Scarus arabicus (Steindachner, 1902)

Pseudoscarus arabicus Steindachner, 1902: 318; holotype: NMW 72746; type locality: Mukalla, Yemen, Gulf of Aden.

Arabian Parrotfish

Figure 4

Material examined: Underwater photograph; SMF uncatalogued [sample of tissue SOC19-468], initial phase, 26 cm SL, Socotra Island, Hadibo fishmarket, 12 April 2019 ; SMF uncatalogued [sample of tissue SOC19-485], terminal male, 46 cm SL, Socotra Island, Hadibo fishmarket, 19 April 2019 .

Distinctive characters: Body depth 2.4–2.7 in SL; dorsal profile of head of terminal males steep and distinctly convex; posterior nostril subequal to anterior nostril; teeth fully fused to form dental plates, less than one-half covered by lips; cutting edge of dental plates slightly irregular; posterior margin of upper dental plate with 4 or 5 small blunt teeth; caudal fin slightly emarginate in terminal males. Meristic values: Pectoral-fin rays 15; median predorsal scales 4, about equal in size; cheek with 2 scale rows, lower row with 4–5 scales.

Colouration: Initial phase gray-brown, the scale edges brown. Terminal males green often suffused with brown. Both phases with head pale blue-green ventrally, green front of snout, a broad pale blue-green band across interorbital which extends slightly behind orbit, dental plates blue-green, dorsal and anal fins colored like body with green-blue margin, and caudal fin with white posterior margin.

Distribution: Restricted to the Arabian region, reported from the eastern Gulf of Aden to the Gulf of Oman (Randall 1995; Lips et al. 2016).

Remarks: Observed individuals and collected specimens match the description of Scarus arabicus (Randall & Bruce 1983; Randall 1995), supporting the record of Zajonz et al. (2019). Individuals on Socotra Island were observed on rocky substrata at depths of 5– 8 m. Data on habitat and depth of collected specimens are not available. Previously known from Socotra Island (Zajonz et al. 2019), the distribution range is extended to the west by the observation of the initial phase and a terminal male in a mixed coral and rock reef area of south-eastern Abd al-Kuri Island.