Diet, Growth, and Potential Competitive Interactions between Age-0 White Perch and Yellow Perch in Oneida Lake, New York

Abstract

Abstract Diet and growth of age-0 white perch Morone americana and age-0 yellow perch Perca flavescens were compared during July–October 1980 and 1987. Both fish species fed on Daphnia pulex in 1980 and growth was rapid; prey biomass per gram of fish was 2–12 times higher for white perch than for yellow perch. In 1987, white perch consumed up to three times more prey biomass than yellow perch, but the subsequent disappearance of D. pulex caused both fish species to switch to macroinvertebrates and growth of both species declined. Between 1977 and 1987, mean weights and specific growth rates of white perch exceeded yellow perch by October in all years, and weights of white perch were closely tied to the density of D. pulex in late summer–early fall (Spearman's rank correlation = 0.58, P = 0.07). Diet overlap for age-0 white and yellow perch was high when D. pulex was present, and the potential for interspecific competition was greatest when these fish were similar in length. Because of a prolonged spawning...