甲若鲹，又称铠鲹，俗名为甘仔鱼，为辐鳍鱼纲鲈形目鲈亚目鲹科的其中一个种。

本鱼分布于印度西太平洋区，东非、南非、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、新几内亚、马绍尔群岛、马里亚纳群岛、帕劳、圣诞岛、澳洲、瑙鲁、所罗门群岛、萨摩亚群岛、新喀里多尼亚、斐济群岛、密克罗尼西亚等海域。

The longfin trevally, Carangoides armatus (also known as the longfin kingfish, longfin cavalla and armed trevally), is a species of inshore marine fish in the jack family, Carangidae. The species is common in tropical to subtropical waters of the Indo-Pacific, ranging from South Africa in the west to Japan in the east, typically inhabiting inshore reefs and bays. The species is easily distinguished by its elongate dorsal and anal fin lobes and filamentous dorsal rays, as well as its scaleless breast. Longfin trevally are pelagic predators, taking a variety of small fish, cephalopods and crustaceans, and reach sexual maturity at around 21 cm. The species has a maximum known length of 57 cm and weight of 3.5 kg. The longfin trevally has a very complex taxonomic history which is closely intertwined with another currently valid species, Carangoides ciliarius, which may yet prove to be synonymous. Longfin trevally are of minor importance to fisheries throughout their range and are considered good table fish, and are occasionally taken by anglers.