Food habits and diet selectivity of the brown bullhead

Food habits of the brown bullhead Ameiurus nebulosus were investigated in June and July 1994 in Perch Lake, Jefferson County, New York to determine feeding selectivity. Twenty-seven prey taxa were identified from 39 brown bullhead (total length, 29-330 mm). Chironomid larvae and pupae constituted the greatest portion of the diet by number of the young of the year brown bullhead (total length, 29-49 mm, N=10). The amphipod Hyalella sp. and chironomid larvae constituted the greatest portion of the diet by number of the juvenile/adults (total length, 115-330 mm, N=29). Diet selectivity of the juvenile/adult brown bullhead was evident based on positive Ivlev electivities for Hyalella sp. and chironomid larvae, and negative electivities for the gastropod Amnicola limosa and the ephemeropteran Caenis sp. Selective feeding was also suggested in the young of the year bullhead which had a high electivity for chironomid pupae. Our use of benthic invertebrate sampling methods provided similar estimates of the invertebrate community of the lake, but none of the individual sampling methods compared well to the brown bullhead diet, also suggesting selective feeding.