Rare-male mating advantage in Drosophila ananassae

Abstract

Summary - Minority-male mating advantage is a phenomenon whereby genetic variability can be maintained in populations without genetic load at equilibrium. Rare-male mating advantage has been shown to be a widespread phenomenon in Drosophila, although it is seen to be absent in some species. During the present investigation, experiments were conducted to study the mating success of wild type and mutant males at different ratios in the Elens-Wattiaux mating chamber using sepia and cardinal mutant stocks and a wildtype stock in order to detect a rare male effect in D. ananassae. In all the experiments the female-choice technique was employed. Red eye males were tested separately with sepia and cardinal mutants. Experiments were conducted at 9 different ratios. The results show that although both types of males are equally successful in mating when present in the same ratio, they are more successful in mating when in a minority. This advantage disappears when the males become common. Thus the present results provide evidence for the existence of a minority-male mating advantage in D. ananassae. Drosophila ananassae - sepia and cardinal mutants - rare male mating advantage