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No1~th Carolina Mussel Atlas <br />~,. •r •-.. r.. <br />I ~ _°~. Spet~ies .~n~ formatr'on and Status <br />:~~~~.,„~.:;..':~,_ IMIt,DLIFE SPECIES & COHSERYATION <br />brook floater Alasmidonta varrcosa (Lamarck, 1819) <br />(interior} <br />(exterior) <br />Please Nate: Red text is defined in the Glossary <br />Page 1 of 2 <br />Description <br />Lamarck described the brook floater in 1819 GC? t0 <br />from the Schuylkill River in Pennsylvania. This .SE'leii <br />species has a fairly small, thin, rhomboidal <br />shaped shell that rarely exceeds 70 mm in <br />length, 40 mrn in height, and 30 mm in width. The conspicuous <br />posterior slope is broad and flat to slightly concave, with numerous <br />short, low corrugations radiating toward the posterior margin at right <br />angles to the growth lines. The periostracum is yellowish or brownish <br />with numerous dark green or black rays. The nacre is glossy, bluish <br />white and grades into a pale orange in the umbo area. The hinge <br />teeth are poorly developed. Each valve has one small thin, triangular <br />pseudocardinal tooth and lateral teeth are lacking. or vestigial. This <br />species has a bright orange foot. <br />Distribution (see map) <br />The brook floater is found in Atlantic Slope river basins from the <br />Savannah River Basin in South Carolina north to the St Lawrence <br />River Basin in Canada. It has also been found in the Greenbrier <br />River (Ohio River Basin) of West Virginia. It is considered more <br />common in the northern park of its range. Distribution by County: <br />Catawba River Basin: Burke Co. (Linville River, Warrior Fork, and <br />Johns River subbasins); Pee Dee River Basin: Surry Co. (Mitchell <br />River Subbasin), Randolph Co. (Caraway Cr. and Little River <br />subbasins), Montgomery Co. (Little River and Barnes Cr. <br />Subbasins); Cape Fear River Basin: Moore Co. (Deep River), <br />Chatham Co. (Rocky River Subbasin}; Neuse River Basin: Orange <br />Co: (Eno River Subbasin) NOTE: All headwater areas that flow into <br />these occupied habitats should receive special management. <br />Habitat Preferences <br />This species inhabits medium size streams and rivers. It prefers <br />clean, swift waters with stable gravel, or sand and gravel substrates. <br />However, individuals found near the mouth of the Linville River in <br />North Carolina were observed in sandy/silty substrate in cracks <br />between boulders along a steep bank, in 1 to 3 feet of water and <br />relatively slow current. <br />Life History <br />The brook floater is a bradytictic breeder. Gravid females have been <br />found from August through May. Identified fish hosts include <br />blacknose dace, golden shiner, longnose dace, margined madtom, <br />pumpkinseed, slimy sculpin and yellow perch (Shultz and Marbain <br />1998) <br />Return to Top of Page <br />Return.to S~ecies_ List <br />llttps//www.nev~rildlif'e.arg/pg07_WildlifeSpeciesCoi~/pg7bl al_S.lltrn' 1 /5/2009 <br />