Phylogeny of Glaucosomatidae inferred from molecular evidence

Most species of glaucosomatids (Teleostei: Glaucosomatidae) are endemic to Australia, except Glaucosoma buergeri that is widely distributed from Australia to Japan. This study elucidated phylogenetic relationships among glaucosomatids based on the morphological characters of the saccular‐otolith sagitta, in addition to molecular evidence of mitochondrial 16S rDNA, cytochrome oxidase I (COI) and cytochrome b (cyt b) sequences, and nuclear rhodopsin sequences. The topologies of individuals' phylogenetic trees, based on 16S rDNA, COI and cyt b sequences, were statistically indistinguishable from one another, and were only slightly different from a tree based on rhodopsin sequences. These molecular tree topologies, however, differed from species relationships in morphology‐based phylogenetic hypothesis proposed in previous studies. Specimens of G. buergeri from Australia and Taiwan showed differences in the sagitta and molecular differentiation at the four genes, suggesting a possible speciation event. Both molecular and morphological evidences indicate that Glaucosoma magnificum is the plesiomorphic sister species of other glaucosomatid species. Glaucosoma hebraicum is the sister species of a clade composed of G. buergeri and Glaucosoma scapulare. Molecular and morphological evidences also support the species status of G. hebraicum.