Female behaviour prior to additional sperm receipt in the hermaphroditic pond snail Lymnaea stagnalis

In many species, sexual resistance by females can fluctuate depending on different physiological and/or ecological conditions. Based on theory, we decided to test whether the simultaneous hermaphrodite Lymnaea stagnalis becomes more reluctant to mate in the female role after receipt of an ejaculate. We aimed to test whether receipt of an ejaculate affects the expression of recipient behaviours, and whether this can have a potential effect on the outcome of mating interactions. We found that the expression of Crawl-out and Biting behaviours increased significantly in recently inseminated snails. Our data also indicated that an increase in expression of these latter behaviours can have direct effects on the outcome of the mating interactions. These findings suggest that under the influence of recent insemination, this hermaphroditic snail is more reluctant to accept another mating in the female role and may try to actively discourage the mounting snail (sperm donor). Hence, despite the fact that these simultaneous hermaphrodites express both sexual functions, there can still be variation in motivation to mate in either role.