Distribution of the Silver Redhorse, Moxostoma Anisurum (Cypriniformes: Catostomidae), In Arkansas (Notes) (Report‪)‬

The silver redhorse Moxostoma anisurum is a medium-sized sucker (adults usually 350-500 mm standard length) that occurs widely, and often is common, in much of the basins of the upper Red River of the North, Great Lakes-St. Lawrence River, upper and mid-central Mississippi River, lowermost Missouri River, and Ohio River, from Alberta to Quebec, south to Alabama, and the eastern and northern Ozarkian uplands (Jenkins, 1980; Page and Burr, 1991). Populations on the South Atlantic slope formerly included in M. anisurum are now recognized as the notchlip redhorse Moxostoma collapsum (Nelson et al., 2004), which is common and generally distributed in major drainages from the Roanoke River in Virginia to the Altamaha River of Georgia. The silver redhorse typically is found in silty to firm-bottomed pools and runs of small to large rivers, natural lakes, and impoundments (Scott and Crossman, 1973). Adjacent to Arkansas, records are fairly numerous in upland provinces above the Coastal Plain, including Tennessee (Etnier and Starnes, 1994) and Missouri (Pflieger, 1997). However, the southwestern extent of the range in the Ozarkian faunal region of Missouri is distributionally peculiar (Miller and Robison, 2004) and the fish is localized or rare in Arkansas. At the time of the publication of Robison and Buchanan (1988), only 12 confirmed specimens of M. anisurum had been collected in Arkansas (Table 1), all from the White River drainage: the White River at Batesville (1969, 1971) and the Current River in Clay-Randolph counties, based on collections at the University of Louisiana at Monroe (NLU) and Tulane University (TU; Robison and Buchanan, 1988; these authors, reporting 10, were unaware of two uncataloged specimens at the University of Louisiana at Monroe from Batesville identified by REJ). A record in 2003 of [greater than or equal to] 2 ripe adults is from the Buffalo River within 1.6 km of its mouth in the White River (Baxter-Marion counties); identity of the apparently discarded specimens was obvious in photographs examined by REJ. Cashner and Brown (1977) did not report the silver redhorse from surveying the (still) unimpounded Buffalo River during 1965-1972, including repeated sampling, amply by electrofishing from a boat, in three reaches within the lower 13 river-km, and overall at 12 stations; they did capture three other species of Moxostoma (identified at Tulane University by REJ). The Buffalo River was the first National River to be designated in the United States, in 1972, and is protected by the National Park Service; its lower section is a wilderness area (http://www.nps.gov/buff/).