Ilyanassa obsoleta, the eastern mudsnail, mostly inhabits the Atlantic Coast of North America. I. obsoleta is also host to several trematode species (Byers, 2008). There are nine known trematode parasites that can infect the mudsnail during larval stages. The goal of the experiment is to identify which parasites infect I. obsoleta in the tidal marsh of Reynold’s Channel in the Southern Bays of Long Island.