The green jack, Caranx caballus (also known as the horse jack), is an abundant species of coastal marine fish in the jack family Carangidae. The species is distributed in the eastern Pacific Ocean along the American coastline from Santa Cruz Island off California in the north to Peru in the south, as well as a number of islands including the Galapagos and recently, Hawaii. The green jack is distinguished from other similar carangid species by a number of features including gill raker and lateral line scale counts, and the presence of an adipose eyelid. It is a moderately large species, growing to at least 55 cm in length and 2.81 kg, although unconfirmed reports suggest a much larger maximum size. It lives in a wide range of continental shelf environments including estuaries, bays, reefs a