The ontogeny of search behavior in the white crappie, Pomoxis annularis

Abstract

Animals that forage for discrete, isolated resources are often characterized as either ‘ambush’ (sit-and-wait) or ‘cruise’ (active) searchers. Juvenile white crappie, Pomoxis annularis, search for zooplankton prey using a saltatory search (SS) strategy. Unlike ambush and cruise search, SS involves scanning for prey only during the brief stationary periods that punctuate repositioning movements. If prey are not found, these fish swim a short distance, stop, and scan again. In this paper, we describe the ontogeny of prey search in the white crappie and compare the search pattern that they employ with that of juveniles. White crappie larvae searched for prey throughout the search space and only during the pauses that punctuated swimming movements. Prey location distances increased with fish size, as did several other components of the predation cycle. We conclude that white crappie larvae employ a search strategy similar to that exhibited by juveniles. We emphasize that, to obtain an accurate assessment of the feeding ecology of early life history stages, the search pattern that they employ must be characterized, and its components quantified.