The Petrochromis is the largest and considered most aggressive herbivores in lake Tangayika and are also found on every rocky shore. Their are numerous speceis of Petrochromis of which include Ephippium, Fasciolatus, Famula, Macrognathus, Orthognathus, Polyodon, and Sp. Red. Petrochromis are also mouthbrooders having sizeable broods of eggs. Petrochromis range in sizes from 6" to 15". They have larger lips than other algae eating species in the Lake and are lined with teeth that can move slightly to accomidate formations of the rocky surfaces for maximum food collection. Keeping these fish in captivity can be challenging. But with patience and attention on adusting their setup they can be kept as easily as any other african cichlid.