The genetics of mate preferences in hybrids between two young and sympatric Lake Victoria cichlid species

The genetic architecture of mate preferences are likely to affect significant evolutionary processes, including speciation and hybridisation. Here, we investigate laboratory hybrids
between a pair of sympatric Lake Victoria cichlid fish species that appear to have recently
evolved from a hybrid population between in similar predecessor species. The species
demonstrate strong assortative mating in the lab associated with divergent male breeding
colouration (red dorsum vs blue). We show in a common garden experiment, using DNA based paternity testing, that the strong female mate preferences among males of the two
species are fully recovered in a large fraction of their F2 hybrid generation. Individual hybrid females often demonstrated consistent preferences in multiple mate choice trials (≥5) across a year or more. This result suggests that female mate preference is influenced by relatively few major genes or genomic regions. These preferences were not changed by experience of a successful spawning event with a male of the non-preferred species in a no-choice single-male trial. We found no evidence for imprinting in the F2 hybrids, although the F1 hybrid females may have been imprinted on their mothers. We discuss this nearly Mendelian inheritance of consistent innate mate preferences in the context of speciation theory.