The mackerel scad (Decapterus macarellus), or speedo, is a species of fish of the family, Carangidae. While it can be considered gamefish, it is usually used as bait. [2] It is popular for consumption in Hawaiʻi, the Philippines and the U.A.E. In Hawaiʻi, mackerel scad are called ʻopelu. [3] In the Philippines they are called galunggong. [4]