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 Families of the Order TRICHINELLIDA 1 Digestive tract complete; anus present; vulva near end of oesophagus........................................... 2 - Digestive tract incomplete; anus absent; intestine dilated into sac or modified to form trophosome; vulva near nerve ring.. 3 2 Spicule and spicular sheath present; stichocytes regularly aligned throughout length of oesophagus........... Capillariidae - Spicule and spicular sheath absent or vestigial; stichocytes irregularly aligned in posterior region of oesophagus................................................................................................ Trichosomoididae 3 Female body divided into thin, anterior region and posterior globular region; stichocytes unicellular; spicule present, spicular sheath poorly developed..................................................................... Cystoopsidae