Thousands of feet beneath the surface of Monterey Bay off California, scientists recently captured footage of a fish with a bulbous, translucent head and green orb-like eyes that peer out through its forehead.

This bizarre creature, known as a barreleye fish (Macropinna microstoma), is very rarely seen. Researchers with the Monterey Bay Aquarium Research Institute (MBARI) have only spotted the species nine times, despite having sent their remotely operated vehicles (ROV) on more than 5,600 dives in the fish's habitat, MBARI tweeted on Dec. 9. 

But last week, a team of scientists deployed MBARI's ROV Ventana and caught sight of a barreleye fish suspended in the water. 

Related: In photos: Spooky deep-sea creatures 

At the time, the ROV was cruising at a depth of about 2,132 feet (650 meters) in the Monterey Submarine Canyon, one of the deepest submarine canyons on the Pacific coast, Thomas Knowles, a senior aquarist at the Monterey Bay Aquarium, told Live Science in an email. "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," he said. 

As a buzz of excitement rippled through the control room, Knowles kept the ROV camera in focus while the ROV pilot Knute Brekke kept the underwater robot pointed at the barreleye. "We all knew that this was likely a once in a lifetime experience," since the elusive creature is seen so very rarely, Knowles said.

In the light of the ROV, the barreleye's eyes glowed bright green and could be easily seen through the clear, fluid-filled shield that covers the fish's head. These eyes are incredibly light-sensitive and can be oriented straight up, towards the top of the fish's head, or straight ahead, according to MBARI. Two dark-colored capsules sit in front of the fish's eyes and contain the organs the animal uses to smell.

The barreleye fish's habitat ranges from the Bering Sea to Japan and Baja California. The fish live in the ocean twilight zone, which lies about 650 to 3,300 feet (200 to 1,000 m) underwater; specifically, barreleyes live about 2,000 to 2,600 feet (600 to 800 m) beneath the ocean surface, near the depth where the water plunges into complete darkness, according to MBARI. 

Scientists have little sense how many of these gelatinous helmet-heads float in the ocean's depths.

"We have no handle on population size, except in a relative sense," Bruce Robison, an MBARI senior scientist, told Live Science in an email. Barreleyes are less abundant than commonly-seen twilight zone fish, such as lanternfish or bristlemouths, and the MBARI team encounters barreleye fish about as often as they do anglerfish, whalefish and gulpers, "which is very rarely," he said.

Based on past observations by MBARI researchers, published in 2008 in the journal Copeia, scientists think that barreleye fish mostly remain motionless as they wait for unwary prey, like zooplankton and jellyfish, to drift overhead. The fish can hover this way thanks to a set of broad, flat fins that extend out from its body. By pointing their verdant eyes straight upward, barreleyes can spot the silhouettes of their prey from above, and the green pigment in their eyes likely helps filter out sunlight from the ocean surface.

Once a barreleye fish spots a bioluminescent jelly or tiny crustacean floating by, it zooms upward to snag the creature in its mouth while rotating its eyes forward, so it can see where it's going. Scientists speculate that M. microstoma may sometimes swipe food from siphonophores — jellyfish-like organisms that cling together in long lines and capture prey in their tentacles, according to a 2009 MBARI video. The barreleye fish's transparent head shield might protect it against the stinging cells in the siphonophores' tentacles — but again, this is speculation.

"Most aspects of their natural history remain unknown and much of what we think we know about them is based on speculation," Robison said. Although M. microstoma was first described in 1939, fishers caught these early specimens in nets that destroyed their transparent head shields. So scientists didn't know about the shields until the 2000s, when MBARI scientists saw a barreleye fish in its natural habitat, he said. As of today, there's still much to learn about the funky fish.

On their recent dive, the team avidly watched the M. microstoma specimen until it swam away and then continued their search for jellies and comb jellies of the deep sea. "We had no ambition to collect this animal," as the aquarium is not adequately set up to care for the poorly understood fish, Knowles said. That said, many other bizarre and wondrous creatures from the deep sea will soon be on display at the aquarium. 

In spring 2022, the Monterey Bay Aquarium will open a new exhibition called "Into the Deep: Exploring Our Undiscovered Ocean," which will feature all sorts of deep-sea creatures, from giant isopods to sea spiders to blood-belly comb jellies, according to the aquarium's website. And like the barreleye fish, many of these creatures look like something plucked straight from a sci-fi novel.

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.

To transform into a butterfly, a caterpillar must first dissolve into a goopy soup within its chrysalis. Now, in striking new videos, scientists have revealed how this goo reassembles into the delicate scales on a butterfly's wings.  

To watch this process unfold in living caterpillars undergoing metamorphosis, the researchers behind the videos reared painted lady caterpillars (Vanessa cardui) in their laboratory, according to the new study, soon to be published in the journal Proceedings of the National Academy of Sciences (PNAS). Once each caterpillar was suspended in its chrysalis, the team carefully carved a small window into the cuticle — the pupae's hard, outermost covering — to expose the developing forewings within. They then sealed these tiny openings with thin panes of glass held in place with a dental composite. The team used a slightly modified version of this technique to uncover the developing butterflies' hindwings. 

Thus exposed, the developing wings could be observed under a microscope as the soup-ified caterpillars continued their metamorphosis, unmarred by the surgical procedure. However, conventional microscopes that use a single, wide beam of light to illuminate their subject could potentially damage the dainty scales. So instead, the team opted to use speckle-correlation reflection phase microscopy, which uses many tiny pinpricks of light to illuminate a subject, according to a statement about the study. 

Related: In photos: Jaw-dropping images reveal science is amazing 

The lights bounced off of different points on the butterfly wings, and the team then constructed detailed maps of the wings' structure by analyzing exactly how and where these points of light reflected. "Using this method, we can isolate the light coming from different layers, and can reconstruct the information to map efficiently a structure in 3D," Peter So, a professor of mechanical engineering and biological engineering at the Massachusetts Institute of Technology (MIT), said in the statement. 

A few days after the start of metamorphosis, the team watched individual cells line up in orderly rows in the butterfly wings; each cell gave rise to a single wing scale by secreting chitin, a type of sugar, the team wrote in the study. As these scales formed, they fell into an alternating pattern of cover scales — which sit on top of the wing — and ground scales — which lie beneath the cover. 

Long, thin ridges then appeared on the surface of the scales, running down their lengths in tidy, parallel lines. A painted lady's entire pupal stage typically lasts about 8 to 12 days, and these ridges appeared about 60% of the way through the process, the authors wrote in their report.

 "A lot of these stages [of metamorphosis] were understood and seen before, but now we can stitch them all together and watch continuously what’s happening, which gives us more information on the detail of how scales form," lead author Anthony McDougal, a research assistant in MIT’s Department of Mechanical Engineering, said in the statement. 

Prior to the new study, researchers had captured snapshots of select stages of this process, but now, we can watch the entire transformation play out like a movie.

Originally published on Live Science.

A ghostly squid with huge, iridescent fins and funky, elbow-like bends in its tentacles is rarely seen, but scientists recently captured stunning footage of the elusive animal during an expedition in the Gulf of Mexico. 

To date, there have been fewer than 20 confirmed sightings of this deep-sea cephalopod, known as a bigfin squid (Magnapinna), and this recent sighting adds one more to the list, according to a statement from NOAA Ocean Exploration.

National Oceanic and Atmospheric Administration (NOAA) scientists spotted the elusive squid on their recent "Windows to the Deep 2021: Southeast ROV and Mapping expedition," during which the team explored poorly understood deepwater areas in the western Atlantic Ocean off the southeastern United States. While filming underwater near the West Florida Escarpment — a steep slope in the seafloor that separates the shallow, coastal waters from the deep Gulf of Mexico — the team noticed a set of spindly blue appendages drifting past their remotely operated vehicle (ROV).

Related: 8 crazy facts about octopuses 

In the footage, the camera turns to reveal the bigfin squid in all its glory, its eight arms and two tentacles strewn out behind it. The creature's large fins — which extend off the main portion of its body, called the mantle — ripple softly in the water, similar to how a stingray's fins flap. The see-through mantle holds the squid's organs, which appear light yellow and pink in the light of the ROV. 

Mike Vecchione, a research zoologist with the NOAA Fisheries National Systematics Laboratory and the Smithsonian's National Museum of Natural History, was onshore watching the ROV footage on a satellite feed as the bigfin squid came into view. He and Richard E. Young of the University of Hawaii first described the bigfin squid family, called Magnapinnidae, in 1998, according to a report in the South African Journal of Marine Science. Since then, three species of bigfin squid have been described, but there may be more bigfin squid species to discover, according to the NOAA statement.  

When the bigfin squid popped up on the ROV feed, Vecchione quickly called the vehicle operators, to share his knowledge of the animal, the statement says. "Magnapinna … all of their arms and tentacles have this extension on them, long, spaghetti-like extension," Vecchione 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." The bigfin squid holds all these appendages out from its body, creating those distinctive elbow-like dents that make its tentacles so recognizable.

The squid was seen swimming about 7,825 feet (2,385 meters) beneath the ocean surface, but in the past, bigfin squid have been spotted as deep as 15,535 feet (4,735 m) down, according to the statement. Members of the bigfin family are widely distributed throughout the world's deep ocean ecosystems, but it's unclear how many there are in total since the cephalopods are seen so rarely. Last year, scientists reported seeing five of the squid near the Great Australian Bight, a large bay in South Australia — the first time any bigfin squid had been spotted in Australian waters, Live Science previously reported.  

Originally published on Live Science.

A pair of bald eagles interlocked their talons during a territorial dispute — or potentially a lover's dance — and crash-landed as a tangled duo onto a Minnesota street early this month. 

A small crowd soon assembled where the bald eagles fell, near the intersection of 41st Avenue and Nathan Lane in Plymouth, according to WCCO 4 News, a local  television station. Video footage showed the entangled eagles struggling on the ground and occasionally letting out loud shrieks. At other moments, the birds laid still, their outstretched wings draped over one another.

The Plymouth Police Department was called to the scene, and in body cam footage, police officer Mitchell Martinson can be heard saying, "They're definitely locked together, kind of out of energy," as he approaches the tangled birds in the roadway. He reached out to the Department of Natural Resources and the University of Minnesota's Raptor Center for guidance, WCCO 4 News reported.

Related: Weird animal facts

Given that bald eagles are often portrayed as mighty and regal birds, this sort of clumsy entanglement may seem like an odd occurrence. But in actuality, eagles get caught in each other's talons more often than you might think, KARE 11 reported.

The entanglements typically happen during in-air fights over territory, and "there are two times of year when we know this to occur," Dr. Victoria Hall, a veterinarian and executive director of the Raptor Center, told KARE 11. In the spring, bald eagles establish mating pairs and may fight for territory while setting up their nests. And in the fall, fights sometimes break out as some bald eagles reclaim nests to use in the winter months.

Each year, The Raptor Center, which specializes in the medical care, rehabilitation and conservation of eagles, hawks, owls and falcons, treats about six bald eagles with injuries endured during such battles. Sometimes, the skirmishes can be fatal, Hall told KARE 11; she recalled one occasion where a pair of eagles became entangled and then plunged to their deaths in a river below.

That said, some bald eagles become entangled during courtship rituals, rather than during territorial disputes, Crystal Slusher of the American Eagle Foundation told NPR. Bald eagles practice a courtship ritual that involves locking talons, diving toward the ground and then separating just before hitting terra firma. In the case of the two eagles in Minnesota, "it could've went wrong and they just didn't let go in time," Slusher said.

However they became entangled, thankfully, the two bald eagles eventually freed themselves and flew away, seemingly no worse for wear. "Eventually the eagles started going at it again and the next thing you knew, they were just flying away," Martinson told WCCO 4 News.

Originally published on Live Science. 

Fishers recently hauled up a surprising catch off the coast of North Africa: a colossal ocean sunfish weighing an incredible 4,400 pounds (2,000 kilograms).

At least that's how heavy marine biologists estimated the mammoth fish to be, based on its girth and the dimensions of sunfish that had previously been captured and weighed. "We tried to put it on the 1,000-kilogram (2,200 pounds) scale, but it was too heavy," marine biologist Enrique Ostale told Reuters. "It would've broken it." 

Fishers in Ceuta, a Spanish territory bordering Morocco, discovered the animal tangled in their nets in early October. They immediately called in Ostale, head of Seville University's Marine Biology Lab in Ceuta, to examine the massive sunfish. After first isolating the creature in an underwater pen attached to the boat, the team briefly hauled the fish into the air, using a crane. 

Related: In photos: The world's largest bony fish

Like other ocean sunfish, all of which belong to the genus Mola, the creature resembled an oblong pancake with huge, googly eyes stuck to its sides. Two massive, winglike fins extended from the top and bottom of the fish; in the ocean, sunfish wave these fins to and fro to propel their hefty bodies through the water.

