Skipjack Shad - Ecology

Ecology

Skipjack shad are a migratory schooling species. They are a euryhaline species that can enter brackish and fresh waters. They can be anadromous but are not obligated to do so because they can complete their life cycle in fresh water (Etiner and Starnes 1993). Skipjack Shad are strongly migratory within rivers and prefer fast flowing water where they are renowned for leaping (Whitehead 199). They are found in clear to moderately turbid waters in large rivers and reservoirs usually within the current over sand or gravel (Page and Burr 1991). In one study, Skipjack shad have been found to feed on other shad/herring species such as the Threadfin Shad, the Gizzard Shad and young of the year herring species. In some extreme cases, it was shown that they could rely on cannibalism to survive (McLean et al.). They are also known to feed on small fishes, mostly shad, while the juveniles feed on insects (Whitehead 1985). The maximum size of the shad/herring utilized by Skipjack Shad was found to be about 30-35% of the Skipjack’s body length (McLean et al. 1985). There is not much data on the predators of the Skipjack Shad. Larger fish species, seabirds, and humans prey 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 (Tibbs et al. 1998). Species abundance would be hurt by the presence of more dams and increasing turbidity and siltation in rivers and reservoirs.