Survival of Whirling-Disease-Resistant Rainbow Trout Fry in the Wild: A Comparison of Two Strains

• DOI: 10.1002/aah.10040
• Publication Date: 2018-08-30T09:54:17Z
• Authors: Brian W. Avila; Dana L. Winkelman; Eric R. Fetherman
• Keywords: 0106 biological sciences; Colorado; Trout; Parasitic Diseases, Animal; 01 natural sciences; Fish Diseases; Rivers; Myxobolus; Oncorhynchus mykiss; Predatory Behavior; Animals; 14. Life underwater; Disease Resistance

Abstract Introduced pathogens can affect fish populations, and three main factors disease occurrence: the environment, host, pathogen. Manipulating at least one of these is necessary for controlling disease. Myxobolus cerebralis, parasite responsible salmonid whirling disease, became established in Colorado during 1990s caused significant declines wild Rainbow Trout Oncorhynchus mykiss populations. Attempts to re-establish have focused on manipulating host resistance. A strain known as GR × CRR was developed stocking by crossing a whirling-disease-resistant German (GR) with River (CRR). The exhibit resistance similar that shown GR, survival reproduction were expected be those CRR. One disadvantage outcrossing backcrossing could decrease resistance, laboratory studies indicated this occur. potential pure lower due domestication. To compare fry between strains, field experiment conducted 1.6-km reaches nine streams. Each stream stocked August 2014 5,000 individuals. In October 2014, April 2015, apparent assessed. Two predation experiments also conducted. revealed short-term influenced stream, growth rate stream. However, after 12 months, there no difference or strains. Laboratory showed did not differ strains when confronted Brown Salmo trutta predation. Our results indicate viable option streams where M. cerebralis enzootic. Further evaluation needed determine whether will survive maturity reproduce.