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
USS Skipjack (SS-184) a "down the throat" spread of three torpedoes that sank the "Kanan Maru" (). Two days later, the submarine intercepted a three-ship convoy escorted by a destroyer and she fired two torpedoes that severely damaged the merchant ship, "Taiyu Maru" (). Then she let go with four more that quickly sank the cargo ship, "Bujun Maru" (). On 17 May, "Skipjack" sank the passenger-cargo ship "Tazan Maru" () off Indochina before heading back to Fremantle. Following participation in performance tests for the Mark 14 torpedo, "Skipjack" sailed for her fourth war patrol on 18 July 1942, conducted along the northwest