Procamallanus (Spirocamallanus) synodi n. sp., 2019

Moravec, František & Justine, Jean-Lou, 2019, New species and new records of camallanid nematodes (Nematoda, Camallanidae) from marine fishes and sea snakes in New Caledonia, Parasite (Paris, France) 26 (66), pp. 1-25 : 12-15

Procamallanus (Spirocamallanus) synodi n. sp.

Figures 7 , 8

urn:lsid:zoobank.org:act:0F58977A-B15C-4888-ABD1245B4016032E

Type host: Sand lizardfish Synodus dermatogenys Fowler ( Synodontidae , Aulopiformes ).

Site of infection: Intestine.

Type locality: Near Récif Toombo, off Nouméa, New Caledonia, 22°32 0 583 S, 166°28 0 978 E (collected 5 November 2008).

Prevalence, intensity and details about fish: 1 fish infected/4 fish examined; 5 nematodes. The infected fish (Fish number JNC 2756) was 120 mm in fork length and 20 g in weight.

Deposition of type specimens: Helminthological Collection , Institute of Parasitology , Biology Centre of the Czech Academy of Sciences, České Budějovice, Czech Republic (male holotype and female allotype, both mounted on SEM stub, N–1203); Muséum National d’ Histoire Naturelle, Paris, France (three paratypes, MNHN JNC 2756 A) .

Etymology: The specific name of this nematode relates to the genitive form of the generic name of the host.

Description

General: Medium-sized nematode with finely transversely striated cuticle. Mouth aperture oval, surrounded by 12 submedian cephalic papillae arranged in three circles, each formed by four papillae; papillae of outer circle distinctly larger; each of four small inner papillae present near margin of oral aperture accompanied by distinct proximal pore; pair of small lateral amphids present ( Figs. 7E , 8A, 8B and 8C ). Buccal capsule orange, thick-walled, longer than wide, with simple, well-developed basal ring. Maximum width/length ratio of buccal capsule 1:1.00–1.23. Inner surface of capsule provided with 10–12 spiral ridges in lateral view, 3–5 of them being incomplete ( Figs. 7B, 7C and 7D ). Muscular oesophagus shorter than glandular oesophagus; both parts of oesophagus slightly expanded near their posterior ends ( Figs. 7A, 7B and 7C ). Intestine brown, narrow. Deirids small, simple, with rounded end situated at level of nerve ring or just posterior to it ( Figs. 7B, 7C, 7F and 8G ). Excretory pore located short distance posterior to anterior end of glandular oesophagus ( Fig. 7A ).

Male (two specimens; holotype; measurements of paratype in parentheses): Length of body 9.38 (9.13) mm, maximum width 231 (218). Buccal capsule including basal ring 66 (81) long, its width 60 (66); basal ring 6 (9) long and 39 (48) wide. Maximum width/length ratio of buccal capsule 1:1.10 (1:1.23). Spiral ridges 12 (12), 0 (5) of which incomplete. Length of muscular oesophagus 354 (340), maximum width 63 (69); length of glandular oesophagus 462 (639), maximum width 78 (93); length ratio of muscular and glandular oesophagus 1:1.31 (1:1.88). Length of entire oesophagus and buccal capsule representing 9 (12)% of body length. Deirids, nerve ring and excretory pore 279 (246), 245 (231) and 462 (476), respectively, from anterior extremity. Posterior end of body ventrally bent, provided with wide, vesiculated caudal alae supported by pedunculate papillae; anteriorly alae interconnected by mound, forming a kind of pseudosucker, and posteriorly reaching to caudal terminal spines ( Figs. 7G, 7J and 8D ). Preanal papillae: three pairs of subventral pedunculate papillae, of which second and third pairs closer to each other than first and second pairs; postanal papillae: six pairs of pedunculate papillae, four subventral and two lateral (last pair representing phasmids); additional two pairs of small, transversely-elongate sessile ventral papillae surrounding cloacal opening ( Figs. 7G, 7J and 8E ). Spicules unequal, with sharply pointed distal ends ( Fig. 7G ); large (right) spicule 225 (330) long; small (left) spicule less sclerotized, 204 (147) long. Length ratio of spicules 1:1.10 (1:2.24). Gubernaculum absent. Tail conical, 123 (126) long, with two (dorsal and ventral) small terminal cuticular spines 3 (3) long ( Fig. 7G ).

