A New Species of Eugnathogobius (Gobiidae) from Peninsular Malaysia

The new estuarine goby Eugnathogobius ganuensis n. sp. is described from 5 specimens (4 males: 27.0–31.5 mm standard length; 1 female: 27.5 mm standard length) collected from a small ditch in the lower reach of the Terengganu River basin, east coast of Peninsular Malaysia. The new species is easily distinguished from other congeners, except E. kabilia, by the following a combination of characteristics: 16 segmented caudal-fin rays; 30 or 31 longitudinal scale lows; high first dorsal fin (especially in males); no head pores; shoulder with oblique black band; transverse black markings on each scale; paired black blotches on caudal-fin base; and distinct black dots on upper caudal fin. Although E. kabilia is very similar to the new species, the latter has a shorter jaw in males (well-extended in the former), high first dorsal fin (low), first dorsal-fin second spine length > 16.8% of standard length (<13.6%), throat yellowish in the fresh condition (whitish), and a yellowish second dorsal fin (reddish in males of E. kabilia). Because the type locality of the new species is clearly not a natural environmental feature and no salinity during the low tide, despite being included in the tidal area, the true habitat is suggested as being the upper reaches of estuarine areas.