Anguillicola crassus Kuwahara, Niimi & Itagaki, 1974

Synonyms: Anguillicola (Anguillicoloides) crassus (Kuwahara, Niimi & Itagaki, 1974) Moravec & Taraschewski, 1988; Anguillicoloides crassus (Kuwahara, Niimi & Itagaki, 1974) Moravec, 2006

Description (after Moravec 2013). With characteristics of the genus. Body darkly coloured, fusiform, rather plump, both ends tapering. Epicuticle almost smooth. Head end rounded. Mouth aperture circular, surrounded by four large dorso-lateral and ventro-lateral cephalic papillae and two small lateral amphids. Buccal capsule heavily sclerotized, its anterior rim bearing a row of 21 to 28 large circumoral teeth (Fig. 26 A). Oesophagus strongly muscular, expanded posteriorly, with a well developed valvular apparatus. Nerve ring at about one-third oesophagus length from anterior end, and excretory pore near oesophageal-intestinal junction. Intestine dark, distended posteriorly (Fig. 26 B). Three large and one small rectal glands, tail conical, very short (Fig. 26 C,D).

Males: 5.77–23.12 long, 0.34–1.77 maximum width. Buccal capsule 0.021–0.027 long, 0.048–0.063 wide. Oesophagus 0.571–0.843 long, 0.135–0.258 maximum width. Oesophageal valves 0.054–0.095 long. Nerve ring and excretory pore respectively 0.210–0.286 and 0.694–0.924 from anterior end. Seminal vesicle well developed. Common cloacal duct opens on prominent process 0.048–0.090 long. Usually six pairs of caudal papillae: two to three preanal, one adanal, two to three postanal (Fig. 26 D). Tail conical, 0.109–0.286 long.

Females: gravid worms 13.08–44.74 long, 1.22–5.00 maximum width. Buccal capsule 0.024–0.027 long, 0.054–0.063 wide. Oesophagus 0.775–1.090 long, 0.204–0.381 maximum width. Nerve ring and excretory pore respectively 0.258–0.299 and 0.857–1.142 from anterior end. Vulva prominent, cone shaped, 3.40–7.01 from posterior end (Fig. 26 E). Uterus occupies most of the body space, containing numerous eggs with developing embryos or ensheathed 2nd -stage larvae 0.244–0.258 long and 0.015 wide (Fig. 26 F). Rectum usually opens into a well-developed papilla-like process. Tail conical, 0.136–0.448 long (26C).

Sites: swim bladder (eels); mesenteries, intestinal wall (paratenic hosts)

Hosts: Anguilla rostrata (1, 2, 3, 4); Microgadus tomcod (5)

Distribution: New Brunswick, Nova Scotia

Records: 1. Aieta & Oliveira 2009 (NB, NS); 2. Rockwell et al. 2009 (NS); 3. Campbell et al. 2013 (NB, NS); 4.

Denny et al. 2013 (NS); 5. Li et al. 2015 (NS)