Fulton's body condition factor K correlates with survival time in a thermal challenge experiment in juvenile Lahontan cutthroat trout ( Oncorhynchus clarki henshawi)

Abstract

Thermal tolerance was measured in an experimental setting using seven full-sibling family groups of hatchery reared Lahontan cutthroat trout ( Oncorynchus clarki henshawi). Body weight and fork length were measured and Fulton's body condition factor ( K) was estimated for each individual. Heritabilities were moderately high for body weight (0.50), upper temperature tolerance (0.44), and K factor (0.50). Estimates of genetic and phenotypic correlations between upper temperature tolerance and K factor were 0.53 and 0.41, respectively. K factor may be an indicator as to the ability of an individual to survive periods of increased water temperature during the summer months.