title: Complex interactions among a nematode parasite (Daubaylia potomaca), a commensalistic annelid (Chaetogaster limnaei limnaei), and trematode parasites in a snail host (Helisoma anceps).
abstract: Many biotic interactions can affect the prevalence and intensity of parasite infections in aquatic snails. Historically, these studies have centered on interactions between trematode parasites or between trematodes and other organisms. The present investigation focuses on the nematode parasite Daubaylia potomaca and its interactions with a commensal, Chaetogaster limnaei limnaei , and a variety of trematode species. It was found that the presence of C. l. limnaei indirectly increased the mean intensity of D. potomaca infections, apparently by acting as a restraint for various trematode parasites, particularly the rediae of Echinostoma sp. In turn, Echinostoma sp. rediae adversely affected the mean intensity of D. potomaca by their consumption of both juvenile and adult nematodes present in tissues of the snail. These organisms not only belong to 3 different phyla but occupy distinct trophic levels as well. The complex interactions among these 3 organisms in the snail host provide an excellent example of biotic interactions influencing the infection dynamics of parasites in aquatic snails.
authors.affiliation: Department of Biology, Wake Forest University, Winston-Salem, North Carolina 27106, USA. zimmmr8@wfu.edu
authors.forename: Michael R
authors.initials: MR
authors.lastname: Zimmermann
authors.forename: Kyle E
authors.initials: KE
authors.lastname: Luth
authors.forename: Gerald W
authors.initials: GW
authors.lastname: Esch
mesh_terms: D000465:Algorithms; D000818:Animals; D004449:Echinostoma / Q000502:physiology*; D005618:Fresh Water; D006790:Host-Parasite Interactions; D009348:Nematoda / Q000502:physiology*; D009657:North Carolina; D009835:Oligochaeta / Q000502:physiology*; D011897:Random Allocation; D012908:Snails / Q000469:parasitology*; D014200:Trematoda / Q000502:physiology