Food Habits and Distribution of the Fishes of Tuckahoe Creek, Virginia, with Special Emphasis on the Bluegill, Lepomis m. macrochirus Rafinesque

Abstract

The food habits (1,773 individuals) and the distribution (2,056 individuals) of 9 families, 26 genera, and 32 species of fishes, were determined for Tuckahoe Creek, a lower piedmont tributary of the James River, Virginia. These species represent 41% of the freshwater fishes known for the entire river basin. Five species accounted for 69% of the col- lection: Etheostoma nigrum (20%), Lepomis macrochirus (18%), Hybopsis leptocephala (15%), Notropis cornutus (11%), and Aphredoderus sayanus (5%). Within the upper two- thirds of the creek there was a trend for the number of species to increase in a downstream direction. Stomach contents of 273 L. macrochirus were mainly insects (65%) and crustaceans (29%). Tendipedids and copepods were particularly important food items although the bluegill consumed a wide variety of animal forms. The selection was a probable reflection of the general availability of potential food. Young fish (0 and 1 age-groups) fed more often on microcrustaceans and dipteran larvae while older fish consumed a higher percentage of coleopterans and hymenopterans. Analysis of stomach contents of other centrarchids showed significant differences. Hemip- terans dominated the diet of Centrarchus macropterus and were important food items for Chaenobryttus gulosus. Entomostracans formed the bulk of the diet of Enneacanthus gloriosus and decapods were eaten primarily by C. gulosus. The largest percentage of coleopterans was taken by Lepomis auritus. The cyprinids were represented by all types of feeders. Notropis cornutus was a true omni- vore (feeding equally on plant and animal matter) and H. leptocephala selected a diet pri- marily of plant material. Dipteran larvae dominated the diet of the percid, E. nigrum (78% of total items) and the pirate perch, A. sayanus (53%). Gambusia affinis fed mainly on Hemiptera (34%). The catostomids consumed predominantly microscopic plants. Specimens of Esox niger less than 74 mm SL ate insects more often (48% as opposed to 16% in larger fish), whereas larger