Gymnothorax griseus ( Lacepède 1803 )

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 : 29-31

Gymnothorax griseus ( Lacepède 1803) —Gray Moray

( Figure 16 )

Muraenophis grisea Lacepède (ex Commerson) 1803: 629, 642, pl. 19 (fig. 3) (locality uncertain). No types known.

Muraena geometrica Rüppell 1830: 118 , pl. 30 (fig. 1) (Massawa, Eritrea, Red Sea). Holotype (unique), SMF 130. — Klunzinger 1871: 617; Borsieri 1904: 219.

Muraena bilineata Rüppell 1838: 84 ( Jidda [Jeddah], Saudi Arabia, Red Sea). Holotype, SMF 911 .

Gymnothorax geometricus : Marshall 1952: 223.

Echidna geometrica: Tortonese 1955: 52 ; Roux-Estève 1956: 62.

Siderea geometrica: Clark et al. 1968: 21 .

Echidna grisea: Tortonese 1968: 9 ; Tortonese 1983: 106.

Siderea grisea: Dor 1984: 29 ; Goren & Dor 1994: 7; Randall & Golani 1995: 870; Khalaf & Disi 1997: 40; Debelius 1998: 15.

Gymnothorax griseus: Khalaf 2004: 35 ; Lieske & Myers 2004: 38; Golani & Bogorodsky 2010: 10; Golani & Fricke 2018: 21.

Red Sea material. Egypt: BPBM 18133 (2, 378–388), Marsa el Mukabeila; HUJ 15062 (7, 252–404), Gulf of Aqaba, El Arkana; HUJ 15164 (3, 503–645), Nuweiba ; USNM 312476 (1, 320), El Himeira ; USNM 312478 (2, 362–373), Gulf of Suez, El Tur . Saudi Arabia: KAUMM 394 [ KAU12-248 ] (1, 197), Farasan Archipelago ; SMF 911 (1, 510, holotype of Muraena bilineata ), Jeddah ; SMF 7186 (1, 198, paratype of Muraena bilineata ), Jeddah ; SMF 35250 (1, 336), Al Khoreybah ; SMF 35807 [ KAU12-438 ] (1, 358), Farasan Archipelago . Eritrea: SMF 130 (1, 213, holotype of Muraena geometrica ), Massawa ; USNM 312472 (2, 219–362), Massawa ; USNM 312473 (1, 174), Melita Bay .

Comparative material. Mozambique: SAIAB 106 (1, 368, holotype of Siderea schonlandi Smith ) . Mauritius: USNM 267367 (2, 180–275) ; USNM 312486 (2, 248–265) ; USNM 312487 (3, 116–138) . Aldabra : USNM 312467 (2, 93–233) . Agalega I.: USNM 312488 (1, 258).

Description. In TL: preanal length 2.2–2.6, predorsal length 9.7–14.0, head length 7.7–11., body depth at anus 15–26. In head length: snout length 5.8–7.1, eye diameter 9.5–13, upper-jaw length 2.8–3.7. Pores: LL 2, SO 3, IO 4, POM 6. Vertebrae: predorsal 3–5, preanal 49–54, total 128–140.

Body moderately elongate; anus slightly before midlength; dorsal fin high, its origin before gill opening. Jaws moderate, of equal length. Eye moderate, over middle of upper jaw. Anterior nostril short and tubular; posterior nostril with a raised rim, above anterior margin of eye.

Teeth short and stout, not sharply pointed, smooth. Intermaxillary teeth in a single peripheral series, one or two median teeth. Maxillary teeth biserial, teeth of inner row larger. Dentary teeth biserial anteriorly, uniserial posteriorly. Vomerine teeth small, conical, biserial anteriorly.

Color: body pale yellowish or whitish gray densely mottled with irregular darker markings forming an obscure honeycomb pattern. Head and anterior nostril lavender-gray, the pores outlined in black. Rows of sensory papillae on head and anterior body marked by small dark spots forming conspicuous lines; one row on snout forming an inverted “U” shape, then continuing posteriorly along side of upper lip; transverse row of slightly larger black spots on nape; spots continuing along lateral line behind head for a varying distance, disappear in large individuals. Iris white.

Maximum size about 650 mm.

Distribution and habitat. Found in the western Indian Ocean from Oman to South Africa and east to the Chagos Archipelago; common in shallow water where it can be seen foraging for food among corals and rocks; reported in depth range of 1– 30 m.

Remarks. One of the most common Red Sea morays, sometimes seen in groups of up to five individuals. Closely related to Gymnothorax thyrsoideus (Richardson) , which occurs in similar habitats in the eastern Indian Ocean and Pacific. The phylogenetic analysis of the mitochondrial COI barcoding gene does not show reciprocal monophyly for specimens of G. griseus and G. thyrsoideus (Richardson) , indicating a very recent divergence of these very similar species. Gymnothorax griseus has sometimes been placed in the genus Siderea , but the type species of that genus is Muraena picta Ahl, 1789 , which has more acute, uniserial teeth. The dentition of Gymnothorax griseus and G. thyrsoideus approaches that of Echidna . In the phylogenetic analysis, two species of Echidna ( E. unicolor Schultz and E. delicatula Kaup ) are within a well-supported clade with G. griseus , G. thyrsoideus and G. pseudoherrei , and E. delicatula is the next closely related species to G. griseus and G. thyrsoideus (see Fig. 48 ), questioning the validity of the currently applied generic concepts.

Specimens from the Red Sea have fewer vertebrae than those from elsewhere (128–134 vs. 132–140 respectively), but in its mitochondrial COI sequences the one included Red Sea specimen does not differ much from either G. griseus outside the Red Sea or from the closely related G. thyrsoideus . The synonymy follows Dor (1984).

There is some uncertainty about the type locality of this species. Randall & Golani (1995: 870) stated “probably Mascarenes,” as it was based on Philibert Commerson’s manuscript and Commerson spent some time in Mauritius after leaving Bougainville’s expedition. However, that expedition was circumglobal and visited many locations before arriving at Mauritius. In his very brief description of Muraenophis grisea, Lacepède stated that “La grise aime les mêmes eaux que l’étoilée et la colubrine” (The gray [ Muraenophis grisea ] likes the same waters as the étoilée and the colubrine [two other species]), but the habitat for those was given as New Britain and Amboina, both far outside the range of Gymnothorax griseus . The illustration given with the description is somewhat ambiguous and could also be interpreted as Gymnothorax thyrsoideus , which does occur in the stated localities. At some point, it might be necessary to select a neotype, but we leave that for another study.

Figures

FIGURE 16. Gymnothorax griseus. A: Dahab, Egypt; B: Sharm el Moya, Egypt. Photos 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.