Guide to the Parasites of Fishes of Canada Part V: Nematoda Author Arai, Hisao P. Author Smith, John W. text Zootaxa 2016 4185 1 1 274 journal article 10.11646/zootaxa.4185.1.1 11620862-ddcf-4c01-b0d9-32867e03d74b 1175-5326 165530 0D054EDD-9CDC-4D16-A8B2-F1EBBDAD6E09 Key to species of Salvelinema 1 Vagina directed anteriorly from vulva; both poles of mature egg with small polar plug and two thread-like filaments, exceptionally three threads on one pole.............................................................. S. salmonicola - Vagina directed posteriorly from vulva; only one pole of mature egg with small polar plug and two thread–like filaments................................................................................................ S. walkeri