Ecology of metazoan parasites infecting Catostomus spp. (Catostomidae) from southwestern Lake Superior

Ecology of the parasite fauna of two abundant nongame fish species, Catostomus catostomus (longnose sucker) and Catostomus commersoni (white sucker), from southwestern Lake Superior was examined. White sucker harbored a total of 17 parasite species compared with 8 species in longnose sucker. Echinorhynchus salmonis and Neoechinorhynchus crassus were the most abundant helminths in both sucker species. The only parasitic copepod found in this study, Ergasilus nerkae, was more prevalent in longnose sucker. In white sucker, Glaridacris catostomi, Capillaria catostomi, Ergasilus nerkae, Allocreadium lobatum, and Isoglaridacris bulbocirrus showed fluctuations in prevalence on a seasonal basis. Several helminth species showed a high degree of microhabitat overlap in the gut (e.g., A. lobatum, G. catostomi, and Echinorhynchus salmonis). Helminths that exhibited a higher mean intensity in certain sections of the intestinal tract included I. bulbocirrus in the anterior portion of the gut and Capillaria catostomi in the posterior region of the gut.