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 upon them. In fact, it is shown that fish species in the family Clupeidae including the skipjack shad comprise up to 45% of the diet of these avian species. The spawning season for skipjack shad is from early March to late April in the southern extent of its range. In the upper Mississippi river drainage spawning time is from early May to early July. Females produce about 100,000 to 300,000 eggs per year, presumably after 2 to 3 years of growth with an average size being Spawning is thought to occur in the depths of main channel over coarse sand-gravel