EFFECTS OF HOST POPULATION FRAGMENTATION AND ISOLATION ON THE GENETIC STRUCTURE OF AN OBLIGATE ENDOPARASIT

Pleurogonius malaclemys is a digenean trematode with a life cycle that begins in Ilyanassa obsoleta as a first and second intermediate host and Malaclemys terrapin as a definitive host. The fluke matures and reproduces within terrapins and, therefore, relies on terrapins for dispersal. Thus, we hypothesized that the genetic structure of flukes would reflect contemporary changes in the connectivity of terrapin populations. Flukes were sampled by dissecting mudsnails collected from eight sites along the eastern United States. Following amplification of the COI mitochondrial marker, 21 haplotypes were identified and a high degree of structure was detected. We propose that this suggests the parasite could serve as a tool for monitoring terrapin populations. This study sets a foundation for the genetic diversity of the fluke, and provides a first step towards developing the species as a proxy for studying terrapin population size, connectivity, and health, which may help conserve both species.