Michigan Department of Natural Resources
Fisheries Research Report No. 2031, 1997
The Importance of Large Benthic Invertebrates to the Diet and Growth
of Yellow Perch in Lake St. Clair, Michigan
Sara Synnestvedt
Abstract.-Yellow perch (Perca flavescens) were collected monthly from Lake St. Clair from May-October, 1993 using a bottom trawl. Data on wet weight, length, age, redworm infestation, somatic tissue dry weight, somatic tissue water content and stomach contents were obtained. Consumption rates were calculated using a bioenergetics model and an algorithm. Wet weights were above the Michigan averages from August-October and growth was much better than perch in Saginaw Bay, Lake Huron, western Lake Erie and some populations in central Lake Erie. Young-of-the-year yellow perch switched to benthic invertebrates in August. Older fish ingested invertebrates, primarily amphipods and Hexagenia sp., in late spring and summer and switched to Orconectes propinquus and fish in the fall. Age 1-2 perch ingested Bythotrephes cederstroemii in September. Age 2-4 perch were much above maintenance rations from July-October. The diet of large invertebrates, especially amphipods and Hexagenia sp., is believed to be the reason for good growth.