Cheadle Center for Biodiversity and Ecological Restoration

Sexual conflict has the potential to drive evolution of both reproductive behavior and genital morphology. This project investigates evidence for sexual conflict in gential morphology of simultaneous hermaphrodite shoulderband snails, Family Xanthonychidae. Shoulderband snails are a group of land snails which occur in coastal, foothill, mountain, and desert habitats across California. This study uses measurement data from 12 species from across Southern California. It focuses on the role of sexual behaviors in shaping the morphology of reproductive organs, including the length of the penis+epiphallus, vagina, bursa diverticulum, and bursa tract. The research findings will provide insight into the natural selection and evolutionary processes that have driven the development of reproductive organs and gross morphology in California land snails. Consistent with coevolution, male (penis + epiphallus) and female (vagina) length showed a strong and significant positive correlation in the data. A strong positive correlation was also found between spermatophore length (flagellum) and the sperm storage organ (bursa diverticulum). This second finding is consistent with sexual conflict as control over use of a donor’s sperm. In addition,this study adds to knowledge about reproductive evolution in simultaneous hermaphrodites and highlights the importance of genital morphology in understanding the evolution of sexual traits in snails. Further studies are needed to explore the functional significance of these correlations and their implications for reproductive strategies and mating behaviors in snails. This study will contribute to a better understanding of diversification in the Land Snails of Southern California.

Poster presented at URCA student colloquim spring 2023.