Lethrinus nebulosus

Lethrinus nebulosus (Forsskål in Niebuhr, 1775)

Common name: Spangled emperor

Figs. 2–5; Table 2

Sciaena nebulosa Fabricius Forsskål in Niebuhr (1775: 52) (Arabia).

Lethrinus alboguttatus Valenciennes in Cuv. & Val. 1830 (Bonin Is; no known specimens).

Lethrinus anatarius Richardson 1845: 145 (Canton, China; no known specimens).

Lethrinus aurolineatus Macleay 1882: 247 (New Guinea).

Lethrinus carinatus Weber 1913: 289 (New Guinea).

Lethrinus centurio Valenciennes in Cuv. & Val. 1830: 301 (Seychelles).

Lethrinus coerorynchus Bloch & Schneider 1801: 278 (Japan); Johnson et al. 1993 (NW Australia).

Lethrinus cyanoxanthus Richardon 1843: 7 (Houtman Abrolhos, Western Australia).

Lethrinus devisianus Whitley 1929: 122 (Queensland).

Lethrinus erythrurus Valenciennes in Cuv. & Val. 1830: 293 (Sri Lanka).

Lethrinus esculentus Valenciennes in Cuv. & Val. 1830: 158 (Seychelles).

Lethrinus fasciatus Valenciennes in Cuv. & Val. 1830: 290 (Sri Lanka).

Lethrinus fletus Whitley 1943 (Gulf of Carpentaria, Australia).

Lethrinus fraenatus Valenciennes in Cuv. & Val. 1830: 291 (Sri Lanka).

Lethrinus gothofredi Valenciennes in Cuv. & Val. 1830; 286 (Gulf of Suez).

Lethrinus guentheri Bleeker 1873: 153 (Japan).

Lethrinus karwa Valenciennes in Cuv. & Val.1830: 311 (Vizagapatam, India).

Lethrinus korely Valenciennes in Cuv. & Val. 1830: 292 (Puducherry, India).

Lethrinus maculatus Valenciennes in Cuv. & Val. 1830: 292 (Puducherry, India).

Lethrinus nebulosus: Sato 1978: 30; Smith 1965: 286; Smith 1986: 598; Carpenter & Allen 1989: 75; Carpenter in Carpenter & Niem 2001:3027.

Lethrinus ornatus de Vis 1884: 458 (Queensland).

Lethrinus perselectus Whitley 1933 (Queensland).

Lethrinus scoparius Gilchrist & Thompson 1908: 168 (KwaZulu-Natal, South Africa)

Diagnosis. Body yellow-brown in life; face with bright blue spots and lines; about eye-sized oval blue spot at origin of lateral line, opercle mostly bright blue; upper pectoral-fin ray blue; pelvic fins blueish distally, and body with irregular lines of blue spots. Preorbital length in head length 2.52–4.30, mean 3.30.

Description. Dorsal fin X, 9, 4 th or 5 th spine longest; anal fin III, 8; pectoral fins 13; pelvic fins I, 5; LL 45–48; scales from 5 th dorsal-fin ray to LL 5 or 5½; scales from LL to 1 st anal-fin spine 14 or 15; circumpeduncular scales 9 + 13 (9 + 15 including LL scales). Exposed portion of opercle fully scaled; small patch of about 12 scales in two vertical rows immediately behind eye; supraorbital patch with 5–9 scales, and small patch of about 8 scales on upper, exposed portion of supracleithrum; inner surface of pectoral peduncle with many small scales. Teeth: few canines in front of upper and lower jaws, more rounded at sides of jaws with smaller, rounded teeth behind.

In SL: head 2.65–3.18, body depth 2.30–2.77; in HL: eye diameter 2.51–4.85, preorbital length 2.42–4.39; eye diameter 0.46–1.16 in cheek height. All other morphometrics are listed in Table 2.

Colour alive and fresh (Figs. 2, 3): head and body yellow-brown; face with many small, blue spots, blue line from eye to middle of upper lip and another from eye onto snout; bright blue bars below and above eye, and blue line from behind eye to a nearly eye-sized, bright blue oval at start of lateral line; opercle with broad blue bar; body with many irregular lines of bright blue spots, more so above lateral line than below; dorsal fin mostly hyaline, spines pale yellow anteriorly; anal-fin membranes yellow-brown; upper and lower margins of caudal fin yellowish, upper edge of pectoral fins bright blue, pelvic fins with bluish tinge. Membranes between pelvic-fin rays with dense, small melanophores. Juveniles (Fig. 4) pale brown with irregular, vertical dark brown stripes, similar to the stress pattern exhibited by adults (Fig. 5).

Colour in preservative: ranges from pale cream-coloured to pale brown, sometimes with various feint markings on the head which were originally bright blue. No other markings except melanophores on pectoral fins.

Maximum recorded size: more than 80 cm FL (Carpenter & Allen 1989); more than 60 cm FL from iSimangaliso Wetland Park.

Distribution. Red Sea to northern KwaZulu-Natal, South Africa, seldom south of the iSimangaliso Wetland Park (27.6°S), all islands, Persian/Arabian Gulf, to coasts of India and Sri Lanka to about 16°N on the East coast of India, and then from Andaman Sea throughout Indonesia, east coast of Australia, to southern Japan and Samoa. It has not been recorded from Bay of Bengal or the South China Sea (Carpenter & Allen 1989: Fig.134). See Discussion below.