Preliminary Assessment of Populations of Longnose Sucker in the Black Hills, South Dakota and Wyoming

The longnose sucker (Catostomus catostomus) is the most widely distributed sucker in North America, ranging throughout Canada, Alaska, the Great Lakes region, the upper Missouri River system, and extending into eastern Siberia.  Isolated, potentially threatened, populations of longnose suckers in the Black Hills, South Dakota and Wyoming, were noted during stream surveys in 1996, and further study to assess their status and conservation requirements was recommended.  This study surveyed all available literature and unpublished archival records to make a preliminary assessment of the status of longnose suckers in the Black Hills.  Results suggest that: (1) disjunct records of longnose suckers in the Black Hills probably reflect actual geographic distribution rather than sampling deficiencies; (2) distribution of longnose suckers within the Black Hills is strongly related to mean annual discharge of streams; (3) longnose suckers in the Black Hills probably represent Pleistocene glacial relict populations.  More intensive monitoring, research, and conservation actions for longnose sucker populations in the Black Hills are recommended.