Dactyloptena gilberti Snyder, 1909

Bogorodsky, Sergey V., Alpermann, Tilman J., Mal, Ahmad O. & Gabr, Mohamed H., 2014, Survey of demersal fishes from southern Saudi Arabia, with five new records for the Red Sea, Zootaxa 3852 (4), pp. 401-437 : 416

Dactyloptena gilberti Snyder, 1909

( Figs. 5 & 6 )

Material examined. SMF 35003 (1: 6.6 cm).

Description. Dorsal-fin rays I + I + V + I,8; anal-fin rays 6; pectoral-fin rays 28/28; pelvic-fin rays I,4; body moderately elongate, body depth 4.1 in SL; scales strong, each with a distinct ridge, caudal peduncle posteriorly with scute-like scales; head length 3.4 in SL; upper surface of the head granular, concavity with irregular rows of granular ridges; interorbital space extremely wide, its width 4.4 (22.6%) in SL, and concave, the depth of concavity 5 in head length; snout very short, wide and rounded, with granular projections arranged in rows, the snout length 6.1 in head length, distance from snout to margin of orbit 1.8 in interorbital width; projections on preorbitale and cheek in irregular rows, those on preorbitale more prominent; opercle and preopercle with irregular rows of scutes; eyes large, their diameter 2.4 in head length; mouth small, subterminal, and protractile; upper jaw largely obscured by bones surrounding eye, reaching to below center of pupil; jaws, palatines, and vomer with minute teeth; posttemporal spine well-developed, but flat against body, reaching to a vertical between bases of second and third dorsal-fin spines of continuous spinous part, the distance from snout to tip of spine 2.5 in SL; angle of preopercle with prominent spine reaching to level between bases of fourth and fifth dorsal spines of continuous spinous part, the distance from snout to tip of spine 2.0 in SL; ventral ridge of preopercular spine finely serrate; anterior two dorsal spines separated from remainder of spinous dorsal fin, first spine elongate, just behind “V”-shaped posterodorsal insertion of cranium, the spine subequal to the head length, its length 3.3 in SL, predorsal length 3.7 in SL; second dorsal fin spine shorter, a little closer to spinous portion than to the first spine, its length 8.2 in SL; last spine tiny, just before soft portion, lying on the end of scute; pectoral fins long, the length 1.2 in SL, reaching middle of caudal fin; pelvic fins just reaching anus; caudal fin truncate, the length 3.7 in SL.

Color (when fresh): grey, suffuse with orange, with scattered orange spots as large as pupil on head and body, white ventrally ( Fig. 5 A); pectoral fins with numerous dark spots and a large black blotch on middle of ray, blue spots and lines inside the middle black blotch and posterior margin of fin ( Fig. 5 B); caudal fin with two, irregular, vertical rows of small orange spots, the posterior margin broadly orange-red.

Distribution. Indo-West Pacific, from southern Red Sea (this study), Somalia and Oman to the Gulf of Thailand and Japan, but not southern Southeast Asia or Australia ( Eschmeyer 1997; Matsunuma et al. 2011).

Remarks. The single specimen was trawled on sand bottom close to an island at a depth of 25– 28 m. The genus Dactyloptena contains six Indo-West Pacific species, two of them previously known from the Red Sea, D. orientalis (Cuvier, 1829) and D. peterseni (Nyström, 1887) . While the former was reported from shallow water, the latter was recorded in the Red Sea from moderately deep water of Gulf of Aqaba ( Baranes & Golani, 1993; Khalaf & Disi 1997). Dactyloptena peterseni differs from the two other Red Sea species in lacking a spine between the elongate first dorsal spine and the continuous part of the spinous dorsal fin. Dactyloptena gilberti differs from D. orientalis by a broader and deeper interorbital space, 18–23% of SL and 12–17% of head length in D. gilberti vs. 13–15% of SL and 8–11% of head length in D. orientalis , respectively ( Poss & Eschmeyer, 1999a). The specimen collected from the Red Sea has a deeper concavity of the interorbital ( Fig. 6 ) than the range given for the species by Poss & Eschmeyer (1999a), 20% of head length instead 12–17%. We suspect this is either due to a higher intraspecific variability than that hitherto reported or due to a slight morphological variation of the Red Sea population of D. gilberti . More material from the Red Sea is required to resolve this issue.

Figures

FIGURE 5. Dactyloptena gilberti, SMF 35003, 6.6 cm SL, Jizan, Saudi Arabia. A. Lateral view. B. Dorsal view.

FIGURE 6. Dactyloptena gilberti, SMF 35003, 6.6 cm SL, anterior view, Jizan, Saudi Arabia.