Once the sunfish had been hoisted on deck, the team measured the animal and determined it to be 10.5 feet (3.2 meters) long and 9.5 feet (2.9 m) wide; for scale, a king-size bed is only 6.6 feet (2.03 m) long by 6.3 feet (1.9 m) wide. After measuring the sunfish and taking photos and DNA samples, the crew released the animal back into the sea, where it soon disappeared into the watery depths. 

"When we arrived there, the feeling was astonishment," Ostale said in a video interview with Reuters. "We couldn't believe our luck because we'd read books and articles about the dimensions that a sunfish can have, but we didn't know we'd [ever] be able to watch it and touch it ourselves."

Based on grooves marking the fish's sides and its stumpy clavus — a rudder-like structure on the back of the fish — Ostale and his colleagues identified the animal as a species called Mola alexandrini, also known as a bump-head sunfish because of the distinctive lump on its noggin. 

Although adult sunfish rank as the largest bony fish on the planet, scientists recently found M. alexandrini babies that measured just a few millimeters in length, Live Science previously reported. The tiny larvae look nothing like their adult counterparts, but over time, they grow to be 600 times their original size and morph into that familiar winged-pancake shape. 

The M. alexandrini captured in Ceuta set a record as the largest sunfish ever caught in the region, in terms of its dimensions, Reuters reported. But in general, the sunfish species can grow even larger and heavier. To date, the heaviest M. alexandrini specimen weighed a whopping 5,070 pounds (2,300 kg), making it the heftiest sunfish specimen ever weighed, Live Science previously reported.

Originally published on Live Science.

In shocking new video footage, a giant tortoise creeps toward a baby bird perched on a log, slowly and steadily cornering the chick before chomping down on its tiny skull. 

The footage ends after the lifeless bird tumbles to the ground, but the researcher who captured the video reported that the tortoise swallowed the chick whole moments later. The chilling video is the first documented case of "deliberate hunting" in any tortoise species, the researchers wrote in a report published Monday (Aug. 23) in the journal Current Biology. 

This dramatic, albeit slow-motion, hunt took place on Frégate Island, part of the Seychelles archipelago in the Indian Ocean off the East African coast. The footage was recorded by Anna Zora, the island’s deputy conservation and sustainability manager, who had been surveying seabird populations in a woodland when she spotted a female Seychelles giant tortoise (Aldabrachelys gigantea) exhibiting some very strange behavior.  

Related: Survival of the grossest: 8 disgusting animal behaviors 

"There was just something odd about the way it was behaving," said senior study author Justin Gerlach, the director of biology studies at the University of Cambridge’s Peterhouse College in the U.K.

Typically, giant tortoises meander about, munching on plants as they go, and they only really walk in a purposeful manner when engaging in aggressive behavior, Gerlach said. For instance, male tortoises might make a beeline toward each other when fighting over mates. The Seychelles tortoise in Zora's video walked with similar deliberation, very unlike how a tortoise would move if engaging in casual eating behavior, Gerlach said.

Zora observed the tortoise's minutes-long approach to a juvenile lesser noddy tern (Anous tenuirostris) that was sitting on a log nearby; the flightless chick had likely fallen from a nest in the trees above. The tortoise clambered onto the log and marched toward the tern, opening its jaws wide and retracting its tongue — as is "typical for aggressive tortoise behavior," the study authors noted. The small bird pecked at the approaching tortoise in vain, while stumbling backward on the log and flapping its wings.

"It does exactly the wrong thing," Gerlach said of the bird. "If it had hopped off the log, it could have got away easily." But because terns nest in trees, the chick likely viewed the ground as a dangerous place, and so it stayed put on the log in spite of the approaching reptile, he said.

The tern's decision proved fatal. After about 90 seconds of pursuit along the log, the tortoise clamped its beak around the bird's head, killing it instantly. "From first approach to the death of the chick, the interaction took seven minutes in total," the authors wrote in their report.

After recording this grisly interaction, Zora emailed Gerlach, who has studied giant tortoises since 1996. When Zora wrote that she’d seen a tortoise hunting a bird, Gerlach was doubtful. "I thought, 'Yeah, that doesn't sound likely. There's some sort of misunderstanding here,'" Gerlach told Live Science. But upon seeing the footage for himself, he was amazed.

"It's clearly trying to injure the bird. And then it goes, it goes all the way and kills it," he said. He and Zora suspect that the tortoise had experience hunting down terns on logs, given that it spotted and approached the chick from some distance away, apparently knowing that it wouldn't fly off as an adult tern would.

Although they primarily stick to a plant-based diet, tortoises occasionally snack on the flesh of dead animals, which are likely a useful source of protein, the authors wrote in their report. Although tortoises' serrated beaks aren't adapted for biting or chewing flesh, if they manage to swallow an animal whole they can still digest the meat, Gerlach said. Tortoises have also been observed munching on bones and snail shells, which provide the animals with calcium, the authors wrote.

In terms of hunting behavior, there are some published reports of tortoises squashing small birds or crabs beneath the edge of their upper shells, but it's unclear whether the tortoises use this as a deliberate hunting strategy or if they're just clumsy, the authors wrote. Anecdotally, there have been several accounts of tortoises seemingly hunting small birds, but until now none had been caught on camera, Gerlach said. The newly documented evidence of a tortoise hunting a bird hints that the animals might hunt other small creatures, perhaps using a variety of strategies, he said.

Gerlach plans to investigate the behavior further to determine how many Seychelles tortoises hunt birds, and how often. He said he wonders whether this behavior may become more common on Frégate as birds recolonize the island, as the island has undergone extensive habitat restoration in recent years. "We may be looking at the redevelopment of behaviors that used to exist in the past," when thriving bird and tortoise populations both inhabited the island, "or we may be looking at the evolution of a totally new behavior," brought on by the recent surge of seabirds, he said.

Whatever the case, the behavior is "so alien to the way we think of tortoises" and suggests that their behavior may be more complex than once thought, Gerlach said.

Originally published on Live Science. 

New high-speed videos show squirrels performing daring, parkour-like stunts — all in pursuit of peanuts.  

In a new study, published Thursday (Aug. 5) in the journal Science, researchers at the University of California, Berkeley tested the agility of fox squirrels (Sciurus niger) on the university campus. Their goal was to learn how the squirrels maneuver through the tree canopy, bounding between branches of different sizes while consistently sticking the landing.

To recruit their bushy-tailed study subjects, the research team ventured into their campus eucalyptus grove armed with peanuts and a squirrel-size apparatus with fixtures for the animals to climb over. The apparatus could be fitted with different rods, meant to simulate tree branches, for the squirrels to leap from. On the other end of the apparatus was a landing perch with an enticing cup of peanuts stuck to its end. The squirrels quickly learned to leap from the rod to the landing perch in order to reach the peanuts, and the researchers adjusted the distance between the rod and the perch, to give the rodents a challenge.

Related: 10 amazing things you didn't know about animals 

When faced with rods of varying bendiness and gaps of different widths, the squirrels quickly adapted their leaping strategy, the team found. "When they leap across a gap, they decide where to take off based on a tradeoff between branch flexibility and the size of the gap they must leap," first author Nathaniel Hunt, who was a doctoral student at Berkeley during the study, said in a statement. (Hunt is now an assistant professor of biomechanics at the University of Nebraska, Omaha.) 

For instance, when launching from a relatively stiff rod, the squirrels started their leap closer to the end of the rod, to minimize their jumping distance to the peanuts. But when launching from a bendy rod that curved under their weight, the squirrels began their leap sooner, presumably to take off from the sturdiest point on the "branch" and reduce the bending motion. 

When leaping across a wide gap, the squirrels sometimes under- or overshot their jumps, but none ever fell, the authors noted in their report. "If they miss, they don't hit their center of mass right on the landing perch; they're amazing at being able to grab onto it," Hunt said in the statement. "They'll swing underneath; they'll swing over the top. They just don't fall."

But when faced with a really huge gap — measuring roughly three to five squirrels long — the rodents took an "unexpected" approach, the authors wrote. The squirrels used the back of the climbing apparatus — a flat, vertical wall — to execute an impressive parkour move, wherein they ricocheted off the wall and quickly reoriented their bodies to land squarely on the peanut perch.

Not only does the new study highlight the remarkable athleticism of squirrels, but someday, the data could be used to design agile robots, according to the statement. Several authors on the paper belong to a consortium funded by the U.S. Army Research Office, and their collective goal is to create the world's first robot with squirrel-like capabilities. Such a robot would be able to make split-second judgments to move nimbly through its environment — just like a squirrel does as it leaps across tree branches.

Originally published on Live Science. 

Last week, wildlife officials in Utah yeeted thousands of fish out of a plane and into 200 high-elevation lakes across the state.

The Utah Division of Wildlife Resources (DWR) has been dumping fish out of airplanes since 1956, Live Science previously reported. In a video that went viral this week, fish can be seen bursting from the underside of a plane, carried downwards in a plume of water; the shiny animals then careen through the air towards the water's surface. The most common species dropped during these flights are various species of trout, a hybrid trout known as splake (Salvelinus fontinalis) and Arctic grayling (Thymallus arcticus), according to Live Science.

Related: 5 surprising facts about lakes 

Although this method of restocking lakes may seem violent for the young fish, because the creatures are only 1 to 3 inches (2.5 to 7.6 centimeters) long at the time of release, the wind actually carries them down quite gently — like leaves fluttering in a breeze, Phil Tuttle, the outreach manager for the southern region office of the Utah DWR, told Live Science in 2018. About 95% of the fish are expected to survive each release. 

During a single flight, the plane carries hundreds of pounds of water and can drop up to 35,000 fish, Utah DWR officials wrote on Facebook. Pilots fly just above the tree line while dropping the fish, or as low as possible while considering other natural barriers like cliffs and mountains, Live Science previously reported. Before the Utah DWR began using planes, people and horses would carry the fish up to the remote mountain lakes on foot; this journey proved more stressful for fish than being tossed from a zooming plane.

If the Utah DWR didn't restock its high-elevation lakes each year, the popular fishing spots would soon be entirely depleted of fish. The fish used for restocking are raised in hatcheries, and most are bred to be sterile to prevent a sudden population boom and ensure they have a minimal impact on native wildlife species.

Originally published on Live Science.

Many residents of Victoria, Australia, evacuated their homes to avoid disastrous floods last week — and upon their return, they found the land, trees and road signs coated in thick veils of shimmering spider silk, according to news reports.

Heavy rains and strong winds triggered flash floods in the Australian state last week, leaving tens of thousands of residents without power, The Guardian reported; two people died when their vehicles became inundated by the floodwaters. The Victoria State Emergency Service had issued flood warnings beforehand, specifically urging residents to evacuate from the Traralgon Creek area, located in the rural Gippsland region of Victoria, according to tweets from Darren Chester, the member of Parliament representing Gippsland.

As the residents of Gippsland evacuated their homes, local arachnids also fled for higher ground. Using a behavior called "ballooning," spiders clambered atop vegetation and flung fine silk threads into the wind; as the threads caught air, the spiders got plucked from their perches and lifted to safety, CNN reported.   

Related: 21 totally sweet spider superlatives 

"When we get these types of very heavy rains and flooding, these animals who spend their lives cryptically on the ground can't live there anymore, and do exactly what we try to do — they move to the higher ground," Dieter Hochuli, an ecologist at the University of Sydney, told CNN affiliate 7News. "This is a surprisingly common phenomenon after floods," he said, adding that sheetweb spiders — a family of arachnids in the genus Stiphidiidae — likely spun the abundance of silk.

When thousands of spiders balloon at the same time, their many silk threads can merge to form a "remarkable carpet of silk, called gossamer, covering shrubs or fields," according to the Australian Museum. Given how much gossamer accumulated in Gippsland, it's possible that millions of spiders took to the air to escape the floods, Ken Walker, a senior insects curator at Museums Victoria, told The Age, a Victoria-based newspaper.  

"To me, it's absolutely beautiful. A silken blanket that undulates throughout vegetation," Walker said. "It also shows the literally tens of thousands, if not millions, of spiders at ground level. Without spiders, we'd have plagues of insects," he added.

Local councillor Carolyn Crossley told BBC News that she noticed the "beautiful" sheets of spider silk while assessing flood damage in the area on Monday night (June 14). "The fact that it didn't separate — it was like these spiders had coordinated to make this incredible landscape art installation or something," she said. Crossley had witnessed this ballooning phenomenon before but never to such a dramatic extent, she said.

The billowing mats of spider silk should disintegrate sometime this week, BBC News reported. Meanwhile, Gippsland continues to recover from the severe flash floods.

Originally published on Live Science.

Mantis shrimp wield a spring-loaded appendage that punches through water with explosive force — and their babies can start swinging just nine days after they hatch.

In a new study, published Thursday (April 29) in the Journal of Experimental Biology, scientists studied larval Philippine mantis shrimp (Gonodactylaceus falcatus) originally collected from Oahu, Hawaii. The team also reared some of the same species from eggs, carefully monitoring their development through time and then zooming in on their punching appendage under the microscope.

