Seasonal Incidence of Bythotrephes Cederstroemi in the Diet of Yellow Perch (Ages 0–4) in Little Bay de Noc, Lake Michigan, 1988

Abstract

Although the cladoceran Bythotrephes cederstroemi is reported in the diets of many fish species in Europe and the Great Lakes, no studies address seasonal and quantitative ingestion of B. cederstroemi by fish of various ages and sizes. As part of a larger, ongoing study, stomach contents were examined from 928 yellow perch ( Perca flavescens) collected from Little Bay de Noc, Lake Michigan, June through October, 1988. Diet through August consisted of several taxa considered typical for yellow perch. During September and October, 116 perch (76–213 mm TL) contained 1-110 (mean = 17.4) B. cederstroemi. Rock bass ( Ambloplites rupestris) was the only other fish species found to have ingested B. cederstroemi in Little Bay de Noc. Within individual fall net samples, from 18 to 72% of the yellow perch contained B. cederstroemi. Yellow perch appeared to prefer B. cederstroemi (when available) over other food items that had composed their diet earlier in the year. Age-0 yellow perch consumed B. cederstroemi, but 1- to 4-yr-old fish may have been more efficient in handling the cladoceran. This paper presents base-line data for fish diets during the early expansion of B. cederstroemi in a new environment.