This species is distinguished by the following characters: body fusiform, elongate and rounded; teeth small and conical, in a single series; gill rakers on first gill arch numerous, 53-63; D1 XIV-XVI, dorsal fins separated by a small interspace (not larger than eye), the second followed by 7-9 finlets; anal fin followed by 7-8 finlets; pectoral fins short, with 26-27 rays; 2 flaps (interpelvic process) between pelvic fins; body scaleless except for corselet and lateral line; a strong keel on each side of caudal-fin base between 2 smaller keels. Colour of back dark purplish blue, lower sides and belly silvery, with 4-6 very conspicuous longitudinal dark bands which in live specimens may appear as discontinuous lines of dark blotches (Ref. 9684).