Growth Rates of the Asiatic Clam, Corbicula fluminea (Müller), in the Kanawha River, West Virginia

Abstract

This study was designed to assess growth rates of Corbicula fluminea under summer and winter conditions. A total of 80 small C. fluminea individuals were segregated into three shell length classes based on initial shell length. Thirty clams were assigned to Class I (<10 mm); 25 to Class II (10 to 11.9 mm); and 25 to Class III (12 to 14 mm), and placed in separate cages in the Kanawha River at Marmet, West Virginia, for a 12 week period (16 July thru 7 October 1983) when mean water temperature was 26.6°C. 'Warm water' growth rates (length/weight) were: Class I, 0.95 mm/week and 0.27 gm/week; Class II, 0.86 mm/week and 0.29 gm/week; Class III, 0.80 mm/week and 0.30 gm/week. An additional 78 clams were assigned to the same shell length classes and maintained in the Kanawha River for a 12 week period (11 October 1983 through 3 January 1984) when mean water temperature was 10.3°C. Thirty-three clams were assigned to Class I; 30 to Class II; and 15 to Class III. 'Cold water' growth rates were: Class I, 0.09 mm/week and 0.009 gm/week; Class II, 0.08 mm/week and 0.013 gm/week. Class III clams were destroyed by a predator. Summer growth rates were approximately 10.7 times higher than winter growth rates based on length and 22-32 times higher based on weight. In addition, smaller clams had higher growth rates than larger clams.