Sequential male mates to look at sperm utilization patterns in the absence of sperm competition. Unfertilized oocytes are represented by unfilled bars, the solid bars are fertilized eggs laid. Ovulation rates increase comparably after fem-1 hermaphrodites are mated to either spe-9 mutant males, or N2 controls (a). (b) shows results after hermaphrodites previously mated to spe-9 mutant males are re-mated to N2 males. As can be seen, there is an immediate shift towards utilization of the N2 male-derived sperm and the production of progeny. The animals not mated a second time to any males continue to show elevated ovulation rates (as compared to unmated controls), indicating the persistence of sperm for the duration of the experiment.