Color patterns and species recognition in four closely related species of Lake Malawi cichlid

We examined interspecific female mating preferences in four closely related species of cichlid belonging to the Pseudotropheus zebra species complex of Lake Malawi. These species differ in coloration but are similar in other respects, suggesting that male color patterns may be important to female mate choice in species recognition. To test this hypothesis, we presented females from each species with a choice of four males, one of her own species and three others that were each of a different species. We also gave each female a choice between the three heterospecific males only. In all four species, females showed a significant preference for conspecific males in the four-way choice and chose the male with the most similar color pattern to the conspecific male in the three-way choice. These results are discussed with reference to the theory of sexual selection on color patterns as a means of sympatric speciation in cichlids.