Comparative Survival of Naturalized Steelhead, Feral Kamloops, and Their Hybridsduring Egg and Fry Stages

摘要

The two strains of anadromous rainbow trout Oncorhynchus mykiss currently beingstocked in the Minnesota water of Lake Superior may have the potential to hybridize, thus compromising the genetic integrity of the naturalized population. Although no evidence of natural reproduction has yet been found in the hatchery strain referred to as kamloops, unusual climatic conditions or inadvertent human intervention may enable their propagation and hybridization with the naturalized steelhead strain, since their spawning runs overlap in time and space. Egg viability and fry behavior experiments were undertaken to evaluate the threat of hybridization and to suggest future management of the two strains.