Mussels of the Mountain Fork River, Arkansas and Oklahoma

Abstract

We surveyed the freshwater mussel fauna (Bivalvia: Unionidae) of the Mountain Fork River, a major tributary of the Little River in eastern Oklahoma and western Arkansas. We found 22 species of unionids as well as the exotic Asian clam (Corbicula fluminea). Total mussel abundance (mussels found/hour) ranged from 0 to 312 with a mean of 40 +/-84 individuals per site. Mussel species richness per site ranged from 0 to 13, with a mean of 6 (+/- 4). The mussel fauna in the Mountain Fork River is dominated by the Interior Highlands endemic the Ouachita kidneyshell, Ptychobranchus occidentalis, the three-ridge, Amblema plicata, the pistolgrip, Tritogonia verrucosa, the plain pocketbook, Lampsilis cardium, and the pigtoe, Fusconaia flava. Rarer species include the Ouachita endemic mussels, the Ouachita creekshell, Villosa arkansasensis, and the Southern hickorynut, Obovaria jacksoniana.