "We also saw several undescribed families and potential new species."

This deep dive through the water column was part of NOAA's North Atlantic Stepping Stones expedition, which the team conducted from June 30 through July 29. The team completed 25 dives, at depths ranging from 820 to 13,124 feet (250 to 4,000 m), in order to survey the elusive deep-sea creatures lurking in the area.

Some discoveries from the mission looked shockingly familiar. A few days earlier in the expedition, the team stumbled upon a yellow sea sponge lounging alongside a pink sea star some 6,184 feet (1,885 m) underwater. Christopher Mah, a marine biologist at Smithsonian's National Museum of Natural History, likened the pair to a "real-life SpongeBob and Patrick" when he saw the image on Twitter.

Originally published on Live Science.

Thousands of jellyfish are gathering by the coast of Rhode Island, and they're not afraid to use their stingers against potential foes, according to news sources.

The jellyfish, known as Atlantic sea nettles (Chrysaora quinquecirrha), thrive in warm waters, which may partially explain the recent population boom over the past month, the Rhode Island Division of Fish and Wildlife Outdoor Education (RIDEM) posted on Facebook. After all, June 2021 was the hottest June on record in North America, according to the European Union's Copernicus program, Live Science reported.

Even so, scientists are puzzled over the cause of the spike. The jellyfish swarms are popping up at a coastal lagoon known as Ninigret Pond and a saltwater lagoon estuary called Green Hill Pond, near the coast. "Their high abundance in the ponds this summer is not fully understood," RIDEM wrote in the post, adding that "their numbers are expected to decline as the summer goes on."

Related: Image gallery: Jellyfish rule!

Swimmers would be wise to avoid the jellies, the RIDEM noted. "Although their sting is not fatal (unless there is a severe allergic reaction), it can cause moderate discomfort and itchy welts," RIDEM representatives wrote in the post.

If you are stung by an Atlantic sea nettle, there are some steps you should take, the RIDEM noted. First, remove any visible tentacles from the affected area with a gloved hand or plastic bag. Then, rinse the sting with vinegar, store-bought sting spray or (in a pinch) saltwater, but not freshwater, "as this can worsen the sting," RIDEM representatives wrote. Moreover, because heat can inactivate the venom, the RIDEM recommended applying a hot pack or hot water to the sting. After that, "an ice pack and hydrocortisone cream can be applied to help with discomfort," the RIDEM noted, adding that you should seek professional medical care if symptoms worsen.

Atlantic sea nettles are found along the U.S. East Coast, from Cape Cod in Massachusetts to the Caribbean and Gulf of Mexico, according to the Aquarium of the Pacific in Long Beach, California. This sea creature has a saucer-shaped medusa (the "bell" part of the body); four thick, long, lacy arms; and between four and 40 long, thread-like tentacles, the aquarium reported.

These jellyfish vary in color, depending on their habitat. Atlantic sea nettles in the Chesapeake Bay and the open ocean tend to be pink to reddish-maroon, with red stripes that point toward their yellow tentacles, while jellies in the low-salt waters of estuaries have white bells and no stripes, according to the Aquarium of the Pacific.

The jellies' bells vary from 4 to 8 inches (10 to 25 centimeters) in diameter. They gobble up ctenophores (comb jellies), as well as young minnows and other small fish, mosquito larvae, bay anchovy eggs, and copepods and other zooplankton, according to the Aquarium of the Pacific.

Few predators, save for sea turtles, prey on Atlantic sea nettles, so their numbers are largely influenced by rain and heat, according to an article in Save the Bay magazine, which focuses on the Chesapeake Bay. These jellies prefer warm, salty water, so their populations tend to spike during dry and hot summers, the magazine reported. 

Jellyfish blooms aren't a rare event, especially in summertime. Overfishing has led to fewer predators that compete with and prey on jellyfish, and nutrient-rich pollution, such as runoff water full of fertilizer, can lead to phytoplankton blooms, creating an all-you-can-eat buffet for jellies, Live Science previously reported. 

However, the overarching reasons behind jellyfish blooms are likely more complex, a 2012 study published in the journal BioScience found, and a 2013 study published in the Proceedings of the National Academy of Sciences suggested that while human activity does appear to effect on jellyfish numbers, jellyfish populations might also naturally rise and fall in decades-long oscillations, although more research is needed to say so for sure.

Originally published on Live Science.

1. Invisible frog

Most creatures hide their internal organs underneath multiple protective layers of skin, tissue and bone. But what if these layers were see-through?

Looking at a glass frog from above, you may not notice anything out of the ordinary. But if you were to flip it over, you would spy a tiny, fast-beating heart, a long, red vein, and a section of squirming intestines breaking down food. These amphibians have evolved to have extremely thin, translucent skin. 

So why did these frogs evolve to be see-through? While these frogs' thin skin puts their entire internal anatomy on full display, when light shines on the frogs from above their silhouette becomes muddled to predators, according to a study published June 9 in the journal Proceedings of the National Academy of Sciences. 

These frogs live in the rainforests of Central and South America and spend much of their time perched on leaves. Because the frogs are surrounded by lush greenery, their vibrant-green topcoats are ideal for camouflage. Meanwhile, their more transparent legs blur the outlines of their bodies, making it tough for predators to recognize the frogs' shape, the study found.

Related: How many organs are in the human body?

2. Wasp-fig relationship

Unlikely relationships are often formed in the wild. For instance, fig wasps have found an unusual home inside figs. The fig "fruit" is actually a bundle of tiny flowers, called an inflorescence, which relies on fig wasps for pollination. In turn, the fleshy inflorescence provides a comfy and safe home for the wasps during their very short lives.

When female fig wasps hatch into the world, they are primed to "sniff out" receptive fig trees, or those whose flowers are ready for pollination, according to The Netherlands Entomological Society. Instinctively, the wasps search out the particular aroma emitted by female fig flowers, according to the U.S. Forest Service. Once they find a fig-in-need, the wasps dig their way into the soft, sweet flower through an opening at the end of the fig "fruit." The hole is so small that many wasps lose their wings and parts of their antennas. Once inside the fig, the female wasps are protected and out of sight, and they are able to lay their eggs. According to the Journal of Nematology, the wasps will not see the outside world ever again. The females die just 24 hours after laying their eggs.

When the fig wasps hatch, the male hatchlings mate with the females, before digging escape routes out of the fig for the females. The male wasps spend their entire lives in the fig and die shortly after producing the tunnels. 

This odd behavior has kept this wasp species alive for over 60 million years, according to an article published in 2005 in the journal Proceedings of the Royal Society B. Figs have these insects to thank for their continued existence, as their movement from one fig to another spreads their pollen.

3. Walking fish

Mexican walking fish (Ambystoma mexicanum), also called axolotls, are quirky creatures: Not only do these "fish" sport a protruding, spiky hairdo, they can also "walk." When they approach the bottom of a lake or canal, they pull out four legs from their sides to crawl around their swampy habitat in Mexico City. 

Although they look like overdeveloped fish, they are actually amphibians. Often amphibians begin their lives equipped with gills so they can breathe underwater until they mature and lose their gills, ready for life on land. But axolotls keep their juvenile gills and remain in the water — a phenomenon called neoteny, according to an article in the journal Nature. 

Never leaving the water, axolotls are found in the lakes of Xochimilco near Mexico City. Growing up to 12 inches (30 centimeters) long, they feed on small insects, worms, mollusks and crustaceans. Historically, these grinning creatures were at the top of the food chain, but invasive fish species — such as tilapia and carp fish, which eat baby axolotls — and pollution are now threatening their survival.

