Fish color varies based on fish age, spawning season and water conditions (turbid vs. clear, warm vs cold, etc.). For these reasons, fish biologists and ichthyologists rely on meristics, which are ...

A few hundred million years ago, fish fins morphed into the arms and legs of terrestrial animals, according to evolutionary theory. So, you’d think science would know just about everything about them ...

Many fish species evolved parts of their fins into sharp, spiny, needle-like elements -- called fin spines -- that function to protect the fish against predators. Such spines have evolved ...