Date of Graduation

Spring 2014

Degree

Master of Science in Biology

Department

Biology

Committee Chair

Daniel Beckman

Abstract

Freshwater drum (Aplodinotus grunniens) are native to wide, slow, meandering rivers of North America. Many of these rivers have been channelized and straightened to accommodate barge travel. The drastic habitat changes along with the expansion of metropolitan areas may have an impact on the growth rates or population structure of this species. Although many state agencies report commercial landings, the freshwater drum’s status as a “rough fish” seems to exclude it from the list of species for which conservation is a concern. There has been little study of age and growth or prey preference of freshwater drum in the lower Missouri River. Although the habitats sampled are essentially connected by the continuous flow of water, I hypothesize that individual populations will vary due to the effects of urbanization or types and amounts of prey consumed. To characterize this population, freshwater drum (n=83) were collected during the months of June and July 2013, using hook and line methods. Length, weight, sex, age data, and gut contents from each specimen were obtained. Analysis of variance was used to compare physical characteristics of the fish with sample site and prey, while ANCOVA was used to examine differences in growth among sample sites. Although no significant variations in growth rates were observed, there were differences in weight, relative weight, and prey at different sites. Invasive Corbicula fluminea and Dreissena polymorpha were found in the guts of many drum and comprised all identifiable bivalve shells found in this study.

Keywords

freshwater drum, growth, relative weight, bivalves, corbicula, zebra mussel

Subject Categories

Biology

Copyright

© Robert Shields

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