The unfertilized eggs are asymmetrical with an average diameter of 0.96-1.65 mm. This is a schooling anadramous species whose oceanic movements are unknown. Spawning runs may begin as early as February, but are most frequent in April. Successful hatches have been reported at salinities ranging from 7.5 ppt at 12.0 oC to 15 ppt at 17 oC. No eggs hatched at a salinity of 22.5 ppt. Shad spawning areas vary in depth and substrate.
Shad seem to prefer areas dominated by shallow water or broad flats with sand or gravel bottoms.
Sufficient water current veloitites are required to keep the shad eggs suspended in the water column. C caused extensive larval abnormalities. Larvae remain near the spawning grounds, usually a short distance downstream. Young remain in the nursery area until water temperatures begin to decrease in the fall. They have minimal commercial importance, incidentally entering the American shad fishery.