Diagnosis: 41-44 bony rings (mode 43) (Ref. 81680), 19-21 (mode 20) trunk rings (before anus)(Ref. 57226, 81680) and 20-26 tail rings (behind anus)(Ref. 81680). 8.0-9.75 total subdorsal rings, 1.75-3.5, usually 2.5 or more, subdorsal trunk rings and 5.25-7.0, usually 5.75-6.5, subdorsal tail rings (Ref. 81680). Head length 4.8-5.6 (mean 5.2) times in SL (Ref. 57226, 81680). Snout 1.5-1.7 (mean 1.6) times in HL (Ref. 81680).

Coloration: general colour of preserved specimens dark brown, but pattern often highly variable within a single sample; lateral part of snout with dark brown blotches or stripes; body plain, blotched or with vague pale mid-lateral trunk stripe; dorsum and belly somewhat paler than flanks; ventral part of head light brown; opercle with numerous small dark brown spots and often a narrow horizontal dark, silvery stripe situated towards upper edge; caudal fin mainly brown with pale edging; other fins hyaline or with fin rays edged with brown; no consistent differences in preserved colouration of various subspecies (Ref. 81680).