Researchers have discovered the first fish that warms its body much like mammals and birds. Has this bottom-dwelling anomaly been hiding in its deep, cold water home, evading scientists for years? Not ...

The opah, or moonfish, is kind of like the Rudolph of the fish world. It's not at all like the other reindeer -- um, I mean fish -- but its unique quality makes it incredibly cool. Well, make that ...

It’s one of the most basic biology facts we’re taught in school growing up: Birds and mammals are warm-blooded, while reptiles, amphibians and fish are cold-blooded. But new research is turning this ...

New research has revealed the opah, or moonfish, as the first fully warm-blooded fish that circulates heated blood throughout its body much like mammals and birds, giving it a competitive advantage in ...