Relationship of Food Habits to Yellow Perch Growth and Population Structure in South Dakota Lakes

We compared summer yellow perch (Perca flavescens) food habits among a wide range of perch population types in six South Dakota lakes. Chironomids were a major dietary component in all populations with mean relative importance (RI) values ranging from 29 to 55. Corixids were a major diety component for high-quality (large proprtion of fish ≥200 mm TL) yellow perch populations, with mean RI values ranging from 22 to 26. Zooplankters were important sources of prey for yellow perch in low-quality (low proportion of fish ≥200 mm TL) populations, with mean RI values ranging from 35 to 51. The fast growth of yellow perch in high-quality populations was attributable to a diet in which macroinvertebrates, specifically chironomids, amphipods and corixids, were the primary prey. Fish were not a substantial component of yellow perch diets in situations were perch attained large size (≥ 300 mm) and experienced fast growth. A significant negative correlation existed between yellow perch mean back-calculated length at age 3 and the mean RI of zooplankton (r=-0.87, P=0.02). The mean RI of macroinvertebrates was positively correlated with yellow perch growth rates (r=0.86, P=0.03) while there was not a significant correlation between the mean RI of fish and perch growth rates (r=0.66, P=0.16).