A Revision of the Indo-Pacific Angelfish Genus Genicanthus, with Descriptions of Three New Species

The Indo-Pacific pomacanthid genus Genicanthus containing nine species is distinguished chiefly by its emarginate to lunate caudal fin (often with produced lobes), relatively short teeth, and sexual dichromatism. Males have either bars or stripes on the body (black on all species except G. bellus which has a yellow stripe) and lack black on the lobes of the caudal fin, whereas females (except the striped G. lamarck and the diagonally banded G. bellus) lack dark markings on the body and all except G. spinus have a prominent black band in each lobe of the caudal fin. G. semicinctus (Waite), known only from Lord Howe Island, is resurrected from the synonymy of G. melanospilos (Bleeker) of the western Pacific. G. caudibicolor (Liénard, in Sauvage) and G. zebra (Liénard, in Sauvage) are regarded as synonyms of G. caudovittatus (Günther) of the western Indian Ocean; the latter, however, is not a synonym of G. melanospilos, as some authors have contended. G. macclesfieldiensis Chan is referred to the synonymy of G. melanospilos. G. fucosus Yasuda and Tominaga is the probable female form of G. semifasciatus (Kamohara), which ranges from the Philippines to Japan. The distribution of G. melanospilos is extended to the New Hebrides, Loyalty Islands, Solomon Islands, Palau Islands, Fiji Islands, New Guinea, and the Ryukyu Islands; that of G. lamarck to the Solomon Islands; and that of G. watanabei to Pitcairn Island, Austral Islands, New Caledonia, and Osprey Reef (Coral Sea).

The following three new species are described: G. spinus (a relative of G. semicinctus) from the Pitcairn Group and Austral Islands; G. bellus from Tahiti and Cocos-Keeling Islands; and G. personatus from Hawaii. The male of the latter has not yet been collected.