Self-fertilization versus cross-fertilization in the hermaphroditic freshwater snail Bulinus globosus

Abstract

Bulinus globosus is an outcrosser that can self-fertilize when isolated before any copulation has occurred. Self-fertilization depression was estimated during two successive generations. In the first generation, selfing was compared to outcrossing. Within each mating system group, selfing and outcrossing were compared again in the second generation. A striking difference was shown in favor of cross-fertilization for number of eggs laid, survival at birth of young snails and number of snails reaching sexual maturity. The overall self-fertilization depression is 0.920 after two generations of selfing. -from Authors