Appearance
The redmouth grouper is laterally compressed and oval shaped with a relatively deep body which is around half of the standard length and a large head. The dorsal profile of the head is straight or slightly concave while the anterior dorsal profile between the eye and the origin of the dorsal fin is convex. It jaw extends past its eye. The dorsal fin has 9 spines and 17-18 soft rays while the anal fin has 3 spines and 8-9 soft rays. The middle soft rays of the dorsal and anal fins are elongated in the adults which results in them having an angular profile. They have a caudal fin which is truncate and asymmetrical pectoral fins. The pelvic fins extend beyond the anus. The colour is dark brown to black, sometimes tinged with orange and a pale vertical bar on the lower flank. The rear part of the spiny portion of the dorsal fin varies in colour from dark orange to brownish red.

