Haplonema Ward & Magath, 1917

Arai, Hisao P. & Smith, John W., 2016, Guide to the Parasites of Fishes of Canada Part V: Nematoda, Zootaxa 4185 (1), pp. 1-274 : 171

Haplonema Ward & Magath, 1917

Generic diagnosis (after Arthur & Margolis 1975). Quimperiidae . Medium-sized worms with anterior end bent dorsally: head with four single or double submedian papillae and two lateral amphids; mouth without lips, opening directly into oesophagus; oesophagus muscular throughout, divided at nerve ring level into two sections, the posterior of greater width than anterior; lateral alae and deirids present. Excretory pore anterior or posterior to oesophago-intestinal junction. Males with caudal papillae present or absent; posterior end strongly curved ventrad; 10 or 11 pairs of caudal papillae, five pairs pre-cloacal, one pair ad-cloacal, four or five pairs post-cloacal; one median pre-cloacal papilla present or absent; spicules equal, gubernaculum present. Females with straight posterior end, vulva slightly behind middle of body; amphidelphic; eggs oval, smooth-shelled, unsegmented or two-celled stage in utero .