4. Pregnant males

Females don't always have to bear the brunt of pregnancy. According to Scientific American, for seahorses, pipefish and sea dragons — members of the Syngnathidae fish family — it's the males that get pregnant. Seahorses and pipefish carry their young inside brood pouches, supplying nutrients such as energy-rich fats through the pouch tissue, while sea dragons' eggs simply stick to the outside of the males’ tail. 

Is there any benefit to this arrangement? Because the females can focus solely on egg-making (leaving other baby-rearing roles to the males), seahorses can give birth in the morning and be pregnant again by the evening, according to National Geographic. This helps the species' numbers increase for a higher chance of survival. 

With the males carrying the babies, the females are also less likely to be drained of energy. Usually, the females expend more energy producing eggs than the males do producing sperm, according to Oxford Academic. By transferring egg-carrying duties to males, the energy demand is shared more evenly.

5. Parasitic mates

Male and female anglerfish are so varied in appearance that you might think they were different species at first glance. The females are up to 60 times longer and half a million times heavier than their male partners; as such, when scientists first observed the males with the female anglerfish, they thought that they were looking at a mom and her young, according to an article published in a journal of the American Society of Ichthyologists and Herpetologists.

The most common images of anglerfish show the females. Found lurking mostly in the darkest depths of the Atlantic and Antarctic oceans, female anglerfish look like the stuff of nightmares: Light rods hang from their faces and terrifyingly large fangs protrude from their mouths. 

But the arrival of the males makes everything even more peculiar. When mating, a male anglerfish acts like a parasite, according to New Scientist. Biting into the side of his chosen female, the tiny male fuses his body with hers so he can steal her nutrients by sucking out her blood. Since the male has no need to swim or see, his eyes, fins and some major organs begin to deteriorate. He gets everything he requires for little effort, while his only responsibilities are to provide reproductive cells when the time is right. At that time, the male and female release their sperm and eggs, respectively, into the water for fertilization, Live Science previously reported.

6. Immortal jellies

Do you ever wish you could jump back in time to when you were young and start life again? As time passes, our bodies are designed to grow, age and eventually die. However, not all species follow this cycle. Meet the immortal jellyfish, Turritopsis dohrnii. 

When injured or in the face of starvation, this jellyfish can push the "reset" button, according to the American Museum of Natural History (AMNH). With that reset, the jellyfish adults reverts back to an earlier developmental stage, in this case a polyp. That new polyp then continues the life cycle and spawns lots of genetically identical medusas, or the tentacled creatures we call jellyfish. Scientists think the immortal jellyfish use a process called transdifferentiation to pull off this rejuvenating feat. In this process, an adult cell that has become specialized for a certain tissue can transform into a different kind of specialized cell, AMNH said. 

At their largest, adults of this jellyfish are still less than 0.2 inches (5 millimeters) across. These jellyfish were first discovered in 1883 in the Mediterranean Sea, but they only gained the moniker of the immortal jellyfish in the mid-1990s. While a German student was studying them in a lab, he noticed the bizarre phenomenon. When the medusa stage of the jellyfish got stressed, it fell to the bottom of the holding jar and reverted straight into polyps, skipping any fertilization or larval stages, according to The Biologist, published by the Royal Society of Biology. The researchers liked it to "a butterfly transforming back into a caterpillar." 

Next, researchers hope to figure out how the jellyfish accomplishes its everlasting life. "The genome of Turritopsis dohrnii is being investigated and decoding it will be the first step towards the search for an 'immortality switch,'" according to The Biologist.

The continuous cycle

Explore how these jellyfish reverse maturity to relive the cycle. Click the numbers below to learn more.

Like a tourist on a cruise ship, the by-the-wind sailor jellyfish (Velella velella) spends its days drifting aimlessly through the open sea, gorging itself on an endless buffet of complementary morsels.

The jelly straddles the ocean's surface with a rigid sail poking just above the water and an array of purple tentacles dangling just underneath. As the sail catches wind, the jelly floats from place to place, capturing tiny fish and plankton wherever it roams. Thriving Velella colonies can include millions of individuals, all just partying and chowing down together in the open water. Life is good.

Until, that is, the wind blows a colony of sailor jellies onto shore.

Every year, on beaches around the world, colonies of sailor jellies become stranded by the thousands. There, they dry up and die, becoming a "crunchy carpet" of dehydrated corpses covering the sand, Julia Parrish, a University of Washington professor and co-author of a new study on mass Velella strandings, said in a statement.

Related: Image gallery: Jellyfish rule!

Sailor jelly strandings are common when seasonal winds change course, but some — like a 2006 event on the west coast of New Zealand — are on another level entirely, with the jellyfish corpses numbering not in the thousands, but in the millions. Why? What force of nature makes some Velella strandings so much larger than others? 

Parrish and her colleagues wanted to find out. So, in their new study (published March 18 in the journal Marine Ecology Progress Series) they delved into 20 years of Velella observations reported along the west coast of the United States.

The observations came from a program called the Coastal Observation and Seabird Survey Team, also known as COASST, which trains citizen scientists to search their local beaches for marine birds that have washed ashore, plus any other unusual animal sightings. COASST's network covers hundreds of beaches stretching from northern California to the Arctic Circle, according to the group's website — and, of course, some members have had run-ins with Velella.

The researchers found nearly 500 reports of Velella strandings in the COASST database, sighted on nearly 300 beaches. According to these reports, the most massive die-offs by far occurred during spring months from 2015 to 2019. During those years, dead jellyfish littered more than 620 miles (1,000 kilometers) of continuous coastline, the researchers found.

Those jellyfish die-offs also coincided with a massive marine heat wave known as "the blob." Beginning in 2013, surface waters off the Pacific coast began heating up to levels never recorded before, Live Science previously reported. The intense warming continued through 2016, tampering with every level of the marine food chain and resulting in mass die-offs of seabirds, baleen whales, sea lions and other creatures. According to the new study, it's likely that the blob drove the mass die-offs of by-the-wind sailor jellyfish reported during those years.

The catch is, those warming ocean waters may have actually been good for the jellies, the researchers said. As the blob increased ocean surface temperatures, certain fish (such as northern anchovies) benefited from longer spawning seasons, providing more food for Velella jellies to gobble up earlier in the year. This may have caused jellyfish populations to spike before seasonal wind changes blew the jellies ashore in the spring.

In other words, the blob may have helped Velella jellies thrive off the Pacific coast, leading to much larger stranding events those years. The sailor jellies could therefore become climate change "winners" as global warming is predicted to increase the frequency of marine heat waves, the researchers wrote. But their success will come at the expense of other, less fortunate creatures — and a whole mess of jellyfish carcasses on our coasts.

"A changing climate creates new winners and losers in every ecosystem," Parrish said in the statement. "What's scary is that we're actually documenting that change."

Originally published on Live Science.

Deep in an underwater canyon off the coast of Puerto Rico, there's a party of balloon-like sea creatures keeping things festive in the abyssal depths.

Their bodies are small — about the size of a golf tee (just over 2 inches, or 6 centimeters, long) — but they're vibrant; when the creatures move and pulse, rows of tiny hair-like cilia refract light into a prism of shining colors.

Researchers at the National Oceanic and Atmospheric Administration (NOAA) first spotted these mysterious party blobs in 2015, sighting three of them near the seabed at a depth of roughly 13,000 feet (4,000 meters). Now, in a paper published Nov. 18 in the journal Plankton and Benthos research, the team has identified the blobs as a new species of ctenophore –- tiny invertebrate predators also known as comb jellies or "sea walnuts" –- called Duobrachium sparksae.

Related: 8 Crazy facts about octopuses

While their wee bodies and shimmering cilia are traits commonly shared among the 100-plus known ctenophore species, the Puerto Rican party blobs still represent an exciting first in marine biology. According to the researchers, this is the first underwater species NOAA researchers have ever described from pictures alone; the team had no access to physical samples for their new study.

