Diagnosis: combined premaxillary tooth plate very broad, 33.5-41.7% of head length vs. 30.1-35.3% in N. boutchangai, and less than 30% in the other species; eye diameter large, 9.1-13.3% of head length vs. smaller in N. maculatum, N. pallidum and N. depierrei, but overlapping with eye size range of the other species; interorbital distance rather large, 28.0-36.6% of head length vs. 24.0% or less in N. akiri, N. depierrei, N. pallidum and N. pembetadi; only 7 soft dorsal-fin rays vs. more than 8 in N. depierrei, N. maculatum, N. pallidum, N. pembetadi, N. thomasi and N. walkeri; dorsal fin spine rather long, 6.9-14.7% of standard length vs. shorter in N. depierrei, N. maculatum, N. pembetadi and N. thomasi (Ref. 94168).

Description: body and head rather depressed, pre-dorsal body depth 16.1-18.0% of standard length, minimal caudal peduncle depth 13.2-15.9% of standard length, head depth 45.9-60.0% of head length; branchiostegal membranes each supported by 12 rays, almost not fused, separated by a deep medial slit, possibly overlapping; total number of 38 vertebrae; dorsal fin relatively high and rounded, spine 6.9-14.7% of standard length; 7 branched dorsal-fin rays; adipose fin moderately deep, 4.0-6.2% of standard length (Ref. 94168).

Colouration: dark brownish gray to pale yellow with numerous black or brown spots and blotches on the head, body and fins, often aligned in transverse bands along the flanks; juvenile colouration more variable, with larger, often confluent blotches, only yellow and light and dark brown alternating bands visible (Ref. 81642, 94168; above colouration refers to live specimens in Ref. 94168 but preserved specimens in Ref. 81642).