Gymnothorax pictus ( Ahl 1789 )

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 : 47-49

Gymnothorax pictus ( Ahl 1789) —Peppered Moray

( Figure 31 )

Muraena picta Ahl 1789: 8 , pl. 2 (right fig.) (East Indies). No types known.

Siderea picta: Dor 1984: 30 ; Goren & Dor 1994: 7; Randall & Golani 1995: 870.

Gymnothorax pictus: Tortonese 1937: 166 ; Tortonese 1983: 106; Golani & Bogorodsky 2010: 10; Golani & Fricke 2018: 22.

Red Sea material. Red Sea: USNM 47605 (1, 494); USNM 47606 (2, 287–300); USNM 47607 (2, 293–347); USNM 47608 (2, 298–335); USNM 47609 (2, 243–250). Israel: HUJ 11428 (1, 410), Eilat.

Comparative material. Aldabra: USNM 264173 (1, 124) ; USNM 289752 (1, 130) ; USNM 312707 (2, 150– 201). Chagos Archipelago : USNM 312706 (2, 425–430). Indonesia : BMNH.1846.2.16.111 (1, 454, holotype of Muraena lita Richardson ) ; BMNH 1867.11 .28.286 (1, 518, holotype of Muraena pfeifferi Bleeker ) ; BMNH 1867.11 .28.332 (1, 110, holotype of Muraena polyophthalmus Bleeker ). Australia : MNHN B.2466 (1, 195, holotype of Muraena elegantissima Kaup ) ; BMNH 1846.9 .11.16 (1, 640, holotype of Muraena siderea Richardson ) . Mariana Is. : MNHN B.3142 (1, 630, holotype of Muraena variegata Quoy & Gaimard ). Hawaii : USNM 50618 (1, 240, holotype of Gymnothorax hilonis Jordan & Evermann ). Galapagos Is .: AMNH 255216 (1, 858+, holotype of Muraena thomsoni Borodin ). Locality unknown : MNHN B.3142 (1, 252, holotype of Muraena pantherina Lacepède ) .

Description. In TL: preanal length 1.8–2.2, predorsal length 6.6–8.8, head length 6.8–8.3, body depth at anus 13–29. In head length: snout length 5.3–7.5, eye diameter 8.6–16, upper-jaw length 2.6–3.7. Pores: LL 2, SO 3, IO 4, POM 6. Vertebrae: predorsal 6–10, preanal 53–62, total 113–135.

Body moderate; anus near midlength; dorsal-fin origin above gill opening. Jaws moderate, of equal length. Eye moderate, over middle of upper jaw. Anterior nostril tubular, short; posterior nostril above anterior margin of eye.

Teeth smooth, moderate in length and pointed. Intermaxillary teeth in a single peripheral series, 6–7 on each side, conical, increasing in size posteriorly; 1–3 median teeth. Maxillary teeth usually uniserial, about 9–13, smaller specimens sometimes with a few larger inner teeth anteriorly. Dentary with 1–4 larger inner teeth anteriorly, about 13–20 smaller outer teeth. Vomerine teeth biserial, diverging anteriorly in large specimens.

Color: variable, usually light tan or gray, usually finely speckled with small dark spots, often grouped to form irregular blotches, sometimes with pale centers, sometimes with irregular edges forming a snowflake-like pattern. Some specimens, like the one described as Gymnothorax hilonis from the Hawaiian Islands, are dark with large spots and narrow interspaces. Iris yellowish white with irregular black circle at margin.

Maximum size about 1.2 m.

Distribution and habitat. Widely distributed in the Indo-Pacific from East Africa to Central America, mainly in shallow water on reef flats and rocky shores to at least 20 m deep. It seems uncommon in the Red Sea, having been collected only on a few occasions. Randall & Golani (1995: 871) listed one specimen. The USNM specimens were collected many years ago. More recent expeditions have failed to collect it, although it has been photographed.

Remarks. It has not been noted previously, but specimens from the Red Sea have much lower vertebral counts than those from elsewhere. Nine specimens from the Red Sea have 53–56 preanal and 113–117 total vertebrae. The 13 specimens examined from Aldabra to Hawaiian Islands have 56–60 preanal and 128–135 total vertebrae. Böhlke & Randall (2000: 247) reported similar numbers for 37 specimens, although they did not give the collection localities. Insufficient attention has been paid to geographic variation in moray eels, so we do not know what recurring patterns might be found in this group. We have no genetic samples from the Red Sea, and no COI sequence data from Red Sea specimens of the species were available from other sources. Hence, we cannot contribute to answering the question, if the observed morphological differentiation within the species is accompanied by genetic divergence in geographically separated populations of the species. In the present phylogeny, Gymnothorax pictus is placed with high support in a joint clade with specimens from several other species that were identified as Echidna nebulosa , E. xanthospilos and G. pseudothyrsoideus by the respective sequence authors ( Fig. 48 ).

Gymnothorax pictus often has been classified in the genus Siderea , whose type species is Muraena siderea Richardson , a junior synonym of the former, together with S. grisea and others. Böhlke & Randall (2000), however, placed Siderea in synonymy with Gymnothorax due to the lack of distinguishing characters.

Figures

FIGURE 31. Gymnothorax pictus, Gulf of Oman, Oman. Photo by A. Nikolaev.

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.