A direct assay of female choice in cichlids: all the eggs in one basket

A novel testing apparatus is presented which affords the researcher maximum control over the testing environment, but allows for the scoring of actual spawning events. Female Metriaclima zebra and Metriaclima benetos chose the appropriate conspecific mate in every mating trial performed. This apparatus provides support for a critical assumption of many cichlid speciation models: that female cichlids use visual cues to recognize conspecifics. These results demonstrate that females are able to identify conspecific mates using only visual cues, and provide further support for the importance of sexual selection in the speciation of these fishes.