A revision of the goby genus Gnatholepis Bleeker (Teleostei, Gobiidae, Gobionellinae), with description of a new species

Species of the tropical gobiid genus Gnatholepis have been misidentified and confused for many years. A gobionelline, Gnatholepis is the only strictly marine genus of that subfamily. Gnatholepis was reviewed from a morphological viewpoint, as recent publications distinguishing species (morphologically and genetically) have not always been in agreement. The genus is considered to include nine described species, with two distinctive sister-taxa (G. argus and G. gymnocara) and seven less easily distinguished taxa: one species-group formed by G. anjerensis, G. knighti, G. ophthalmotaenia andG. yoshinoi and another species-group of G. cauerensis, G. pascuensis and G. thompsoni. Of these, the G. cauerensis species- group is the most complex, with several subspecies-names available. There is also a distinctive taxon from the Red Sea that represents a new species, described herein.