Comparison of Hatchery Performance Attributes among Three Strains of Age-0 Coaster Brook Trout

Abstract

The hatchery performance attributes of three strains (Lake Nipigon [Nipigon], Siskiwit Bay [Siskiwit], and Tobin Harbor [Tobin]) of fingerling coaster brook trout Salvelinus fontinalis were compared during a 12-week laboratory experiment. Despite similar initial sizes, the final mean length and weight of Nipigon fish (94.1 mm and 9.9 g) were significantly greater than those of the Siskiwit (86.7 mm and 7.7 g) and Tobin (90.4 mm and 7.2 g) strains. There were no differences in mean specific growth rates in length and weight or mean daily growth rate in length among the strains. However, there was a difference in the mean daily absolute growth rate in weight, the Nipigon and Siskiwit strains (0.10%/d and 0.08%/d, respectively) displaying a greater rate of growth than Tobin Harbor (0.07%/d) fish. Mean survival rates (range = 97–98%) and relative weights (range = 100.1–101.1 g) did not differ significantly among the three strains. Based on our results, we recommend that these strains of fingerling coaster brook trout be reared similarly in hatchery environments and that strain selection for rehabilitation stocking purposes consider hatchery residence time and the natural genetic variation of the source population of broodstock fish.