Occurrence of Sanguinicola occidentalis Van Cleave and Mueller, 1932 in Perca flavescens and Campeloma decisum from a Michigan Creek

Sanguinicola occidentalis (Trematoda: Sanguinicolidae) infected 58 (48%) of 120 yellow perch collected in 1997 and 40 (50%) of 80 yellow perch collect ed in 1998 from Silver Creek in lower Michigan. The mean intensity and mean abundance of this blood fluke were higher in 1998 than in 1997. The fluke was found in the bulbous arteriosus of the perch heart, free in the petri d ishes when the gill filaments were teased apart, and in the body cavity was hings, and 1 individual was associated with an eye. Of the 269 S. occidenta lis examined from perch, none had eggs. Most perch examined and infected we re only 1+ yr in age. Spearman's correlation coefficients between S. occide ntalis intensity and host length in 1997 and 1998 were not significant. An additional 25 yellow perch (0+ yr in age) collected in 1998 were not infect ed. Thirty-seven (33%) of 113 snails (Campeloma decisum) examined in July a nd August 1999 from Silver Creek were infected with S. occidentalis.