Warmer oceans mean fish require more oxygen, but their gills are not growing at the same rate as their metabolism, which is causing their body size to diminish.
Find out everything there is to know about fish and stay updated on the latest news with the comprehensive articles, interactive features and fish pictures at LiveScience.com. Learn more about these fascinating creatures as scientists continue to make amazing discoveries about fish.
A glow-in-the-dark shark that has a mouthful of pointy teeth and an impressively large bulbous nose is also quite small — about the weight of a pineapple, according to a new study.
In the inky darkness of the ocean's abyss swims the world's deepest living superpredator: a fish with a long, eel-like body; the face of a lizard; and a mouth full of sharp teeth.
For a reef fish species, sloppy, slimy lip dribbles serve as a vital defense against its coral prey's venomous stings.
The graceful whale swims by undulating its wide tail up and down, while the shark swims by moving its tail side to side. Why the difference?
When three great white sharks mysteriously washed ashore along the coast of South Africa, researchers weren't sure what to think.
Swallowed fishhooks are a deadly and unexplored threat to freshwater turtles, and a new study is the first to estimate the impact of fishhook deaths on turtle populations.
A previously unknown ghost shark with rabbit-like teeth and a bulky head is making waves in record books; it's the 50th ghost shark species known to science, a new study reported.
Would you like to cross paths with a hairy tarantula from Colombia or a Thai newt that looks like a "Star Trek" Klingon? If the answer is yes, you're in good company.
Next time he's vacationing in Hawaii, President Barack Obama might just bump into his new namesake: a pink, yellow and blue coral-reef fish that researchers have named in the president's honor.
A South American fish with uncannily human-like chompers has been unexpectedly showing up on Michigan anglers' hooks.