"The cameras on the [remotely operated] Deep Discoverer robot are able to get high-resolution images and measure structures less than a millimeter," study co-author Allen Collins, a NOAA fisheries scientist, said in a statement. "We don't have the same microscopes as we would in a lab, but the video can give us enough information to understand the morphology in detail."

Despite their name, comb jellies are not related to jellyfish, though they do share a similar gelatinous appearance. D. sparksae is no exception, with eight rows of prickly cilia wrapping around a translucent body. That body ends at two points attached to long, thin tentacles, giving the creature an appearance like a floating balloon with two "dangly bits," each attached to its own string, Collins said.

One of the three specimens the team encountered seemed to be "anchored" to the seafloor by its tentacles, the researchers wrote. Using a pair of lasers on their underwater robot, the researchers measured the approximate length of that specimen's body and tentacles, finding the tentacles to be roughly five times as long as jelly's body (each tentacle was 12 inches, or 30 cm, long). When the jelly moved, it moved "like a hot air balloon," maintaining a specific altitude above the ocean floor, said lead study author Michael Ford, also of NOAA.

Many questions remain about these elusive, deep-sea jellies, including what role they play in their ecosystem. More video footage of the blobs will provide additional clues, but to conduct a crucial DNA analysis researchers will have to get their gloves on an actual intact specimen. That may be easier said than done, as jelly-like animals have a very short shelf-life outside of the deep sea, the researchers said.

"Even if we had the equipment, there would have been very little time to process the animal because gelatinous animals don't preserve very well; ctenophores are even worse than jellyfish in this regard," Collins said. "High-quality video and photography were crucial for describing this new species."

Originally published on Live Science.

Later this summer, around the time school usually starts in North America, thousands of invasive jellyfish-like creatures in the Baltic Sea will begin eating their children.

Any parent who has just spent a summer in close quarters with their kids might understand the motivation, but it's far more than mere annoyance that drives the Baltic jellies to their annual baby jelly buffet. According to a new study published May 7 in the journal Communications Biology, cannibalism may simply be a fact of life for jellies living in nutrient-poor waters outside their natural habitats, providing adults a few extra weeks of energy after they've decimated local prey populations.

"In some ways, the whole jelly population is acting as a single organism, with the younger groups supporting the adults through times of nutrient stress," study co-author Thomas Larsen, of the Max Planck Institute for the Science of Human History in Jena, Germany, said in a statement. "Overall, it enables jellies to persist through extreme events and low food periods, colonizing farther than climate systems and other conditions would usually allow."

Walnut invaders

For their new research, the authors studied a population of warty comb jelly (Mnemiopsis leidyi — a jellyfish relative also known as a "sea walnut") living in Kiel Fjord, a long inlet of the Baltic Sea near northeastern Germany. Comb jellies are native to the western Atlantic Ocean near North and South America, but were introduced to the comparatively cold waters of the Baltic in the 1980s. These invaders of the Baltic Sea face much longer periods of low food availability than their Atlantic cousins, but have nevertheless managed to thrive, the researchers wrote.

Related: Sometimes this comb jelly has an anus. And sometimes it doesn't.

Part of their success in the Baltic is owed to the comb jelly's "bloom-and-bust" reproductive cycle. In late summer, Baltic comb jellies enter a period of rapid reproduction, or a "bloom," when each jelly releases hundreds of eggs and sperm cells into the water simultaneously, increasing local populations by the thousands. (M. leidyi is hermaphroditic, meaning it can fertilize its own eggs.)

This new army of larvae is ready to feast, devouring all the prey the itty-bitty jellies can find — mostly tiny zooplankton, a cornerstone prey item in aquatic food webs — eating until there's literally nothing left. That's the bloom; then comes the "bust." Soon after the local prey population collapses, so too does the larval jelly population, which starves to death.

These bloom-and-bust events have huge downstream effects on the local food web, decimating the prey that other sea creatures depend upon and causing significant population drops for local fish that can't compete with the invasive jellies, a 2007 study in the journal Aquatic Invasions found. Strangely, though, even after the larval jellies and their prey die off, adult comb jellies continue to thrive through the ensuing famine. How?

According to the authors of the new study, the reason is cannibalism. While sampling the population of Baltic comb jellies and their prey in August and September 2008 (the period right before and after that year's jelly bloom), the researchers discovered an adult jelly with two baby jellies captured inside its auricles — the gelatinous sacs that direct prey toward a jelly's mouth.

The grisly scene (captured in the photograph above) helped explain the team's findings that adult jellies continued to grow for weeks after their prey and larvae died off. But to prove there was indeed cannibalism afoot, the researchers needed to confirm that the adult jellies were actually getting a nutrient boost from these captured babies.

So, in September 2016, the team incubated adult and larval jellies together in a lab. Within 36 hours, the adults devoured any juveniles in their tank. A subsequent analysis showed that the cannibalized larvae accounted for about 4% of the total carbon and 2.5% of the total nitrogen content in each adult's body, giving the cannibal adults significantly higher nutrient concentrations than jellies in the non-cannibal control group, which ate only tiny crustaceans called copepods.

"To our knowledge, we have presented the first unequivocal evidence that adult M. leidyi cannibalize their own larvae," the researchers concluded in the study. "Since larvae cannot survive winters in the species' northernmost habitats, our study suggests that the primary purpose of M. leidyi larvae is to gather and store energy and nutrients for adults."

Simply put: After a jelly bloom devours the local prey, adults begin to eat their babies. This post-bloom cannibal feast appears to give adults the nutrient boost they need to continue growing for several more weeks amid food-scarce conditions, the researchers said, allowing them to become ever more competitive predators in the cold Baltic waters.

• Photos: See the World's Cutest Sea Creatures
• Dangers in the Deep: 10 Scariest Sea Creatures
• Image Gallery: Rich Life Under the Sea

Originally published on Live Science.

Upside-down jellyfish pulse on the ocean floor, their frilly arms stretched skyward as they release venom-filled blobs of mucus into the surrounding water, where the slime "stings" passing swimmers, new research reveals.

These jellyfish (Cassiopea xamachana) look like strange, squidgy plants stuck to the ocean floor, and they tend to assemble in groups that resemble bizarre flower beds. Upside-down jellies can be found living in the mangrove forests and lagoons of southern Florida, Hawaii, the Indo-Pacific Ocean and the Caribbean, according to the Monterey Bay Aquarium. Snorkelers who visit those areas sometimes develop a strange itching sensation on their skin, as if the water itself stung them. 

"You start to feel this tingling … More than just itchiness, like when an itch turns into a painful discomfort," said Cheryl Ames, a museum research associate and an associate professor of applied marine biology at Tohoku University in Japan. 

But until now, nobody knew the actual cause.

In a new study published today (Feb. 13) in the journal Communications Biology, Ames and her colleagues finally cracked the case: From these upside-down jellyfish's spot on the seafloor, they deploy an arsenal of cellular bombs armed with stinging cells called nematocytes. When the bombs make contact with a passing swimmer, they release venom that irritates the skin. If a bomb bumps into a tiny brine shrimp, one of the upside-down jellies' favorite snacks, its venom kills the animal on contact. 

A jelly-filled mystery 

Those familiar with stinging water may have heard of so-called sea lice, creatures often blamed for the painful sensation associated with upside-down jellies. Sea lice are parasites that prey on fish, but the term serves as a colloquial "catchall" for anything that causes water to sting, Ames said.  

None of the proposed explanations held up to scrutiny. "We initially thought that there would maybe be some tentacle bits from other jellyfish" floating through the water, perhaps detached during a massive spawning event, as can happen, Ames said. Another theory posited that jellyfish still in their larval stage (and thus microscopic) might float through the water and sting people. But researchers have visited the habitat so many times and never seen the adult stage of that hypothetical larval jelly, she added. 

