Summer food habits and prey taxa and size electivity of age-0 white bass in a South-Central Nebraska irrigation reservoir

Abstract

Understanding consumption patterns and preferences of particular life stages for fish species can clarify potential dietary overlap and identify energy flow within aquatic communities. Age-0 white bass (Morone chrysops) have been documented to consume a variety of prey items and zooplankton are a common occurrence. The importance of particular zooplankton taxa and available sizes will likely impact prey selectivity, which is not understood for age-0 white bass. The objectives of this study were to evaluate food habits, prey electivity, and size selectivity of age-0 white bass in an irrigation reservoir from July to September 2015 and 2016. By number, age-0 white bass consumed mostly zooplankton from July to September. Consumption of fish become an important component of the diet for 22% of fish starting at 80 mm TL. Calanoida were the primary zooplankton taxa consumed and selected for by age-0 white bass. In relation to other zooplankton taxa, Calanoida were one of the most abundant taxa groups available and age-0 white bass displayed size selective feeding by consuming the larger Calanoida available in the environment. While Calanoida are not the largest taxa available, their high density appears to result in higher consumption by age-0 white bass compared to other available taxa.

Keywords:

• White bass
• Calanoida
• food habits
• prey electivity
• zooplankton

Acknowledgements

We thank staff of the Kearney Field Office of the Nebraska Game and Parks Commission and the University of Nebraska at Kearney for help in the field and lab, especially J. Kreitman, B. Newcomb, B. Eifert, C. Hadan, J. Hasz, B. Roberg, T. Jackson, S. Eilers, B. Peterson, J. Thiessen, B. Schall, M. Perrion, B. Andersen, M. Wright, J. Laux, B. O’Connor, K. Miller, T. Kozeal, Z. Ondrak, and J. Cabela. We thank J. Hirsch for zooplankton expertise and J. Davis for graphical assistance.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This project was funded by the Nebraska Game and Parks Commission through Federal Aid in Sport Fish Restoration, Project F-160-R.

Notes on contributors

Brett T. Miller is a former MS student and currently a district fisheries biologist for the Kansas Department of Wildlife, Parks and Tourism in Clay Center, Kansas.

Casey W. Schoenebeck is a former associate professor of biology at the University of Nebraska at Kearney. He is currently the Sentinel Lakes Program coordinator in the Fisheries Research Unit for the Minnesota Department of Natural Resources in Glenwood, Minnesota.

Keith D. Koupal is an irrigation reservoir specialist in the Fisheries Division for the Nebraska Game and Parks Commission in Kearney, Nebraska.