How fish become male or female is far weirder and more varied than the XX-female, XY-male chromosome system of humans. (Though even the human story can get complicated .) ...

Researchers in Colorado have made a startling discovery. Fish, apparently male, are developing female sexual organs. Scientists believe it's the result of too much estrogen in the water and they ...

A gene has been found in male cichlid fish that evolved to lure female fish so that male cichlids can deposit sperm in the females mouths. The gene is associated with egg-like markings on the fins ...