Haplonema immutatum 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 : 173

Haplonema immutatum Ward & Magath, 1917

Description (after Arthur & Margolis 1975). With characteristics of the genus.

Males: 11.82–15.50 (10.40–11.64) long; maximum width 0.21–0.27 (0.25–0.28). Cuticle striated. Head with four submedian single papillae and two lateral amphids. Lips absent, mouth opening directly into oesophagus, 0.673–0.828 (0.724–0.811) long. Nerve ring 0.301–0.361 (0.304–0.336) from anterior end. Excretory pore slightly anterior to oesophago-intestinal junction. 0.723 in one syntype (0.680–0.689) from anterior end. Lateral alae extending from anterior end to level of 1st pair caudal papillae. Digitate deirids anterior to oesophago-intestinal junction, 0.504–0.616 (0.483–0.525) from anterior end ( Fig. 100 A). Testis origin as in H. hamulatum (see above). Spicules long, slender, about equal: left one 0.584–0.747 (0.740–0.756), right one 0.573–0.712 (0.738–0.758) long. Gubernaculum small, curved ventrally, 0.051–0.054 (0.050–0.054) long. Ten pairs caudal papillae ( Fig. 100 B). Phasmids not observed. Caudal alae absent. Tail 0.164–0.201 (0.195–0.208) long.

Females: 13.29–15.57 (11.69–14.74) long. Head and oesophagus structure and cuticular striations as in males. Oesophagus 0.678–0.805 (0.680–0.856) long. Nerve ring 0.320–0.369 (0.286–0.3740 from anterior end. Excretory pore slightly anterior to oesophago-intestinal junction, 0.515 in one syntype (0.585–0.763) from anterior end. Lateral alae extending from anterior end to slightly anterior to anus. Digitate deirids slightly anterior to oesophagointestinal junction, 0.565–0.577 (0.425–0.569) from anterior end. Vulva in posterior half of body, 8.61–9.81 (7.19– 9.48) from anterior end ( Fig. 100 C). Muscular vagina directed anteriorly, 0.230–0.268 (0.212–0.336) long. Uteri amphidelphic. Eggs 0.052–0.069 x 0.039–0.052 (0.044–0.064 x 0.034–0.045). Tail 0.221–0.297 (0.209–0.253) long. Phasmids distinct, anterior to mid-length of tail.

Site: intestinal lumen

Host: Amia calva

Distribution: Ontario

Records: Bangham & Hunter 1939; Bangham 1955

Figures

FIGURE 100. Haplonema immutatum Ward & Magath, 1917. A. male, anterior end, ventral view; B. male, posterior end, lateral view; C. female, vulvar region, lateral view. (Redrawn from Arthur & Margolis 1975)