Female (two ovigerous specimens; allotype; measurements of paratype in parentheses. Measurements of one nongravid specimen in brackets): Length of body 12.10 (11.74) [7.05] mm, maximum width 286 (218) [190]. Buccal capsule including basal ring 75 (66) [60] long and 72 (66) [51] wide; basal ring 9 (9) [ 6] long and 45 (39) [ 39] wide. Maximum width/length ratio of buccal capsule 1:1.04 (1:1.00) [1:1.18]. Number of spiral ridges 11 (11) [ 10], of which 4 (3) [ 3] incomplete. Length of muscular oesophagus 394 (422) [286], maximum width 75 (81) [54]; length of glandular oesophagus 530 (666) [394], maximum width 90 (111) [66]; length ratio of muscular and glandular oesophagus 1:1.35 (1:1.58) [1:1.38]. Length of entire oesophagus and buccal capsule representing 5 (10) [ 11]% of body length. Deirids, nerve ring and excretory pore 285 (285) [219], 245 (272) [190] and 544 (598) [408], respectively, from anterior extremity. Vulva equatorial or somewhat postequatorial, 6.03 (6.19) [3.86] mm from anterior extremity, at 50 (53) [55]% of body length. Vulval lips not elevated. Vagina directed posteriorly from vulva. Uterus filled with eggs (with eggs) [without eggs]. Tail broad, conical, its posterior end narrowed to form narrow conical protrusion provided with 2 (2) [ 2], dorsal and ventral, small terminal cuticular spikes; length of entire tail 171 (114) [96]; protrusion 24 (27) [ 45] long, 15 (15) [ 15] wide, length of spines 3 (3) [ 3] ( Figs. 7H, 7I , 8F ).

Remarks

The present nematodes belong to the same morphological group of Procamallanus (Spirocamallanus) as the previous two species, P. bothi n. sp. and P. hexophtalmatis n. sp. By the length of the right spicule, they resemble nine very similar species occurring in the Indo-Pacific region, viz. P. anguillae , P. bothi n. sp., P. gobiomori , P. hexophtalmatis n. sp., P. guttatusi , P. istiblenni , P. monotaxis , P. rigbyi and P. variolae (see above). However, in having deirids located at or near the level of the nerve ring, they resemble only P. hexophtalmae and P. variolae , whereas deirids in other species are situated approximately in the mid-point between the buccal capsule and the nerve ring (in P. istiblenni in 2/3 of this distance).

In contrast to the new species, the female tail of P. hexophtalmatis n. sp. is widely rounded (vs conical), deirids are located slightly anterior to the level of the nerve ring (vs deirids at or just posterior to this level), the excretory pore is at the level of the junction of both parts of the oesophagus (vs at a short distance posterior to the anterior end of the glandular oesophagus), the vulva is slightly pre-equatorial (vs equatorial or somewhat postequatorial), the vagina is directed anteriorly (vs posteriorly) from the vulva and the males and females are distinctly longer (male 15.5 mm, gravid female 24.0 mm vs males 9.1–9.4 mm, subgravid females 11.7–12.1 mm).

Procamallanus (S.) variolae differs from the new species in the shape of the female tail (rounded vs conical), in having a distinctly pre-equatorial vulva (vs vulva equatorial or postequatorial), a largely different length ratio of the muscular and glandular parts of the oesophagus (1:1.1–1.3 vs 1:1.3–1.9) and in that the males and females of this species are longer (males 10.5–12.7 mm, gravid female 24.5 mm vs males 9.1–9.4 mm and subgravid females 11.7–12.10 mm); the buccal capsule of P. variolae is larger (84–87 × 60–66 µm in males and 99 × 78 µm in female vs 66–81 µm in males and 66–72 × 66– 72 µm in subgravid females). Moreover, the hosts of both P. hexophtalmatis and P. variolae belong to other fish families than that of the new species ( Pinguipedidae and Serranidae , respectively vs Synodontidae ).

Procamallanus (S.) synodi n. sp. is the first species of this genus reported from a fish of the family Synodontidae .

Figures

Figure 7. Procamallanus (Spirocamallanus) synodi n. sp. from Synodus dermatogenys. (A) Anterior end of male, lateral view; (B) same, larger magnification; (C) anterior end of female, dorsoventral view; (D) buccal capsule of male, lateral view; (E) cephalic end, apical view; (F) deirid; (G) posterior end of male, lateral view; (H) tail of female, lateral view; (I) tail tip of female, lateral view; (J) tail of male, ventral view.

Figure 8. Procamallanus (Spirocamallanus) synodi n. sp., scanning electron micrographs. (A, B) Cephalic end, subdorsoventral and apical views, respectively; (C) region of oral aperture, apical view (arrows indicate circumoral pores); (D) posterior end of male, lateral view; (E) tail of male, lateral view; (F) tail tip of female, lateral view; (G) deirid. (a) amphid; (b) cephalic papilla of external circle; (c) cephalic papilla of middle circle; (d) cephalic papilla of internal circle; (e) cloaca; (f) phasmid.