Related: Dangers in the deep: 10 scariest sea creatures

With the mystery still unsolved, the scientists realized that, whenever they were stung, they were swimming near upside-down jellyfish at low tide, while the jellies pumped out murky clouds of mucus. To find out if these oddball jellies were the culprit, the researchers looked at samples of the jellies' mucus under high-resolution microscopes. They spotted tiny, jelly-filled spheres floating within the fluid that appeared to be packed with cells and algae. 

"We were really kind of in awe and shock, and saying, 'What are these? Has anyone seen these?'" Ames said. "None of us could figure out immediately what they were." 

The team uncovered one stray study from 1908 that mentioned the strange spheres, but those researchers had wrongly identified the structures as parasites of the jellyfish. By analyzing the molecules and proteins in the spheres, Ames' team confirmed that the spheres came from the jellyfish and were dispersed from spoon-shaped pads on the animals' arms. 

A minefield of mucus and toxic "bombs" 

Stinging cells called nematocytes coat the outermost layer of the bumpy spheres; when touched, these cells leak venom from long, stringy structures on their surfaces, stinging unwary creatures that run into them. In addition to stinging nematocytes, cells covered in hairlike threads called cilia stud the surface of the spheres. These cilia wave in the water and act as tiny propellers that send the spheres spinning off in every direction. The team named the free-wheeling spheres "cassiosomes," after the Cassiopea genus. 

"The discovery of motile, nematocyte-containing cellular structures ... in Cassiopea demonstrates an unexpected way of organization," Tamar Lotan, head of the Department of Marine Biology at the University of Haifa in Israel, told Live Science in an email. 

"Nematocytes are found mostly on the jellyfish tentacles," said Lotan, who was not involved in the new study. "However, this upside-down jellyfish actually builds a [minefield] around itself, a defense layer of mucus that contains these cassiosome bombs."

So, how can you avoid swimming through a toxic minefield on your next trip to the Florida Keys?

"When it's low tide … obviously, there's less water around — and you're closer to the jellyfish, and you're more likely to disturb them," said co-author Allen Collins, a zoologist at the Smithsonian's National Museum of Natural History and the National Oceanic and Atmospheric Administration's National Systematics Laboratory. We don't know yet if upside-down jellyfish release more cassiosomes in response to certain disturbances or at certain times of the day, Collins added. 

So, if you see upside-down jellies while you're swimming, it may be best to admire the squishy creatures from a distance to avoid floating through their snotty clouds of stinging spheres.

• Sea science: 7 bizarre facts about the ocean 
• Survival of the grossest: 8 disgusting animal behaviors 
• Pick your poison: Some venom can be healing 

Originally published on Live Science. 

Year after year, science marches on, delivering findings that fascinate, educate and awe us. And then there are those other results, the ones that make you sit up and think, "Did we really need to know that?" So, here's a tribute to the sillier side of science, with 14 of the strangest scientific stories from 2019. 

Comb jelly sometimes has an anus

Some of the greatest things in life are short-lived, but having an orifice from which to expel waste seems like something that should stick around. Yet for Mnemiopsis leidyi, an anus appears to be a matter of choice. Prior studies had concluded that the jellyfish relative, also known as a warty comb jelly or sea walnut, sported a permanent defecation center. But as researchers with the Marine Biological Laboratory in Woods Hole, Massachusetts, discovered this year, the end of M. leidyi's digestive track turned out to be an opening that "appears and disappears" in a regular rhythm. That makes the sea walnut, to date, the only known animal with a "now-you-see-it, now-you-don't" anal orifice, though further investigations may help explain how permanent anuses evolved in other creatures.

Your tongue can smell

It's well known that smell and taste are linked. A large part of the complex information about food flavors that your brain analyzes comes from their smell. But when researchers at the Monell Chemical Senses Center in Philadelphia grew human taste cells in a lab and exposed them to odor molecules, the cells unexpectedly responded like olfactory cells, which are found in your nose. While this was the first demonstration of such sensors in human taste cells, olfactory responses have been found in other odd places in the body, including in the gut, sperm cells and, bizarrely, even hair. 

Spider spins web in man's ear

Eek! When a man in eastern China checked into a hospital complaining about "a crawling sensation" in his right ear, one of the last things doctors probably thought they'd find was a spider. The tiny arachnid appeared to be squatting very comfortably near the tympanic membrane, or eardrum, after spinning a web that covered the patient's entire ear canal. A doctor tried to snatch the spider with tweezers, but that failed and the physician eventually succeeded in flushing the critter out with a squirt of saline. This nightmare-inducing scenario caused no harm to the patient and is luckily quite rare, though perhaps not rare enough.

Mathematical puzzle about 42 solved

If there's one thing that fans of Douglas Adams' sci-fi series "The Hitchhiker's Guide to the Galaxy" know, it's that the answer to the meaning of life, the universe and everything is 42 (the one thing they don't know is the actual question). But this year, mathematicians discovered a candidate question after centuries of frustration. The result came from a stumper known as the Diophantine equation, which asks whether you can you express every number between 1 and 100 as the sum of three cubes. The question is named for the ancient mathematician Diophantus of Alexandria, who proposed a similar conundrum 1,800 years ago. Answers for most of the numbers between 1 and 100 had already been discovered, but a solution for 42 required a global network of 500,000 computers, which crunched through huge numbers of possibilities to find that (-80538738812075974)^3 + (80435758145817515)^3 + (12602123297335631)^3 = 42. There, doesn't that feel satisfying?

Thieves abscond with 1,600-lb. undersea observatory 

The police blotter in your town might include some occasional gems, but perhaps nothing compares to this. On Aug. 21, a 1,630-lb. (740 kilograms) piece of equipment at the bottom of the Baltic Sea, off the coast of Kiel in northern Germany, went missing. That day, the detector, which was run by the GEOMAR Helmholtz Centre for Ocean Research and which collected environmental data from the ocean floor, suddenly went silent. At first, researchers suspected that something had gone wrong with the communications transmission. But when divers went to check on the site, they found that the entire observatory had disappeared, with just a shredded power cable left behind. No storm, tide or large animal could have moved the station, GEOMAR said in a statement, adding that the lost data was "priceless." 

Bagged salads contain frogs, toads, lizards and bats

Prepackaged salad greens are a miracle of modern convenience. But in a study released this year, researchers found that since 2003, shoppers have discovered unwelcome additions to their kale and romaine: frogs, lizards, rodents and even a bat. The study cataloged 40 examples of bagged salad purchases in 20 states that came with unexpected wildlife stowaways, in whole or in part. And in 10 instances, the animals were still alive. "It remains unclear whether these occurrences indicate a food-safety crisis or a complaint against food quality," the study concluded. Further observations will be necessary to pinpoint when and how the animals found their way into salad bags and what steps might be taken to keep the creatures out, the authors added.

Flat-Earthers plan to sail past edge of the planet

Look out for this delusion-filled event next year: In 2020, the Flat Earth International Conference (FEIC) is planning a cruise to the purported edge of the planet to search for the ice wall that holds back the oceans. The Greeks demonstrated that the Earth was a sphere more than 2,000 years ago, but that hasn't stopped some extremely imaginative folks from continuing to say that our planet is a pancake-like disk with the North Pole smack in the center and an edge surrounded on all sides by ice. Exactly how the flat-Earthers plan to navigate remains a mystery, as our modern global positioning system (GPS) relies on a network of dozens of satellites orbiting a spherical planet. Were the Earth actually flat, GPS would need only three satellites to pinpoint any location on the planet's surface. 