The appendage, called the raptorial appendage, works similar to a bow and arrow, in that the tip of the appendage gets pulled back, "nocked" against a spring-like mechanism and then let loose in a sudden release of elastic energy, said first author Jacob Harrison, a graduate student in the biology program at Duke University. "While we have a pretty great understanding of how it functions in the adults … we didn't really have a solid understanding of how it develops," Harrison told Live Science.

Related: Smash! Super-stabby mantis shrimp shows off in video

Now, in a "remarkably complete and carefully controlled" study, Harrison and his team have started to unravel the mystery of when mantis shrimp start throwing down like lightning-fast boxers, said Roy Caldwell, a professor of integrative biology at the University of California, Berkeley, who was not involved in the study.

And furthermore, since larval mantis shrimp have transparent shells, "what's new about this study is [that] the transparency of the raptorial apparatus allows them to see in great detail exactly what's going on," Caldwell said. "That hasn't been possible in looking at adults," whose exoskeleton is opaque, he said.

Slower than expected, but still impressive 

When adult mantis shrimp unleash a flurry of strikes, the tips of their appendages can slice through the water at about 50 mph (80 km/h), according to National Geographic. But a mathematical model, published in 2018 in the journal Science, hinted that baby mantis shrimp might throw even faster punches than adults, assuming they take up boxing at a young age. 

This model, developed in the same lab Harrison works in, zoomed in on the spring mechanism mantis shrimp use to deliver punishing blows. "We see these mechanisms all over biology," from jumping frogs and insects to stinging jellyfish that fire venom-filled capsules into their prey, Harrison noted. 

The model hinted that these spring-loaded mechanisms should generally become less efficient at larger scales, and therefore, smaller springs with less mass should generate higher acceleration when let loose. Another model that specifically focused on mantis shrimp revealed a similar result, indicating that larger mantis shrimp species strike more slowly than smaller species, the researchers reported in 2016 in the Journal of Experimental Biology. 

Harrison and his team wanted to see if these models held up in larval mantis shrimp, since of course, they're smaller than adults of their species. So the team searched for tiny, translucent mantis shrimp in Hawaii in the dead of night. "If you go out where you can find adult mantis shrimp, you can actually stick a light in the water, and mantis shrimp will come like a moth to a flame," Harrison said. That said, larval crabs, shrimp and fish also flock to the light and get scooped up in the same buckets as the mantis shrimp; so therein lies the challenge.

These free-swimming shrimp larvae had matured enough to exit the burrow in which they hatched, so they tended to be at least 9 to 14 days old at the time of capture, Harrison noted. To collect data on even younger mantis shrimp, Harrison also collected an egg clutch from a female G. falcatus found at Wailupe Beach Park. The eggs hatched in transit on their way to Duke University, but the team still managed to raise the puny mantis shrimp for 28 days in their lab.

Related: Six bizarre feeding tactics from the depths of our oceans

With mantis shrimp in hand, the team carefully observed how the larvae developed through time. G. falcatus larvae were previously known to progress through six larval stages, each marked by the larva molting its exoskeleton. The team found that, in the first and second larval stages, the larvae huddled together at the bottom of the tank; by the third stage, they began swimming but did not throw any punches. 

But by the fourth stage, around day 9 to 14, "larvae began striking and 'waving' their raptorial appendages as they swam through the water," the authors wrote in their report. At this point, the raptorial appendages had fully formed and closely resembled an adult's, in terms of structure, and the larvae also began snacking on larval brine shrimp that the team provided. Each larva measured about the size of a grain of rice at this juncture.

The team shot high-speed, high-resolution video of the strikes by the older larval mantis shrimp they'd scooped from the ocean, to see just how they hurl their appendages through water. This required placing the rice-size larvae into a custom rig and securing them with glue, so they'd stay in frame and in focus. The footage enabled the team to not only examine the speed and mechanics of each punch, but also to watch as elements of the spring mechanism slid to and fro under the transparent exoskeleton. 

"What we found was that they could produce really high accelerations and velocities relative to their body size," Harrison said. These metrics specifically measure how rapidly the larvae appendages can transition from stillness to striking, so in this respect, the larvae were "roughly on par with a lot of the adult species," he said.

However, in terms of their overall speed, the larval strikes only traveled about 0.9 mph (1.4 kph) — an order of magnitude slower than the adult strikes. 

"The finding that was a little bit surprising was that the speed of the strike is less than what we see in adults," Caldwell said. This difference in speed may be related to the actual materials making up the spring, he said; perhaps the spring itself or the "latch" that nocks the appendage in place, differs in larval and adult mantis shrimp, limiting the amount of elastic energy that the larvae can deploy. 

Related: Dangers in the deep: 10 scariest sea creatures

The water surrounding the mantis shrimp may also impact their striking speed, Harrison suggested.

To teeny marine creatures, like larvae, water feels quite viscous, more like molasses than water as we experience it, he said. It may be that, as mantis shrimp mature, they can better overcome the stickiness of the water and execute faster strikes.

And despite being slower than adults, the larvae still threw punches that were five to 10 times faster than the reported swimming speeds of similarly sized organisms and more than 150 times faster than their favorite brine shrimp snacks can swim, the authors wrote. Evolutionarily, there may not be much pressure for larvae to increase their striking speed before reaching maturity, Caldwell said.

The study is also limited in that the team only collected video of defensive strikes, provoked by irritating the larvae with a toothpick, Caldwell noted. "We know, in adults, there's considerable ability to modulate the strength of the strike depending on what it's being used for," whether that be defense, or capturing or stabbing prey, he said. So the speed of the strike may differ somewhat, depending on its purpose.

Looking forward, Harrison and his team plan to probe what factors limit the larval mantis shrimps' striking speed, as well as when the shrimp overcome this limitation in the course of development, he said. They also want to examine whether the raptorial appendage develops similarly across the hundreds of mantis shrimp species, he added. 

"The larval stomatopods," another term for mantis shrimp, "are basically a black box, we know very little about them," Caldwell noted. "Almost anything done on larval stomatopods is new and interesting … They've just literally scratched the surface in terms of looking at morphology."

Originally published on Live Science. 

If you should see someone walking around central England with a 4-foot-long (1.2 meters) rabbit in tow, call the authorities. That rabbit may be Darius — the current record holder for the world's largest rabbit — who went missing from his Worcestershire home last weekend.

"It is believed the Continental Giant rabbit was stolen from its enclosure in the garden of the property of its owners overnight on Saturday (10 April - 11 April)," the local West Mercia Police said in a statement. "The rabbit is quite unique in the fact it is 4ft in size and has been awarded a Guinness Record for being the biggest rabbit in the world."

Darius was awarded his impressive title in April, 2010. At the time, he measured a whopping 4 feet 3 inches (129 cm) long — a true titan, even among his species.

Darius is a Flemish Giant rabbit, which is the largest breed of rabbit on Earth. According to the Maryland Zoo, an average Flemish Giant can weigh about 15 pounds (7 kilograms) and measure 2.5 feet (0.76 m) long. They are a domesticated breed, originally bred for meat and fur beginning at least 300 years ago.

Today, Flemish Giants are largely raised as companion animals. Annette Edwards, Darius' owner, called her prize-winning bunny "very laid-back" in a 2015 interview, adding that giant rabbits are even easier to raise than smaller breeds, because they act "more like dogs" than flighty, burrowing rabbits from the wild.

Edwards is offering a reward of 1,000 British pounds (roughly $1,400) for Darius' safe return.

Originally published on Live Science.

When octopuses snooze on the seafloor, their skin sometimes pulses with an array of colors, and at other times, they become pale and plain. These alternating patterns mark two distinct stages of the octopus sleep cycle, a small study suggests.

During "active sleep," when an octopus's skin ripples with dazzling colors, the cephalopod may experience something similar to our rapid-eye movement (REM) sleep, the authors wrote in the study, published March 25 in the journal iScience. Humans do most of their dreaming during REM sleep, but for now, we don't know if cephalopods also drift off to dreamland — or what they'd dream about, if they did.

"This whole speculation about dreaming, we must take it with caution," said senior author Sidarta Ribeiro, a neuroscientist at the Brain Institute of the Federal University of Rio Grande do Norte, Brazil. He noted that the octopus's episodes of active sleep occur in brief bursts, lasting from a few dozen seconds to just over a minute. 

Related: 8 crazy facts about octopuses 

"In mammals ... the active sleep, what we call REM sleep is much longer. It lasts minutes, dozens of minutes," Ribeiro told Live Science. So, "even if there is ... some sort of inner narrative going on in the octopus's mind as it's going through active sleep, it's very unlikely that it's a whole story," he said. More likely, an octopus might dream in short scenes, like video clips pulled from a longer movie, he said. 

But even if octopuses don't dream during these fleeting moments of active sleep, the sleep state may still play an important role in the creatures' learning and memory, similar to how human memories become reinforced during REM, Ribeiro said. The authors plan to study the influence of different sleep states on octopus learning in the future.

Psst, are you asleep? 

Octopuses change color using chromatophores, or specialized pigment organs that expand and contract under the skin, altering the colors and patterns on its surface, Live Science previously reported. While awake, octopuses can change color to blend in with their surrounding environment, but it's unknown why the animals continue to shift color while at rest, and few studies of octopus sleep have explored the phenomenon.

In past studies of the common octopus (Octopus vulgaris), scientists have only described so-called "quiet sleep," when the animal sits very still and its skin turns a ghostly white color, first author Sylvia Medeiros, a doctoral student at the Brain Institute, told Live Science. The vibrant, "active" sleep state has been described more thoroughly in the common cuttlefish (Sepia officinalis), a related cephalopod, but these studies didn't check whether the cuttlefish were truly asleep or just in a "state of quiet alertness," Medeiros noted in the iScience report.

To confirm that an animal is truly asleep, scientists test its "arousal threshold," meaning the amount of time it takes the creature to react to a stimulus. For example, while awake, an octopus will quickly react to physical vibrations of its tank or to videos of scuttling crabs played just outside the glass. A sleeping octopus will take far longer to react, or may not respond at all, since it must first be roused from slumber.

Related: Why do people 'twitch' when falling asleep?

The team conducted these arousal experiments with four tropical octopuses of the species Octopus insularis, which Medeiros collected 6 miles (9.7 kilometers) from their lab in Brazil. The authors captured video recordings of the octopuses to assess their behavior while alert and at rest. Noting patterns in the cephalopods' behavior, they then tested the animals' arousal thresholds in different behavioral states; for instance, they tested the animals both when they were alert and exploring their tanks and when they became still and appeared to rest.

The researchers found that the octopuses are not only genuinely sleeping during active sleep, but the animals also switch between quiet and active sleep in a predictable pattern.

"The relationship between quiet and active sleep that they identified is particularly exciting," said Sara Stevens, an aquarist with Butterfly Pavilion in Westminster, Colorado, who was not involved in the study. "It verifies patterns we've anecdotally witnessed across the octopuses we've had in our care over the years," Stevens told Live Science in an email. However, since the new work only included four octopuses of the same species, larger studies will be needed to confirm the results, she noted.

A distinct sleep pattern 

The team observed that colors disappear from the octopuses' skin during "quiet sleep," and their pupils contract into thin slits. In this state, the animals become quite still except for the occasional soft, slow movements of their suckers and arm tips. Periods of quiet sleep can last from a few minutes to about half an hour.

"Quiet sleep pretty much always precedes the active sleep," Ribeiro said. "It's usually the long quiet sleep episodes," lasting more than six minutes, "that lead to an active sleep episode," he added.    

A dramatic visual change marks the shift between quiet and active sleep. The chromatophores on the octopus's head and mantle — the bulbous structure that houses the animal's organs — display "sudden simultaneous darkening." The animal then begins twitching, contracting its suckers, moving its eyes and increasing its ventilation rate. The octopus also expands and contracts its pupils, while vibrant colors wash over its whole body.  

Though its pupils sometimes dilate, the octopus doesn't react to visual stimuli in this state — similar to how a person can sleep with their eyes open. These sudden bouts of movement and color occur periodically, at roughly 30- to 40-minute intervals.

"It really resembles what you see in reptiles and birds: Long, quiet sleep followed by short, brief episodes of active sleep," Ribeiro said. Mammalian sleep follows a similar pattern but the active sleep, namely REM, typically lasts longer than in other animals, he said.

Related: 7 mind-bending facts about dreams

In mammals, the shift into REM sleep is accompanied by physiological changes that help convert short-term memories into long-term memories in the brain, Ribeiro noted. It's still unclear whether active sleep serves a similar purpose in birds or reptiles, and in the case of octopuses, we have no clue, he said. 

The authors plan to study whether changes in an octopus's sleep cycle affect its ability to learn new tasks; for instance, they may study how well sleep-deprived octopuses can learn and remember how to free food from closed containers. In addition to behavioral tests, the team plans to study whether octopuses express specific genes or build particular proteins during active sleep, as mammals do during REM.

