ASSESSMENT OF VARIATION IN AGE, GROWTH, AND PREY OF FRESHWATER DRUM (APLODINOTUS GRUNNIENS) IN THE LOWER MISSOURI RIVER

摘要

Freshwater drum (Aplodinotus grunniens) are native to wide, slow, meandering rivers of North America. Drastic habitat changes along with the expansion of metropolitan areas may have an impact on the growth rates or population structure of this species. To characterize these populations, we collected freshwater drum (n = 83) during the months of June and July 2013, using hook and line methods. We used analysis of variance to compare age, physical measurements, and volume of prey items consumed by fish, among sample sites. We used analysis of covariance to examine differences in growth among sample sites and sexes. Although we observed no significant variations in growth rates, there were differences in weight, relative weight, and prey among 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.