A review of the tuskfishes, genus choerodon (labridae, perciformes), with descriptions of three new species

Abstract

The Indo-West Pacific labrid genus Choerodon comprises 27 species assigned here to six subgenera based on genetic and morphological evidence. Three of the subgenera are monotypic with distinctive morphological features, another two comprise species with a relatively deep body and generalised form and the remaining is a complex of small species referred to below as dwarf tuskfishes. Twenty-three species have valid scientific names, three are undescribed and one requires a replacement name because the name in use is a junior homonym. More than half of the species of Choerodon occur in northern Australian waters while only four are distributed in the western Indian Ocean, with two of the four currently undescribed. Among the undescribed species, Choerodon cypselurus sp. nov. is described from two individuals collected on the Saya de Malha Bank in the central part of the Indian Ocean and assigned to the subgenus Aspiurocheilus on the basis of body form and merstic values. Choero don skaiopygmaeus sp. nov. is a dwarf species described from seven individuals collected off Somalia. The absence of life colour information for type specimens makes comparison with described species difficult, but the species is distinguished by pigmentation and morphometric evidence. The third new species, Choerodon aurulentus sp. nov., the largest of known dwarf tuskfishes, is described from two specimens collected on the northern Norfolk Ridge at the north-eastern extent of the Tasman Sea between New Caledonia and New Zealand. Choerodonoides japonicus Kamohara, l958 is a junior homonym of Labrus japonicus Valenciennes, in Cuvier and Valenciennes, 1839, and is replaced by Choerodon albofasciatus nom. nov. Primary synonymies, synopses, known distributions and a dichotomous key to known species are provided.