EFFECTS OF ALTERNATIVE PREY AS A BUFFER TO PREDATION OF CHANNEL CATFISH (ICTALURUS PUNCTATUS) BY LARGEMOUTH BASS (MICROPTERUS SALMOIDES)

Abstract

EFFECTS OF ALTERNATIVE PREY AS A BUFFER TO PREDATION OF CHANNEL CATFISH (ICTALURUS PUNCTATUS) BY LARGEMOUTH BASS (MICROPTERUS SALMOIDES) By Shelley Christine Nellis, B.S. A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Biology at Virginia Commonwealth University. Virginia Commonwealth University, 2010 Director: MICHAEL L. FINE Professor, Department of Biology Channel catfish have pectoral spines that lock to defend against gape-limited predators such as largemouth bass. Previous work indicated that spines increase survival of channel catfish exposed to bass but did not determine whether bass avoid catfish if less dangerous species are available. We presented bass with channel catfish and two alternatives, bluegill and goldfish, and compared order of ingestion, ingestion time, percent of successful strikes, and time spent chasing each prey species. We also presented the three species in a jar study that standardized position in the water column as well as in a net-pen study. The order of ingestion was suggestive of a preference for goldfish, then bluegill and finally channel catfish. Handling time was greater for channel catfish, less for bluegill, and the least for goldfish. Fewer catfish were eaten when other prey were available. Bass appear to avoid channel catfish if alternative prey is available.