Summer Feeding Patterns of White Perch, Channel Catfish, and Yellow Perch in the Susquehanna River, Maryland

Abstract

Diel feeding patterns of white perch, yellow perch, and channel catfish were investigated by electroshocking in the lower Susquehanna River during the summer and early fall of 1982 and 1983. On several occasions, ambient densities of benthic and drifting invertebrates were also estimated. Stomach content analysis identified that trichopterans, primarily Cheumatopsyche sp., were the dominant prey item, accounting for at least 40% of diet biomass for each fish species. The amphipod Gammarus fasciatus and chironomids accounted for more than 40% of the yellow perch and channel catfish diets, respectively, but contributed less than 10% to the diet of the other fish species. Diurnal feeding patterns were most apparent for yellow perch, whose feeding was limited almost exclusively to daylight hours. Species composition and relative abundance in the diets of all three fish were more like the composition and abundance of the benthos than of the drift, suggesting that most foraging occurred on the bottom rather than in the water column. The timing and composition of drift did not appear to be related to prey selection by any of these fish species.