Nannoperca pygmaea Morgan, Beatty & Adams 2013

This species is distinguished by the following characters: small mouth; deeply notched dorsal fin; poorly developed two-part and interrupted lateral line; differs from N. australis, N. oxleyana and N. variegata in having an exposed and serrated preorbital bone and jaws just reaching to below the anterior margin of the eye (vs. a smooth and hidden preorbital and the jaws reaching to at least the pupil); from N. vittata by having 5-10 thin lateral stripes most obvious below lateral line and poorly developed tube scales (vs. well developed), a more distinct haloed blackish spot resembling an ocellus at the base of the caudal fin, the hind margin of the scales on the caudal peduncle are without distinct pigment, and the belly is without a colour pattern; from N. obscura in having a distinct ocellus at the base of caudal fin (vs. an indistinct barring), as well as a dark spot behind operculum and lack of dusky scale margins; from N. balstoni, in having an exposed rear edge of the preorbital (vs. hidden under the skin), fewer transverse scale rows (13 vs. 15-16), a smaller mouth (rarely reaching eye vs. reaching well beyond the eye), ctenoid body scales (vs. cycloid), generally fewer pectoral rays and a smaller maximum size (Ref. 93277).

Dorsal spines (total): 7 - 9; Dorsal soft rays (total): 8; Analspines: 3; Analsoft rays: 6 - 7

The species is rare and restricted in its range. Inhabits tannin stained, acidic and shallow Melaleuca rhaphiophylla streams (Ref. 93277).