A species of Glossogobius with bilobed mental frenum; predorsal area with scales extending forward to just before posterior preopercular margin; cheek, operculum, pectoral base, prepelvic area and anterior midline of belly naked; first dorsal fin with 3 dark spots, centred on fourth, fifth and sixth dorsal spine, respectively; second dorsal-fin rays usually I,10; anal-fin rays I,8; pectoral-fin rays 16-17; predorsal scale count 11-13; cheek papilla lines composed of single row of papillae; papilla line 6 absent and vertebrae 11+17.
Glossogobius muscorum is most similar to G. bellendenensis from Queensland. All are characterised by reduced predorsal scale coverage, no prepelvic or pectoral base scales and
small body size (see discussion of G. bellendenensis for comparison of these species). The species can also be confused with the sympatric Glossogobius concavifrons, which has scales on the pectoral base and prepelvic area, predorsal scales reaching to near the eye, more numerous precaudal vertebrae (13–15) and a more compressed head. Separation of juveniles below 20 mm SL is difficult because the scales are not well developed in Glossogobius concavifrons at that size. (Ref. 80299).