title: Helminth position within the intestine of naturally infected pike (Esox lucius) relative to host stomach contents.
abstract: The positions of 3 cestode species, Triaenophorus crassus Forel, Triaenophorus nodulosus (Pallas), and Proteocephalus pinguis LaRue, and a nematode, Raphidascaris acus (Bloch), within the intestine of naturally infected pike (Esox lucius L.) were evaluated with respect to the presence or absence and state of digestion of host stomach contents. The positions of scolices and strobilae of the cestodes did not vary with respect to host stomach contents. By contrast, R. acus was anterior (near the stomach) when the stomach contained partially digested items, posterior when the stomach was empty, and in an intermediate position when the stomach contained only intact items. These results are interpreted as migration of R. acus, but not T. crassus, T. nodulosus, or P. pinguis, in response to feeding activity of the host. Adult and larval R. acus migrated, but the extent of migration was reduced in hosts harboring T. crassus, more so for larval than adult R. acus.
authors.affiliation: Department of Zoology, University of Manitoba, Canada.
authors.forename: A W
authors.initials: AW
authors.lastname: Shostak
authors.forename: T A
authors.initials: TA
authors.lastname: Dick
mesh_terms: D000818:Animals; D002589:Cestoda / Q000502:physiology; D002590:Cestode Infections / Q000469:parasitology / Q000662:veterinary; D005393:Fish Diseases / Q000469:parasitology*; D005618:Fresh Water; D006373:Helminthiasis / Q000469:parasitology; D006374:Helminthiasis, Animal; D006376:Helminths / Q000502:physiology*; D007422:Intestines / Q000469:parasitology*; D008350:Manitoba; D009348:Nematoda / Q000502:physiology; D009349:Nematode Infections / Q000469:parasitology / Q000662:veterinary; D012487:Salmonidae / Q000469:parasitology*; D012621:Seasons