Growth of introduced Stizostedion hybrids (S. vitreum x S. canadense) was examined from July 1983 to December 1985. Hybrids averaged 296 and 442 mm TL at ages 1 and 11. Condition factors (K) of hybrids increased with age, while relative weights (W,) were within the acceptable range (95-105) for all but 3 months of the first 2 years following introduction. Both condition indices decreased sharply during the spring and early summer. Reduced abundance of small shad due to winter mortality and altered predator-prey relationships during spring and early summer may seasonally impact condition of hybrid Stizostedion.