Far from its home in Indonesia, a brightly colored creature moved around in an aquarium. Scientists peered into the tank, studying their pet-turned-specimen — and discovered it was a new species.

The fish weighed 608 pounds, which is also about the same size as an adult male grizzly bear. It garnered the second highest bid at the Toyosu Market since records began in 1999 ...

In rare video footage, a male whale shark has been spotted biting at his female partner during courtship. Before now, we knew ...

The largest fish in the world is kinkier than we first thought, rare footage reveals ...

Killifish, or egg-laying toothcarps, are known for their ecological adaptability and species diversity. Two families of ...

The ocean giants are the largest fish in the world, but their everyday lives and behaviors in the wild are elusive and ...