Biological Diversity, Ecological Health and Condition of Aquatic Assemblages at National Wildlife Refuges in Southern Indiana, USA Author Simon, Thomas P. Author Morris, Charles C. Author Robb, Joseph R. Author McCoy, William text Biodiversity Data Journal 2015 3 4300 4300 http://dx.doi.org/10.3897/BDJ.3.e4300 journal article http://dx.doi.org/10.3897/BDJ.3.e4300 1314-2828--4300 Orconectes (Rhoadesius) sloanii (Bundy 1876) Distribution Muscatatuck NWR: 5, 6, 10, 13-15, 20 Big Oaks NWR: 5, 7-13, 15, 16, 20, 23, 25, 27, 29, 30, 32 Extensive survey of southwestern Ohio and southeastern Indiana documented the distribution and status of Sloan's crayfish. Closer inspection of St John's (1988) distribution maps show that areas included within the Big Oaks National Wildlife Refuge were represented by only Sloan's crayfish and did not possess the invasive rusty crayfish. Our sampling results found similar results as St. John (1988) . Ecology Sloan's crayfish was collected at 76.5% of the sites in the Big Oaks refuge. Relative abundance averaged 13.6 individuals per site. Mean density of Sloan's crayfish was 0.272 individuals per square meter. Sloan's crayfish was collected at 36.8% of the sites on the Muscatatuck refuge. Relative abundance averaged 9.14 individuals per site. Mean density of Sloan's crayfish was 0.182 individuals per square meter. Conservation Sloan's crayfish ( Orconectes sloanii ) is a species of special interest to US Fish and Wildlife Service, Region 3, which has experienced intensive invasion threats from the rusty crayfish ( Orconectes rusticus Girard 1852). Nutrient impacts are pervasive throughout the Vernon Fork watershed. The Muscatatuck NWR receives runoff drainage through Sandy Branch and Mutton Creek from the City of Seymour, Indiana, and from high density residential land uses. Sloan's crayfish is stable and has a relatively high relative abundance in the Big Oaks and Muscatatuck National Wildlife Refuges. No instances of rusty crayfish were observed in either of the refuges (Table 4).