ET might look like pasta

In April, a NASA-led report in the journal Astrobiology suggested that future alien hunters keep their eyes peeled for fettuccine or capellini. That's because such pasta-shaped formations accumulate at the edges of hot springs here on Earth, built, in part, by microbes. At the Mammoth Hot Springs in Yellowstone National Park, the water ranges in temperature from 149 degrees Fahrenheit to 162 degrees Fahrenheit (65 to 72 degrees Celsius), with an acidic pH of 6.2 to 6.8, There, heat-loving microscopic creatures create mats from calcium carbonate that look like long, mucus-y pasta strands. Should similar formations appear on other planets, they might fossilize and allow scientists to glimpse the handiwork of alien microbes. 

Sea gull snatches Chihuahua

A brown-and-white, 4-year-old Chihuahua named Gizmo was minding his own business in a garden in Paignton, Devon, a seaside town in the southern part of the United Kingdom. Suddenly, a gull clutched the tiny pup in its beak. Though the event sounds strange, it's definitely a possibility, experts told Live Science. Such birds are omnivores, eating fish, invertebrates, vegetables, discarded human food and sometimes small mammals such as rats, moles and even rabbits, Viola Ross-Smith, a science communicator with the British Trust for Ornithology, told Live Science. Chihuahua lovers the world over shouldn't lose sleep over it, though; while such attacks can happen, "they are very rare," Ross-Smith said. 

Double-headed rattlesnake named Double Dave

Herpetologists Dave Schneider and Dave Burkett, who work with the Herpetological Associates in Pemberton, New Jersey, discovered a rare, two-headed baby rattlesnake in the wild near Pine Barrens, a heavily forested area in the southern tip of the state. Such bicephalic animals, as they're known, rarely survive to maturity unless in captivity. The scientists took the little creature in, fed and cared for it, and named it Double Dave. "It appears the head on the right side is the more dominant one," Schneider told ABC News. "But every once in a while, the other head will want to go in a different direction."

Brainless, single-celled blob can make sophisticated decisions

Next time someone calls you a brainless blob, take it as a compliment. It turns out that even these simple organisms can undertake complex decision-making processes. When exposed to an irritant, the Stentor roeselii — a relatively large, trumpet-shaped, single-celled creature — will try multiple tactics to avoid the problem, including stretching around the offending substance, trying to push it away with hair-like projections called cilia, contracting itself away from the irritant and, if all else fails, swimming away. This ability to "change its mind" rather than follow a simple, preprogrammed set of instructions suggests that single-celled organisms are "much more sophisticated than we generally give them credit for," Jeremy Gunawardena, a systems biologist at Harvard University, said in a statement.

NASA fed moon rocks to roaches 

In an effort to make sure there was nothing harmful living on the moon, Apollo scientists fed lunar samples to cockroaches, dumped the rocks in fishbowls and injected them into mice. "We had to prove that we weren't going to contaminate not only human beings, but we weren't going to contaminate fish and birds and animals and plants and you name it," Charles Berry, who was in charge of medical operations during Apollo, said in a 1999 oral history. After Apollo 11, the first mission to land humans on the moon, NASA opened its precious cache of moon rocks and exposed them to representative species: Japanese quail for birds, a couple of nondescript fish, brown shrimp and oysters for shellfish, German cockroaches and houseflies for creepy-crawlies, and even a few plants, which were grown in lunar regolith and seemed to flourish. The Apollo 11 astronauts themselves stayed in quarantine for three weeks following their mission. No lunar microbes were discovered. 

Poop knife fails at cutting

According to a widely circulated anthropologist's report from the 1990s, an Inuit man once crafted a knife from his own poop during a freezing storm, killed and butchered a dog with the implement, and disappeared into the darkness riding a sled made from the animal's rib cage. Turns out the popular ethnographic account might have been a tall tale the Inuit man invented to pull the anthropologist's leg. Intending to get to the bottom of the story, researchers at Kent State University in Ohio adopted an eight-day arctic diet consisting of mostly protein and fatty acids. They then squatted and chilled their bodily specimens to temperatures of minus 58 F (minus 50 C), forming poop blades and keeping them frozen with dry ice. The excrement implements were plenty hard, but they didn't hold up to scrutiny, entirely failing to cut meat and instead just leaving brown streaks like filthy crayons. 

Thousands of penis fish wash up on shore

Drakes Beach, north of San Francisco, became host to an unusual sight when thousands of penis fish inundated it one winter day. What is a penis fish, you may ask? Oh, just your usual plump, pink, extremely phallic-looking 10-inch (25 centimeters) creature. These organisms are actually a type of nonsegmented marine worm native to the Pacific Coast between southern Oregon and Baja California, Mexico. Normally, they burrow in sand, forming tube-like tunnels in which they live and eat. A storm likely broke apart these sandy domestic formations, smashing thousands of cozy burrows and leaving their residents strewn across the beach.

Originally published on Live Science.

When scientists discover a round, lumpy object that they can't totally explain, they have a special name for it: A blob.

Blobs come in all shapes and sizes. Some are as small as cells, others as big as galaxies. Some blobs live underwater, others deep in space or far below Earth's crust. Every blob is a good blob, but some blobs are great blobs. As 2019 draws to a close, wobble along with us as we recall the nine best blobs of the year. (Arranged from smallest to largest.)

The newt blob

Fun fact: All life begins in blob form. You did, your mother did and this adorable baby salamander did. While your own personal blobbiness is probably only recorded in a blurry ultrasound photo, certain amphibians lay transparent eggs, making their earliest stages of development visible to anyone with a microscope. In February 2019, photographer Jan van IJken shared this incredible time-lapse video of one such amphibian (an alpine newt) transforming from a single cell into a living, breathing tadpole.

The whole video is stunning, but the highlight may come at about the three-minute mark. That's when, after dividing from one cell into millions, the amphibious blob finally folds in on itself and begins to take on a familiar fetal shape. By the end of the video, a baby salamander hatches and swims away. Godspeed, young blob!

The jelly blob

Jellyfish may be the most famous blobs in nature, and for good reason — with more than 2,000 species around the world, these unmistakably amorphous animals are easy to find near pretty much any coast on Earth.

This year, one jellyfish encounter earned top blob marks for us. In July, a pair of divers in England came face-to-faceless-head with a hulking barrel jellyfish (Rhizostoma pulmo) — a rarely seen species that can grow about as large as a full-grown human. (Luckily, they caught the encounter on video).

The squid gel blob

That wasn't the only human-size blob divers bumped into this year. There was also the gelatinous sac researchers found while investigating a sunken ship near Norway. That sac, as large as the divers themselves, was transparent and encased a strange yellow object. Upon inspection with a flashlight, the divers saw that the object appeared to be a clump of squid ink, and it was surrounded by hundreds of thousands of itty-bitty squid eggs.

The team determined that the sac belonged to a species of 10-armed cephalopod called the southern shortfin squid (Illex coindetii), which can lay about 200,000 eggs at a time in sacs like this one. In case the phrase "squiddy eggy blob" doesn't quite do it for you, the researchers also gave the sac a special name: "blekksprutgeleball," meaning "squid gel ball" in Norwegian.

The 'penis fish' blobs

In this year's blob news most likely to get you in trouble with HR, thousands of wiggly, 10-inch-long "penis fish" washed up on a California beach in early December.

In reality, these sausage-shaped castaways are not fish (or penises) at all, but a species of North American marine worm known as the "fat innkeeper worm." Their name comes from their penchant for building U-shaped burrows in the sand, which other tiny beach creatures like to sneak into in order to steal whatever food the innkeeper worm happens to throw away. How did thousands of these unfortunately-named, unfortunately-shaped blobs end up strewn across the beach? A storm likely tore up all their burrows and left the worms destitute. Keep that in mind the next time you have a bad day: At least you are not a homeless penis fish.

