Scarus ferrugineus Forsskål, 1775

Scarus ferrugineus Forsskål in Niebuhr, 1775: 29; neotype: BPBM 18158; type locality: Dahab, Gulf of Aqaba, Red Sea. Rusty Parrotfish

Figure 6

Material examined: Underwater photographs.

Distinctive characters: Body depth 2.5–2.8 in SL; dorsal profile of head of terminal males nearly straight from before eye to dorsal fin; posterior nostril slightly smaller than anterior nostril; teeth fully fused to form dental plates, two-thirds or more covered by lips; cutting edge of dental plates usually slightly irregular, sometimes nearly smooth; upper dental plate with 1–2 conical teeth posteriorly in terminal males; caudal fin double emarginate in terminal males. Meristic values: Pectoral-fin rays 15; median predorsal scales 6–7, fifth scale largest; cheek with 3 scale rows, lower row with 2–4 scales.

Colouration: Initial phase light gray-brown, the scale edges narrowly dark, with three dark gray-brown bars on body; head gray, with a white spot at corner of mouth; posterior part of dorsal and caudal fins yellow. Body of terminal males blue-green, scales rimmed with magenta, with pale bar in the middle, green posteriorly; head dorsally green suffused with yellow, sometimes with small green spots and short bands dorsally on snout and interorbital space; snout and chin green extending as stripe to below eye, two short stripes extending from posterior edge of eye; caudal fin deep blue, the upper and lower lobes pale blue-green.

Distribution: Entire Arabian Region, from the northern Red Sea around the Arabian Peninsula, including the eastern Gulf of Aden and Socotra, to the Arabian /Persian Gulf (Randall & Bruce 1983; Randall 1995; Buchanan et al. 2015; Lips et al. 2016).

Remarks: Observed individuals match the description of Scarus ferrugineus (Randall & Bruce 1983; Randall 1995), supporting the record of Zajonz et al. (2019). Individuals were observed in coral-dominated habitats at all islands of the archipelago at depths of 3–15 m, though the species is moderately rare. Scarus persicus Randall & Bruce, 1983 is a closely related species but its initial phase lacks yellow on the caudal peduncle and the caudal fin. Terminal males of S. persicus have a dark bar centred on body, nearly always small green spots and irregular narrow green stripes present dorsally on snout and interorbital area, the chin with a green bar, and head anteriorly without green mask.