At some point, they also hope to record the electrical activity of octopus neurons during sleep, but that presents an incredible challenge, the authors said. For starters, the squishy, boneless creatures lack solid body parts that scientists could easily attach electrodes to, Ribeiro said. What's more, the curious animals tug and pull at anything placed on their bodies, Medeiros said. 

"Adding water into the equation takes it to a completely different level of difficult," Stevens added. 

Among these many challenges, a huge question still remains: Do octopuses dream or not? 

"My hunch is yes, but we are open to everything," Ribeiro said. 

Until the team can collect neural recordings from octopuses, it may be possible to study their theoretical dreams by taking detailed recordings of the colors and patterns on their skin, he noted. If an octopus dons a certain color scheme during sleep that corresponds to a behavior in its waking life, such as courtship, that could potentially provide a window into what the animal is dreaming about. The scenario is similar to observing a dog growl and twitch in its sleep, as if dreaming of chasing rabbits. 

But again, using pigment patterns to read octopus dreams may be a reach at this point, as more research is needed to understand octopus sleep states at a fundamental level, Ribeiro said. 

Originally published on Live Science. 

A walrus spotted on an Irish beach yesterday (March 14) may have floated there from the Arctic Circle after falling asleep on an iceberg.

A 5-year-old girl walking with her father spotted the blubbery newcomer.

The young girl, named Muireann, pointed out the walrus to her dad, Alan Houlihan, as they walked on Valentia Island in County Kerry. "I thought it was a seal at first, and then we saw the tusks," Houlihan said, according to IrishCentral. "He kind of jumped up on the rocks. He was massive. He was about the size of a bull or a cow, pretty similar in size; he's big, big." 

Most walruses (Odobenus rosmarus) live near the Arctic Circle, where they hunt for shellfish in shallow water and clamber up onto the icebergs and beaches to rest, Live Science previously reported. The humongous creatures rarely crop up along the Irish shoreline. The first recorded walrus sighting there occurred in 1897, but no other walruses were seen until the 1980s, the Irish public service broadcaster RTÉ reported. Since then, fewer than two dozen additional walruses have been spotted in Ireland.

Related: 15 of the largest animals of their kind on Earth 

The washed-up walrus seen on Valentia Island is thought to be quite young, based on the length of the animal's tusks, RTÉ reported. Full-grown walruses can grow tusks as long as 3.3 feet (1 meter), while the recently sighted walrus's tusks were roughly 12 inches (30 centimeters) long. The walrus's body measured more than 6 feet (2 m) from snout to tail.

How does a young walrus end up in County Kerry? "I'd say what happened is, he fell asleep on an iceberg and drifted off, and then he was gone too far, out into the mid-Atlantic or somewhere like that, down off Greenland possibly," Kevin Flannery, a marine biologist with the Dingle Oceanworld Aquarium, told The Independent.  

"He could also be island-hopping and went to Iceland and on to Shetland, but that's unlikely," Flannery said. I'd say he came in out of the Atlantic." After traveling thousands of miles, the walrus is likely exhausted and hungry, he added.

"Hopefully, he'll get a few scallops around Valentia," Flannery said. "If he regains his strength, hopefully he'll make his way back up" to the Arctic.

Houlihan said the sleepy walrus still gave him and his daughter "a bit of a show" when they spotted it, according to The Irish Examiner. "It's brilliant. He was sitting on the rock now, kind of posing; at one stage there, he threw up a fin, and it looked like he was giving us all the birdie," he said. 

Originally published on Live Science.

When scientists drilled a half-mile-long (900 meters) hole into an Antarctic ice shelf, they found something surprising: a rock covered with unknown animals on the seafloor below. 

In fact, the scientists weren't looking for marine life at all; they were geologists planning to gather sediment samples from the ocean floor. They'd set up camp on the Filchner-Ronne Ice Shelf, a large body of floating ice in the southeastern Weddell Sea, where they spent many hours shoveling snow and using hot water to bore a narrow hole through the ice. With the hole complete, they lowered a camera with their sediment corer, to scope out the seafloor more than 1,000 feet (300 m) below the bottom of the shelf.

They hoped to hit mud, "but instead, they hit a rock. And that's incredibly bad luck for them," said Huw Griffiths, a marine biogeographer with the British Antarctic Survey. However, the team later showed their video footage to Griffiths, and though the rock blocked their path to the sediment, the camera picked up something Griffiths never expected to see: a community of sponges and other unknown filter feeders clinging to the stone.  

Related: Antarctica: The ice-covered bottom of the world (Photos) 

"It's a place where, essentially, we didn't expect this kind of community to live at all," Griffiths said. Some of the creatures had squat, round bodies, while others had thin stalks that stretched into the surrounding water; parts of the rock were also coated in a thin layer of fuzz, which could possibly contain tiny, threadlike organisms. 

"This is showing us that life is more resilient, and more robust, than we ever could have expected, if it can put up with these conditions," said Griffiths, who, along with his colleagues, published a paper about the serendipitous discovery Feb. 15 in the journal Frontiers in Marine Science.

Other animals have been discovered beneath Antarctic ice shelves in the past, but those included mobile animals such as fish and arthropods, a group of invertebrates that includes crustaceans, Griffiths said. Besides the occasional jellyfish, which can get swept beneath the ice by ocean currents, the only animals seen in the frigid, pitch-black water were those that actively moved around to gather food, he said.

But stationary filter-feeding animals, like sponges and corals, remain fixed in one spot and sustain themselves on food that happens to float by. Tiny phytoplankton — microscopic marine algae — serve as a huge source of nutrients for entire marine ecosystems, including these filter feeders, and the phytoplankton rely on sunshine for photosynthesis. 

In the context of ice shelves, the nearest source of sunshine lies in the open water at the edge of the shelf; intuitively, you wouldn't expect sponges to grow far from that edge, because few phytoplankton would be likely to reach them. 

But lo and behold, several species of stationary filter feeders showed up on this rock, located 160 miles (260 kilometers) from the edge of the Filchner-Ronne Ice Shelf. What's more, due to the pattern of ocean currents in the area, any phytoplankton that the animals could feed on would first be swept farther away and then loop back under the ice shelf. In other words, the food would "have to come the long way around to get to these animals," Griffiths said.

Following the ocean currents, the sponges are about 370 to 930 miles (600 to 1,500 km) away from the nearest sources of fresh phytoplankton, Griffiths said. Much of this available food might be eaten by other animals or else sink to the ocean floor, as some phytoplankton die along the way, he said. And yet, against all odds, the newfound sponges still have enough fuel to grow. 

"For me, that's really exciting, because these animals must be getting enough food from somewhere," Griffiths said. This raises a multitude of questions about how much food the creatures need to survive, whether their metabolism slows or stops when food becomes scarce and whether they gather extra fuel in a way we don't yet understand, he said.

Related: Ocean sounds: The 8 weirdest noises of the Antarctic

So far, everything the scientists know about these creatures comes from less than a minute of video footage. Studying the animals further will present a huge challenge, since no research vessel can get close to them, Griffiths said. "We're going to have to develop technologies and things that can go and do that for us on their own," he said. 

These tools might include miniature underwater vehicles that can be operated remotely or run autonomously; the vehicles would have to fit through narrow boreholes, he said. The robots could gather sediment and water samples that scientists could then examine for nutrients and DNA. The robots could also collect tiny samples of the sponges themselves; however, given that the ecosystem may be rare, scientists will have to figure out how to do so without disrupting the surrounding environment, Griffiths noted. 

That raises another huge question: How many other rocks are teeming with undiscovered life beneath the Antarctic ice? In total, ice shelves cover about 580,000 square miles (1.5 million square km) — an area about twice the size of Texas — of the Antarctic continental shelf, according to a statement from Frontiers in Marine Science. But in terms of the seafloor beneath, scientists have photographed only the equivalent of one tennis court, Griffiths said.

Having barely glimpsed this mysterious ecosystem, scientists can't yet fully understand how threats such as climate change might impact the unique species living there, or how losing any of these species might affect the overall environment, Griffiths said. 

"Two ice shelves collapsed in Antarctica in my lifetime. How many unique species ... have we already lost, without even knowing we'd lost them?" Griffiths said, referring to the Wilkins and Larsen ice shelves. "Although this ice shelf we're studying is a lot more stable than those that collapsed, it's still going to be vulnerable to climate change."

Originally published on Live Science. 

A sleek, spotted ocelot slinks down to a watering hole for a drink, when suddenly, a jaguar leaps from the shadows and bites down on the small cat's neck.

Scientists captured footage of this unusual attack in the Maya Biosphere Reserve of Guatemala in March 2019; they recently described the rare predator-on-predator interaction in a paper published Dec. 28 in the journal Biotropica. 

In the past, remnants of ocelots have been found in jaguar feces, suggesting that the larger feline predator sometimes preys upon the smaller one, according to a statement. Jaguars can grow to be between 200 and 250 pounds (90 and 113 kilograms), depending on their sex, while ocelets only reach about 18 to 44 lbs. (8.2-19.9 kg). Both cats are carnivores and feed on animals such as fish, frogs, rodents and monkeys — however, on occasion, an ocelot will end up on the menu of a voracious jaguar.

Until now, such an attack had never been caught on camera.

Related: Beasts in battle: 15 amazing animal recruits in war 

"Although these predator-on-predator interactions may be rare, there may be certain instances when they become more prevalent, and one of those could be over contested water resources," study author Daniel Thornton, an assistant professor in the School of the Environment at Washington State University, said in the statement. In other words, predators like jaguars and ocelots are more likely to clash if they're driven to the same few watering holes.

The team captured footage of the jaguar-ocelot attack in a particularly dry month during a drought year. These seasonal periods of dryness may become more pronounced as the climate continues to warm, meaning watering holes may become scarcer than in the past, Thornton said. 

"The more isolated and rare water resources become, the more they're going to become hotspots of activity," Thornton said. This activity may include more predator-predator interactions, as captured in the new footage, according to the statement.

In the video, the unsuspecting ocelot enters from the right and walks away from the camera toward the water's edge. As it stoops toward the watering hole, a male jaguar leaps from the left, a blur of spots and limbs. The large cat quickly grabs the ocelot by the neck and drags it off into the night.

On a different occasion at the same watering hole, the team also spotted two jaguars fighting each other; in total, they observed seven jaguars that regularly visited the site. Jaguars typically avoid one another and establish their own territories, so it's unusual for so many to come in close contact, according to the statement.

Originally published on Live Science. 

A mother bear and her cub were shot and killed while trying to board a nuclear submarine in Russia, according to news reports.

The sub was docked near the village of Rybachiy in Russia's far-eastern Kamchatka Peninsula, which has served as a submarine construction base since the 1960s. In a video shared on social media on Nov. 8, crewmembers aboard the sub watch as the two bears swim up from the adjacent bay and climb aboard the vessel's deck.

According to the Moscow Times, naval personnel called a local hunting instructor to dispatch the bears with a "specialized hunting weapon." In an unedited version of the video, a shotgun blast rings out before the bear cub falls from the sub's deck and into the bay.

Why the bears were heart-set on becoming submariners is anyone's guess, but the Russian military has already been barraged with social media scrutiny for killing the creatures, seemingly without cause. A spokesperson from the Russian Navy's Pacific Fleet told the Russian news agency Interfax that the bears had been seen several times in recent days, and posed a threat to villagers.

One crewmember who can be heard speaking in the video echoes this sentiment. "There's no other way," he says, according to the Moscow Times (which translated the clip from Russian). "If you chase it out, it'll wander into the villages. That's how you fight bears in Kamchatka."

An estimated 24,000 wild bears inhabit the Kamchatka Peninsula, according to BBC News. If the mother and cub were searching for food, as the Russian Navy spokesperson suggested, then they are hardly the first of their kind to venture into human territory in search of sustenance. In February 2019, more than 50 polar bears invaded a town in the Russian Arctic when thinning sea ice forced them away from their regular hunting grounds, Live Science previously reported. Climate change has caused the Arctic to warm twice as fast as the rest of the world, resulting in huge declines in sea ice every year, according to a December 2018 report released by the National Oceanographic and Atmospheric Administration (NOAA).

Originally published on Live Science.

Delicate ferns lay across the still water, when suddenly, a writhing caterpillar bursts to the surface, followed closely by a determined wasp. Wrenching the caterpillar into position, the wasp quickly injects the wiggly creature with eggs before releasing it back into the water. Sound like the plot to a twisted sci-fi flick?

This parasitic wasp was recently discovered, in real life, in Japan and aptly named Microgaster godzilla, after the famous fictional monster. It is the first aquatic wasp to be caught on film while diving underwater to hunt down its host, namely, moth caterpillars called Elophila turbata.     

