A taxonomic revision and cladistic analysis of the oxudercine gobies (Gobiidae: Oxudercinae)
The gobiid subfamily Oxudercinae was revised to assess the monophyletic nature of the subfamily; the intergeneric relationships within the subfamily; the relationships of oxudercines to other gobiid genera; the recognisable species and their distinguishing characters; and the distribution patterns of the subfamily and component taxa. The following results were obtained: (1) The Oxudercinae can be defined on the basis of derived states of certain neurocranial bones and muscles, eye position, nasal flap morphology, the palatine-ectopterygoid arrangement, reduction in size of the premaxillae ascending processes, and in having a single anal fin pterygiophore anterior to the first hemal spine. (2) Within the subfamily, one undefined and nine monophyletic terminal assemblages are recognised, with relationships amongst them based on derived states of various morphological features. These assemblages are recognised at the generic level and one new genus (Zappa) is described; a key to the genera is provided. Thirty four species are recognised of which one (Boleophthalmus birdsongi) is described for the first time. Each species is described in detail and a key is provided for each genus. (3) Two monophyletic assemblages (one comprising three genera, the other seven) are recognised at the tribal level. Defining characters for each tribe are provided and illustrated. (4) Biogeographic analysis indicated that nine of the ten genera are distributed in an area bounded by the Arabian Gulf to the west, southern Japan to the north, northern Australia to the south, and Papua New Guinea to the east. The remaining genus, Periophthalmus, overlaps and exceeds the above limits, ranging from west Africa eastward to Samoa. Species-specific correlations linking Periophthalmus with mangrove distributions are discussed.