Effects of Copulation Duration on Fertility and Sexual Receptivity of Females in Drosophila elegans

Abstract

Abstract In Drosophila elegans, copulation duration is shorter in the brown morph (about 11 min) than in the black morph (25–35 min). In this study, it appeared that sperm transfer also occurred at an earlier stage of copulation in the brown morph than in the black morph and both sexes were responsible for the control of sperm transfer. In the HK (brown morph) strain, number of eggs produced per female decreased to some extent when copulation was interrupted 3 min after the start of copulation. In the OH (black morph) strain, the rate of sperm transfer was low when copulation was interrupted 3 or 5 min after the start of copulation. Thus, shortened (3–5 min) copulation was disadvantageous in this species. However, adaptive significance of prolonged (>10 min) copulation of the black morph was not apparent in the present experiments. Females of the HK strain recovered receptivity earlier than those of the OH strain irrespective of male-type in the previous mating: i.e., the former will mate more times in th...