Research Symposium

BIO

Robbyn Dykeman is a first year Environmental Science student at Florida State University. Robbyn plans to go into the entomology field and do research around the world. Currently, however, he is working in the Levitan Lab with Melanie Medina and studiying the mating habits of sea slugs.

The effect of size differences on mating and egg-laying in a simultaneous hermaphrodite: the sea slug Doto chica

Abstract

While numerous studies have examined the effect of body size on mating interactions in simultaneous hermaphroditic animals, those with both male and female sexual functions within a single individual, our understanding of how these animals choose mates and reproduce is less comprehensive compared to species with separate sex animals. This study investigates how size differences between pairs affects mating duration and oviposition in the sea slug Doto chica, a local simultaneous hermaphrodite. In laboratory experiments individuals of varying sizes were paired in experiments with only a single choice given, and mating duration was recorded. Following mating, the number of eggs laid was quantified to assess reproductive investment. Although not significant, our results showed a trend of reduced mating duration with greater size disparities between mates and no significant change in number of eggs laid with increasing size differences. These findings suggest that size differences may not influence reproduction, potentially via transfer of different amounts of sperm based on size, and how different sized individuals may be better at mating, or using energy in different ways. Further research is necessary to determine whether there truly are no patterns arising due to mate choice, or other social aspects like recent mating history, helping us understand more of sexual selection in simultaneous hermaphrodites.

Keywords: Mate choice, hermaphrodites, eggs