Ichthyscopus lebeck (Bloch et Schneider, 1801)

Limmon, Gino V., Wibowo, Kunto, Peristiwady, Teguh, Kusumah, Ruby V. & Afrisal, Muhammad, 2024, First Southern Hemisphere record of the longnosed stargazer, Ichthyscopus lebeck (Actinopterygii: Perciformes: Uranoscopidae), Acta Ichthyologica et Piscatoria 54, pp. 37-41 : 37

Ichthyscopus lebeck (Bloch et Schneider, 1801)

Fig. 1

Material examined.

MZB. 26859, 309.5 mm SL, MZB. 26860 mm SL, 290.2 mm SL, Jakarta Bay , 5°57′S, 106°42′E, Jakarta, Indonesia (purchased at the Tanjung Pasir Fish Landing Port, Banten, Indonesia, 3 Nov. 2022, by K. Wibowo; see Fig. 2 for the collection site) .

Description.

Meristic and morphometrics shown in Table 1 . Body elongated, progressively compressed posteriorly, moderately deep, its depth 2.7-3.2 in SL. Head large, slightly convex dorsally, mostly encased in irregular low vermiculated bone. Interorbital fossa rounded posteriorly, extending well beyond posterior margin of orbits, its mid-longitudinal length shorter than interorbital width. Orbit oval, its diameter noticeably greater than that of eyes. Nostrils with short, stiff, densely branched fimbriate edges; anterior nostril circular, distinctly shorter than eye diameter; posterior nostril circular, elongated, its length about equal to longitudinal orbit diameter; its posterior margin about level with posterior margin of eye. Mouth large, opening prominently upward; both lips with single row of long compressed fimbriae. Upper jaw with dense band of minute villiform teeth. Lower jaw with sharp uniserial spaced canines. Chin smooth, lateral surface without barbels. Opercular margin distinctly fimbriate dorsolaterally, weakly crenulated ventrally. Cleithral spine short, with sharp tip, covered by fleshy skin flap; tip of spine at about middle of skin flap. Cleithral flap fimbriated ventrally, posterior tip of flap reaching level with middle of pectoral fin. Narrow, low fleshy groove from inside opercular opening to about one-fourth to one-third length of uppermost pectoral fin ray; tiny fimbriae present on ventral margin of groove; posterior end of groove with small flap. Preopercle, opercle, and subopercle without spines. Dorsal fin with 2 approximately equal length spines, and 17-18 rays, becoming progressively longer posteriorly; origin of dorsal fin about level with origin of anal fin; posterior end of dorsal fin base slightly anterior to posterior end of anal fin base. Anal fin with 18 soft rays, first ray short, length of fourth to fifteenth ray about equal; membrane between rays (except three posteriormost rays) relatively deeply concave. Pectoral fin with 18 rays, blade-like and rounded posteriorly, fifth ray longest. Pelvic fin large, with small skin-covered spine and 5 branched rays; posterior tip of depressed fin distinctly beyond posterior margin of opercle. Caudal fin somewhat rounded, tips of branched rays extending slightly beyond surrounding membrane. Ventral surface of abdomen with three developed skin flaps; medial flap longest, extending from anteriormost of isthmus to anterior margin of anus; lateral flaps located on each side of medial flap, on posterior two-thirds of abdomen and extending to middle of second or third anal-fin ray. Third or fourth to eighteenth rays associated with short oblique skin flaps on each side; flaps lowering progressively posteriorly. Small rectangular posteroventrally oblique cycloid scale rows on body (some rows anteroventrally oblique on midlateral body surface in smaller specimen). Anterodorsal and ventral surfaces of body and lateral surface behind pectoral fin base naked. Vertebrae 9 + 16 (Fig. 1D ).

Color when fresh.

(Fig. 1A-C ). Head pinkish to white laterally, brown dorsally. Nape uniformly brown without distinct white blotches. Upper portion of body dark brown, with ca. 2 or 3 rows of white blotches, from slightly less to larger than eye diameter, running from above cleithral flap to caudal peduncle. Lower and ventral portions of body white. Dorsal fin dark, with a series of white blotches near base and outer edge. Pectoral fin dark yellowish, pinkish or whitish distally, with a large white transverse blotch anteriorly. Pelvic and anal fins yellowish to pinkish-white. Upper portion of caudal fin dark with ca. two pale white blotches; lower portion yellowish to pinkish.

Figures

Figure 1. Fresh specimen of Ichthyscopus lebeck from Indonesia; MZB. 26859, 309.5 mm SL. (A) lateral view; (B) dorsal view; (C) ventral view; (D) radiograph.

Figure 2. Collection site (star) of the specimens of Ichthyscopus lebeck from Indonesia; examined in this study.