Fish

One of the largest ancient fish on record, known as Dunkleosteus, was actually half as long, but still super chunky, a new study finds.

Pictures from a submarine dive to the 20,000-foot-deep Kermadec Trench in the South Pacific reveal weirdos from the deep, some of which may be new to science.

Researchers in South Africa have unearthed 360 million-year-old fossils belonging to a newly described voracious fish species that preyed on our ancestors.

Researchers stumbled across a bizarre species of blind cave fish with a mysterious, horn-like structure protruding from its head and a lack of scales or pigmentation.

Jewel damselfish living on coral reefs surrounding rat-infested tropical islands have become less territorial and less aggressive due to a bizarre ecological link between the two species: bird poop.

Mouthbrooding fish under stress may sometimes resort to cannibalism and eat their young. Scientists' discovery of the behavior was "a complete accident."

New research reveals exactly how inbred the Devils Hole pupfish is.

A new study has revealed that a 6,000-pound giant sunfish found dead in the Azores is the heaviest bony fish ever recorded.

An unusual surge in anchovy populations has led to the fish raining down on San Francisco. Here's why.

A 661 pound giant stingray caught in the Mekong River is the largest freshwater fish ever recorded.

For millions of years, megalodon was the top predator in marine ecosystems. Then great whites came along and ruined everything.

A conservation educator caught a record-breaking alligator gar in a bayou near Houston.

Scientists exploring the depths of Monterey Bay unexpectedly encountered a rare and unique species of dragonfish.

A new study has found that, after being misidentified for decades, a stunning rainbow fish is actually a brand-new species.

Hearts have become iconic symbols of Valentine's Day, but when it comes to hearts in the real world, one size doesn't fit all — particularly in the animal kingdom.

Two paddleboarders encountered a colossal sunfish in Laguna Beach, California.

Fishers in the Netherlands caught an enormous, bright-yellow catfish recently. The species is common, but the yellow body may be the result of a genetic disorder.

An angler fishing in Tampa Bay was surprised to reel in an unusual fish that looked just like a flour tortilla.

A 100-pound opah fish, also known as a moonfish, was recently found washed up on a beach in Oregon hundreds of miles from its normal habitat.