The blue runner is a schooling, predatory fish, predominantly taking fish in inshore environments, as well as various crustaceans and other invertebrates. Fish living offshore feed nearly exclusively on zooplankton. The species reaches sexual maturity at between 225 and 280 mm across its range, with spawning occurring offshore year round, although this peaks during the warmer months. Larvae and juveniles live pelagically, often under sargassum mats or jellyfish until they move inshore. The blue runner is of high importance to fisheries, with an annual catch of between 6000 and 7000 tonnes taken from the Americas in the last five years. The species is also a light tackle gamefish, taking baits, lures, and flies; but is often used as bait itself, being a mediocre table fish. There has been some suggestion that the eastern Pacific species "Caranx caballus", the green jack, may be conspecific with "C. crysos", although this currently remains unresolved.