Cucullanellus cotylophora (Ward & Magath, 1917) Petter, 1974

Arai, Hisao P. & Smith, John W., 2016, Guide to the Parasites of Fishes of Canada Part V: Nematoda, Zootaxa 4185 (1), pp. 1-274 : 166-168

Cucullanellus cotylophora (Ward & Magath, 1917) Petter, 1974

Synonyms: Dacnitoides cotylophora Ward & Magath, 1917 ; Dichelyne cotylophora (Ward & Magath, 1917) Gendre 1927 (?1928)

Description (after Baker 1984). With characteristics of the genus. Body robust. Cuticle relatively thick, 0.020– 0.050 near mid-body, with faint irregularly spaced striations. Mouth opening slightly inclined dorsally, dorsoventrally elongated in large specimens, surrounded by raise collarette with rib-like thickenings. Six small inner labial papillae, and four outer double cephalic papillae present. Cheilostom absent. In large worms (> 5 mm long), oesophastom well developed, consisting of anterior dorso-ventrally elongate ring forming the mouth and extending posteriorly in a funnel-shaped triradiate structure lining the lumen of anterior third of oesophagus; three lobes of funnel portion with sharp processes on outer edges

extending into oesophageal musculature; ventral edge of oesophastomal ring with short bilobed process extending on top of adjacent oesophageal tissue; dorso-lateral edges of ring with pair of blindly ending, wide, flat cuticular processes extending posteriorly over exterior surface of oesophagus; lateral edges of ring with pair of blindly ending elongate processes extending posteriorly over surface of oesophagus and connected to lining of oesophageal lumen by thin cuticular connective running through oesophagus. In small worms (<2 mm long) oesophastom relatively weakly sclerotized, oesophastomal ring more ovoid in apical view than in larger worms;

dorso-lateral and lateral pairs of blindly ending processes on ring relatively short and undeveloped; lumen of

oesophastom relatively thin. Oesophagus wide at anterior and posterior ends. Excretory pore posterior to

oesophagus. Ventral intestinal caecum well developed in large worms, extending anterior to oesophagus; less well

developed in small worms ( Fig. 96 A). Anterior pair of digitiform deirids near posterior end of oesophagus; another

pair deirid-like digitiform papillae just posterior to mid-body.

Males: 1.14–6.48 long. Oesophagus 0.212–0.567 long. Nerve ring 0.084–0.208, and excretory pore 0.253–

0.824 from anterior end. Tail 0.078–0.151, spicules 0.233–1.024, and gubernaculum 0.050–0.098 long. Ten pairs

and one unpaired caudal papillae present ( Fig. 96 B): tail with one lateral pair, two subventral pairs, and one

subdorsal pair; area adjacent to and just anterior to cloaca with three pairs closely spaced subventral papillae and

one unpaired papilla on cloacal lip; pre–cloacal region with three pairs subventral papillae distributed relatively

anteriad. Large pair lateral phasmids near middle of tail. Large mature males with 18 pairs muscle cells extending

to large protruding pre-cloacal sucker. Small males have poorly developed sucker, not protruding. Spicules of large

worms heavily sclerotized with lateral alae in medial portion; in small worms spicules weakly sclerotized, alae not

differentiated. Gubernaculum heavily sclerotized in large worms. Testis relatively undifferentiated in small worms,

not patent with developing vas deferens. Testis connected to vas deferens when worms 2.2 long; sexual maturity

seen at 3.5 long.

Females: 1.19–7.17 long. Oesophagus 0.221–0.655 long. Nerve ring 0.074–0.229, excretory pore 0.291–0.914,

and vulva 0.075–4.47 from anterior end. Tail 0.086–0.191 long, conical with pair large lateral phasmids near

middle ( Fig. 96 C). Amphidelphic, each uterus with up to 100 eggs at 1–4 cell stage. Eggs 0.070–0.073 x 0.047–

0.055.

Site: intestinal lumen

Hosts: Ambloplites rupestris (6); Ameiurus melas (2); Ameiurus nebulosus (3); Aplodinotus grunniens (2, 13); Centrarchidae gen. sp. (17); Esox americanus vermiculatus (2); Lepomis gibbosus (19); Lepomis macrochirus (2); Lota lota (10, 18); Luxilus cornutus (16); Micropterus dolomieu (2, 6, 19, 21); Micropterus salmoides (2, 6); Morone americana (9, 19); Morone chrysops (2, 14); Perca flavescens (1, 2, 3, 4, 5, 6, 7, 8, 10, 11, 12, 15, 16, 19, 20, 21, 22, 23); Sander vitreus (2, 6, 19)

Distribution: Manitoba, Ontario, Quebec

Records: 1. Smedley 1934 (ON); 2. Bangham & Hunter 1939 (ON); 3. Bangham 1941 (ON); 4. Bangham & Venard 1946 (ON); 5. Worley & Bangham 1952 (QC); 6. Bangham 1955 (ON); 7. Tedla 1969 (ON); 8. Tedla & Fernando 1969a (ON); 9. Tedla & Fernando 1969b (ON); 10. Dechtiar 1972a (ON); 11. Tedla & Fernando 1972 (ON); 12. Cannon 1973 (ON); 13. Anthony 1982 (ON); 14. Anthony 1984 (ON); 15. Baker 1984a (ON); 16. Baker 1984b (ON); 17. Anthony 1985 (ON); 18. Anthony 1987 (ON); 19. Dechtiar & Christie 1988 (ON); 20. Dechtiar & Lawrie 1988 (ON); 21. Dechtiar & Nepszy 1988 (ON); 22. Dechtiar et al. 1988 (ON); 23. Choudhury & Dick 1996b (MB)

Figures

FIGURE 96. Cucullanellus cotylophora (Ward & Magath, 1917) Petter, 1974. A. large male [> 5 mm long], anterior end, lateral view; B. large male, posterior end, ventral view; C. phasmid of gravid female, dorsal view. (Redrawn from Baker 1984 a)