Female remating in Drosophila ananassae: Evidence for sperm displacement and greater productivity after remating

In Drosophila ananassae, female remating with respect to productivity and s perm displacement was studied by employing different mutant strains and a w ild type strain. In all the experiments, the continuous confinement techniq ue was used. The comparison of productivity between once-mated (control) an d remated females reveals that the productivity of remated females is signi ficantly higher than that of once-mated ones in all the crosses. The P2' va lues (the proportion of second male progeny produced after remating) were c alculated to test sperm displacement in each cross of remated females. In a ll the crosses, high P2' values (0.91-0.94) were found which indicate sperm precedence of second male to mate suggesting the existence of sperm displa cement in D. ananassae. Furthermore, female productivity is increased after remating in D. ananassae.