大甲鲹，俗名为铁甲、扁甲，为辐鳍鱼纲鲈形目鲈亚目鲹科的其中一个种。

本鱼广泛分布于印度西太平洋区，红海、马尔代夫、斯里兰卡、孟加拉湾、安达曼海、印度、日本、中国沿岸、**、越南、菲律宾、印尼、泰国、马来西亚、圣诞岛、澳洲、马里亚纳群岛、瑙鲁、密克罗尼西亚、所罗门群岛、马绍尔群岛、新喀里多尼亚等海域。该物种的模式产地在美洲。

The torpedo scad, Megalaspis cordyla (also known as the hardtail scad, finny scad, finletted mackerel scad and cordyla scad), is a species of moderately large marine fish classified in the jack and horse mackerel family, Carangidae. The torpedo scad is distributed throughout the tropical Indo-Pacific region, ranging from South Africa in the west to Tonga in the east, extending to Japan in the north and Australia in south. It is a schooling pelagic fish which occupies the surface layers of both inshore and offshore oceanic waters. The torpedo scad is easily identified by both its 'torpedo' shaped body and a series of detached finlets at the rear of both the dorsal and anal fins. The largest recorded individual was 80 cm long and weighed 4 kg, although it is more common at lengths less than 40 cm. It is a predatory species, taking a variety of fish, cephalopods and crustaceans by both active and filter feeding. There is a shift in diet as the species grow; however fish is the dominant prey in all size classes. Torpedo scad reach sexual maturity at 22 cm in females and 26.4 cm in males, with spawning occurring between March and July in India, where significant research into larval growth and morphometrics has been carried out.