title: A new opecoelid species (Trematoda: Opecoelidae) from the threespine stickleback Gasterosteus aculeatus L. in California.
abstract: Plagioporus kolipinskii n. sp. (Trematoda: Opecoelidae) is described from the intestine of the threespine stickleback, Gasterosteus aculeatus L., from Lobos Creek, a freshwater stream in Presidio, San Francisco County, California. Plagioporus kolipinskii is morphologically somewhat similar to 4 (P. serotinus , P. angusticollis , P. macrouterinus , and P. shawi []) of the 12 currently recognized North American species of the genus, but can be readily distinguished from all 4 in possessing a much larger acetabulum and a larger ovary relative to the testes. In addition, the new species can be distinguished from P. angusticollis by a smaller cirrus sac; from P. macrouterinus by the elongated shape of its body and reduced extent of its uterus (the uterus of P. macrouterinus extends posteriorly to the intersection of the testes); from P. shawi by a much-shorter cirrus sac (which reaches the ovary in P. shawi), an unlobed ovary (as opposed to a quadrilobed ovary in P. shawi), and fewer eggs that are also larger relative to body size.
authors.affiliation: Division of Natural Science, St. Norbert College, DePere, Wisconsin 54115, USA.
authors.forename: John K
authors.initials: JK
authors.lastname: Tracey
authors.forename: Anindo
authors.initials: A
authors.lastname: Choudhury
authors.forename: Jan Marie
authors.initials: JM
authors.lastname: Cheng
authors.forename: Sibdas
authors.initials: S
authors.lastname: Ghosh
mesh_terms: D000818:Animals; D002140:California; D005393:Fish Diseases / Q000469:parasitology*; D005618:Fresh Water; D007411:Intestinal Diseases, Parasitic / Q000469:parasitology / Q000662:veterinary*; D007422:Intestines / Q000469:parasitology; D023701:Smegmamorpha / Q000469:parasitology*; D014200:Trematoda / Q000033:anatomy & histology / Q000145:classification* / Q000302:isolation & purification; D014201:Trematode Infections / Q000469:parasitology / Q000662:veterinary*