Daphnia lumholtzi, an Exotic Zooplankton, Invading a Nebraska Reservoir

Authors

Brian C. Peterson, University of Nebraska KearneyFollow
Nicolas J. Fryda, Nebraska Game and Parks Commission, KearneyFollow
Keith D. Koupal, Nebraska Game and Parks CommissionFollow
Wyatt Hoback, University of Nebraska at KearneyFollow

Date of this Version

3-2005

Document Type

Article

Citation

THE PRAIRIE NATURALIST, Volume 37, No. 1, March 2005, pp 11-19.

Comments

Published by the Great Plains Natural Science Society. Used by permission.

Abstract

A limnological assessment project by the University of Nebraska at Kearney and the Nebraska Game and Parks Commission collected weekly vertical zooplankton tows during May through September 2002 at Harlan County Reservoir in Nebraska. Beginning on 5 August 2002, the exotic Daphnia lumholtzi (Cladocera: Daphniidae) appeared at a density of 0.04 1.1 in one of fifteen standardized sampling stations. By 6 September 2002, D. lumholtzi was found in all fifteen stations at an average density of 2.17 ± 3.10 1.1 with a site maximum density of 11.43 1.1 • Length measurements of D. lumholtzi ranged from 0.80 mm to 5.66 mm with a mean length of 2.38 ± 1.107 mm. During sampling, the abundance of D. lumholtzi increased relative to the native Daphnia retrocurva from less than 1 % to greater than 45% of all zooplankton collected. Our finding represents the first account in a Nebraska water system of D. lumholtzi, a native of Africa, Asia, and Australia, and shows a northern expansion in the Great Plains of this exotic species.