Overlapping territories of Pseudosimochromis curvifrons males and other herbivorous cichlid fishes in Lake Tanganyika

Abstract Males of the herbivorous cichlid fish Pseudosimochromis curvifrons established mating territories 3–10 m in diameter, which included both spawning and feeding sites. Territorial males attacked conspecific males and also other species. Only conspecific males were chased out of the territories. Territorial males attacked other species at the spawning sites while courting or waiting for females and at other sites in their territories while patrolling and foraging. Attacks against herbivorous species were more frequent than against non‐herbivores since herbivores were much more abundant. Territories of four abundant herbivorous cichlids largely overlapped the territories of P. curvifrons males. Symbiotic relationships were not detected between the species. Instead, they were aggressive towards each other but coexisted by segregating feeding sites in the overlapping areas. The aggressive coexistence of P. curvifrons males with other herbivores may have resulted from the energetic costs of defending their relatively large territories against all food competitors. Interspecific food‐resource partitioning may also have facilitated the coexistence.