Pomacentridae - Damselfish
Many of the over 315 species in this family actively defend territories on reefs, not only against members of the same species but against many other species as well. Some aggressively attack other fish and even scuba divers. The functions of the territories are multiple, but one of the most important appears to be in providing food for the fish. These fish are herbivores and defend their algae gardens. Damesfishes that do not defend garden territories fall mostly into two general categories: shoaling fish that feed on plankton above the reef, and fish that are commensal with anenomes.