Esch, G.; Barger, M.; Fellis, J.: Transmission of Parasitic Helminths: Style, Elegance, Complexity

Traditionall, the field of parasitology has dealt with eukaryotic animals, to the exclusion of viruses, bacteria, fungi, etc., which is the way we will approach our presentation. Our focus will be on certain ecological aspects of the life cycles and life-history strategies employed by digenetic trematodes, a diverse group of platyhelminths that includes some 25,000 described species. More specifically, our interests rest with the nature of host/parasite interactions within molluscan intermediate hosts and the manner in which these interactions, or lack thereof, function in structuring trematode infracommunities within these molluscan intermediate hosts. Literature in this area suggests that predation/competition may be a significant structuring force for infracommunities in certain marine prosobranchs, but not others, and that temporal/spatial factors may be involved as structuring forces in at least some freshwater pulmonates. These, and other, issues will be discussed.