Neobythites lombokensis, Uiblein & Nielsen, 2018

Uiblein, Franz & Nielsen, Jørgen G., 2018, Review of the steatiticus - species group of the cuskeel genus Neobythites (Ophidiidae) from the Indo-Pacific, with description of two new species, Zootaxa 4387 (1), pp. 157-173 : 160-161

Neobythites lombokensis n. sp.

( Figures 1–2 , Tables 1, 3)

Neobythites meteori: Nielsen 2002: 57 , fig. 47.

Neobythites sp. 2: Gloerfelt-Tarp & Kailola 1984: 88 –89 (colour photo).

Holotype. ZMUC P77744 (93 mm SL), SE of Lombok Island , Indonesia, Eastern Indian Ocean, 8°58’S, 116°34’ E, JETINDOFISH, sta. TGT 1717, bottom trawl, 150–280 m depth, July 1981.

Diagnosis. No spines on hind margin of preopercle; dorsal fin-rays 91; anal-fin rays 72; pectoral fin-rays 29; precaudal vertebrae 13; total vertebrae 53; pseudobranchial filaments 3; long gill rakers on anterior arch 7; head length 23.0 % SL; pelvic-fin length 13.0 % SL, pelvic fins not reaching beyond anus; orbit length 5.2 % SL, 22.5 % head length, and 53 % upper-jaw length; longest gill filament 2.2 % SL and 9.4 % head length; ocellus spot originating just behind at a vertical line through anus, the ocellus-spot distance being 43.0 % SL, and the spot covering 14 dorsal-fin rays; dorsal and anal fins not or only patchily pigmented; no vertical bars on body; otolith length 4.8 % SL, sulcus length 3.2 % SL, and ostium height 26.0 % sulcus length.

Description. Body rather elongate; complete lateral line running close to dorsal edge; head and body covered with cycloid scales; origin of dorsal fin well behind opercle; origin of anal fin slightly anterior to midpoint of fish; tip of pectoral fin well in front of anal fin origin; pelvic fins reaching halfway to origin of anal fin; blunt snout shorter than diameter of eye; upper jaw ends below posterior half of eye; anterior nostril with low rim and larger posterior nostril a mere hole; spine absent on posterior margin of preopercle; opercular spine strong and straight; anterior gill arch with 2–3 short and 1 long raker on upper branch, 1 long raker in angle and lower branch with 5 long and 6 short rakers; gill filaments twice the length of the long rakers; three distinct pseudobranchial filaments.

Otolith ( Nielsen 2002, fig. 48B). Otolith oval, its height 1.5 times in its length; sulcus large, 1.5 times in otolith length; ostium length 1.7 times in sulcus length; ostium height 2.3 in ostium length.

Dentition. Premaxillaries and dentaries with irregular tooth rows, teeth on outer rows needle-like. Blunt teeth on subtriangular vomer and palatines. Two median basibranchial tooth patches, the anterior oblong and posterior smaller and circular.

Axial skeleton (from radiograph). Precaudal 13 and caudal vertebrae 40; tip of all neural and haemal spines thin and pointed; first neural spine half length of second spine; vertebrae 3–5 with slightly depressed neural spines; bases of vertebral spines 5–8 enlarged; parapophyses present on posterior seven precaudal vertebrae; pleural ribs on vertebrae 3–13; epipleural ribs not observed.

Colour (fresh fish; Figure 1B 2 ). Body mottled pale-brown to brown, becoming paler posteriorly, abdomen whitish blue, lateral line indistinct; head brown dorsally and pale brown below and behind eye, gill cover pale; ocellus with large black spot, its horizontal diameter more than twice of orbit length, placed above anterior part of anal fin; posterior parts of dorsal fin and nearly entire anal fin patchily covered with pale-brown or brown pigment; no margin or band on anal fin.

Colour (preserved fish; holotype after 36 years of preservation, Figure 1B1 ). Body and head mottled brown, abdomen and eyes bluish, lateral line indistinct; gill cover transparent, inside of peritoneum with many black spots of various sizes; ocellus spot dark-brown; patchily distributed traces of brown pigmentation on dorsal and anal fins.

Etymology. Named after the type locality, SE off Lombok Island, southern Indonesia.

Distribution. Single type specimen trawled SE of Lombok Island, Indonesia, Eastern Indian Ocean, at 150– 280 m depth.

Biology. The holotype is an unripe female caught between the lower shelf and upper continental slope. Its intestinal contents were unidentifiable except for parts of a small bivalve, suggesting a benthic lifestyle.

Comparisons. Neobythites lombokensis n. sp. differs from all congeners in the following combination of characters: a single ocellus placed on dorsal fin at mid-body, no preopercular spines, 7 developed gill rakers, head length 23.0 % SL, gill filament length 2.2 % SL, orbit length 22.5 % head length and 1.9 times in upper-jaw length, and otolith sulcus length 3.2 % SL.

Neobythites lombokensis seems most similar to N. meteori , sharing the following characters: dorsal fin with one ocellus, preopercular spine absent, pelvic fins ending anterior to anus, teeth needle-like and less than eight long rakers on anterior gill arch. Neobythites lombokensis differs from N. meteori in having a larger ocellus spot (spot covering 14 vs. 9 dorsal-fin rays), the ocellus placed above anterior part of anal fin (vs. above anus), and shorter gill filaments (9.4 vs. 13.0 % head length), respectively.

Remarks. In a review of the genus Neobythites from the Western Indian Ocean, Nielsen (1995) described seven new species. One of these, N. meteori , was based on a specimen from off Socotra Is. Furthermore, a specimen from off Lombok was referred to N. meteori but not designated as a paratype because of a number of differences from the Socotra specimen. Subsequent examination of the Lombok specimen showed that it represented an undescribed species of Neobythites , which is herein described.

Figures

FIGURE 1. Indo-Pacific Neobythites steatiticus species group. All photographs at left side and F show preserved fishes; the remaining five photographs at right side show fresh fishes, photographed on board immediately after capture. A) Neobythites gloriae n. sp. USNM 309008, HT, 158 mm SL, inner Gulf of Oman; B) N. lombokensis, ZMUC P 77744, HT, 93 mm SL, SE off Lombok, preserved (B1) and fresh (B2; side reversed); C) N. longipes, ZMUC P77740, 98 mm SL, SE off Lombok, preserved (C1) and fresh (C2); D) N. malayanus, ZMUC P77742, 138 mm SL, SE off Lombok, preserved (D1) and fresh (D2); E) N. malhaensis, ZMUC P77840, PT, 135 mm SL, Saya de Malha bank, preserved; F) N. meteori, ZMH 5621, HT, 102 mm SL, off Sokotra, preserved; G) N. steatiticus, ZMUC P771752, 162 mm SL, off Myanmar, preserved (G1) and fresh (G2); H1) N. stefanovi, ZMUC P77841, PT, 198 mm SL, Gulf of Aden, preserved; H2) N. stefanovi, SMF 26785, 111 mm SL, Red Sea, fresh. Photographers: Oddgeir Alvheim (G2), Thomas Gloerfelt-Tarp (B2, C2, D2), Marcus Krag (A, B1, C1, D1, E, G1, H1), Ralph Thiel (F), Michael Türkay (H2). The blue bars indicate 1 cm length for the respective specimen.

FIGURE 2. Distribution of studied specimens of Neobythites, with numbers indicating multiple sampling events.