Greenway's grunter is a small, slender golden to silvery-grey grunter which is covered in large scales, each with a dark margin and a dark blotch on the lower part of the caudal fin. The juveniles have a dark spot at base of the soft-rayed part of the dorsal and anal fin bases. The larger adult fish may develop thick, fleshy, lips and when caught individuals may show broad, vertical bars. This species has a maximum standard length of, although is a more common standard length.
The adults of Greenway's grunter are found in moderately to swiftly flowing streams in both clear and turbid water where there is a mixedsubstrate of sand and rock. Its biology is little known, but in 1969 a collection of 100 specimens of this fish suggested that are found in fast flowing rapids where the water was green in colour and the visibility was as low as. It is an omnivorous species feeding on algae and small invertebrates. The eggs are guarded and fanned by the male parent. It is thought likely that this species spawns in the wet season.