Gymnothorax nudivomer (Günther 1867)

Smith, David G., Bogorodsky, Sergey V., Mal, Ahmad O. & Alpermann, Tilman J., 2019, Review of the moray eels (Anguilliformes: Muraenidae) of the Red Sea, with description of a new species, Zootaxa 4704 (1), pp. 1-87 : 40

Gymnothorax nudivomer (Günther 1867) —Yellowmouth Moray

( Figure 24 )

Muraena nudivomer Günther in Playfair & Günther 1867: 127 , pl. 18 ( Zanzibar). Lectotype, BMNH 1867.3 .9.48, designated by Günther 1870: 104.

Lycodontis cf. nudivomer: Ben Tuvia & Steinitz 1952: 4 .

Gymnothorax nudivomer: Fowler & Steinitz 1956: 271 ; Goren & Dor 1994: 7; Randall & Golani 1995: 864; Khalaf & Disi 1997: 40; Lieske & Myers 2004: 34; Golani & Bogorodsky 2010: 10; Golani & Fricke 2018: 22.

Lycodontis nudivomer: Smith 1962: 438 .

Red Sea material. Israel: BPBM 18286 (1, 560), Eilat; HUJ 15178 (8, 202–562), Eilat; HUJ 15182 (2, 460–675), Eilat; SMF 4523 (2, 600–715), Eilat. Egypt: BPBM 13891 (1, 442), Taba; HUJ 17023 (1, 676), Ras Burka; USNM 191670 (1, 312); USNM 312753 (1, 480), El Himeira.

Comparative material. Mauritius: MCZ 5912 (1, 768, holotype of Gymnothorax insignis Seale ) . Hawaii: USNM 50869 (1, 860, holotype of Gymnothorax xanthostomus Snyder ) .

Description. In TL: preanal length 2.0–2.3, predorsal length 9.4–11, head length 7.4–8.5, body depth at anus 15–19. In head length: snout length 5.1–5.8, eye diameter 9.0–14, upper-jaw length 2.6–3.1. Pores: LL 2, SO 3, IO 4, POM 6. Vertebrae: predorsal 3–4, preanal 52–53, total 126–139.

Body moderate; anus slightly behind midlength; dorsal-fin origin well before gill opening. Jaws moderately short, of equal length or lower jaw slightly protruding. Eye moderate, over middle of upper jaw. Anterior nostril tubular, short; posterior nostril elliptical, with a slightly raised rim, above anterior margin of eye.

Teeth uniserial, serrate, moderately stout and pointed, most compressed and blade-like. Intermaxillary teeth in a single peripheral series, 6–7 on each side, increasing in size posteriorly; 1–2 median teeth. Maxillary teeth uniserial, about 7–11. Dentary with 14–21 teeth, largest ones anteriorly. Vomerine teeth small, in a single short series, not obvious, apparently absent in large adults.

Color: head and body light to medium brown becoming darker posteriorly, covered with ocellated white or bluish white spots, increasing in size posteriorly. Gill opening yellow within a large black blotch. White spots on dorsal and anal fins sometimes joined to form a continuous white margin. Inside of mouth yellow in life. Eye pale with black bar.

Maximum size about 1 m.

Distribution and habitat. Widely distributed in the Indo-Pacific from East Africa and the Red Sea to Hawaiian Islands and French Polynesia, primarily at depths of 30–271 m, occasionally shallower. Usually seen with its open distinctive yellow mouth.

Remarks. There appears to be some geographic variation in the number of vertebrae. Four specimens from Hawaiian Islands have 137–139, two specimens from Mauritius and the Comoros have 132–133, and four specimens from the Red Sea have 134–135 ( Randall & Golani 1995, plus our own observations). Castle & McCosker (1986: 171) reported 126–129, without giving the locality but presumably from the East African coast. Specimens from the Red Sea apparently have fewer and smaller white spots on the body posteriorly ( Randall 1983). Randall & Golani (1995) reported that this species is commonly seen at depths of 15 m or less in the northern Red Sea; the second author confirms this. Still, no specimens of G. nudivomer were collected during the field surveys of the present study, but one sequence was available from a specimen collected in the southwestern Indian Ocean ( South Africa). Gymnothorax elegans is the next closely related species according to the present phylogeny ( Fig. 48 ).

Figures

FIGURE 24. Gymnothorax nudivomer, Dahab, Egypt. Photo by S.V. Bogorodsky.

FIGURE 48. Unrooted maximum likelihood phylogeny of Indo-Pacific moray eels (Muraenidae) based on partial mitochondrial COI. Branch support values were obtained by 100 bootstrapped replicates; only bootstrap values above 50 percent are shown. The scale bar represents average number of nucleotide substitutions. (A) = specimen sequenced in this study; (B) = sequence retrieved from BOLD; (C) sequence retrieved from CRIOBE; (G) = sequence retrieved from GenBank; (R) = sequence retrieved from Reece et al. (2010); (ID) = species ID re-assigned herein; (ID-H) = specimen re-assigned as of Huang et al. (2019); (SAU) = collected in Saudi Arabia; (ISR) = collected in Israel.