"The wasp suddenly emerges from the water to parasitize the host, similar to how Godzilla suddenly emerges from the water in the movies," study author Jose Fernandez-Triana, a research scientist with the Canadian National Collection of Insects, said in a statement. In the movies, Godzilla also interacts with a monster called Mothra, who appears either as a caterpillar or full-grown moth. Since moth caterpillars serve as a host for M. godzilla eggs, "we had biological, behavioral and cultural reasons to justify our choice of a name," Fernandez-Triana said.

"Of course, that and having a bit of fun, because that is also an important part of life and science!" he added. Fernandez-Triana and his team described the newfound species in a study published Nov. 4 in the Journal of Hymenoptera Research.

Related: Ick! 5 alien parasites and their real-world counterparts

"Usually, taxonomic descriptions of parasitoid wasps are based on dead specimens, with very few details — often none — on its biology," Fernandez-Triana noted. In this study, the researchers had the rare opportunity to rear live wasps from larvae and observe exactly how they plant their eggs in unwary hosts. 

To do so, the team scooped E. turbata caterpillars from ponds in the Osaka and Kyoto Prefectures of Japan. As mature wasps began to emerge from inside the collected caterpillars, the team spotted specimens with distinct yellow, brown and orange-yellow patterns on their bodies. They analyzed the morphology and DNA of these wasps and determined them to be a newfound species.

To see the wasps in action, the team placed female M. godzilla specimens and their caterpillar hosts into aquariums and got the cameras rolling.

In the wild, E. turbata caterpillars encase their bodies in bits of vegetation and sit suspended just under the water's surface. In the lab video, an M. godzilla wasp can be seen feeling around for these homemade cases using its curved antennae. When it locates a caterpillar, the wasp slips beneath the water, staying down for several seconds, and wrestles the moth larvae out of its casing. The wasp then uses its enlarged, curved claws to grip and pull the grub to the surface, according to the study. 

Related: Survival of the grossest: 8 disgusting animal behaviors 

Holding the exposed caterpillar in place, the wasp inserts a tube-like organ called an ovipositor into the caterpillar’s body and sends its eggs down. "In all cases we observed, oviposition occurred above water, where the host larvae went trying to escape the wasp," the authors wrote. "The wasp can also pierce through the case for oviposition," when it's not fully removed, they added.

The wasps can sometimes force caterpillars out of their case without diving underwater, the authors noted. However, the wasp earned its monstrous name for the characteristic way it rises from the water after forcing its host into submission.

Originally published on Live Science. 

Scientists have captured rare footage of a teeny, tiny squid swimming near the Great Barrier Reef; the squid is the only living member of its genus and has never before been observed alive and in its natural habitat. 

"Researchers were all surprised to see this squid as it was nothing like any of us had seen before," Valerie Cornet, a masters student at James Cook University in Australia who is currently conducting research with the Schmidt Ocean Institute, told Live Science in an email. The ram's horn squid (Spirula spirula) swims with its body in an unusual vertical position with its arms and tentacles pointed up; at the bottom end of the squid, two ear-shaped fins ripple in the water to keep the animal afloat. In the footage, the squid can also be seen zooming downward through the water column while remaining perfectly vertical. 

Schmidt Ocean Institute researchers spotted the squid using a remotely operated vehicle (ROV) — an underwater machine that can be controlled from the ocean surface — while mapping the northern Great Barrier Reef off the coast of Cape York in Australia. While the ROV was cruising at a depth of about 2,760 feet (842 meters), the team saw a small, cylindrical creature pop up on their video feed. 

Related: Sea science: 7 bizarre facts about the ocean 

The researchers' voices can be heard in the background of the video footage, making observations about the animal as they maneuvered the ROV closer:

"Yeah, that definitely looks like a squid."

"And an interesting one at that!"

"... a little shy!" one added, as the squid zipped downward through the water and out of frame. 

"The squid remained upright unmoving as we zoomed in closer to get a better view, but then started swimming off rapidly downwards," Cornet said. "We kept following it around for a couple minutes to study and comment on its unique shape and staring eyes."

The team later identified the cephalopod as a ram's horn squid, named for a coiled shell that sits inside the rounded end of its elongated body. The brown-red-hued squid typically measures less than 2 inches (35-45 millimeters) in length, and while at rest, it floats vertically with its arms pointing up and the mantle — the main body of the squid that contains the shell and internal organs — pointing down. The light shell is thought to give the squid buoyancy.

The squid also emits light from a bioluminescent organ located at the tip of the mantle; this may help the squid avoid predators by minimizing the appearance of its silhouette from above, Cornet said. 

"It is particularly interesting as it is rare to see this squid alive, but we often find its open coil shell washed up on beaches," Cornet said. "This is the first time filming the squid with its characteristic 'head down' position," she added.

Related: 24 underwater drones – The boom in robotics beneath the waves

S. spirula is the only living member of the genus Spirula, family Spirulidae and order Spirulida, as all other known members of these evolutionary groups have gone extinct, the Schmidt Ocean Institute wrote in a tweet announcing the discovery.

S. spirula specimens have been found as deep as 5,577 feet (1,700 m) underwater, and scientists think the squids lay their eggs at this depth and that the eggshells withstand over 1,100 pounds (0.5 metric tons) of pressure from the water above, she added. But because the squid hasn't been studied alive in the wild, little is known about its distribution or behavior, Cornet said.

For instance, "the social structure of this species is currently unknown," Cornet said. "It was previously thought that these were a type of schooling squid, but having discovered it alone, this may not be the case."

In addition to spotting the elusive squid, the researchers discovered a number of undescribed species of corals, sponges and jellies while mapping the Great Barrier Reef. What's more, they also found a never-before-seen coral reef that stands taller than the Empire State Building. Samples and footage gathered during the fruitful expedition will keep the researchers busy for years to come, Cornet said.

Originally published on Live Science. 

Ogre-faced spiders hang from their webs, and like gymnasts, they flip backwards to snatch flying insects from the air. To hear their prey coming, the spiders "listen" for the flap of tiny wings using a special organ in their spindly legs, a new study has found.

The organ looks like a patch of parallel slits cut into the spider's exoskeleton; located near the tip of each leg, each slit measures between 0.0000003 and 0.000007 inches (10-200 nanometers) in length. These tiny slits contain nerve cells that detect minute changes in pressure caused by sound waves rippling through the air; the organ then sends this information to the brain. 

Thus equipped, ogre-faced spiders (Deinopis spinosa) can hear sounds up to 6.5 feet (2 meters) away and pick up frequencies between 100 and 10,000 hertz, according to a new study, published Oct. 29 in the journal Current Biology. Humans can hear sounds between about 20 and 20,000 hertz, for context.

"It's very alien to us because we don't have a sensory system like this," said study author Jay Stafstrom, a postdoctoral researcher studying sensory biology at Cornell University. 

Humans, of course, use their eardrums to detect sounds, but spiders don't have eardrums. That said, Stafstrom and his colleagues suspected that the ogre-faced spider might rely on some form of hearing to snag flying prey from the air — and the new study supports that suspicion. 

Related: 21 totally sweet spider superlatives

The authors found that certain sounds sent the spiders flipping; as if on cue, the arachnids would hear the sound and perform a sudden half-backflip as if launching toward a passing bug. Ogre-faced spiders can be found in forested regions of Australia, Africa and parts of the United States, including Florida, according to Cosmos Magazine; the teeny spiders, which measure less than an inch (1.5-2.5 cm) in length, hide among palm fronds and other vegetation and use their nimble acrobatics to catch moths, mosquitoes and flies that fly past.

The flip is "ballistically rapid, it's very quick … and they're surprisingly accurate," in terms of enabling the spider to catch prey on the fly, Stafstrom told Live Science. "From such a tiny little spider, with a tiny little brain, it's very impressive."

In general, ogre-faced spiders are better known for their impressive vision than their hearing. "They've got the biggest eyes of any spider," Stafstrom said. The spiders hide from predators throughout the day, camouflaged to blend in with the plants they live on. At night, the arachnids emerge and use their two huge, night-vision eyes to spot crawling insects on the ground below. To catch the creepy-crawlies, the spiders hang suspended from a web near the ground and ensnare bugs in a tiny, stretchable net that they hold between four legs.

The spiders deploy the same net to catch flying insects, but they contort their bodies backwards to aim the net upward, rather than lurching down toward the ground. It wasn't initially clear, however, if the spiders relied on their night-vision to aim the net at flying prey.

In a previous study, published 2016 in the journal Biology Letters, Stafstrom set out to determine whether ogre-faced spiders even needed their eyes to capture flying insects. He blindfolded the spiders using dental silicone, a kind of opaque plastic, and found that they could no longer capture crawling prey from the ground, but they could still pluck flying insects right out of the air. Clearly, they were relying on some other sense besides vision, Stafstrom said.

In the new study, Stafstrom and his co-authors played different sounds for the spiders to see if any would trigger their signature backflip. When exposed to low-frequency sounds, between 150 Hz and 750 Hz, the spiders lurched backwards and stretched their nets as if to catch a bug. These low-frequency sounds mimic the wingbeat patterns of various flying insects, the authors noted. The authors found that no sounds of any frequency caused the spiders to aim forward toward the ground, confirming that the spiders use their vision, not hearing, to catch crawling prey.

Related: Creepy, crawly and incredible: Photos of spiders

Compared with low-frequency sounds, high-frequency tones did not send the spiders somersaulting. However, electrical recordings of the spiders' brain cells revealed that specific groups of brain cells, or neurons, react to high frequencies, specifically between 1,000 Hz and 10,000 Hz; the sensory organ in the spiders' legs reacted to the same range of sounds. The authors speculate that, since flying insects don't flap their wings at such high rates, the spiders might also listen for the high-pitched call of predator birds.

"It might be an early warning sign, that a bird that could end your life may be in the vicinity," Stafstrom said. "We're really interested in knowing, 'Can these spiders hear bats?'" he added, but the study didn't include frequencies high enough to mimic most bat chirps.

While the study of spider hearing remains quite new, several other arachnid species can also hear sound, Stafstrom noted. 

For instance, jumping spiders sense and respond to sounds more than 9.8 feet (3 m) away, Live Science previously reported. Jumping spiders have pressure-sensitive leg hairs that respond to the movement of air particles around them. Ogre-faced spiders also have these special leg hairs, and jumping spiders have the same sensory organ in their legs as the ogre-faced does. 

"We suspect that both spiders are using both systems," but that has yet to be confirmed, Stafstrom said.

With the discovery that ogre-faced spiders use their hearing to capture prey, Stafstrom and his team now wonder how well the spiders can discern which direction a given sound is coming from. They plan to place the spiders in an arena and play sounds from various angles, to see whether the spiders change up their acrobatic routine to aim their net in the corresponding direction.

Originally published on Live Science. 

Some marine snails soar through the water by flapping their squidgy appendages to and fro, similar to butterfly wings — now, scientists have discovered that the shape of the snails' shells also helps them zip through the sea.

The new study, published Sep. 7 in the journal Frontiers in Marine Science, shows that large snails with slim, elongated shells cut through the water more quickly than small snails with round, coiled shells. The small snails swim slower, in part, due to their small wings, but their size and speed also make it so they can't easily overcome resistance from the surrounding water, study author David Murphy, an assistant professor in the Department of Mechanical Engineering of the University of South Florida, told Live Science in an email. "The larger snails can easily overcome the effects of this viscosity," or the water's resistance to flow, and those with streamlined shells cut through the water even more easily, he said. 

The streamlined snails slip through water similar to how an airplane wing carves through air.

Related: Sea science: 7 bizarre facts about the ocean 

While large snails swim faster than the small ones, all nine snail species that the authors studied travel similar distances when searching for food, according to a statement. The snails, which measure about 0.03 to 0.5 inches (0.9 to 13.1 millimeters) in length, each travel between 162 and 984 feet (50 to 300 meters) per day, swimming skyward to feed at the surface at night and sinking down to rest during the day.  

When swimming, the snails can cover between one and 24 body lengths per second, rising in a zig-zagging spiral; when done for the night, they sink down at a slight angle, descending with similar speed. The large snails gracefully glide through the water as they sink, thanks to their elongated shells.

Seven of the snail species included in the study are fondly known as "sea butterflies" for their fluttering wings; in past research, Murphy and his colleagues found that sea butterflies flap their wings in a figure-eight pattern, similar to the movement of fruit flies, and called the creatures "honorary insects," Live Science previously reported.

Murphy and his lab study animals that fly both in and out of the water, and they plan to design tiny aquatic and aerial vehicles inspired by different organisms, Murphy said. The vehicles "could be used in many different applications. For example, they could take data under the water surface and then pop back into the air to transmit data," he said.

Originally published on Live Science. 

"Why did the fox steal my shoes?" sounds like the start of a brain-teasing riddle or an annoyingly viral song. But for people in Berlin, it was an existential question spurred by the knowledge that a local fox was the culprit behind a string of shoe thefts.

About two weeks ago, Christian Meyer, a resident of Berlin's Zehlendorf neighborhood, noticed that one of his new and expensive running shoes had disappeared from his porch, and he decided to investigate the theft, German news site Tagesspiegel reported. 

