Current Distributional Information on Freshwater Mussels (family Unionidae) in Mississippi National Forests
Little is known about the distribution of freshwater mussels in Mississippi national forests. Review of the scant available information revealed that the national forests harbor a diverse mussel fauna of possibly 46 or more species (including confirmed, probable, and potential occurrences). Occurrence of 33 species is confirmed. Because of the geographic, physiographic, and drainage basin diversity of Mississippi national forests, there is considerable variation in mussel communities among the national forests. Three distinct fauna1 groups are represented in Mississippi national forests, each with a characteristic assemblage of species. One species of potential occurrence is a federally endangered species, 1 species of confirmed occurrence is a candidate for listing, and 11 species of confirmed or probable occurrence are considered of special concern by the American Fisheries Society (Williams and others 1993). None of the national forests have been surveyed adequately, and specific population data are almost completely lacking. This review of existing information represents the first of a three-phase program needed to comprehensively evaluate the mussel resources of Mississippi national forests. Phase two involves an exhaustive, qualitative field survey of Mississippi national forests to document precise distribution of species and location of important communities. Phase three consists of a quantitative study of important communities in order to assess reproductive characteristics and viability and to establish baseline density estimates for monitoring of future population trends.