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 Capillaria 1 Male tail with large ventro-lateral lobes, and large paired caudal papillae; gravid worms with vulvar appendage; parasitic in marine fishes........................................................................................ 2 - Ventro-lateral lobes on male tail indistinct, and large paired caudal papillae; vulvar appendage absent; parasitic in fresh-water fishes.............................................................................................. 3 2 Spicule relatively short, ca 0.2 long. Pacific Ocean............................... Capillaria ( Procapillaria ) margolisi - Spicule relatively long, ca 1.0– 1.4 in length. Atlantic Ocean......................... Capillaria ( Procapillaria ) gracilis 3 Evaginated spicular sheath spiny proximally only; mature eggs with non-protruding polar plugs................................................................................................ Capillaria ( Capillaroides ) catenata