Occurrence of Bunodera sacculata Van Cleave and Mueller, 1932 in Perca flavescens from Silver Creek and Silver Lake,Michigan

Bunodera sacculata (Trematoda: Allocreadiidae) infected 65 (54%) of 120 yellow perch collected in 1997 and 40 (50%) of 80 perch from Silver Creek in 1998. and 17 (30%) of 56 perch in 2000 from Silver Lake in lower Michigan. Gravid B. sacculata occurred in the pyloric ceca and anterior intestine. There were differences in monthly trends (July through August) in prevalences, mean intensities, and mean abundances of B. sacculata in Silver Creek between 1997 and 1998. The mean intensity +/- SD (8.2 +/- 9.1) and mean abundance (4.1 +/- 7.8) of B. sacculata were significantly higher in 1998 than in 1997 and 2000. An additional 20 perch (0+ in age) collected from the creek in July 1998 were all infected and had the highest mean intensity of 21.3 +/- 14.1.