Meyer quickly learned that he was not the thief's only victim, and a tip helped him catch the fox bandit red-handed (or red-pawed) with two blue flip-flops in its mouth, according to Tagesspiegel. Days later, Meyer spotted the fox again; he followed it into a thicket, where Meyer crawled around for close to an hour. There, he discovered the fox's secret stash of more than 100 shoes, "most of them just gnawed on a little," Tagesspiegel reported.

Related: Viral video: What the fox actually sounds like

Meyer captured a photo of the thieving fox and its ill-gotten stash, which Tagesspiegel editor Felix Hackenbruch shared on Twitter on July 26. The shoe pile contained sneakers, clogs, sandals and slippers in a range of colors, shapes and sizes, though the most numerous shoes by far were Crocs.

Still unknown: Why the fox stole the shoes, and why this particular canid had a thing for Crocs. But this isn't the first time that an urban fox has demonstrated a seeming shoe fetish. In August 2019, a fox in Melbourne, Australia, repeatedly visited a woman's porch and stole three boots over the course of a week; the woman captured the thief's antics on security camera footage, which she posted on YouTube.

A pair of foxes in Kyoto, Japan, pilfered more than 40 pairs of sandals in 2018 before the duo was apprehended in a stakeout involving five police officers, The Guardian reported that year. In 2009, in the small town of Foehren in western Germany, a female fox stole about 110 to 120 shoes in just one night, presumably "for her cubs to play with," according to Reuters. In 2013, a writer described waking up one morning in his London home to find that a fox had placed seven shoes in the middle of his lawn, "ranging in size from that of a toddler to an adult trainer." 

It's unknown if all of these foxes were acting independently or if their actions were linked, perhaps as part of an international shoe-stealing cartel with a nefarious purpose that humans can only imagine.

Meanwhile, in Berlin, most of the fox's victims have been reunited with their shoes — except for Meyer, whose stolen sneaker is still missing, Tagesspiegel reported. 

And if the fox knows where the shoe is, it's not saying.

Originally published on Live Science.

When their pollen supply runs short, bumblebees bore tiny half-moon-shaped holes in the leaves of flowering plants, causing blooms to appear weeks ahead of schedule. 

Bee-bitten plants bear flowers about two weeks to a month sooner than untouched plants, according to a new study, published today (May 21) in the journal Science. Researchers attempted to recreate these bee-bite patterns using metal forceps and a razor, but even then, the damage inflicted by bees boosted flower production more effectively than the scientists could; bee-bitten plants bloomed eight to 25 days before the artificially damaged ones did, depending on the plant species. 

Some plant species flower early in response to drought, or in response to infections caused by certain pathogens, but few studies have explored how animal behaviors might prompt plants to bloom early, said study author Mark Mescher, a professor of environmental systems science at ETH Zürich. Mescher and his coauthor Consuelo De Moraes, a professor of biocommunication and ecology at ETH Zürich, spotted bumblebees munching on leaves during an unrelated experiment, and they wondered why.

Related: 7 amazing bug ninja skills  

"It started really with observing the behavior," Mescher said. Other researchers told the team that they'd also observed bees biting leaves, anecdotally, but no formal studies had probed why the insects did it, he said. 

In early laboratory experiments, buff-tailed bumblebees (Bombus terrestris) appeared to ramp up this biting behavior when deprived of pollen, a key food source for both bee larvae and the worker bees themselves, the authors noted. To test the hypothesis, the team deprived one group of worker bees of pollen for three days, while a different group was provided "abundant pollen resources." When released into enclosures full of flowerless tomato and black mustard plants, the deprived bees began nibbling at the leaves with gusto. The satiated group, in contrast, inflicted only minor amounts of leaf damage.

To confirm that the hungry bees weren't simply eating the leaves, or carrying bits back to their hive, the authors placed paper cones beneath the plants to catch falling debris. Leaf bits accumulated in the cones, and no leaf residue appeared back at the hive, they noted. The bee-inflicted damage resembles tiny half-moons, carved by the insects' mandibles, or pinprick holes poked out with their proboscises (tubular mouthparts), De Moraes said. "But it's quite quick," with each cut only taking a second or so to complete, she added. 

Related: Naughty by nature: The most disgusting and deadly flowers 

The team observed this biting behavior in both their laboratory bees and wild colonies that visited plants housed on rooftops at the ETH Zürich campus. In the wild bees, the team noted that biting behavior dropped off once the outdoor plants began to flower, bolstering the idea that the bees damage leaves when their available pollen supply runs low. 

While several species of wild bumblebees, including B. terrestris and B. lucorum, ravaged the flowerless foliage, honeybees and common furry bees that visited the roof would not, Mescher noted. "The honeybees just ignored the plants that didn't have any flowers," he said. "Who knows, but I'd be surprised if there were other pollinators [besides bumblebees] that were doing this." 

But why would only bumblebees beat up plants to boost their flower supply? That the scientists don't know yet, they said. Bumblebees do exhibit so-called "nectar-robbing" behaviors, where they slice into plant parts that house nectar beyond the confines of a flower, and the leaf-biting behaviors may be related to that, Mescher said. But we don't know for sure yet. 

Looking forward, the team plans to study precisely how bee-inflicted damage drives plants to bloom early, and whether the same biochemical changes occur in plants subjected to drought, pathogens or other environmental stressors. It may be that fatty acids in bumblebee saliva trigger a reaction in flowering plants, as is true of some caterpillar species, De Moraes said. Alternatively, the bees may release some unknown chemical cue, or else damage the leaves in a highly specific way that scientists cannot yet replicate, she added. 

If cues from bees can accelerate flowering, "scientists might realize a horticulturist's dream by deciphering the molecular pathways through which flowering can be accelerated by a full month," Lars Chittka, a professor of Sensory and Behavioural Ecology at the Queen Mary University of London, wrote in a letter in the journal Science accompanying the new paper.

"An encouraging interpretation of the new findings is that behavioral adaptations of flower visitors can provide pollination systems with more plasticity and resilience to cope with climate change than hitherto suspected," he wrote. In other words, as climate change alters when various plants bloom, understanding how bumblebees influence flowering could help farmers manage their crops. 

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•  7 insects you'll be eating in the future 
•  6 unexpected effects of climate change 

Originally published on Live Science. 

To the naked eye, deep-sea sponges seem to sit totally still, confined to one spot on the ocean floor. But in reality, the squidgy creatures move quite a bit and sometimes let out mighty "sneezes" by contracting their entire bodies at once. 

You may miss your chance to say "gesundheit," though, because sponge sneezes happen in slow motion, according to a recent study. 

Researchers at the Monterey Bay Aquarium Research Institute (MBARI) caught the behavior on camera using time-lapse photography, according to a statement describing the study. Their cameras sit some 2.5 miles (4,000 meters) below the ocean's surface, at a long-term study site called Station M, situated about 136 miles (220 kilometers) off the central California coast. While perusing old time-lapse photos of the seafloor, one researcher caught sight of something unexpected. 

"Everyone was watching sea cucumbers and urchins snuffling around on the seafloor, but I watched the sponge. And then the sponge changed size," lead author Amanda Kahn, a former MBARI postdoctoral scholar, said in the statement. 

Related: Six bizarre feeding tactics from the depths of our oceans 

Kahn and her co-author Clark Pennelly, an atmospheric researcher at the University of Alberta, took a closer look at the images and found that several glass sponges, which stick up from the seafloor like tulips, seemed to contract and expand in a rhythmic pattern over time. The researchers saw similar movements from sputnik sponges, which periodically unfurled and retracted their "parasol-like" filaments in the surrounding water. "It's not yet known what the timing of those rhythms are or why they happen the way they do," Kahn added. 

Sponges typically filter nutrients from the water for nourishment, and previous research suggested that the creatures cannot filter feed as efficiently when they contract their bodies, according to the statement. Co-author Sally Leys, a professor in the Department of Biological Sciences at the University of Alberta, has observed similar behavior in freshwater sponges, which can become irritated by particles circulating in the water and contract to push the contaminated liquid from their bodies — similar to how we rid our mouths and noses of dust when we sneeze. 

A freshwater sponge can take about 40 minutes to complete a single sneeze, according to the MBARI statement. In the new footage, sneezes took hours or even weeks to complete. "The deep sea is a dynamic place, but it operates on a different time scale … than our world," Kahn said. 

The study was first published Jan. 2 in the journal Deep Sea Research Part II: Topical Studies in Oceanography. A finalized version of the paper will appear in a special issue of the same journal this summer. 

• Sea science: 7 bizarre facts about the ocean 
• The 10 weirdest sea monsters 
• The world's biggest oceans and seas 

Originally published on Live Science. 

Once upon a research grant, scientists strapped three dead alligators into weighted harnesses and deposited the corpses 6,600 feet (2 kilometers) down in the Gulf of Mexico. 

The first gator was overrun with giant pink crustaceans within a day and slowly eaten from the inside out. 

The second gator was devoured down to its skull and spine after 51 days. 

And the third gator? Well, nobody knows; its corpse was ripped from the harness and carried off by an unseen predator within a week, leaving behind some torn rope and unsettled sand.

This is either the least-satisfying fairytale ever, or the results of a strange new marine-food-cycle study described in the journal PLOS ONE. (Answer: It's both.)

Related: Beastly Feasts: Amazing Photos of Animals and Their Prey

The authors of the study (published Dec. 20) set out to test how carbon-hungry creatures of the deep, dark ocean would react to a food source they'd never seen before — namely, the scaly carcass of a freshwater gator (Alligator mississippiensis). 

Denizens of the deep ocean can't afford to be picky eaters; it's too dark and cold down there for plants to undergo photosynthesis, and nutrients are scarce. 

"The deep ocean is a food desert, sprinkled with food oases," study co-author Clifton Nunnally, of the Louisiana Universities Marine Consortium, said in a video about the experiment, released last April. "Some of these oases are vents in the ocean floor where chemicals come out or food falling from the ocean's surface."

Research into these "food falls" has mostly focused on large mammals, like whales, whose corpses provide a blubbery banquet for sea creatures large and small. While freshwater gator corpses can be cast into the ocean by hurricanes and other adverse weather, the ecological aftermath of such a "gator fall" has never been observed before now. Could the worms, crustaceans and other residents of the ocean floor find a way to penetrate the gators' thick hides and liberate the tasty meat within? The researchers didn't think it likely — however, they were quickly proven wrong.

When the team sent a camera-wielding robot to check on the first gator one day after laying it to rest at the bottom of the Gulf, they found the corpse being picked apart by huge, pill-bug-like isopods (Bathynomus giganteus) — some of which had already burrowed inside the gator and begun eating it from the inside. These crustaceans, the researchers noted, can store the energy from a single meal for months or years at a time, meaning that the hungry buggies scavenging the dead gator wouldn't have to work for more food for quite some time.

The second gator fared even worse. When the researchers revisited the corpse 51 days after deployment, it was picked clean, down to the bones. Those bones were caked in a mysterious brown fuzz, which a DNA analysis revealed to be a newly discovered species of bone-eating worm (genus: Osedax). This is the first time any Osedax species has been detected in the Gulf of Mexico, the researchers noted.

The final gator corpse disappeared from its harness before the researchers could spot any marine creatures eating it, but it's clear that the gator didn't wake up and swim away on its own. Considering that the creature and the harness weighed a combined 80 pounds (36 kilograms), it would have taken a large predator to chomp through the rope and haul the carcass away. A shark is the likeliest culprit, the researchers hypothesized.

So, to conclude the tale of “The Gators Who Fell Into the Sea,” many a bottom-feeding marine creature slaked its appetite on the tasty reptilian flesh — including some brown, bone-eating worms that nobody knew existed. And they all lived happily ever after, until their corpses were devoured in kind. The End.

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Originally published on Live Science.

If a bunch of exploding stars hadn't forged the universe's heaviest elements billions of years ago, there would be no iron for our Maidens, no lead in our Zeppelins and no rocks to roll all nite.

This is to say, nature has never needed humans in order to be totally metal — and 2019 was no exception. This year was so metal that cockatoos taught themselves to headbang, cows rode hurricanes across the sea and black holes got so heavy that they defied physics.

In humble appreciation of these epic stories and others, we offer the following collection of 10 times nature was totally metal in 2019.

1. Walrus mom sinks boat

A walrus is a saber-toothed torpedo wrapped in 2,000 lbs. (900 kilograms) of rippling blubber. You probably don't spend much time thinking about how brutal these arctic sea units are — unless you've had the misfortune of getting too close to one or her calves.

That was the case for a group of Russian marine scientists in September, when they landed on a remote island in the Russian Arctic during a research expedition. According to a report from the Russian Geological Society, the team piloted its landing craft a bit too close to a mother walrus and her babies, prompting mama to attack the vessel — and wreck it. "The boat sank," the report said, though, luckily, "all the landing participants safely reached the shore."

The mother walrus and her family were also unharmed. When was the last time you headbanged a boat to death and walked away unscathed? 

