Flathead Catfish Habitat Use and Predation on a Stunted White Perch Population in Branched Oak Reservoir, Nebraska

Abstract

ABSTRACT Flathead catfish (Pylodictis olivaris) were stocked for recreational angling in Branched Oak Reservoir, Nebraska in 1981 and subsequently in 1994 through 1996. During 1999 and 2000, additional fish were stocked to act as predators on an abundant white perch (Morone americana) population. We studied food habits and habitat use of flathead catfish to evaluate their utilization of white perch. Flathead catfish were sampled by electrofishing every other week from May through September of 2001. Flathead catfish were separated into five size classes and pulsed gastric lavage was performed on up to six individuals per size class. One flathead catfish per 250 mm size class and ten white perch (150–175 mm) were placed in each of eight experimental feeding enclosures to establish baseline consumption rates. Seventy four percent of all captured flathead catfish were found near rocky habitat, which comprised only 25% of the reservoir shoreline. Flathead catfish consumed mostly white perch and crayfish. Flathead catfish confined in enclosures fed on white perch at a lower than expected rate.