TL;DR: Today tilapia is used as a common name for a large number of species within the cichlid tribe Tilapiini particularly the species in the three genera Tilapia, Sarotherodon and Oreochromis, especially the larger species most commonly caught in wild fisheries or those used in aquaculture.
Abstract: Today tilapia is used as a common name for a large number of species within the cichlid tribe Tilapiini particularly the species in the three genera Tilapia, Sarotherodon and Oreochromis, especially the larger species most commonly caught in wild fisheries or those used in aquaculture. Trewavas (1983), in her major monograph, loosely defined the tribe Tilapiini as an African and Levantine assemblage which included the following genera: Tilapia, Sarotherodon, Oreochromis, Danakilia, Iranocichla, Tristramella, Pelmatochromis, Pterochromis, the endemic genera of Barombi Mbo in Cameroon (Konia, Myaka, Punga, Stomatepia), and some specialized genera from the rapids (Steatocranus, Gobiocichla). However, Stiassny (1991) puts forward a more restrictive grouping based on morphology of the lower pharyngeal jaw and believes that Trewavas’s inclusion of Pelmatochromis, Pterochromis, Steatocranus and Gobiocichla in this grouping is premature, but she concedes that they may be included in the future. The tilapiines are distinguished from the other great African assemblage the Haplochromini by the structure of the apophysis on the base of the skull for the articulation of the upper pharyngeal bones. In tilapiines the facets are formed from the parasphenoid alone whereas in the Haplochromini the basioccipital can form up to one half of each facet (Trewavas, 1983).
TL;DR: Six of the Barombi cichlids (Stomatepia mariae, S. pindu, Konia eisentrauti, Pungu maclareni, Sarotherodon lohbergeri, and S. linnellii) kleptoparasite freshwater crabsPotamon africanus.
Abstract: Although kleptoparasitism, or food-stealing, is common in birds and some carnivorous mammals, reported instances are exceedingly rare in fishes. We studied the behaviour and ecology of the 11 endemic tilapiine cichlids of Lake Barombi Mbo, Cameroon, West Africa. Here we report that six of the Barombi cichlids (Stomatepia mariae, S. pindu, Konia eisentrauti, Pungu maclareni, Sarotherodon lohbergeri, andS. linnellii) kleptoparasitize freshwater crabsPotamon africanus.
TL;DR: The results suggest the evolutionary stability of chromosomal set; therefore, the large-scale chromosomal rearrangements seem to be unlikely associated with the sympatric speciation in Barombi Mbo.
Abstract: Cichlid fishes are the subject of scientific interest because of their rapid adaptive radiation, resulting in extensive ecological and taxonomic diversity. In this study, we examined 11 morphologically distinct cichlid species endemic to Barombi Mbo, the largest crater lake in western Cameroon, namely Konia eisentrauti, Konia dikume, Myaka myaka, Pungu maclareni, Sarotherodon steinbachi, Sarotherodon lohbergeri, Sarotherodon linnellii, Sarotherodon caroli, Stomatepia mariae, Stomatepia pindu, and Stomatepia mongo. These species supposedly evolved via sympatric ecological speciation from a common ancestor, which colonized the lake no earlier than one million years ago. Here we present the first comparative cytogenetic analysis of cichlid species from Barombi Mbo Lake using both conventional (Giemsa staining, C-banding, and CMA3/DAPI staining) and molecular (fluorescence in situ hybridization with telomeric, 5S, and 28S rDNA probes) methods. We observed stability on both macro and micro-chromosomal levels. The diploid chromosome number was 2n = 44, and the karyotype was invariably composed of three pairs of meta/submetacentric and 19 pairs of subtelo/acrocentric chromosomes in all analysed species, with the same numbers of rDNA clusters and distribution of heterochromatin. The results suggest the evolutionary stability of chromosomal set; therefore, the large-scale chromosomal rearrangements seem to be unlikely associated with the sympatric speciation in Barombi Mbo.