Ophichthus lentiginosus, E, John, 2010

E, John, 2010, Deepwater Indo-Pacific species of the snake-eel genus Ophichthus (Anguilliformes: Ophichthidae), with the description of nine new species, Zootaxa 2505, pp. 1-39 : 25-26

Ophichthus lentiginosus sp. nov.

Figures 26–28

Holotype. MNHN 1997-0 601, 563 mm, female, from Vanuatu (15o40'S, 167o 0 1'E), Campaigne MUSORSTOM 8, Sta. no. CP 1136. captured by otter trawl in 398–400 m during Oct. 1994.

Paratype. MNHN 1987-1244, 628 mm, male, from Hienghene, New Caledonia (20o40'S, 164o55'E), Sta. p 1-78-05, from 400 m, presumably trapped (as were other Laboute specimens) by P. Laboute in 1978.

Diagnosis. A stout species of Ophichthus , subgenus Coecilophis , with: tail 55–56% and head 10.6–12% of total length; dorsal-fin origin behind pectoral-fin tips; pectoral fins not elongate, shorter than upper jaw; posterior nostril a hole in upper lip covered by a flap; head pores minute, SO 1+4, IO 1+4, POM 3+6; teeth not enlarged, conical and stout, biserial on maxillary, uniserial on vomer and mandible; coloration uniform brown, pale ventrally, overlain throughout with minute dark punctations, median fins pale. Mean vertebral formula 16/55.5/142, total vertebrae 140–144 (n=2).

Counts and measurements (in mm) of the holotype and those of the paratype (in parentheses). Total length 563 (628); head 59.6 (74.2); trunk 192.4 (203.8); tail 311 (350); predorsal distance 92 (104); pectoralfin length 20.6 (~21); pectoral-fin base ~5 (8.9); body depth at gill openings ~26 (~27); body width at gill openings ~22 (~27); body depth at anus ~23 (~25); body width at anus ~21 (~23); snout 11.6 (14.0); tip of snout to rictus 21.6 (23.6); eye diameter 8.1 (10.0); interorbital distance 11.6 (12.2); gill-opening height ~7 (~11); isthmus width ~16 (~15). Vertebral formula 17/57/144 (15/54/144).

Description. Body stout ( Figure 26 ), compressed in posterior tail region, depth at gill openings 22–23 in TL. Branchial basket wider and deeper than body. Head and trunk 2.2–2.3 in TL; head 8.5–9.4 in TL, 4.7–5.7 in trunk. Snout short, rounded when viewed from above. Snout bisected on underside by a short groove which reaches to anterior base of anterior nostrils. Lower jaw slightly included, curved such that upper and lower lips do not meet when mouth is closed. Mouth moderately elongate, rictus slightly behind rear margin of eye. Eye large, 2.4–2.7 in upper jaw and 7.4 in head, its center well behind middle of upper jaw. Tube of anterior nostril short, barely reaches lower lip when deflected ventrally. Lip barbels absent. Posterior nostril a hole above upper lip, completely covered by an anterior flap. Dorsal-fin origin immediately behind level of pectoral-fin tips. Dorsal fin low, in a groove for its entire length. Anal fin higher, in a groove shallower than that of dorsal. Pectoral fins rounded, not elongate, less than upper jaw in length. Pectoral-fin base in upper half of gill opening.

Head pores ( Figure 27 ) minute, inconspicuous. Single median interorbital and temporal pores. Supraorbital pores 1+4, infraorbital pores 4+2, lower jaw pores 5–7, preopercular pores 3. Lateral-line pores present but difficult to enumerate.

Teeth ( Figure 28 ) small, stout, conical, slightly recurved, not closely spaced. Intermaxillary with a rosette of 7–9 teeth, followed by a pair and then a row of 13 linear vomerine teeth, becoming slightly smaller posteriorly. Maxillary dentition biserial. An inner row of 15–16 begins at level of posterior nostril. An outer row of 15–18 followed by a patch of 2–3 pairs of smaller teeth. Mandibular teeth uniserial, 25–26 in the row.

Color in ethanol tan along flanks and dorsal surface, pale ventrally, the entire body overlain with fine dark freckles. Anterior nostrils, lower half of posterior nostrils, palate, median fins, posterior third of pectoral fins, tail, and peritoneum unpigmented.

Size. The largest known specimen is 628 mm, a mature male.

Etymology. From the Latin lentiginosus , meaning freckled, in reference to its general coloration.

Distribution. Known only from the type specimens, from Vanuatu and New Caledonia, at 398– 400 m.

Remarks. The new species is most similar to Ophichthus urolophus and to O. microstictus . It differs from O. urolophus in having a larger snout (5.1–5.3 in HL, vs. 5.3–6.4) and in having biserial rather than uniserial maxillary dentition. It differs from Ophichthus microstictus in its dorsal-fin origin (slightly behind the pectoral-fin tips rather than slightly before) and by having fewer vertebrae (140–144 vs. 151–156).

Figures

FIGURE 26. Holotype of Ophichthus lentiginosus, MNHN 1997 - 0601, 563 mm, from Vanuatu.

FIGURE 27. Head of holotype of Ophichthus lentiginosus, MNHN 1997 - 0601, 563 mm.

FIGURE 28. Dentition of holotype of Ophichthus lentiginosus, MNHN 1997 - 0601, 563 mm.