Neobythites unimaculatus Smith & Radcliffe, 1913

Uiblein, Franz & Nielsen, Jørgen G., 2023, Five new ocellus-bearing species of the cusk-eel genus Neobythites (Ophidiidae, Ophidiiformes) from the West Pacific, with establishment of three new species groups, Zootaxa 5336 (2), pp. 179-205 : 187-188

Neobythites unimaculatus Smith & Radcliffe, 1913

Figure 1 , Tables 1 , 2

Neobythites unimaculatus Smith & Radcliffe in Radcliffe, 1913: 140, pl. 7 (fig. 2) (near Mabul Island , 4°10′50″N, 118°39′35″E, Borneo, 310 fathoms; holotype: USNM 74127 ).

Neobythites nigromaculatus Kamohara, 1938: 67 , fig. 37 (type locality Mimase market, Japan).

New material examined (see Nielsen 2002 for all other material examined including types). MNHN 2005-3413, 130 mm SL, Coral Sea, 15°6′0″S, 156°57′0″E, Salomon 2 cruise, R / V Alis, st. CP 2317, beam trawl 215–300 m, 16 Nov. 2004 .

Diagnosis. Hind margin of preopercle with two spines; dorsal-fin rays 90–99; anal-fin rays 73–81; pectoral-fin rays 27–30; precaudal vertebrae 12–13; total vertebrae 53–57; pseudobranchial filaments 4–8; long rakers on anterior gill arch 8–12; head length 21–25% SL; pelvic-fin length 12–20% SL, fins not reaching anus; orbit length 4.0–5.4% SL and 18–24% HL; longest gill filament 1.2–2.2% SL and 5.0–9.7% HL; dorsal fin with large ocellus placed slightly behind line through anus, spot distance 43–50% SL and spot covers 5–11 dorsal-fin rays, rarely extending ventrally onto body; preserved specimens with dark-brown ocellus spot; no vertical bars on body; otolith length 5.1–5.8% SL, sulcus length 3.9–4.7% SL, and ostium height 14–18% sulcus length and 20–24% ostium length.

Distribution and size. Japan to northwestern Australia and eastward to Fiji Islands at 146–567 m depth. New record for Coral Sea. Known up to 218 mm SL.

Comparisons. Neobythites superocellatus n. sp. differs from the three other australiensis -group species with a larger central ocellus which is positioned further posteriorly on the dorsal fin and the spot extending onto the body; it differs also in having more anal-fin rays, total vertebrae and gill rakers, and a higher otolith ostium height relative to sulcus and ostium length; it differs from N. australiensis and N. nigriventris in having more dorsal-fin rays and from N. australiensis in having a shorter head and gill filaments; it differs from N. nigriventris in having shorter pelvic fins.

Neobythites australiensis differs from N. nigriventris in absence vs. presence of black-speckled pigment on abdomen, the combination of slightly more pectoral-fin rays and pseudobranchial filaments, slightly more dorsal-fin rays and vertebrae above anal-fin origin, and slightly longer postorbital; it differs from N. unimaculatus in the combination of slightly more pectoral-fin rays and pseudobranchial filaments, a slightly larger ocellus spot and slightly higher otolith ostium related to sulcus and ostium length.

Neobythites nigriventris differs from N. unimaculatus in presence vs. absence of black-speckled pigment on abdomen, more pectoral-fin rays, and slightly longer and higher ostium related to sulcus length.

Remarks. Neobythites superocellatus has the largest ocellus of all ocellus-bearing congeners and its ocellus is also unique in covering a large number of vertical scale rows on body and connecting to a vertical bar ventrally.

The specimen from Japan reported by Okamoto et al. (2011) as N. australiensis was found to be an undescribed species and is reported further below as part of the newly established kenyaensis species group. Neobythites australiensis has no anterior ocellus, but has spots in some specimens.

Neobythites unimaculatus requires a revision. The wide distribution of this species and the wide ranges of several counts and measurements deserve a detailed comparative study among the different populations, involving material from the distribution area of the putative junior synonym N. nigromaculatus ( Japan to Taiwan)

Figures

FIGURE 1. Species of the australiensis group. (A) Neobythites superocellatus n. sp., HT, MNHN 2021-0457, 95 mm SL, Solomon Sea (M. Krag); (B) N. australiensis, PT, ZMUC P771325, 188 mm SL, W Australia (side-reversed; M. Krag); (C) N. nigriventris, HT, CSIRO H 2310-03 (side-reversed; H. O’Neill); (D) N. unimaculatus, MNHN 2005-3413, 130 mm SL, Coral Sea (M. Krag); with 10 mm scale bars.