Clavinema mariae (Layman, 1930) Yamaguti, 1935

Arai, Hisao P. & Smith, John W., 2016, Guide to the Parasites of Fishes of Canada Part V: Nematoda, Zootaxa 4185 (1), pp. 1-274 : 43-44

Clavinema mariae (Layman, 1930) Yamaguti, 1935

Synonyms: Philometra mariae Layman, 1930 ; Philometra americana Kuitunen-Ekbaum, 1933 ; Philometra sp. of Arai (1967 partim)

Description (after Margolis & Moravec 1987). With characteristics of the genus. Males unknown.

Females: body of gravid and subgravid worms distinctly narrower in posterior half. Cuticle smooth. 23.6–48.5

long; maximum width 0.74–1.90. Gravid worms with larvae in uteri 33.7–48.5 long; maximum width 0.74–1.49.

Head end rounded, with elevated oesophageal bulb region (0.115 long and 0.322 wide) in larger worms. Mouth

papillae not observed. Mouth slightly depressed. Anterior end of oesophagus forming a conspicuous, strongly

muscular bulb, well separated from posterior cylindrical portion of oesophagus; bulb 0.202–0.326–0.235–0.398.

Small, not well demarcated oesophageal gland situated about middle of posterior portion of oesophagus. Entire

oesophagus including bulb 0.958–1.442 long ( Fig. 29 A). Oesophagus opens into intestine through distinct valves.

Nerve ring encircles anterior end of cylindrical portion of oesophagus, 0.281–0.446 from anterior end ( Fig. 29 A).

Intestine dark and broad throughout, attached by short ligament to ventral body wall near posterior end ( Fig. 29 C).

Uterus containing eggs, developing embryos, and larvae. Larvae 0.300–0.426 long and 0.009–0.018 maximum

width. Vulva absent. Uterus reaches anteriorly to posterior end of oesophageal bulb in gravid worms ( Fig. 29 A) or

near it in subgravid worms ( Fig. 29 B). Anterior ovary tubular, well developed. Posterior ovary directed anteriorly,

its distal end pointing backwards. Uterus reaching posteriorly almost to posterior end of intestine. Posterior end of

body rounded, lacking projections or papillae ( Fig. 29 C).

Sites: body cavity, fins, musculature, subcutaneous

Hosts: Anoplarchus purpurescens (2); Cottus asper (9); Gobiesox maeandricus (1, 2); Parophrys vetulus (3, 4, 7); Pholis laeta (5, 6); Pholis ornata (1, 2); Platichthys stellatus (1, 2, 4, 8); Paraplagusia bilineata (1, 2); Xiphister atropurpureus (1, 2)

Distribution: British Columbia, Pacific

Records: 1. Kuitunen-Ekbaum 1933c (PA); 2. Kuitunen-Ekbaum 1938 (PA); 3. Margolis 1952a (PA); 4. Margolis 1952b (PA); 5. Arai 1967a (PA); 6. Arai 1969 (PA); 7. Margolis 1970 (PA); 8. Lewis 1978 (PA); 9. Margolis & Moravec 1987 (BC, PA)

Figures

FIGURE 29. Clavinema mariae (Layman, 1930) Yamaguti, 1935. A. gravid female, anterior end; B. subgravid female, anterior end; C. gravid female, posterior end. (Redrawn from Margolis & Moravec 1987)