Redmouth grouper
(Aethaloperca rogaa)

The redmouth grouper is laterally compress 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. The oral cavity, gill cavity, and upper jaw membranes are reddish to orange, thus the common name.

The juveniles have a wide white rear margin to the caudal fin and a thin white margin along the soft-rayed portion of the dorsal fin.

The maximum total length is 60 centimetres (24 in).

The redmouth grouper has an Indo-West Pacific distribution which extends from the Red Sea and Persian Gulf south along the East African court to South Africa, east to the Phoenix Islands in Kiribati, and north to southern Honshu, Japan.

In Australia it has been recorded from Rowley Shoals and the Kimberley region in Western Australia, Ashmore Reef, the Timor Sea, and the northern Great Barrier Reef as far south as Wheeler Reef in Queensland.

This species is likely found around all the tropical islands of the Indian Ocean, although it has not been reported from Mauritius yet.

It has been recorded from Europa Island in the Mozambique Channel.