LAKE MALAWI CICHLIDS.
Order Perciformes
Family Cichlidae
Subfamily ( Pseudocrenilabrinae )
Genus Petrotilapia.
Endemic to Lake Malawi. The genus name comes from the word petro (rock) because in nature these fish can always be found scraping algae from the surface of underwater rocks. Representatives of the genus, ranging in size from 15 to 20 cm, are the largest members of the “Mbuna” group. The structure of the teeth and mouth are the most striking distinguishing characteristics of this genus. The appearance of the mouth, tooth structure, and their size clearly distinguish representatives of this genus among other cichlids of the “Mbuna” group. All fish of these species are quite pugnacious, and therefore, already at the time of purchase, they should be selected so that there is some harmony in the aquarium community.
Intraspecific aggression is strong; other varieties are generally ignored. Territory size is variable, but usually quite large. Typical algae eaters that consume vegetation and microorganisms from the surface of rocks. All members of this genus are omnivorous and unusually voracious. When kept in an aquarium, the fish must be provided with a sufficient amount of coarse plant food and animal-based foods should be avoided. Due to their size and aggressiveness, they are difficult to consider as a standard aquarium fish, but in tanks of 500 liters or more, some species can be kept quite successfully.
— Petrotilapia microgalana [Ruffing, Lambert & Stauffer, 2006]. (English — Nkhata Orange, Small Blue). Lake Malawi. 15-18 cm. Males are grayish-blue with transverse stripes. A dark submarginal stripe is present on the dorsal fin. Full coloration is acquired in adulthood. Females are light beige with 5-7 brown vertical stripes on the flank. Juveniles are bright yellow. They have a bad reputation due to their large size and significant aggressiveness. Set up the aquarium with plenty of rocks and hiding places. It is possible to keep them with other Mbuna and even with Tropheus and Petrochromis species. Weekly water changes and adequate filtration are mandatory. Algae eaters.
— Petrotilapia tridentiger [Trewavas, 1935]. Synonym: Jodotropheus declivitas. Lake Malawi. Up to 25 cm, in an aquarium 15-20 cm. Lips are very prominent — thick. The main distinguishing feature of these fish is the presence of a peculiar rasp on the jaws in the form of numerous small tricuspid teeth, which creates the impression that they cannot close their mouths. In the lake, Petrotilapia inhabit the shallowest rocky biotopes, where algae grow abundantly, forming the basis of their diet.
Adult males range from gray-blue to lilac-purple, with orange-yellow streaks on the fins and dark stripes across the body. Females are brownish-yellow with transverse hatching. All the charm lies in the coloration of the fins. Greenish-blue, with orange-red ray streaks, they are densely dotted with orange spots — egg-guides (at the ends of the anal and dorsal fins). Juveniles are brownish with vertical stripes. A golden form is known.
The character of Petrotilapia cannot be called angelic, but they do not practice special aggressiveness or prolonged pursuit of their victims. Intraspecific aggression is strong, while other varieties are generally ignored. Territory size is variable, but usually quite large. Due to their size and aggressiveness, they are difficult to consider as a standard aquarium fish, but in tanks of 500 liters or more, some species can be kept quite successfully. Typical algae eaters that consume vegetation and microorganisms from the surface of rocks, which is certainly helped by the structure of their teeth and jaws.
The multi-row rasp of triangular teeth indicates this fish’s preference for various types of Aufwuchs, although it does not disdain free-swimming algae and soft aquatic vegetation. These fish “scrape” stones and shelters, positioning themselves at a right angle to the substrate. Plankton also forms part of the natural diet of these fish. Omnivorous and unusually voracious. When kept in an aquarium, the fish must be provided with a sufficient amount of coarse plant food and animal-based foods should be avoided. Aeration, filtration, and water changes are mandatory. They reach maturity at 8-12 months. Males are polygamous. The female incubates eggs in her mouth. dH 8-20°; pH 7.2-8.5; T 23-26°C.
Placidochromis electra, johnstoni, milomo, phenochilus.
Otopharynx lithobates, Otopharynx tetraspilus, Otopharynx tetrastigma. 
