Energetics, Food Consumption, and Growth of Young Yellow Perch in Oneida Lake, New York

Abstract

Abstract A study to determine the energy content of young (age-0) yellow perch Perca flavescens and their prey, measure metabolism, and relate energy supply and intake to fish growth was conducted in Oneida Lake, New York during the summers of 1975–1977. Growth rates in these years were similar in early summer when young yellow perch were 20 to 50 mm total length and fed almost exclusively on Daphnia pulex but varied widely in late summer when the diet was more diverse. In early summer, food intake averaged 23% of body energy content, young yellow perch assimilated about 68% of the daily ration, and gross efficiency averaged 27%. Comparison of observed growth and energy available for growth calculated from an energy budget indicated estimates of food intake and respiration were reasonable. In years when the D. pulex population collapsed in late summer, young yellow perch shifted to alternate prey and growth declined. Variation in first-year growth, mediated by D. pulex abundance, may determine the contrib...