Uropterygius macrocephalus (Bleeker 1864) —Largehead Snakemoray (Figure 44) Gymnomuraena macrocephalus Bleeker 1864: 54 (Ambon I., Molucca Is., Indonesia). Holotype (unique), BMNH 1867.11.28.335. Uropterygius makatei Gosline: Randall & Golani 1995: 874. Uropterygius macrocephalus: Golani & Bogorodsky 2010: 11; Golani & Fricke 2018: 24. Red Sea material. Egypt: HUJ 9418 (1, 136), Gulf of Aqaba, Nabq. Comparative material. Mauritius: USNM 342094 (8, 102–299). Réunion: MNHN B.3140 (1, 236). Indonesia: BMNH 1867.11. 28.335 (1, 185, holotype). Marshall Is.: BPBM 29073 (1, 320). Fiji: USNM 259858 (2, 160–135). French Polynesia, Marquesas Is.: USNM 409356 [MARQ-356] (1, 158). Austral Is.: USNM 424083 (1, 227). Description. In TL: preanal length 1.8–2.4, head length 6.3–8.3, body depth at anus 16–28. In head length: snout length 5.3–8.7, eye diameter 14–19, upper-jaw length 2.6–3.8. Pores: LL 1, SO 3, IO 4, POM 6. Vertebrae (Red Sea specimen in parentheses): predorsal 90–99 (97), pre-anus 41–44, pre-anal fin 92–99 (98), total 103–115 (108); the holotype has 103 vertebrae. Body moderate; anus before midlength; gill opening below mid-side. Snout moderate, jaws about equal length. Eye rather small, over middle of upper jaw. Anterior nostril tubular; posterior nostril above anterior margin of eye. Teeth biserial, conical, smooth. Intermaxillary teeth in five rows across, peripheral teeth small, intermediate and median teeth larger; 2–3 median teeth. Maxilla with an inner series of larger, depressible teeth and an outer series of smaller teeth, both series continuous with intermaxillary teeth, the combined inner series with 9–18 teeth, the outer with 27–40. Dentary with 8–16 large inner teeth and 29–49 smaller outer teeth. Vomerine teeth uniserial, long, conical, about 4–9. Color: dark gray-brown, usually with several rows of complexly dendritic, light brown blotches; tip of tail pale yellowish; nostrils and head pores whitish. Maximum size at least 429 mm. Distribution and habitat. Throughout the Indo-Pacific from the Red Sea to the coast of Mexico and Central America; in shallow water, generally less than 15 m. Common in the Pacific, but rarely collected in the Indian Ocean. Remarks. This species was reported by Randall & Golani (1995) as Uropterygius makatei, but the distinction of that species from U. macrocephalus is not clear, and recognizing it is perhaps premature. The species needs to be studied over its entire range to determine whether it is a single species or a complex. Its apparent rarity in the Indian Ocean compared to the Pacific is difficult to explain. The Mauritius specimens cited above were collected by rotenone at a shallow, rocky shore station and were among the last fishes to emerge. Perhaps they are particularly resistant to rotenone and thus more difficult to collect. That does not explain their apparent abundance in the Pacific, however. The only other record from the Indian Ocean that we are aware of is a specimen reported by Quéro & Saldanha (1995) collected more than a century ago at Réunion (MNHN B.3140). The first author examined this specimen recently in Paris and confirmed its identification. In the COI-based phylogeny (Fig. 48), four close but well divergent clades from various localities have been identified as U. macrocephalus, and we are currently unable to decide, which (if any) of these represents the species.

Published as part of 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, pp. 1-87 in Zootaxa 4704 (1) on pages 67-68, DOI: 10.11646/zootaxa.4704.1.1, http://zenodo.org/record/3563576