A revision of the gobiid fish genus Mugilogobius (Teleostei: Gobioidei), and its systematic placement

WA Museum Records and Supplements | Updated 7 years ago

ABSTRACT – The gobiid fish genus Mugilogobius and 13 closely-related genera form a monophyletic group within the subfamily Gobionellinae of the family Gobiidae. Included with Mugilogobius in this group are the genera Brachygobius, Caecogobius, Calamiana, Chlamydogobius, Eugnathogobius, Gobiopterus, Hemigobius, Mistichthys, Pandaka, Pseudogobius, Redigobius, Stigmatogobius and Tamanka, which are discussed and compared. The entire group consists of about 105 species, which have been greatly confused in the literature. The genera Mugilogobius and Tamanka are revised, and full descriptions of the species included. The genera Brachygobius, Calamiana, Caecogobius, Chlamydogobius, Eugnathogobius, Hemigobius, Pandaka, Pseudogobius, Redigobius and Stigmatogobius are diagnosed, nominal species are listed and an indication of the probable number of valid species given.

Mugilogobius includes 25 species, of which eight are described as new. The genus is defined by a combination of characters. Most species of Mugilogobius occur in estuarine to fresh waters, with some species widespread in the Indowest Pacific and others restricted to a single waterbody. There is a speciescomplex in the tectonic lakes of Sulawesi, characterised by vertebral pattern and several character reversals.

Cladistic analyses of the Mugilogobius-group indicate that Chlamydogobius (restricted to Australia) is the sister-group to Mugilogobius. The monophyletic genus Tamanka is sister to the Mugilogobius-Chlamydogobius group. Hemigobius is the sister group to Pseudogobius. Brachygobius and Pandaka form a closely related group. Stigmatogobius is derived compared to Redigobius, a genus with the most plesiomorphic characters of the whole Mugilogobius-group. Eugnathogobius appears to be paraphyletic.

The Gobionellinae thus includes the Mugilogobius-group and a second monophyletic group in which are placed the genera Awaous, Evorthodus, Ctenogobius, Gnatholepis, Gobionellus, Oligolepis, Oxyurichthys and Stenogobius. The relationship of Redigobius and Rhinogobius to these groups is somewhat equivocal. All these gobionellines share certain characters, particularly those of the dorsal pterygiophore formula, epural number, vertebral number, headpore arrangement and a tendency to occur in freshwater to estuarine habitats.