Microhabitat analysis of bass tapeworm, Proteocephalus ambloplitis, infrapopulations in four species of centrarchids from Gull Lake, Michigan (Micropterus dolomieu, Micropterus salmoides, Ambloplites rupestris, Lepomis macrochirus)

A total of 242 centrarchids (54 Micropterus dolomieu, 88 M. salmoides, 50 Ambloplites rupestris and 50 Lepomis macrochirus) were collected from April–September 2000 and April–July 2001 from five locations in Gull Lake, Michigan and examined for Proteocephalus ambloplitis. The overall prevalence of P. ambloplitis in smallmouth and largemouth bass was 100%. The number of P. ambloplitis, from each microhabitat in the fish host, was compared between females and males of the same species and females and males of different species. Proteocephalus ambloplitis had a significantly higher overall mean intensity ±SD (72.5 ± 44.8) and a higher mean intensity in the ovaries (34 ± 18.9) of smallmouth bass when compared to largemouth bass. In smallmouth bass the gonads were most heavily infected and in largemouth bass the liver and mesentery were the most infected organs. Rock bass and bluegill were examined to investigate their role in the transmission of P. ambloplitis to the definitive host. Based upon the dietary composition of the smallmouth and largemouth bass, other second intermediate hosts may also be involved in the transmission of P. ambloplitis. Proteocephalus ambloplitis may be contributing to a reduction in the reproductive potential of smallmouth bass from Gull Lake, Michigan.