Ichthyofilaria canadensis Appy, Anderson & Khan, 1985

Arai, Hisao P. & Smith, John W., 2016, Guide to the Parasites of Fishes of Canada Part V: Nematoda, Zootaxa 4185 (1), pp. 1-274 : 44-45

Ichthyofilaria canadensis Appy, Anderson & Khan, 1985

Description (after Appy et al. 1985). With characteristics of the genus.

Males unknown.

Holotype (gravid female): 22 long; maximum width 0.275. Anterior part of body narrows abruptly at excretory pore level; anterior end bluntly rounded. Posterior part of body tapers to pointed tip. Mouth opening circular, surrounded by delicate cuticular ring. Four poorly defined median cephalic papillae present. Amphidial pores prominent. Muscular portion of oesophagus 0.275 long, swollen anterior and posterior to nerve ring. Glandular part of oesophagus about 0.100 long, extending slightly into intestine. Oesophageal gland with several nuclei and extending posterior to oesophago-intestinal junction as vermiform appendix . Nerve ring 0.180 and excretory pore 0.295 from anterior end ( Fig. 30 A). Intestine inflated anteriorly, contains fine granular material; posteriorly, intestine reduced to ligament attached to hypodermis 0.303 from posterior end. Anus apparently not patent ( Fig. 30 B). Vulva 14.5 from anterior end; vagina narrow, directed posteriorly before dividing into uteri ( Fig. 30 C). Uteri amphidelphic, didelphic, thin-walled and filled with 1st -stage larvae (microfilarioid in form and ensheathed) and developing embryos. Anterior ovary narrow, poorly developed, and extending to oesophageal region. Posterior ovary well developed, reflexed, and ending in narrow ligament attached to hypodermis adjacent to intestinal ligament ( Fig. 30 B).

Paratypes (15 gravid worms): 19 (8–28) long; maximum width 0.313 (0.127–0.469). Nerve ring 0.185 (0.155– 0.229) and excretory pore 0.330 (0.242–0.447) from anterior end. Total length oesophagus 0.382 (0.263–0.375). Vulva 12.2 (4.6–18.7) from anterior end. Anus 0.320 (0.259–0.389) from posterior end. Sites: body cavity, mesenteries

Hosts: Lycodes lavalaei ; Lycodes vahlii

Distribution: Atlantic

Record: Appy et al. 1985

Figures

FIGURE 30. Ichthyofilaria canadensis Appy, Anderson & Khan, 1985. A. holotype, anterior end, lateral view; B. holotype, posterior end, lateral view; C. paratype, vulva and vagina, lateral view. (Redrawn from Appy et al. 1985)