A community of rare fish enthusiasts collects endangered species of freshwater fish from lakes and springs around the world, ...

A fish-eat-fish world Male cichlids have a strict, highly visible social hierarchy. Dominant males, which have higher levels of androgen hormones, are larger, more aggressive, and more colorful ...

The cichlid fish of Africa's Great Lakes have formed new species more rapidly than any other group of vertebrates. A new study shows that the ease with which these fish can develop a biological ...