Nebraska Game and Parks Commission


Date of this Version



1979 Nebraska Technical Series No. 7, Nebraska Game and Parks Commission


Chapter 1 Lethal and Preferred Temperatures of Lake McConaughy Rainbow Trout Versus Domestic Strain Rainbow Trout By R. Vancil, G. Zuerlein and L. Hesse

Chapter 2 A Nitrifying Filter-Cooling Condenser System for Total Water Re-use in Cold-Water Fish Holding or Rearing Applications By L. Hesse, G. Zuerlein and R. Vancil

Chapter 3 Biochemical Genetic Analysis of Two Strains of Nebraska Rainbow Trout By J. Seeb and L. Wishard

The self-sustaining rainbow trout population living in Lake Mcconaughy and the North Platte River tributaries is unique to the Great Plains region. The population spends most of its adult life in the reservoir, but moves into tributary streams to spawn. Two spawning runs occur. The largest is from September through November followed by a reduced migration. in March and April of the following spring. Rainbow trout fingerlings spend about a year in the stream before smolting and migrating to the reservoir. Fishing for Mcconaughy rainbows in the tributaries and reservoir began in the late 1940's. Concern for the maintenance of this fishery prompted several investigations which were directed at development of a management plan. From these studies it was evident that the McConaughy rainbow possessed a selective advantage over hatchery origin fish stocked in the streams and reservoir. Temperatures, normally too high for successful rainbow survival, were often encountered in the streams and the eutrophying Lake McConaughy. This study was designed to compare the temperature tolerance and preference of Mcconaughy rainbow trout with hatchery origin fish. Chapter 1 describes the results of this study. Chapter 2 describes the laboratory facility developed to hold fish for relatively long periods while conducting the experiments. Chapter 3 contains the results of studies designed to characterize the genetic differences between hatchery fish from Massachusetts and the self-sustaining Mcconaughy rainbow trout. The Pacific Fisheries Research Laboratory in Olympia, Washington, was contracted to perform an electrophoresis characterization of the frequency of biochemical genetic variants among the McConaughy and hatchery rainbow groups.