Conservation of the Ouachita Creekshell [Villosa arkansasensis (Lea 1852)]: reproduction and host fish suitability

S.E.S. Seagraves¹, J.L. Farris^1,2, J.L. Harris¹, and A.D.. Christian^1,2.¹Department of Biological Sciences, Arkansas State University, State University, Arkansas 72467, ²Environmental Sciences Program, Arkansas State University, State University, Arkansas 72467

The Ouachita creekshell, Villosa arkansasensis, is considered endemic to the Ouachita River drainage and is an Arkansas species of special concern. The objectives of this project were: 1) to determine the period of gravidity for V. arkansasensis, 2) to determine suitable host fish. Female V. arkansasensis were observed to be gravid beginning in October and continuing through August of the following year. Like other Villosa species, V. arkansasensis was assumed to be bradytictic (long term brooders), becoming gravid in late summer, early fall and releasing glochidia in late spring, early summer. Host fish suitability trials for the Saline River resulted in two suitable host fish, shadow bass (Ambloplites ariommus) and Creole darter (Etheostoma collettei) out of 20 total fish species tested. The most successful suitable host fish was determined to be the shadow bass with 15 of 20 total transformations. Continued monitoring for gravid females will be conducted through 2006 and a host suitability trial for the Ouachita River will be performed in spring 2006. This study can hopefully contribute to better management of this species by determining if distribution and abundance of suitable host fish is of ecological significance to V. arkansasensis.