Cucullanus heterochrous Rudolphi, 1802

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

Cucullanus heterochrous Rudolphi, 1802

Description (after Berland 1970). With characteristics of the genus. Body fairly stout and of even breadth, greatest width just behind oesophagus. Head straight or slightly bent dorsally, and only slightly swollen. Cuticle transversely striated throughout, 0.003–0.007 thick. Mouth a dorso-ventral slit. Collarette surrounding the mouth well developed, the inner face with about 50 teeth on either side. Characteristic two pairs large papillae and one pair amphids on head. Internal circle of six relatively large papillae. Dorsal half of pseudobuccal capsule wide. Peribuccal rim lies well within mouth opening. Oesophagus relatively short, straight at nerve ring level but slightly dilated just behind it ( Fig. 94 A).

Males: 5.33–7.55 long; maximum width 0.17–0.22. Oesophagus 0.77–0.94 long. Nerve ring 0.31–0.38, deirids 0.69–0.75 and excretory pore 0.91–1.08 from anterior end. Pre-cloacal sucker present. Left spicule 0.78–1.08 long, right spicule 0.71–0.97 long; one spicule, usually the left one, has a screw-like tip, whilst the other is usually straight and more blunt. Both spicules carry broad alae. Gubernaculum 0.046–0.059 long. Pointed tail narrows abruptly behind cloaca. In addition to the usual 11 pairs of caudal papillae there is one large median papilla behind the cloaca ( Fig. 94 B).

Females: 7.50–10.78 long; maximum width 0.21–0.29. Oesophagus 0.93–1.03 long. Nerve ring 0.37–0.42, deirids 0.82–0.96, excretory pore 1.11–1.19 and vulva 4.56–6.50 from anterior end. Protrusion (“post-cloacal lip”) behind anus ( Fig. 94 C). Eggs 0.072–0.091 x 0.042–0.049.

Site: alimentary tract

Hosts: Hippoglossus stenolepis (2, 3); Limanda ferrugineus (1); Pseudopleuronectes americanus (1) Distribution: Atlantic, Pacific

Records: 1. Ronald 1963 (AT); 2. Blaycock 1996 (PA); 3. Blaycock et al. 1998a (PA)

Figures

FIGURE 94. Cucullanus heterochrous Rudolphi, 1802. A. anterior end, lateral view; B. male, tail, ventral view; C. female, tail, lateral view. (Redrawn from Berland 1970)