An analysis of the feeding rate of white crappie

Abstract

The diet composition and feeding rate of animals is an important determinant of their fitness. We have studied the feeding behavior of white crappie, Pomoxis annularis, using videotapes of crappie feeding in the laboratory on various types and densities of zooplankton under different temperature regimes. We have determined the time taken by white crappie to complete the cycle of searching for prey, pursuing and attacking located prey, and reinitiating search. The time spent in search increases with decreasing temperature, but decreases when white crappie are feeding on large prey. Run and pursuit swimming speeds increase from 2 cm sec−1 at 4°C to 6 cm sec−1 at 20°C and then declines. Run and pursuit swimming speeds also increase when white crappie are feeding on large prey. These rates have been developed into a simple time budget of white crappie feeding. This budget accurately predicts white crappie feeding rates when each individual search is almost always successful. Some of the ramifications of this work on current theories predicting planktivorous fish feeding rates are discussed.