Raphidascaris (Ichthyascaris) etelidis, MORAvEC & Justine, 2012

MORAvEC, František & Justine, Jean-Lou, 2012, Raphidascaris (Ichthyascaris) etelidis n. sp. (Nematoda, Anisakidae), a new ascaridoid nematode from lutjanid fishes off New Caledonia, Zoosystema 34 (1), pp. 113-121 : 115-116

Raphidascaris (Ichthyascaris) etelidis n. sp. ( Figs 1-3 )

DEPOSITION OF SPECIMENS. — Muséum national d’Histoire naturelle, Paris ( MNHN JNC2616 , JNC2617 , JNC2623 , holotype, allotype and 30 paratypes; JNC2459 and JNC2460 , voucher specimens).— Institute of Parasitology , Biology Centre of the Academy of Sciences of the Czech Republic, České Budějovice (N-969, 4 paratypes) .

TYPE LOCALITY. — Off New Caledonia, South Pacific Ocean.

ETYMOLOGY. — The specific name of this nematode relates to the genitive form of the generic name of the host.

TYPE HOST. — Deep-water longtail red snapper, Etelis coruscans Valenciennes, 1862 ( Lutjanidae , Perciformes ).

OTHER HOST. — Crimson jobfish, Pristipomoides filamentosus (Valenciennes, 1830) (Lutjanidae) .

SITE OF INFECTION. — Intestine.

PREVALENCE AND INTENSITY. — Etelis coruscans : 3 fish infected/5 fish examined; 2-38 (mean 9) specimens per fish. Pristipomoides filamentosus : 2/2; 1-10 (mean 5).

DESCRIPTION

Medium-sized, whitish nematodes with transversely striated cuticle. Lips nearly equal in size (dorsal lip slightly smaller than ventrolateral lips), broader than long, without lateral membranous flanges; pulp with two distinct anterior lobes, each internally with terminal pocket-like depression. Dorsal lip bears two subdorsal double papillae at approximately anterior ⅓ of its length; each ventrolateral lip with one double subventral papilla, one small single papilla and amphid situated laterally ( Figs 1B, F ; 2A, C ). Interlabia absent. Narrow lateral alae extend along whole body length, united anteriorly close to ventrolateral lips on one side of body ( Figs 1A ; 2B, C ) and form cordons on tail ( Fig. 2D, E ). Oesophagus short; posterior half markedly broad ( Fig. 1A ). Ventriculus transversely oval; ventricular appendix relatively short. Excretory pore posterior to level of nerve ring. Tail of both sexes conical.

Male

Seven specimens; measurements of holotype in parentheses.

Length of body 13.87-27.65 (19.19) mm, maximum width 435-830 (666). Lips 82-136 (109) long. Length of oesophagus 1.34-2.30 (2.30) (7.8-12 [12]% of body length), maximum width 204-340. Nerve ring and excretory pore 381-625 (476) and 482-775 (775), respectively, from anterior extremity. Ventriculus 109-163 × 163-286 (109 × 218); ventricular appendix 585-925 (585) long, 122-177 (122) in maximum width. Posterior end of body curved ventrally. Spicules equal, alate, pointed, 345-474 (474) long, representing 1.5-2.5 (2.5)% of body length. Total of 60-65 (62) pairs of small subventral papillae present, 44-49 (49) being preanals and 12-13 (13) postanals; papillae of several posteriormost preanal pairs and of postanal pairs very small; postanal papillae of third pair from posterior extremity doubled ( Fig. 2F ). Anterior cloacal lip with poorly developed unpaired median papilla. Tail 109-163 (122) long, ending in small appendage provided with many cuticular spines or protuberances ( Figs 1E, I ; 3D, E ). Ventral and subventral surface of body in region of genital papillae bearing distinctly modified cuticle ( Figs 2F ; 3E, F ).

Female

Seven gravid specimens; measurements of allotype in parentheses.

Length of body 24.13-26.89 (26.63) mm, maximum width 775-938 (775). Lips 122-150 (122) long. Length of oesophagus 2.15-2.42 (2.30), representing 8.1-9.4 (8.1)% of body length, maximum width 299-476 (299). Nerve ring and excretory pore 503-639 (503) and 745-979 (979), respectively, from anterior extremity. Ventriculus 136-163 × 272-313 (150 × 313); ventricular appendix 612- 1047 (1047) long, maximum width 109-177 (109). Vulva situated in anterior region of body, 3.33- 4.69 (4.30) mm from anterior extremity, at 14-18 (16)% of body length; vagina directed posteriorly from vulva. Uterus forms coils in region posterior to vagina, extending posteriorly to level of rectum. Eggs numerous, suboval to almost rounded, thinwalled, smooth, with uncleaved contents ( Fig. 1D ); size 54-57 × 45-54 (54 × 48). Tail 544-639 (639) long; tip with numerous minute cuticular spines ( Figs 1E ; 2D ).

Figures

FIG. 1. — Raphidascaris (Ichthyascaris) etelidis n. sp. from Etelis coruscans Valenciennes, 1862; A, anterior end of male, lateral view; B, anterior end of female, dorsal view; C, tail of gravid female, lateral view; D, egg; E, tip of female tail, lateral view; F, dorsal lip; G, posterior end of male,lateral view;H, posterior end of male (smaller magnification) showing all pairs of caudal papillae, lateral view; I, tail of male, lateral view. Scale bars: A, H, 300 µm; B, C, G, 200 µm; D, E, 30 µm; F, 100 µm; I, 50 µm.

FIG. 2. — Raphidascaris (Ichthyascaris) etelidis n. sp. from Etelis coruscans Valenciennes, 1862, scanning electron micrographs; A, dorsal lip;B, anterior end, lateral view (arrow indicates joining lateral alae);C, region of cephalic end with subventral lip, ventrolateral view (arrow indicates ventral connection of lateral alae); D, posterior part of female tail, lateral view;E, posterior end of male,sublateral view; F, male tail with postanal papillae, lateral view (arrow indicates double papilla). Abbreviations: a, amphid; d, double cephalic papilla; p, phasmid; s, single cephalic papilla. Scale bars: A, D, F, 10 µm; B, C, 20 µm; E, 50 µm.

FIG. 3. — Raphidascaris (Ichthyascaris) etelidis n. sp. from Etelis coruscans Valenciennes, 1862, scanning electron micrographs; A, posterior end of male (with complete number of paired preanal papillae),ventral view;B, same (number of paired papillae incomplete), somewhat larger magnification; C, posterior end of male (region of small caudal papillae),ventral view;D, distribution of caudal papillae on male tail, ventral view; E, posterior part of male tail with distinctly modified subventral cuticle, lateral view; F, detail of modified subventral cuticle on male tail, lateral view. Scale bars: A, B, 100 µm; C, 20 µm; D, 10 µm; E, 50 µm; F, 2 µm.