The mantle blobs

About halfway between your feet and the center of Earth, two continent-size mountains of hot, compressed rock pierce the gut of the planet. Technically, these mysterious hunks of rock are called "large low-shear-velocity provinces" (LLSVPs), because seismic waves always slow down when passing through them. But most scientists call them simply "the blobs."

In March, Eos (the official news site of the American Geophysical Union) shared an awesome 3D animation showing the most-detailed view of the blobs ever. The blobs begin thousands of miles below Earth's surface, where the planet's rocky lower mantle meets the molten outer core. One blob lurks deep below the Pacific Ocean, the other beneath Africa and parts of the Atlantic. Both of them stand about 100 times taller than Mount Everest and are as large as continents. Despite their massive scale, scientists don't really have any idea what the blobs are or why they're there. Could they impact volcanic activity? Maybe. They're too deep to study directly so, for now, these blobs must remain shrouded in mystery.

The moon blob

Not to be totally outshined by its neighbor, the moon also revealed a mysterious subterranean blob this year, too.

In April, NASA scientists discovered what they're calling an "anomaly" of heavy metal hidden deep below the moon's South Pole-Aitken basin (the largest preserved impact crater anywhere in the solar system). A gravitational analysis suggests the metal blob lives hundreds of miles below the moon's surface, weighs about 2.4 quadrillion U.S. tons (2.18 quintillion kilograms) and is about five times larger than the Big Island of Hawaii. The anomaly appears to be weighing down the South Pole-Aitken crater by more than half a mile, and may be altering the moon's gravitational field.

The sun blob

The sun's corona constantly breathes wispy strings of hot solar wind into space — but, once in a while, those breaths become full-blown burps. According to a study in the February issue of the journal JGR: Space Physics, every few hours the plasma underlying solar wind grows significantly hotter, becomes noticeably denser, and pops out of the sun in rapid-fire orbs capable of engulfing entire planets for minutes or hours at a time. Officially, these solar burps are called periodic density structures, but astronomers have nicknamed them "the blobs," due to their lava-lamp-blob-like appearance.

These blobs are hundreds of times larger than Earth and can potentially pack twice as many charged particles as the average solar wind. Astronomers think they're related to solar storms (explosions of magnetic field activity on the sun's surface), but their true origin and function remains as unclear as the water in your lava lamp.

The neutron star blob

In 1987, a star in the Milky Way's nearest satellite galaxy erupted in a supernova explosion, leaving a cloud of colorful cosmic debris in its place. Behind that debris should be a neutron star (an ultradense stellar corpse) but astronomers have been unable to find one for the last 32 years. Now, in a study published in November, researchers think they've found that missing neutron star hiding in a "blob" of brighter-than-average radiation at the cloud's core. If verified, this discovery will not only solve a decades-old mystery, but will also confirm that the only thing better than a blob is a blob with a prize inside.

The galaxy blobs

In a galaxy of blobs, two bubbles reign supreme: The Fermi Bubbles.

The Fermi Bubbles are twin blobs of high-energy gas ballooning out of both poles of the Milky Way's center, stretching into space for 25,000 light-years apiece (roughly the same as the distance between Earth and the center of the Milky Way). The bubbles are thought to be a few million years old, and likely have something to do with a  giant explosion from our galaxy's central black hole — but observations are scarce, as they are typically only visible to ultra-powerful gamma-ray and X-ray telescopes. This September, however, astronomers writing in the journal Nature detected the bubbles in radio waves for the first time, revealing large quantities of energetic gas moving through the bubbles, possibly fueling them to grow even larger.

Will the Milky Way's biggest blobs get even bigger? Stay tuned in 2020 to find out.

• The 12 Strangest Objects in the Universe
• 15 Unforgettable Images of Stars
• 9 Strange Excuses for Why We Haven't Met Aliens Yet

Originally published on Live Science.

What in the name of Neptune's beard is that thing? A ghost? An alien? The ghost of an alien?

Such were the questions that vexed a team of deep-sea scientists aboard the Nautilus research vessel earlier this month, when their underwater recon robot encountered a limp, limbless creature hovering like a ghostly lantern over the Pacific seafloor. As the team watched, the bell-shaped blob suddenly transformed, ballooning into a long, translucent windsock with a mysterious red splotch stuck to its innards.

The blob, the researchers revealed in a recent video of the encounter, was no alien (it's never aliens), but one of the rarest-seen and least-studied jellyfish in the sea. 

It's called Deepstaria (named for the research vessel that first discovered the genus in the 1960s), and has been seen only a dozen or so times in the last half-century. Researchers don't know much about the armless, shapeshifting sack, but they do know it has a habit of expanding its body to engulf any prey trusting enough to swim nearby.

That could explain the red splotch inside the jelly's belly. When the researchers zoomed in on the shapeshifting jelly, they saw that the red hanger-on was a tiny, still-living isopod — a type of bottom-feeding crustacean — that may have willingly swum into the jelly's open body for protection from fiercer, less-blobby predators. Such "resident isopods," as the researchers called them, have been observed clinging onto other Deepstaria specimens too, though it’s not clear whether they share a symbiotic relationship.

Little, in general, is known about Deepstaria jellies or their isopod consorts, as so few specimens have been studied. The Nautilus team found this deep-sea duo some 2,500 feet (750 meters) underwater in the Central Pacific, about halfway between the continental United States and Australia. Perhaps they’ll find more Deepstaria — or something even weirder — as their adventures through the deep darkness continue through October.

• In Photos: Spooky Deep-Sea Creatures
• Photos: Deep-Sea Expedition Discovers Metropolis of Octopuses
• In Photos: The Wonders of the Deep Sea

Originally published on Live Science.

A pair of divers swimming off the southwestern tip of England hit the jelly jackpot last week after crossing paths with a hulking barrel jellyfish (Rhizostoma pulmo) — a rarely seen species that can grow about as large as a full-grown human. Luckily, they filmed the whole thing.

The divers — biologist Lizzie Daly and underwater cinematographer Dan Abbott — shared the encounter in a Facebook video posted Saturday (July 13) as part of the Wild Ocean Week campaign — a series of videos showcasing the oddities of the deep to help raise money for the United Kingdom's Marine Conservation Society.

Daly and Abbott were diving off the coast of Cornwall, U.K., when they saw the giant jelly emerge from the murky water. Also called the dustbin-lid jellyfish, the species is characterized by eight puffy arms capped by stinging tentacles and a large, globular head that lends the creature its unglamorous nickname. Barrel jellyfish sometimes wash up on the shore, Daly told Vice, but it's rare for a diver to swim face-to-faceless-head with one of the massive blobs. [Marine Marvels: Spectacular Photos of Sea Creatures]

While the barrel jellyfish is the largest species of jelly found in U.K. waters, it's a mere shrimp when compared to the lion's mane jellyfish (Cyanea capillata), the largest known species in the world. This coldwater jelly is known for its galaxy of 1,200 long, trailing tentacles, which can bring an individual creature's total body length to up to 120 feet (36.5 meters) — which is longer than the average blue whale.

This tangle of tentacles is so massive that a single lion's mane jelly may be able to sting 50 to 100 people in just a few minutes if currents carry the jelly too close to a populated coast — a fun fact that a group of unlucky New Hampshire beachgoers learned the hard way in 2010.

• Dangers in the Deep: 10 Scariest Sea Creatures
• In Photos: Spooky Deep-Sea Creatures
• 15 of the Largest Animals of Their Kind on Earth

Originally published on Live Science.

Here's a jellyfish video with a twist ending … actually, make that 40 or 50 twists.

