Seasonal occurrence and community structure of helminth parasites from the eastern American toad, Bufo americanus americanus, from southeastern Wisconsin, U.S.A.

From April to September 1996, 47 American toads, Bufo americanus americanus Holbrook, were collected from Waukesha County, Wisconsin, U.S.A., and examined for helminth parasites. Forty-six (98%) of 47 toads were infected with 1 or more helminth species. The component community consisted of 6 species, 3 direct-life-cycle nematodes, and 3 indirect-life-cycle helminths (2 trematodes and I metacestode). Totals of 2,423 individual nematodes (92%), 45 trematodes (2%), and 155 cestodes (6%) were found, with infracommunities being dominated by skin-penetrating nematodes. A significant correlation existed between wet weight and overall helminth abundance, excluding larval platyhelminths. Helminth populations and communities were seasonally variable but did not show significant differences during the year. However, a number of species showed seasonal variations in location in the host, and these variations were related to recruitment period.