Callogobius sclateri ( Steindachner 1879 )

Delventhal, Naomi R., Mooi, Randall D., Bogorodsky, Sergey V. & Mal, Ahmad O., 2016, A review of the Callogobius (Teleostei: Gobiidae) from the Red Sea with the description of a new species, Zootaxa 4179 (2), pp. 225-243 : 239-241

Callogobius sclateri ( Steindachner 1879)

( Figure 7A )

Eleotris sclateri Steindachner 1879: 157 ( Society Islands ; holotype NMW 30901).

Diagnosis. Callogobius sclateri is distinguished from congeners by the following combination of characters: interorbital pores present; preopercular canal absent; temporal canal absent; scales in lateral series 27–32; pelvic fins separate or with only a minute basal membrane, without frenum and with fifth ray subequal to fourth; preopercular papillae row (Row 20) not continuous with transverse opercular row (Row 21).

Brief description. Moderately stout-bodied with rounded caudal fin <40% SL in length. Scales mediumsized, cycloid anteriorly, ctenoid from the first to third spine of the first dorsal fin to the caudal-fin base (exceptionally long ctenii on caudal peduncle scales), scales in lateral series 27–32. Dorsal-fin rays VI + I,9, analfin rays I,7; pelvic fins separate or joined by a minute basal membrane, fifth ray just slightly shorter or about equal to length of fourth and frenum absent. Anterior nostril slightly longer than posterior nostril. Head pores present with interorbital canal normally containing pores B’, C, D, E, F, G and H’ (pore C sometimes absent), preopercular and temporal canals absent. Preopercular papillae row (Row 20) not continuous with transverse opercular row (Row 21), more than 10 transverse mandibular papillae rows (Row 16) on each side.

Head, body and fins usually with fine speckling, particularly in larger specimens. Head with dark brown bars extending from eye, one oblique anteriorly to upper lip, one posteriorly to preopercular margin, and one ventral just posterior to gape. Body with up to four brown bars, one from base of first dorsal fin extending from basal fin spot and narrowing to below outer third of pectoral fin, an oblique brown bar linking posterior bases of second dorsal and anal fins extending irregularly into second dorsal-fin membranes, a broad dark brown bar at base of caudal fin, and another short bar on lower half of body below origin of second dorsal fin. First dorsal fin mostly dark, second dorsal fin mottled or broadly striped. Pectoral fin with dark diagonal marking along upper margins in juveniles, which can become broader, more vertical, curved and/or diffuse in larger specimens. Caudal fin with faint, fine barring to dark. Coloration in preservation similar to live coloration.

Distribution and habitat. Callogobius sclateri is distributed in the Indo-West Pacific and the Red Sea. Habitat information not recorded in the Red Sea, although capture depth ranges from 0– 16 m.

Remarks. In the Red Sea, Callogobius sclateri , C. flavobrunneus , and C. clarki are frequently confused due to similarly-shaped moderately stout bodies, and color pattern of four wide bars. Callogobius sclateri differs from C. clarki by having head pores in specimens at least 14 mm SL (vs. none) and in having separate pelvic fins (vs. united at least two-thirds length). Callogobius sclateri shares the separate pelvic fins with C. flavobrunneus , but differs in having lower counts of scales in lateral series (27–32 vs. 34–40), fifth pelvic-fin ray subequal to fourth (vs. significantly shorter), and pectoral-fin color pattern (dark upper edge or diffuse vertical bands vs. medial dark markings). Callogobius sclateri has a similar color pattern to C. sp. A ( Fig. 7 B), but the latter has partially united pelvic fins and fewer scales in lateral series (22–25 vs. 27–32). These differences were confirmed through examination of the holotype of C. sclateri ( NMW 30901) by NRD and SVB.

Representative Red Sea material (4 specimens, 14.0– 21.8 mm SL). Egypt: USNM 298412, 1 male and 1 female, 14.0– 20.5 mm SL ; USNM 298419, sex uncertain, 1 specimen, 21.8 mm SL; USNM 296964, male, 21.4 mm SL.

Figures

FIGURE 7. A. Callogobius sclateri (Steindachner), preserved specimen, USNM 298419, female, 22.1 mm SL, Ras Burqa, Gulf of Aqaba, Egypt. B. Callogobius sp. A, live coloration, SMF 35772, juvenile, 14.5 mm SL, Yabua Island, Saudi Arabia. Photos by RDM (A), SVB (B).