Identity of Diphyllobothrium spp. (Cestoda: Diphyllobothriidae) from Sea Lions and People along the Pacific Coast of South America

Authors

Robert L. Rausch, University of WashingtonFollow
Ann M. Adams, United States Food and Drug AdministrationFollow
Leo Margolis, Fisheries Research Board of Canada

Date of this Version

4-2010

Comments

Published in the Journal of Parasitology (April 2010) 96(2): 359-365. Copyright 2010, the American Society of Parasitologists. Used by permission.

Abstract

Host specificity evidently is not expressed by various species of Diphyllobothrium that occur typically in marine mammals, and people become infected occasionally when dietary customs favor ingestion of plerocercoids. This report mainly concerns two species, Diphyllobothrium pacificum and Diphyllobothrium arctocephalinum, for which sea lions (Otariidae) are final hosts. The taxonomic status of those cestodes has not been clearly discernible because of misinterpretation of relationships; complex synonymies have resulted from misidentification(s). Stiles and Hassall in 1899 obtained, but did not describe, cestodes from the northern fur seal (Otariidae; Pribilof Islands). That taxon was subsequently studied by several investigators, with diverse conclusions. The valid designation is D. pacificum (Nybelin, 1931). In 1937, Johnston and Drummond described separately two conspecific cestodes from sea lions near Australia, designated D. arctocephalinum and Diphyllobothrium arctocephali. Both names have been listed incorrectly as synonyms of D. pacificum.