Morphology and taxonomy of Salvelinema species (Nematoda: Cystidicolidae), swimbladder parasites of Pacific area salmonids

The morphology of two Salvelinema Trofimenko, 1962 species, S. salmonicola (Ishii, 1916) and S. walkeri (Ekbaum, 1935), swimbladder nematodes of salmonids, was studied in detail, including scanning electron microscopy (SEM), on the basis of newly collected materials from Oncorhynchus masou, O. mykiss and Salvelinus malma from Japan and from Oncorhynchus clarki, O. kisutch and O. nerka from North America (Vancouver Island, B.C., Canada and Gulf of Alaska). Both nematode species proved to be morphologically very similar, differing substantially in the numbers and arrangements of egg filaments. Deirids were described for the first time for Salvelinema. Salvelinema iwana (Fujita, 1928), S. amemasu (Fujita, 1939), S. kosugii (Fujita, 1939), S. ancorhynchi (Fujita, 1939) and S, salvelini (Fujita, 1939) (= S. ishii (Fujita, 1941)) were synonymised with S. salmonicola. Comephoronema Layman, 1933 is re-erected as a valid genus I elated to Salvelinema.