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 planes were moved to the massive sail to cut down on flow-induced noise near the bow sonar arrays. They were known as sail planes or fairwater planes. The "Skipjack"s were the first class built with sail planes; they were later backfitted on the "Barbel"s. This design feature would be repeated on all U.S. nuclear submarines until the improved , the first of which was launched in 1988. The small "turtleback" behind the sail was the exhaust piping of the auxiliary diesel generator. The "Skipjack"s also introduced the S5W reactor to U.S. nuclear submarines. It was known as ASFR (Advanced Submarine