Skipjack tuna important prey species for sharks and large pelagic fishes and is often used as live bait when fishing for Marlin. It has no scales, except on the lateral line and the corselet (a band of large, thick scales forming a circle around the body behind the head). It commonly reaches fork lengths up to and a weight of . Its maximum fork length is and maximum weight is . Ageing skipjack tuna is difficult, and the estimates of its potential lifespan range between 8 and 12 years. Skipjack tuna is a batch spawner. Spawning occurs year-round in equatorial waters, but
Skipjack-class submarine Fleet Reactor) during development. The S5W was used on 98 U.S. nuclear submarines of 8 classes and the first British nuclear submarine, , making it the most-used US Navy reactor design to date. "Skipjack" was authorized in the FY 1956 new construction program and commissioned in April 1959. Each hull cost around $40 million. "Skipjack" was certified as the "world's fastest submarine" after initial sea trials in March 1959, although the actual speed attained was classified. The "Skipjack"s remained the fastest US nuclear-powered submarines until the first of the "Los Angeles" class entered service in 1974. This was due to