Cucullanus elongatus Smedley, 1933

Arai, Hisao P. & Smith, John W., 2016, Guide to the Parasites of Fishes of Canada Part V: Nematoda, Zootaxa 4185 (1), pp. 1-274: 160-163

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Cucullanus elongatus Smedley, 1933


Cucullanus elongatus Smedley, 1933  

Synonym: Cucullanus smedleyi Campana-Rouget, 1957  

Description (after Berland 1983). With characteristics of the genus. Body exceptionally long for a cucullanid, up to over 30 in males, and 40 in females. Head rounded, slit-like mouth opening shifted slightly to dorsal side. Double club-shaped oesophagus. Narrow isthmus between anterior and posterior swollen portions of oesophagus surrounded by nerve ring. Excretory pore between nerve ring and intestine. Cuticle thin in anterior body, increasing to about 0.007 at mid-body, and to about 0.010 near anus. Cuticular striations relatively fine throughout. Pair of lateral deirids at about level of mid-oesophagus, and pair of lateral papillae near mid-body ( Fig. 93 View FIGURE 93 A). Mouth opening oval, surrounded by collarette, provided on inner face with about 60 short triangular teeth on each side.

Two pairs of large cephalic papillae and one pair lateral amphids external to collarette. Raised, smooth, tubular peribuccal rim lying internal to collarette. Posterior to peribuccal rim on each side a large, bilobed, rounded structure (“peribuccal tooth”) projects into pseudobuccal capsule. Cuticular lining of oesophagus and pseudobuccal capsule complex, with cuticular structures extending into surrounding muscles. Tail simple and conical, tapering evenly to a point.

Males: 25.54–30.90 long, tapering posteriorly but widening at pre-cloacal sucker; maximum width 0.33–0.40. Oesophagus 1.96–2.32 long. Nerve ring 0.53–0.60, deirids 1.18–1.44 and excretory pore 1.59–1.79 from anterior end. Small spine on post-cloacal wall. Testis single, in anterior body, a loop extends forward to some distance posterior to oesophagus. Left spicule 1.19–1.45, and right spicule 1.19–1.52 long. Gubernaculum 0.064–0.101 long. Proximal cavity or sac ventral to gubernacular limbs, Y-shaped in ventral view. Ten pairs caudal papillae: five pairs pre-cloacal, five pairs post-cloacal. One pair small phasmids ( Fig. 93 View FIGURE 93 B).

Females: 38.41–43.25 long; maximum width 0.47–0.54. Oesophagus 2.21–2.51 long. Nerve ring 0.60–0.63, deirids 1.29–1.48, excretory pore 1.64–2.05 and vulva 21.38–24.74 from anterior end. Phasmids at about midlength of long tapering tail ( Fig. 93 View FIGURE 93 C). Eggs 0.082–0.099 x 0.040–0.047.

Site: intestinal lumen

Hosts: Ophiodon elongatus   (1, 2, 5); Sebastes caurinus   (3, 4); Sebastes maliger   (4); Sebastes nebulosus   (6);

Sebastes ruberrimus   (4)

Distribution: Pacific

Records: 1. Smedley 1933; 2. Margolis 1952b; 3. Arai 1969; 4. Sekerak & Arai 1977; 5. Berland 1983; 6. Holmes