Fish

Sharks: They are the stuff of legend and the stuff of nightmares. But which are the biggest? Here are the top 10.

By Carrie Tatro

Unlike most species on Earth, the male seahorse, rather than the female, does the gestating and delivery. And he does it in his own unique way, a new study found.

By Jesslyn Shields

It's hard to imagine Nemo catching some z's in the Great Barrier Reef. But fish do need rest. Do they sleep like we do?

By Allison Troutner

The elusive hagfish is a master at hiding in holes and crevices, but its main defense is its ability to release a noxious, suffocating and sometimes poisonous slime when attacked.

By Mark Mancini

Porbeagles are related to great whites, but while they're also athletic killers, they're smaller and far less ferocious. And what's with the funny dog name?

By Mark Mancini

Decades before Discovery started its wildly successful Shark Week, Americans were transfixed by stories of shark-infested waters.

By Janet M. Davis

The showy lionfish is a stunning beauty. But this invasive species, which was released into the wild in the 1980s, is wreaking havoc on delicate reef ecosystems worldwide.

By Wendy Bowman

The lemon shark isn't as aggressive as some other sharks and it isn't quite as yellow as its name suggests.

By Katie Carman

This denizen of the frigid deep not only lives a crazy long life, it also can grow up to 24 feet in length and eating its flesh can make humans "shark drunk."

By Katie Carman

Most species of the rarely seen anglerfish live up to a mile beneath the ocean, where the females lure prey with a head-dangling hook appendage and permanently fuse with male suitors. It doesn't get much stranger than that.

By Katie Carman

The swordfish's nose might look crazy weird, but these gladiators of the sea are perfectly outfitted for ocean battle.

By Jesslyn Shields

The snakehead fish can breathe air, double its population in 15 months and has a huge appetite, which is not a good thing for native species.

By Jesslyn Shields

Humuhumunukunukuapua'a, the colorful little fish with the craaaaazy long name, is Hawaii's state fish, but it wasn't always.

By Jesslyn Shields

The basking shark, an endangered species, may look like a fearsome predator, but is actually a filter-feeder, gathering zooplankton and other tiny animals, such as shrimp, in bulk as it roams the seas with a wide open mouth.

By Mark Mancini

Piranhas are some of the most feared fish in the world, but is their reputation for ferocity a bit overblown?

By Jesslyn Shields

They're swimming in water all day so how could they ever get thirsty? The answer might surprise you.

By Nathan Chandler

A Texas man caught an alligator gar estimated to be over 300 pounds in May 2022. The alligator gar is sometimes referred to as a "living fossil" and, while it may look threatening, it's harmless to anything larger than itself.

By Michelle Konstantinovsky

The colorful superstars of backyard water gardens are actually ornamental varietals of domesticated carp.

By Michelle Konstantinovsky

It's one of the gentle giants of the sea. It loves sunbathing, dining on crabs and taking deep dives to the ocean floor.

By Mark Mancini

The blobfish is actually pretty average looking in its normal habitat, but becomes a blob when it transitions from the pressure at depth to the water's surface.

By Jesslyn Shields

The cleaner wrasse fish passed the mirror test, which is considered the gold standard for determining self-awareness.

By Michelle Konstantinovsky

Scientific divers from the California Academy of Sciences discover new species of dazzling, neon-colored fish.

By Michelle Konstantinovsky

Commercial fisheries accidentally kill around 100 million — yes, 100 million — sharks each year. The solution to this problem might lie in magnets.

By Jesslyn Shields

A new study seems to suggest that sharks prefer jazz to classical music but the researchers set us straight.

By Alia Hoyt

Cuttlefish can avoid detection by holding a disguise for long periods of time.

By Amanda Onion