Bathygobius mystacium and B. geminatus

Bathygobius mystacium is both morphologically and genetically distinct from most other New World Bathygobius species, although it overlaps with B. geminatus in some meristic counts and morphometric measurements. The neighbor-joining tree of Tornabene et al. (2010) showed these two species as being genetically similar, however the phylogeny from our concatenated dataset failed to resolve the placement of B. mystacium . Bathygobius geminatus was resolved as the sister species to the B. soporator group, however we refrain from including this species in the B. soporator group as the posterior probability value of this relationship was a modest 0.70. The relationships between B. geminatus, B. mystacium and their congeners were variable and were not well-supported across each of the individual gene trees. The Wagner parsimony tree from Miller & Smith (1989) generated from morphological data shows B. mystacium as the basal member of a clade also containing B. soporator and B. andrei . This relationship is not supported by any of our analyses.