A shadowy shape is visible in the distance, just under the surface of the ocean. The shadow swims closer, revealing itself to be a shark—an incredibly massive shark. Weighing as much …

Fish are vertebrates (vertebrates have backbones) that live in water. They breathe using special organs called gills.

Meet the real "Nemo," the colorful clownfish. Find out how these fish can reproduce even though all their young are born male.

Pufferfish can inflate into a ball shape to evade predators. Also known as blowfish, these clumsy swimmers fill their elastic stomachs with huge amounts of water (and sometimes air) and blow …

How to be a smart fish eater.Many kids turn up their noses at the thought of eating fish because, well, it can smell “fishy.” While it is usually a healthful source of protein in the diet, there may …

Get your arms around the largest fish in the sea—whale sharks weigh in at up to 60 tons. Find out what tiny creatures keep these gentle giants alive.

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A betta fish (Betta splendens) photographed in Lincoln, Nebraska. Also known as Siamese fighting fish, they originally hailed from Southeast Asia but are now popular pets found in …

What is a barracuda? Barracuda have a formidable reputation as ruthless predators—even depicted in Disney Pixar’s Finding Nemo as the merciless villain that kills Nemo’s mother. …

Meet the incredible parrotfish, whose coral-crunching bite can be heard on tropical reefs worldwide. Find out how they change genders to promote a harem lifestyle.