Reproduction
Physella heterostropha is a monoecious organism meaning that it has both sets of reproductive organs. P. heterostropha can self fertilize but studies done shows that outcrossing is the preferred method of reproduction as it adds genetic diversity among the snails (Wethington 1997). Self-fertilization under some circumstances is preferred due to the fact that copulating is energetically expensive and can interfere with egg-laying and shorten life expectancy (Wethington 1997).
P. heterostropha males are sexually mature at 5.7 weeks and females are mature at 7.3 weeks(Wethington 1997). Self fertility begins approximately at 22 weeks (Wethington 1997). P. heterostropha are widespread due to their high rate of reproduction as they lay up to 50-100 on a weekly basis (Freshwater Gastropods 2011). The eggs laid are soft, crescent shaped masses (Thorp 2011).
