oa South African Journal of Science - Interochromis, a new genus of the Tanganyikan cichlid fish

Abstract

A new genus, Interochromis, is erected on the basis of morphological and ecological reviews on a cichlid species, Limnotilapia loocki, endemic to Lake Tanganyika. This species is an epilithic algal grazer, not browser, feeding mainly on unicellular algae, as in Petrochromis, and also a maternal mouthbrooder incubating larger eggs as in Petrochromis. Its intestinal coiling pattern is of the Petrochromis type and more complicated than that of the browsers. Osteologically, the shapes of the neurocranium, maxilla and suspensorial complex are similar to those of Petrochromis. Its jaw dentition is intermediate between that of grazers and browsers. The outer jaw teeth, except lateral ones, have the bicuspid crown bent linguad well with the slender stalk and are clearly larger than inner teeth, which have the tricuspid crown. L. loocki differs from a congener, L. dardennii. It resembles the grazers, Petrochromis spp., rather than the browsers, Simochromis spp., Pseudosimochromis curvifrons and Tropheus moorii. Though it has been proposed to synonymise the genus Limnotilapia with the genus Simochromis, it seems reasonable that L. loocki should be placed in a distinct new genus.