Studies on the ecology of the papillose allocreadiid trematodes of the yellow perch in Algonquin Park, Ontario

Abstract

Distribution and abundance of adult worms of Bunodera sacculata, Bunodera luciopercae, and Crepidostomum cooperi were examined. Bunodera species were restricted to perch, were found in fish from both deep and shallow water, but were more common in large rather than small lakes. Infection was independent of sex of perch for all three flukes. Bunodera luciopercae, and to a lesser extent B. sacculata, increased in incidence with increase in length and age of perch, but C. cooperi did not. Incidence of Bunodera species declined in summer; C. cooperi incidence did not. It was experimentally determined that differential sensitivity of adults of all three species to increased temperature was related to seasonal changes in incidence. The microhabitat of juvenile B. luciopercae was the gallbladder, but of B. sacculata and C. cooperi it was the intestine. Adults of C. cooperi were found predominantly in the intestinal ceca, of B. sacculata anterior intestine, and of B. luciopercae posterior intestine. The coexistence of these three closely related species is discussed in terms of the temporal and spatial differences of habitat utilization.