Prey selectivity and feeding periodicity of logperch larvae in Acton Lake, Ohio

Abstract

Prey selectivity and feeding periodicity were determined from 263 gut analyses performed on logperchPercina caprodes larvae collected from Acton Lake during 26 May to 24 June 1983. Prey were observed only in larvae >7.4 mm total length. Larvae fed almost entirely on cladocerans and cyclopoid copepods; nauplii were conspicuously absent from the diet. Piscivory was observed in 9 larvae. Larvae showed increasing preference for cladocerans throughout the study period and decreasing preference for copepods despite the fact that copepods were 5–10 times more abundant than cladocerans. These trends coincided with a six-fold increase in the abundance of the microcrustacean component of the zooplankton community. Although cladocerans are more easily captured than copepods, there appeared to be a threshold density for cladocerans that had to be attained before logperch larvae actively sought these forms as prey. Analyses made at 3 h intervals over a 24 h period indicated a feeding peak at 2100 h, with the fewest number of prey items observed in the guts of fish taken at 0600h.