Does male-mating attack in the herbivorous cichlid,Petrochromis polyodon,facilitate the coexistence of congeners?

Abstract– Coexistence through male-mating attack in 3 herbivorous cichlids, Petrochromis polyodon, P. trewavasae and P. famula , was investigated on a shallow rock substratum in Lake Tdnganyika, Africa. All 3 species maintained individual feeding territories that rarely overlapped and were defended against both conspecifics and congenerics. All 3 species took similar foods from rock surfaces. Larger fish were dominant over smaller territorial neighbours irrespective of species. Male P. polyodon , the largest and most aggressive fish, attacked conspecific males far beyond their feeding territories in terms of mating tactics. Removal experiments suggested that such attacks result in male P. polyodon territories being separate. The space between P. polyodon feeding territories can be occupied by congeneric fishes.