The fish of the genus Petrotilapia, contain the largest mbuna in Lake Malawi. The fish have mainly tricuspid teeth, that they use to comb through the aufwuchs, pulling off diatomous algae, microorganisms, and loose particles. Plankton is also eaten by Petrotilapia. Territorial males will protect are area that varies between 7 to 20 meters squared against conspecifics, though heterospecifics are mostly ignored. Males of this Petrotilapia typically lives in depths between 10 to 15 meters. Males are sky blue with yellow patterns in the unpaired fins. Females found somewhat shallower, are grey/brown with a melanistic chessboard like pattern to a striking yellow colour, depending on their mood.