Callanthias splendens

Callanthias australis has a continuous dorsal fin which is supported by 11 spines and between 10 and 12 soft rays while the anal fin has 3 spines and 10 or 11 soft rays. It has a moderately elongated body with a small, oblique mouth. The shape of the caudal fin varies from emarginate to almost truncate with larger individuals developing long filaments from the tip of each lobe. The colour of juveniles is light pink with light blue fins. The females are pale red to orangey-red with silvery on the lower face and throat and pale fins. The males have a purplish red head and front of the body with the rear body being red. The dorsal and anal fins are brown while the caudal fin is bluish purple with red tips and a yellow centre. This species has a maximum published standard length of 49 cm (19 in).

Callanthias australis is found in the southwestern Pacific Ocean and into the southeastern Indian Ocean. In Australia this species is found from Moreton Bay in Queensland south and west to Rottnest Island in Western Australia, it is also found off Norfolk Island in the Tasman Sea. In New Zealand it is found to the north of the range of C. allporti being found from the Kermadec Islands south to Castlepoint and Westport in the northern South Island. In New Zealand this species has the common name of Northern splendid perch while C. australis is the Southern Splendid perch. The magnificent sea perch is found at depths of between 20 and 365 m (66 and 1,198 ft) on deep reefs and rocky pinnacles, although juveniles are found in water as shallow of 10 m (33 ft) in inshore waters.

Callanthias australis has the specific name australis which means "southern", this species was described by Ogliby as a subspecies of C. platei.