Argentina elongata is a herring smelt of the family Argentinidae, found around southern Australia, and New Zealand, at depths of between 328.08 and 1096.50 ft (100 and 600 m). Its length is up to 9.84 in (25 cm).
Argentina elongata is an elongate fish with a sharply pointed snout, a short but high first dorsal fin, and an adipose second dorsal fin set well back near the deeply forked caudal fin. The pelvic fins are set well back, about half way along the length of the body. The scales are only loosely attached and are easily lost.
Coloration is yellowish on the body with a distinct brilliant silver band along each side. Small individuals have eight pale brown bands across the back but these disappear with age.