Protozoan and Metazoan Parasites of Fishes from the Headwaters of the Parsnip and McGregor Rivers, British Columbia: A Study of Possible Parasite Transfaunations

Abstract

Results are presented of a study to determine the possible extent of parasite transfaunation across the Continental Divide as a result of a proposed water diversion in northeastern British Columbia. Fish populations in the headwater areas of the McGregor River (Pacific drainage) and of the Parsnip River (Arctic drainage) were sampled during August–November 1976 and during June–September 1977. Eighty-eight species or higher taxonomic groups of parasites were recovered from 1489 host specimens, representing 13 genera and 20 species of fishes. Eimeria cotti from Cottus cognatus and Rhabdochona zacconis from Catostomus macrocheilus have not been previously recorded from North America. New Canadian records are Chloromyxum granulosum, C. montschadskii, Leptotheca sp., Myxidium macrocheili, Myxobolus aureatus, M. microthecum, Neomyxobolus ophiocephalus, Unicauda crassicauda, and Wardia sp. Twenty-six parasites show disjunct distributions in the study area. Three forms (Ceratomyxa shasta, Cryptobia salmositica, and Haemogregarina irkalukpiki) are identified as posing the greatest threat to the fisheries resources of the immediate area and also to the downstream areas. Based in part on these studies, the British Columbia Hydro and Power Authority, in a public announcement, suspended engineering studies of the proposed diversion.