Goldfish possess genetic traits that allow them to swell up to four pounds—the size of a Chihuahua. Experts say that's why ...

The clicking of flattened teeth, discovered by accident, could be “the first documented case of deliberate sound production in sharks,” evolutionary biologist Carolin Nieder, of Woods Hole ...

Something fishy is going on. A pet store goldfish went from “cute to brute” after it was found in a Pennsylvania waterway – with experts now warning against dumping unwanted fish into ponds ...

Releasing a goldfish into the wild can create "an invasive problem that can last decades," the U.S. Fish and Wildlife Service said Brenton Blanchet is a writer-reporter at PEOPLE. He has been ...

Medically reviewed by Jennifer Steinhoff, MD Several treatments are available that can help alleviate jaw tightness and ...

A massive "Megalodon"-like goldfish caught last year in Pennsylvania has led to a new warning from the U.S. Fish and Wildlife Service-- don't let your pet fish loose in the wild. Last month ...