A QUANTITATIVE STUDY OF INSEMINATION AND GAMETE EFFICIENCY IN DIFFERENT SPECIES OF THE RHABDITIS-STRONGYLOIDES GROUP (NEMATODA)

Aspects of sperm transfer and reproduction were quantified in 5 species of the Rhabditis strongyloides group. Adult virgin males and females were given a single opportunity to copulate. Insemination was more efficient in R. strongyloides, R. punctata and R. nidicolis than in R. orbitalis and R. cutanea. The number of spermatozoa emitted by males during copulation greatly exceeded the number of eggs subsequently laid by the females. Most of the eggs hatched successfully. The females, therefore, employed their gametes more efficiently than the males. Loss of spermatozoa into the surrounding medium, both during and after copulation, was observed in all species.