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 shad was much more abundant in the Upper Mississippi River basin before it was impounded. Currently, the skipjack shad is most abundant in the Upper Mississippi River below the mouth of the Ohio River. They are known as an "early-run" species as they migrate to spawn in the early spring. The skipjack shad is restricted to the Gulf of Mexico and its drainage, in the United States. The Gulf of Mexico drainage includes the ACF (Apalachicola/Chattahoochee/Flint River) basin, the Mississippi basin, and the Rio Grande basin. Records indicate that this species was more abundant in the upper Mississippi River before it