Masked grouper
(Gracila albomarginata)

Distribution

Indo-Pacific: northern Mozambique to French Polynesia, north to Okinawa, south to the northern Great Barrier Reef. Unknown from the Red Sea and Persian Gulf.

Max length : 40 cm TL

Dorsal spines (total): 9; Dorsal soft rays (total): 14-16; Anal spines: 3; Anal soft rays: 9 - 10.

Readily identified by the white square on their sides, blue in natural light. Differs from all shallow water Micronesian Cephalopholis except C. polleni by having truncate tail. Characterized further by: greenish or reddish brown to brownish grey body color, with several narrow curved dark bars on the midlateral part of the body; dark brown spot midlaterally on the caudal peduncle; 3-5 blue lines across head; oblong body, slightly compressed, depth contained 2.6-3.3 times in SL; width of body 1.8-2.3 times in depth

Head smaller compared to other groupers, head length 2.9-3.2 times in SL; evenly convex dorsal head profile; slightly convex interorbital area, width greater than eye diameter; narrow preorbital, depth distinctly less than eye diameter, preorbital depth 10-15 times in HL; rounded preopercle, finely serrate, smooth and fleshy lower edge; ventral edge of subopercle and interopercle smooth; posterior and anterior nostril subequal in size; posterior part of maxilla with hook-shaped or step-like expansion on ventral edge in adults; well developed supramaxilla; pair of small canines at front of jaws; presence of palatine teeth; 2 rows of teeth on midside of lower jaw, inner teeth depressible and twice as long as outer teeth.