Most of the crustacean inventories at GWMP have focused on amphipods, thus little is known of the other crustacean species that likely occur here. Nine species of amphipod and two species of Caecidotea isopod have been documented from GWMP. One of the amphipods found within GWMP is a species new to science, currently known as Stygobromus sp. 15, until it is given a species epithet. The other eight species of amphipods known from GWMP are Crangonyx shoemakeri, Crangonyx stagnicolous, Crangonyx palustris, Synurella chamberlaini, Gammarus fasciatus, Gammarus minus, Stygobromus pizzinii, and Stygobromus tenuis. A Grass Shrimp (Palaemonetes sp.) is occasionally found in Dyke Marsh. Eighteen species of copepod have been documented within GWMP. Two non-native crayfish, the Red Swamp Crayfish (Procambarus clarkii) and the Virile Crayfish (Orconectes virilis), and three native species, the Devil Crayfish (Cambarus diogenes), Appalachian Brook Crayfish (Cambarus bartonii) and Spiny-checked Crayfish (Orconectes limosus) have been found in streams and wetlands of GWMP.