2. Reindeers form mosh pit

Rudolph the red-nosed reindeer didn't go down in history for his combat prowess. Clunky and herbivorous, reindeer are much better at running away from predators than they are at fighting them. Spook enough reindeer at once, however, and their mad dash for safety could transform into an unstoppable force of nature.

In February, a PBS documentary called "Wild Way of the Vikings" showed what it looks like when this happens. It's called a "reindeer cyclone." When threatened (say, by a wolf's fangs or a hunter's arrow), a herd of reindeer may stampede over the ground in a spiral shape that makes it impossible for a predator to target any individual member of the herd. These cyclones once confounded Viking hunters in Norway, the documentary explains. But now, thanks to some stunning drone footage, we modern gatherers can marvel at the awesomeness of this furry mosh pit while chewing on beef jerky from the safety of our homes.

3. Headbanging worms wake sea

If reindeer prove that nature didn't need humans to invent the mosh pit, these deep-sea worms prove that nature didn't need us to invent headbanging either.

Lurking within sea sponges up to 550 feet (167 meters) deep off the coast of Japan, the paper clip-size worms called Leocratides kimuraorum are nearly transparent and exceptionally quiet — until it's time to rock out. When two worms engage in what researchers describe as a "mouth fight," they charge each other mouth-first, expand their throat muscles to create a high-tension bubble and then butt heads until those bubbles burst in an ear-splitting "pop." In a July 8 study, researchers found that each pop can reach up to 157 decibels in water, making these headbanging brawls some of the noisiest animal interactions in the sea (not bad for a bottom feeder).

4. Grasshoppers go biblical

"Grasshopper blizzard" sounds like a rough-draft name for one of the 10 plagues that was cut from the Old Testament before printing. But the people of Las Vegas got to experience such an event firsthand this summer when tens of thousands of migrating bugs swarmed the city several nights in a row.

Following a rainy spring that filled the Mojave Desert with lots of tasty vegetation, swarms of well-fed desert grasshoppers collectively flew northward this July as part of their regular seasonal migration. This year, their path took them directly over Las Vegas. Perhaps enticed by the bright lights or promise of free drinks, tens of thousands of the bugs alighted on the Strip, blanketing the sidewalks and seething around streetlights like living snow flurries.

So dense was the swarm that meteorologists mistook it for a storm when the cloud of insects appeared on weather radars on July 27. A few weeks later, the harmless bugs were gone, leaving, as so many Vegas visitors do, with nothing.

5. Cannibal galaxies collide

Galaxies cannibalize each other all the time. The Milky Way eats other galaxies; our neighboring Andromeda galaxy does it. And when the two inevitably crash into each other about 4 billion years from now, they will do it to each other. Justice is sweet (and apparently tastes like stars).

Astronomers aren't sure exactly what will happen when our galaxy smashes into Andromeda, but it will probably be messy. Once-dormant black holes could spark to life, stars will ricochet quadrillions of miles out of orbit, and crackling cosmic radiation will stain the sky in every direction. For a picture of what this could look like, take a gander at the ongoing galactic pileup known as NGC 6052. As shown in an epic photo snapped by the Hubble Space Telescope in March, two large galaxies in the Hercules constellation (about 230 million light-years away from Earth) smash into each other like a buzz saw biting through wood.

Studying this cosmic carnage could help astronomers find some clues about the crash that awaits the Milky Way. Or it could just be a nice reminder that life is futile and meaningless. Either way!

6. Bunker ants eat their dead

In cannibal news closer to home, a bunch of ants fell into a nuclear fallout shelter in Poland and have been eating each other to survive for years.

That's what scientists discovered when they found a colony of roughly 1 million wood ants trapped in a bunker near the German-Polish border in 2015. The ants were once part of a larger colony living over a 1960s-era nuclear base, but they had apparently fallen through a ventilation pipe that ended in a long drop to the bunker floor. Escape was impossible and food nonexistent; to survive, the unlucky castaways must have taken to eating each other's corpses, the team reported in an appropriately spooky Oct. 31 study. Indeed, in an analysis of 150 corpses from the room, 93% showed signs of being eaten. (Metal.)

Cannibalism isn't new to wood ants; the species is known to feed its young with the corpses of fallen enemies racked up during ant turf wars, the researchers noted. On a second trip to the bunker, the team installed a wooden board connecting the bunker's floor to the ceiling pipe. Most of the ants escaped within the year, free at last to cannibalize their enemies instead of their comrades, as nature intended. 

7. Dragon grows invisible fangs

Besides having a totally awesome name, the deep-sea dragonfish (genus Aristostomias) has one of the most metal jaws in nature. The eel-like predator's jaw can yawn open at 120-degree angles, allowing a dragonfish to devour prey more than half its size. (Imagine a toddler swallowing a newborn. Yikes.) You might think the sight of chompers like these would be enough to send sea critters running in fright, but the dragonfish's fangs are virtually invisible, not even reflecting the light from the fish's own bioluminescent body.

How is this feat of carnivorous camouflage possible? A study published in June looked at dragonfish fangs under an electron microscope, finding an array of grain-size nanocrystals speckled across each tooth's enamel that prevent light from scattering. The same trick could inspire human-size cloaking devices, the researchers wrote, allowing devious Muggles to skulk around like it's lights out at Hogwarts, hiding in plain sight. 

8. World's oldest death march discovered

Fossils are awesome because they show us how animals lived long ago, when snakes had legs and penguins were the size of middleweight boxers. But fossils are metal because they also show us how those animals died.

Take these baby fish, who perished in a perfectly preserved school when an underwater avalanche crushed them 50 million years ago. Or take this spiky worm, whose final commute across the muddy seafloor was immortalized in what scientists call the earliest "death march" in the fossil record, dating to roughly 550 million years ago. That dead millipede got scientists particularly excited in September, because it proved that animals have been mobile since at least the Ediacaran period (635 million to 539 million years ago), even earlier than was previously estimated. So long, ancient corpse worm. We salute you.

9. Tsunamis ravage sun

In case you've forgotten, Earth's sun is a constantly exploding ball of awesome. It's home to towering fountains of plasma; "lava lamp blobs" of mystery matter 500 times larger than Earth; and a writhing magnetic field that twists, turns, snaps and lashes out into space every 11 years or so, seriously screwing with Earth's power grid. In July, scientists added new phenomena to that list, these known as "terminator events." They're basically cataclysmic magnetic field collisions at the sun's equator.

Besides having a 1,000% epic name, these "terminator" collisions may result in twin tsunamis of plasma tearing across the star's surface in both directions, according to a February 2019 study. Yes, that means tsunamis of plasma, on the sun, moving at 1,000 feet (300 m) per second for weeks at a time. There is nothing not metal about this … save for the fact that, at the moment, the tsunamis are only theoretical. (The researchers who described them were looking at magnetic field patterns and data models, not physical observations.) Nevertheless, we challenge scientists to be bold and give the next version of the Parker Solar Probe a surfboard … and maybe some speakers for blasting Dick Dale.

10. Dead metal planet rots in space

Finally, we end on the most literally metal story of the year. In April, astronomers discovered the shattered remains of a dead planet orbiting a dead sun in a desolate solar system 400 million light-years away from Earth. The expired planet's broken heart is made of actual heavy metal, and this world orbits at breakneck speed through a dirty cosmic boneyard full of other chunks of dead planets.

How did these worlds die? Their own star probably engulfed them in flames as it ballooned outward during the final phases of its life, then devoured any leftovers after collapsing into a white dwarf (the superdense, gravitationally intense husk of a dead star). The remaining planetary chunk that makes up the newfound, dead world may have survived only by the strength of its heavy metal core, which now flies around the dead star like a missile, completing an orbit every 2 hours.

Mourn the dead planet and its dead star if you like, but do not pity them; one day, astronomers say, after our sun runs out of fuel and inevitably collapses, our solar system will probably look much the same.

Happy holidays!

• 9 Times Nature Was Totally Metal in 2018
• The 12 Strangest Objects in the Universe
• Top 10 Ways to Destroy Earth

Originally published on Live Science.

Gruesome new video shows mice attacking an adult albatross on the World Heritage Site of Gough Island in the South Atlantic.

It's an alarming new behavior from the invasive mice, which have long been known to attack albatross chicks and eat them alive. The Royal Society for the Protection of Birds (RSPB), a charity in the United Kingdom, released the disturbing video on Dec. 5.

Related: See Photos of Mice Attacking Albatross Adults & Chicks

"We have known for more than a decade that the mice on Gough Island attack and kill seabird chicks," RSPB field assistant Chris Jones said in a statement accompanying the video release. "While this is already of great concern, attacks on adults, which can produce dozens of chicks in their lifetime, could be devastating for the populations' chances of survival. … [T]hese gentle giants could now be lost even more rapidly than we first predicted."

Gough Island is a speck of land in the South Atlantic. House mice (Mus musculus) were introduced by sailing ships in the 1700s. The rodents quickly gained a foothold on the island, attacking and devouring the chicks of a variety of seabirds, including the critically endangered Tristan albatross (Diomedea dabbenena). A 2018 study funded by RSPB found that the mice are responsible for wiping out 2 million seabird eggs and chicks each year. With a ready source of largely defenseless prey at hand, the mice have evolved to be 50% larger than the average house mouse, according to RSPB.

In the new video, a mouse scurries into the nest of a Tristan albatross, brazenly crawling onto the adult bird's back and beneath its feathers. The bird turns uncomfortably and tries, apparently unsuccessfully, the reach the mouse with its beak. Albatrosses lay only one egg every other year, so every loss of an egg, chick or adult matters for population numbers.

The Tristan albatross range includes the southern Atlantic and Indian oceans, from Australia to South Africa to Argentina. There are an estimated 3,400 to 4,800 adults left in the wild, according to the International Union for Conservation of Nature (IUCN). The birds are threatened at sea by longline fishing, which can snare and entangle hunting albatross. On islands where the birds nest, rats and mice are a major threat. Gough island is now the breeding ground for 99% of the world's population of Tristan albatross.

Mice on Gough also threaten the Atlantic petrel (Pterodroma incerta), an endangered black-and-white seabird whose population is also concentrated ont Gough Island. There are an estimated 1,800,000 Atlantic petrels still in the wild, according to the IUCN, but their population has been declining by between a third to a half over the last three generations.

To stanch the losses, the RSBP is working with the government of Tristan da Chunha, a territory of Great Britain, to eradicate mice on Gough Island. The goal is to spread rodent-specific poisons  across the island by 2020. The project is seeking donations at www.goughisland.com.

• 9 Times Nature Was Totally Metal
• Beastly Feasts: Amazing Photos of Animals and Their Prey
• 15 of the Largest Animals of Their Kind on Earth

Originally published on Live Science.

To raise awareness about prediabetes, a new campaign features something most people can't resist — adorable animal videos.

With videos staring puppies, hedgehogs and baby goats, the campaign aims to teach people about their risk of prediabetes by walking them through a brief, 1-minute prediabetes risk test.

"Hedgehogs on vacation. A perfect way to spend a minute," one ad starts, while a background video shows hedges lounging on a tropical beach. "So is taking a 1-minute prediabetes risk test," the ad says.

The goal of the government-backed campaign is to encourage people to learn their risk of prediabetes and discover how to reduce their chances of developing the condition. More than 1 in 3 American adults, or 84 million people, have prediabetes, but nearly 90 percent don't know they have it, according to the Centers for Disease Control and Prevention (CDC). The CDC put together the campaign in partnership with the American Diabetes Association, the American Medical Association and the Ad Council. [Animal Morality: 6 Amazing Videos]

People with prediabetes have abnormally high blood sugar levels, and although the levels are not high enough to diagnose these individuals with diabetes, people with prediabetes often go on to develop type 2 diabetes. This can increase the risk of serious health problems such as blindness, heart attack or stroke, the CDC says.

"The number of Americans estimated to be at risk for developing type 2 diabetes is staggering," Dr. William T. Cefalu, chief scientific medical and mission officer of the American Diabetes Association, said in a statement for the campaign. With the campaign "we hope to heighten awareness about prediabetes and help more Americans learn their risk so they can make the lifestyle changes necessary to reduce their risk and delay or prevent the onset of type 2 diabetes," Cefalu said.

The prediabetes risk test, which is also available online, includes questions such as "Are you a man?", "[Do you have a] family history of diabetes?" and "Are you over age 60? 50? 40?" Men, people who are older and those with family members who have diabetes are at higher risk for prediabetes.

The new campaign follows a similar prediabetes campaign from last year, which also featured a prediabetes risk test and humorous ads.

"With this year's campaign, we hope to educate more people, in more places, about the seriousness of prediabetes and to inspire them to take action against an often-reversible condition," said Michael Paterson, executive creative director of Ogilvy, the advertising agency that developed the campaign pro bono for the Ad Council. "Through a lighthearted and fun tone, we found more people were willing to take the test — and who doesn't love to watch baby goats?"

