Cucullanus robustus Yamaguti, 1935

Park, Joong-Ki & Moravec, Frantisek, 2008, Redescription of Cucullanus robustus (Nematoda: Cucullanidae) from the conger eel Conger myriaster off Korea, Zootaxa 1729, pp. 1-7 : 2-5

Cucullanus robustus Yamaguti, 1935

(Figs. 1, 2)

General. Body whitish, medium-sized. Oral opening dorsoventrally elongated, narrow, surrounded by raised narrow membranous ala (collarette) and by row of numerous small buccal denticles. Two pairs of submedian cephalic papillae and pair of lateral amphids present. Oesophagus muscular, expanded at both ends; anterior expansion forming relatively large pseudobuccal capsule (oesophastome); posterior extension slightly narrower than oesophastome. Oesophagus opens into intestine through large oesophageal valves. Nerve ring situated approximately at one third of oesophagus from its anterior end. Deirids small, recurved at their tips, located near middle of oesophagus. Excretory pore slightly in front of or nearly at level of posterior end of oesophagus. Tail conical, sharply pointed at its end.

Male (3 specimens). Body length 14.71– 5.78 mm; maximum width 642–684. Length of entire oesophagus 1.43–1.51 mm (approximately 9.1–10.3% of body length); its maximum width 233–304; minimum width 117–124. Length of oesophastome 319–332, representing 21–23% of entire length of oesophagus. Distances of nerve ring and excretory pore 474–527 and 1.31–1.48 mm, respectively, from anterior extremity. Ventral preanal sucker well developed, oval, 329–332 in length. Spicules almost equal, 1.3–1.6 mm long, with membranous alae. Gubernaculum well sclerotised, 173–174 long and 10–12 wide. Eleven pairs of caudal papillae (including phasmids) present: 5 pairs preanal (all subventral), 1 pair adanal (lateral), 5 pairs postanal (3 subventral, 2 lateral). Of 5 pairs of preanal papillae, first and second pairs situated anterior and posterior to ventral sucker, respectively; fourth and fifth laid close to cloacal opening, and third papillae located at approximately two-third of distance from second pair of papillae to cloacal aperture. A single unpaired, median papilla-like structure present at level of fifth pair of preanal papillae, anterior to cloacal opening. Of 5 pairs of postanal papillae, first, second and fifth pairs subventral and third (phasmids) and fourth pairs lateral: first lies just posterior to cloacal line and the rest (2nd–5th) located at posterior half of caudal length. Tail conical, 302–306 long, with pointed end.

Female (6 specimens). Body length 18.18–24.48 mm, maximum width 649–965. Entire oesophagus 1.39–1.62 mm long (6–8% of body length); maximum (at middle of oesophastome) and minimum widths (just posterior to nerve ring) of oesophagus 175–244 and 78–108, respectively. Pseudobuccal capsule 271–358 long (20–25% of entire oesophagus). Distances of nerve ring, deirids, and excretory pore 482–534, 851–1039 and 1.24–1.41 mm, respectively. Vulva with rather elevated lips, situated at 11.1–15.0 mm, 7.2–9.5 mm from anterior end (60–66% of distance of the entire body length from anterior end). Uterus contains numerous thinwalled, oval eggs 76–84 long and 43–47 wide. Tail 409–524 long, with sharply pointed tip. Phasmids situated laterally at about mid-length of tail ( Fig. 2 H).

FIGURE 1. Cucullanus robustus Yamaguti, 1935 from Conger myriaster in Korea. A, B— anterior end of male, lateral and dorsoventral views, respectively; C— vulva; D— posterior end of male, ventral view; E— tail of female, lateral view; F— posterior end of male, lateral view; G – tail of male, lateral view; H— embryonated egg. Scale bars: A, B = 500 µ m; C, E = 100 µ m; D, G = 200 µ m; F = 300 µ m; H = 50 µ m.

Host: Conger myriaster ( Congridae , Anguilliformes ).

Site of infection: Intestine.

Locality: Off southern coast of South Korea near Haenam City, Republic of Korea (collected in September 2005).

Deposition of voucher specimens: Voucher specimens deposited in the Helminthological Collection of the Institute of Parasitology in Č eské Bud jovice (Cat. No. N-884).

Figures

FIGURE 2. Scanning electron micrographs of Cucullanus robustus Yamaguti, 1935. A— cephalic end, lateral view; Bbuccal denticles; C— deirid; D— excretory pore; E, F — tail of male, subventral and ventral views, respectively; Gpostanal papilla; H— tail of female, lateral view. Abbreviations: a – c, third-fifth pairs of preanal papillae; d, unpaired median preanal papilla; e, adanal papilla; f – j, first-fifth pairs of postanal papillae; k, spicule; l, phasmid.