Damselfish form one of the largest families of reef fish inhabiting warm coastal waters. These small oval-bodied fish vary greatly in color and pattern, and they display interesting behavioral characteristics. Most species, especially algae-feeding species, are territorial and aggressive toward intruders, particularly when guarding their nesting sites. They are often seen darting to and from catching food in the passing current. Female damselfish lay their eggs on the substratum and are guarded by the male.
Anemone fish live in symbiosis with large anemones.