In a new, 1-minute clip taken by a snorkeler off the coast of Spain, a wee jellyfish ventures too close to an air-filled bubble ring rising up on a strong current. When the jelly touches the ring, the bubble doesn't burst — instead, it sucks the unsuspecting medusa into its swirling heart and sends the jelly spinning like a blurry, pink cyclone.

According to Victor Devalles, the photographer/snorkeler who took the video, he blew the bubble ring in hopes that it would pass around the jelly, providing a different, slightly more majestic photo op.

"Those bubble rings are just air in a vortex current, so the jellyfish was stuck in that stream twisting and spinning so fast," Devalles told the U.K. news site Mirror.

Luckily, Devalles added, the jelly didn't seem to be injured by its wild ride and swam off shortly after the ring stopped spinning.

While jellyfish get caught up in strong currents all the time, they're pretty good at reorienting themselves afterward. In a 2015 study in the journal Current Biology, researchers attached GPS devices to several jellyfish and watched as they moved with or against ocean currents. The researchers found that jellyfish are able to actively swim against currents when they feel that they are starting to drift. This natural current-avoidance behavior could be responsible for the phenomenon of jellyfish "blooms," in which millions of individual jellies converge on a single area, the researchers reported.

If the jellyfish in Devalles' video ever makes it to such a meetup, at least it'll have quite the story to tell.

• Image Gallery: Jellyfish Rule!
• Photos: See the World's Cutest Sea Creatures
• Dangers in the Deep: 10 Scariest Sea Creatures

Originally published on Live Science.

A newfound fossil site in China is teeming with bizarre, primitive species that have never before been found any place on Earth. The bounty of creatures includes a spiny, segmented animal known as a mud dragon, and several jellyfish with preserved tentacles.

Paleontologists discovered this treasure trove of fossils, which are incredibly well-preserved, along the banks of the Danshui River in southern China. The dozens upon dozens of creatures date to the Cambrian Period (490 million to 530 million years ago), when Earth's animal diversity was booming at an unprecedented pace.

Scientists collected hundreds of specimens and identified fossils of 101 animals. Of those, more than half are new species that have yet to be described, the researchers reported in a new study. [Image Gallery: Cambrian Creatures: Primitive Sea Life]

"It is a huge surprise to find a new deposit of such incredible richness and with such a large proportion of species that are completely new to science," study co-author Robert Gaines, a professor in the Geology Department at Pomona College in California, told Live Science in an email.

Researchers in China discovered the site while exploring early Cambrian rocks nearby. During their lunch break by the river, the scientists noticed "a striking pattern of alternating gray and black stripes" in the rocks of the river bank. This type of sediment pattern indicates areas where ancient mudflows once surged — flows that may have buried and preserved ancient organisms, Gaines explained.

The scientists started chipping away at the rock, and sure enough, they soon detected the first of the site's exceptional fossil remains, now known collectively as the Qingjiang biota, they wrote in the study.

All told, the team uncovered fossils of more than 50 species unknown to science. Many of the fossils — bell-shaped jellyfish, spiky worms, armored arthropods and more — retain an astonishing level of detail in their preserved soft tissues, such as gills, digestive systems and even eyes.

"Qingjiang is a new window on a different type of early Cambrian ecosystem," Gaines said.

As in other rich fossil deposits of well-preserved Cambrian life — the Burgess Shale deposits in Canada and the Chengjiang deposits in China's Yunnan Province — the Qingjiang animals had been quickly swallowed by mudflows and then buried in fine-grain soils, Gaines said. As sediment "cemented" around the tiny bodies, it locked out microbes and halted the process of decay.

This preserved "exquisite primary organic remains of creatures like jellyfish and worms that usually leave no fossil record," he said.

In fact, jellyfish and sea anemones, which are among the earliest known animals, are far more numerous in the Qingjiang biota than in the Burgess Shale or Chengjiang sites, the researchers reported.

What's more, the Qingjiang fossils' condition is substantially better than that of fossils at the other Cambrian sites. At Burgess Shale, the formation of the Rocky Mountains heated and compressed the fossils; though anatomical details remained, the fossils were reshaped from their original forms, according to Gaines. And in Chengjiang, groundwater that flowed over the fossil deposits over millions of years also carried away some of the detail of their original shapes.

"The Qingjiang fossils, however, are pristine, and appear much as they would have after they were fossilized in the Cambrian period," Gaines said.

The findings were published online today (March 21) in the journal Science.

• These Bizarre Sea Monsters Once Ruled the Ocean
• Photos: 508-Million-Year-Old Bristly Worm Looked Like a Kitchen Brush
• Photos: 'Naked' Ancient Worm Hunted with Spiny Arms

Originally published on Live Science.

Like a rainbow or a sunset, the anus of the warty comb jelly is a fleeting marvel.

An anus is a gateway for solid-waste removal from an animal's digestive system; in most animals, the anus is reliably found in one location all the time. But Mnemiopsis leidyi, a jellyfish relative that is also known as a warty comb jelly or sea walnut, is not "most animals."

M. leidyi's anus isn't fixed in place on its gelatinous body. Instead of a permanent opening, a so-called anal pore appears when the jelly needs to defecate and then disappears immediately afterward, leaving unblemished skin behind, according to a new study. [Image Gallery: Jellyfish Rule!]

M. leidyi belongs to a group of marine invertebrates called ctenophores (TEEN-oh-fours). Unlike such close relatives as sponges and jellyfish, ctenophores — especially their bodily functions — are poorly understood, Sidney Tamm, a researcher with the Marine Biological Laboratory in Woods Hole, Massachusetts, wrote in the study.

In fact, prior studies had concluded that M. leidyi had a permanent anus. But when Tamm used video microscopy to closely examine M. leidyi larvae and adults, he discovered that their anuses were intermittent, and that the jellies' defecation took place through an opening "which appears and disappears" in a regular rhythm, Tamm reported.

Now you see it; now you don't

After M. leidyi gulps down prey, the meal travels through a six-part digestive system. Eventually, the food ends up in a central stomach that feeds into canals for pooping, which dead-end at the body's surface as lobes, Tamm wrote in the study.

Tamm observed that when a jelly was ready to defecate, the shape of its stomach would change — narrowing into a rectangular box — and its anal canals would widen. Two minutes later, the esophagus "crumpled," preventing more food from entering the stomach. Lobes at the ends of paired anal canals filled with waste particles and began to swell, with one lobe protruding significantly.

As that lobe reached "maximum volume," a pore opened and released a stream of poo as particles and clumps, Tamm reported. But before the pore opened, the skin of that lobe appeared "uniformly smooth," and there was no sign that the pore had opened there before.

Then, when all the waste had been released, "the pore closed completely and disappeared," Tamm wrote. From start to finish, the entire process lasted from 2 to 3 minutes in M. leidyi larvae and juveniles measuring up to 0.8 inches (2 centimeters) long, and 4 to 6 minutes in adults with body lengths between 1.2 and 2 inches (3 and 5 cm).

M. leidyi is to date the only known animal with a "now-you-see-it-now-you-don't" anal pore. Further investigations of its elusive anus may help to explain how permanent anuses evolved in other animals, according to the study.

The findings were published online Feb. 22 in the journal Invertebrate Biology.

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• Dangers in the Deep: 10 Scariest Sea Creatures
• Image Gallery: Rich Life Under the Sea

Originally published on Live Science.

Weird, brilliant blue creatures with feather-like tentacles are washing ashore on the beaches of New Jersey, surprising beachgoers who aren't used to seeing turquoise blobs dotting the shore, according to news reports.

These jellyfish-like critters are commonly known as blue buttons (Porpita porpita), but they aren't native to the Garden State. Instead, it appears that Hurricane Florence carried the tropical animals out of the Gulf Stream, a powerful current in the Atlantic Ocean, and pushed them northward up the East Coast.

