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 from the s that preceded the "Skipjack"s. Unlike the "Skate"s, this new design was maximized for underwater speed by fully streamlining the hull like a blimp. This required a single screw aft of the rudders and stern planes. Adoption of a single screw was a matter of considerable debate and analysis within the Navy, as two shafts offered redundancy and improved maneuverability. The so-called "body-of-revolution hull" reduced her surface sea-keeping, but was essential for underwater performance. Also like "Albacore", the "Skipjack"s used HY-80 high-strength steel, with a yield strength of , although this was not initially used to increase the