Growth Rates of the Freshwater Mussel, Anodonta imbecillis Say 1829, in Five West Virginia Wildlife Station Ponds

Abstract

Growth rates of a thin-shelled, freshwater bivalve mollusc, Anodonta imbe- cillis Say 1829, were studied for 3 yr (May 1984 through June 1987). A total of 487 A. imbecillis individuals were collected from five ponds at the McClintic Wildlife Station (Mason County, West Virginia). Mussels were measured for initial shell length, numbered and replaced in their respective ponds. Summer growth was determined from the recovery of 139 individuals, and annual growth was calculated for 81 recovered mussels. Increase in shell length was inversely correlated with initial shell length (r-values of -0.827 and -0.851 for summer and annual increases, respectively). A 10-yr length-age growth curve, based on annual data, was calculated for this mussel species. Growth is rapid over the 1st 4 yr; after the 4th yr, increases in shell length are slight. One of the study ponds (Pond 12) was contaminated with waterborne nitroaromatic residues. Growth of mussels from this pond was noticeably lower than that of mussels in noncontaminated ponds.