"It's not something I've ever seen before, and I've been walking down that beach since I was 10 years old. I'm 55 now," Holly Horner, a professional wildlife photographer from Egg Harbor, New Jersey, told the Asbury Park Press, after spotting blue buttons on a beach in Brigantine last week. [In Photos: Spooky Deep-Sea Creatures]

Although they look like jellyfish, blue buttons are another type of creature (or rather, set of creatures) altogether. They fall into the scientific class Hydrozoa, whose members are each made up of colonies of hydroids — tiny predators that are related to jellyfish. The most famous hydrozoan is probably the Portuguese man o' War (Physalia physalis), which can deliver a venomous sting so powerful that it can kill fish and even injure humans, according to National Geographic.

But the blue button is not nearly as treacherous as the Portuguese man o' War. Because they have a mild sting, blue buttons can irritate the skin but they're not that dangerous to humans, Paul Bologna, an associate biology professor at Montclair State University in New Jersey, told the Asbury Park Press.

Even so, the blue button's sting is venomous enough to keep the creature well-fed. The round, yellowish-brown "button" part of the blue button is usually about an inch wide and has tentacle-like strands hanging off it. (This button is gas-filled, which helps the blue button float in the water, according to the Encyclopedia of Life.) These strands, or hydroid branches, zap free-floating marine animals known as zooplankton, which the blue button then eats for dinner, according to the National Park Service.

Bologna added that he's seen blue buttons off the Florida coast but never in New Jersey. And he doesn't expect them to survive in the Garden State much longer.

"Most likely, they will all die off when the water temperature drops, so they may hang around for a few more weeks," Bologna told the Asbury Park Press. "In general, they are not dangerous, but like all 'jellyfish,' they do have stinging cells, so caution is always the best bet."

Originally published on Live Science.

A family on New Zealand's North Island were enjoying an early morning walk on Pakiri Beach last week when they came across a monstrous, gooey blob with a gelatinous grape-colored center. Although it resembled a tossed-out Jell-O mold, it wasn't for eating — the glob was an enormous lion's mane jellyfish (Cyanea capillata).

Eve Dickinson and her family had seen several jellyfish on the beach that morning, and they were pretty amazed, she told Auckland Now.

"Then we saw this massive one that seemed different from all of the others," Dickinson said. "It was incredible." [Image Gallery: Jellyfish Rule!]

Lion's mane are the largest species of jellyfish, with a bell that can grow up to 7 feet (2.1 meters) across and a thick mop of hair-like tentacles that reach nearly 120 feet (36.6 meters) long, according to Oceana, a nonprofit ocean research and conservation organization. They're much more recognizable in the water, where they gracefully drift with the currents.

These globular invertebrates spend most of their time offshore, floating around in the open ocean. But they're common in waters around New Zealand during the summer, Diana Macpherson, a marine biologist at the National Institute of Water and Atmospheric Research in New Zealand, told Auckland Now.

Similar to most other species of jellyfish, the lion's mane use their powerful stinging tentacles to stun and capture prey. The tentacles' stinging cells, called nematocysts, eject poison when they come into contact with small fish, crustaceans or other jellyfish. Fortunately, lion's mane aren't deadly to humans, although a sting from their tentacles is likely to be a bit painful.

Lion's mane jellyfish typically exhibit dark yellow or red coloration in the center of the bell, but the one the Dickinsons found stood out for its vibrant dark red-purple center.

"We spent ages looking at it because of its beautiful colors and shape," Dickinson told Auckland Now. "My boy said it reminded him of a volcano."

Original article on Live Science.

Humans like to study ocean creatures. Humans, badly adapted to spending time underwater, need tools to do that. Unfortunately, most human tools are hard, while many ocean creatures are soft and delicate. A team from Harvard University's Wyss institute (which studies "bio-inspired engineering) hopes to solve that problem with a new, soft, folding "Pokeball"-like device, described in a paper published yesterday (July 18) in the journal Science Robotics. 

The device, the result of a collaboration between engineers, designers and marine biologists, looks like a soft, plastic, four-fingered claw when it's open. Then, a single motor drives it to fold along all of its joints, forming a hollow, 12-sided container around whatever it's trying to snatch, the researchers wrote. [24 Underwater Drones – The Boom in Robotics Beneath the Waves ]

The researchers tested the device, which they call a "Rotary Actuated Dodecahedron" (RAD), first at Connecticut's Mystic Aquarium and then in the open ocean near Monterey, California. Mounted to a uncrewed underwater vehicle and controlled remotely via joystick, it successfully captured squid and jellyfish unharmed, they reported.

You can watch the video demonstrating the RAD's capabilities below:

Originally published on Live Science.

The ROV, dubbed Hercules, recorded the unusual jellyfish — named Deepstaria enigmatica after the Deepstar 4000, a deep-sea submersible designed by the French explorer Jacques Cousteau — off the coast of Mexico's San Benedicto Island in the Pacific Ocean in November 2017, according to a new study published in the May 9 issue of the journal American Museum Novitates.

"It's just this crazy, weird alien thing," lead study researcher David Gruber, a professor of biology at the City University of New York and a Radcliffe fellow at Harvard University, told Live Science. "We barely know anything about it." [Image Gallery: Jellyfish Rule!]

Scientists have published studies on D. enigmatica only about a dozen times since 1966, when three researchers aboard the Deepstar 4000 captured the first specimen. Unfortunately, this specimen was incomplete; the jellyfish was so large, it couldn't be completely sucked up by the submersible's suction sampler, the researchers said.

Although that jellyfish was incomplete, "much of the existing information about D. enigmatica is from this specimen," which now resides at the British Natural History Museum, the researchers wrote in the study.

Here's what researchers do know about the odd creature. First, D. enigmatica has no tentacles, so it hunts by encapsulating prey within its gelatinous, umbrella-like body. And there aren't any reports on the species' diet, but like other jellyfish, it probably eats small fish, crustaceans and other jellyfish, Gruber said.

As Hercules began to film the jellyfish — a large jelly more than 2 feet (68 centimeters) long with a diameter of 1.8 feet (56 cm) — it closed its body in a rapid ripple. Gruber said the jellyfish may have mistaken the vibrations from the ROV as tasty prey and thus tried to bag it.

"[The jellyfish] sensed that maybe it had something potentially inside of it, and it closed," Gruber said.

Jelly fall

After recording the mysterious jellyfish for about 10 minutes at nearly 3,200 feet (974 meters) below sea level, Hercules took a dive to the ocean floor — this time, at about 2,900 feet (899 m) below sea level, east of Mexico's Socorro Island.

Among the dense forest of sponges and corals, Hercules filmed bright-red crabs feasting on a dead Deepstaria, making it the first scientific record of a Deepstaria "jelly fall," which is akin to animals eating a dead whale after a whale fall, the researchers said. (There are two known species of Deepstaria: D. enigmatica and D. reticulum, and it's not clear which species the crabs were eating, Gruber noted.)

"There was a little crab party going on around this jelly," Gruber said. Food is so scarce in the deep sea, it's no wonder that animals down there were gobbling up this jellyfish, he said.

Gruber and his colleagues plan to explore more of the ocean with ROVs like Hercules, which can carry high-tech cameras (in this case, the Canon ME20F-SH) and whose spotlights can be dimmed to that of a mere penlight.

"Usually when submarines go down, they go down with these big, powerful lights because they don't want to bump into things and crash," Gruber said. "It's like being at a party outside and the cops come and shine a flashlight in your face. That's the kind of way we normally approach deep-sea life."

The low-light Hercules even managed to film a blue, bioluminescent creature known as Tomopteris swimming around the jellyfish.

"That's a feature that's normally missed using other cameras," Gruber said.

Original article on Live Science.