Todd A. Crowl

Possible Competitive Effects of Two Introduced Planktivores on White Crappie

Field and laboratory experiments were conducted to investigate possible competitive effects of the introduced species inland silversides (Menidia audens) and threadfin shad (Dorosoma petenense) on the native white crappie (Pomoxis annularis) population in Thunderbird Reservoir, Oklahoma. Field collections of zooplankton and stomach analyses were augmented by laboratory feeding experiments with the introduced planktivores and white crappie, alone and in combination. Field samples indicated that silversides, shad, and crappie, showed positive selectivity (Strauss' L) for Daphnia. Feeding...