Prediabetes can be reversed with weight loss and changes in diet and exercise, according to the CDC. If people take the risk test and it shows they are likely to have prediabetes, they should consult their doctors to confirm the diagnosis and also learn about lifestyle changes that can help prevent type 2 diabetes, said Dr. David O. Barbe, president of the American Medical Association.

Original article on Live Science.

Even the editors of serious scientific journals are not immune to the charms of sleepy koalas and penguins playing with robots. The video team at Nature picked their top 10 favorite science stories involving cute animals (and some bots) of this year. Here are their choices:

10.  Monkeys use how-to videos to get bananas

Can you teach monkeys in the wild how to solve a puzzle with educational TV? According to this experiment in Brazil, you can. Using mini movie theaters (composed of a laptop screen in a cardboard box installed in a tree), researchers showed that wild marmosets could learn how to open a container and get a banana slice simply by watching a how-to video. The findings were published in September in the journal Biology Letters.

9. "Magneto dogs"

Dogs tend to poop while aligned with the north-south axis of the Earth's magnetic field. That's the conclusion German and Czech researchers arrived at after spending two years watching 70 dogs relieve themselves. The authors of the study, which appeared in the journal Frontiers in Zoology, are still grasping for an explanation. The discovery of this long-overlooked quirk, while considered cute by Nature, was also deemed worthy of an IgNobel Prize, an award that honors the absurd in science.

8. Dumbo octopod

Researchers collected some amazing footage of marine life in the Gulf of Mexico this year during an expedition aboard the National Oceanographic and Atmospheric Administration (NOAA) ship Okeanos Explorer. One highlight was a rare video of a dumbo octopod with its arms coiled into tight spirals.

7. Dancing frogs

Fourteen new species of Micrixalus frogs were discovered in western India this year. The males of the species have a peculiar habit of flicking their legs. (Females are apparently attracted to good dancers.) The frogs were described in the Ceylon Journal of Science.

6. Cute lizards. Troubling find.

For anole lizards in the Caribbean, it turns out that shipping lanes are starting to have a bigger influence than geography on how species island-hop, scientists explained in a Nature study this year. Trinidad, for example, though somewhat isolated in the southern edge of the Caribbean, is home to one native anole lizard but four invasive anoles, Quanta magazine reported. Meanwhile, Cuba is large but economically isolated because of a U.S. trade embargo; it has 64 native anoles but no exotic species.

5. Coin-size robot swarm

These insectlike robots were apparently cute enough to make the cut. Researchers at Harvard built an army of more than 1,000 miniature robots that can race into formation, creating three-dimensional patterns, such as a starfish shape. The machines are wired to mimic creatures like ants and bees, which gather in huge numbers to build complex structures. The work was described in the journal Science in August.

4. Monkeys with great hair

Secretive saki monkeys are sometimes called toupee monkeys for their floppy mop of hair. This year, scientists announced that they found five new species of the creatures in Brazil, Peru and Bolivia. The new research, published in the summer issue of the journal Neotropical Primates, brought the number of known saki species to 16.

3. Jumping spider

"Cute" might be more than a little subjective here. Jumping spiders are famous for their good vision. For his close-up shot of just two of the eight eyes of a jumping spider, photographer Noah Fram-Schwartz won third place in Nikon's annual microphotography contest in October.

2. Penguin bots

How do you infiltrate a penguin colony if you're a human? Send a robot spy. Better yet, send a robot spy disguised as a penguin chick. That's what a team of researchers did to get close to a colony of emperor penguins in Antarctica. The notoriously shy birds were quite receptive to their robotic interloper. The penguins let the rover get close enough to read their ID tags; some even vocalized at the fake chick. The unusual methods were described in Nature in November.

1. Tree-clinging koalas

Scientists finally discovered why koalas hug trees: It keeps them cool. On French Island, near Melbourne, Australia, temperatures can spike to more than 104 degrees Fahrenheit (40 degrees Celsius) during the summer. Through thermal imaging, researchers found that koalas in this habitat were often clinging to trees that were much cooler than the ambient air temperature, sometimes by as much as 9 degrees F (5 degrees C). The findings were published in June in Biology Letters.

Follow Megan Gannon on Twitter. Follow us @livescience, Facebook & Google+. Original article on Live Science.

When octopuses go hunting for prey, they sometimes end up "dining" on members of their own species, and the cephalopods seem to have a taste for their victims' arm tips.

Divers have captured video of this octopus-on-octopus action in the wild for the first time on video.

In a new study, researchers described three cases of cannibalism in the common octopus — Octopus vulgaris — recorded with a camcorder by scuba divers in Ría de Vigo, Spain, located on the northeastern Atlantic coast. In two of the cases, the predators had started to eat the tips of the arms of their prey by the time the divers found them. [See Images of the Cannibalistic Octopus]

And, in one of the cases, the predator had access to more "traditional" prey in the form of mussels, but it still chose to feed on another, smaller octopus.

Although scientists had been aware of cannibalism occurrences among members of O. vulgaris, the previously reported cases were known only from analyses of stomach contents and laboratory observations, the researchers wrote in the study published Sept. 8 in the Journal of Comparative Psychology.

However, "this behavior has never been described from direct observations in the wild by scuba diving," said study author Jorge Hernández-Urcera of the Institute of Marine Research (IIM) in Vigo, Spain.

The researchers documented the first of the three cannibalism cases on Dec. 11, 2012, at a depth of 40 feet (12 meters), on a rocky bottom off the Cíes Islands, which are part of the National Park of the Atlantic Islands of Galicia (NAPAIG). A male octopus weighing about 4.85 pounds (2.2 kilograms) was holding in its grasp a smaller octopus without visible sexual characteristics, which weighed a bit less than a pound (about 400 grams). [See Video of the Cannibalistic Octopus in Action]

"The animal was dead, showing a pale white color and the tips of its arms had been eaten," the researchers wrote.

The second case was recorded July 13, 2013, on a sandy bottom about 60 feet (18 m) below the surface near the Estelas Islands. A male octopus of about the same weight as the in first case carried an octopus weighing a bit more than a pound (540 grams) inside a ball-shaped sack that it had formed with its arms and web – the skin between its arms that it can spread to capture prey.

The diver who recorded the case realized that "the prey was still alive, because it poked and moved one of its arms between the dorsal pair of arms of the predator," the researchers wrote. The diver disturbed the predator, which in turn let go of the prey, letting it escape, and therefore the researchers classified this case as "an attempted predation."

The third recorded case occurred Nov. 26, 2013, at a depth of about 45 feet (14 m), on a rocky bottom off the Cíes Islands, also within NAPAIG. A female octopus of almost 4 pounds (1.8 kg) was holding an octopus weighing less than a pound (about 350 grams), of unknown sex. The prey was already dead when the diver saw it, "with a pale white color and the tips of the arms eaten," the researchers wrote.

Cannibalistic behavior in octopuses may be motivated by various factors, the researchers said.

When octopuses are in captivity, and too many of them are introduced to the same aquarium or an on-growing cage – a type of floating cage in which octopuses are reared, they may resort to cannibalism as a means of defending their territory, Hernández Urcera said.

"The existence of territoriality in octopuses is, however, controversial," he said, adding that studies have shown varying results on this phenomenon.

Territoriality, the lack of available prey and the vulnerability of smaller males to being eaten by larger females are some of the potential reasons for cannibalistic behavior among octopuses in the wild, Hernández Urcera told Live Science.

However, the researchers think the most probable cause of cannibalism in the cases observed is the high net energy gained from preying on other octopuses.

For example, when an octopus feeds on a smaller member of its species, it receives the same amount of energy it would get by feeding on a large number of mussels — its common prey, Hernández Urcera said. But the cost of capturing another octopus is lower than the energy cost of snagging all of those mussels. In addition, an octopus may choose to feed on another member of its species instead of mussels because itcan get more protein per gram from octopus meat than from mussels. Moreover, handling another octopus requires less energy than opening the number of mussels whose weight would be equivalent to the weight of meat provided by a single octopus.

The research was conducted under the leadership of Angel Guerra of the Institute of Marine Research in Vigo, as part of the Cefaparques Project funded by Spanish National Research Council.

Follow Agata Blaszczak-Boxe on Twitter. Follow Live Science @livescience, Facebook & Google+. Original article on Live Science.

The Internet is a friendly place for cute and weird animal behaviors caught on camera, from foxes jumping on trampolines to dogs playing with deer. But beyond entertaining the masses, these amateur viral videos sometimes document behaviors that are rarely seen, and they could help scientists understand how species interact with each other, some researchers say.

"They're not substitutes for good, hardcore research, but they're very valuable for people who aren't going to see certain things," Marc Bekoff, a former professor of ecology and evolutionary biology at the University of Colorado, Boulder, told LiveScience this week. "From a pedagogical point of view, I wish I had had more access to YouTube videos. I would have probably used them in my classes."

Take the famous "snowboarding" crow that was caught repeatedly sliding down an icy roof using a plastic lid. A Russian video of the playful behavior was uploaded to YouTube in January 2012. In its first six months online, it had been viewed more than 670,000 times.

Ximena Nelson, a biologist at the University of Canterbury in New Zealand, said she had witnessed similar sledding behavior in the kea parrot, but noted that it's very rare to see. Nelson said in an email that "citizen science can give us a much better idea of the variety of interesting play behaviors, tool use, or other behavior that is relatively rare that can be found among other animals."

Nelson and her colleague Natasha Fijn, of the Australian National University, argue in a recent article in Animal Behavior that these clips could provide evidence and valuable insights on uncommon or even unknown animal antics.

Some scientists are already putting such resources to use. A study published recently in the journal Wildlife Research surveyed photos and videos of whale sharks that vacationers have uploaded to social media sites like Flickr and YouTube. The study found that scientists could use 85 percent of these images to successfully identify individual sharks, which could help scientists track and learn more about the huge animals.

Footage uploaded by citizens could be especially helpful in deepening our understanding animal play, which is understudied, sometimes difficult to observe, and a favorite subgenre of viral animal videos, the researchers say.

"Some of the videos have opened the door for thinking about cross-species relationships," Bekoff said. Dogs tend to be featured heavily in these kinds of clips, and they could challenge the notion of "man's best friend" as they show canines spontaneously playing with a remarkable range of animals, including monkeys, dolphins, deer, sheep, killer whales, horses and alpacas.

"One could conclude that dogs are not particularly anthropocentric or even canine-centric in relation to play bouts: they appear to play with any species that are willing to reciprocate," Nelson and Fijn write.

But not all animal videos are created equal. Nelson and Fijn say scientists need to be wary of clips that have been altered in post-production editing, which, they say, might be a reason why footage from tightly edited wildlife films has not been used in academic studies of animal behavior.

Email Megan Gannon or follow her @meganigannon. Follow LiveScience on Twitter @livescience. We're also on Facebook & Google+. Original article on Live Science.

Aphids may not be able to fly, but they can fall pretty well: Like defenestrated cats, the common insects usually land upright, to paraphrase a new study.

The study, published yesterday (Feb. 4) in the journal Current Biology, found that a common insect called pea aphids land upright 95 percent of the time after falling off a leaf. Pea aphids, which live off the sap of plants, don't possess any specialized appendages to help them glide or fall, unlike certain insects. So how do they do it?

 In the study, aphids were made to let go of a leaf and freefall when researchers placed aphid-eating ladybugs nearby. The researchers then filmed the falling aphids and analyzed the footage, creating a mathematical model to explain how these sap-swilling insects accomplish this feat.

"What puzzled us was that the aphids did not seem to do much in order to right themselves," Gal Ribak, study co-author and a researcher at the Technion-Israel Institute of Technology, said in a statement. "Their body posture remained fairly constant during the entire fall." [Watch aphids land on their feet.]

The researchers found that it all has to do with the body shape of the aphid, as well as the position of its legs. When the aphids fall, they assume a uniform position, with legs outstretched. The air whistling past the falling insect gradually forces the body into the upright position, where it is most aerodynamically stable, according to the study. This trait, called "static longitudinal stability," is an important design feature of aircrafts that allows them to fly as straight as possible with minimal input from a pilot, keeping the plane from being knocked off course by wind and turbulence. The body shape of pea aphids also possesses this quality, the study found.

This trait was likely selected for by evolution because it allows aphids to escape near-certain death at the jaws of a predator like a ladybug. In the study, more than half of the aphids examined were able to latch on to an angled plant stem with their feet after falling, preventing them from hitting the ground, where their chances of survival would plummet. 

Researchers also dropped dead aphids to see if the positioning of the legs made a difference. It did: Only 52 percent of the dead bugs landed upright. Somehow the aphids know where to orient their legs to maximize their aerodynamic stability, letting gravity carry them to the ground feet-first. 

Reach Douglas Main at dmain@techmedianetwork.com. Follow him on Twitter @Douglas_Main. Follow OurAmazingPlanet on Twitter @OAPlanet. We're also on Facebook and Google+.