Relative Weight of Brown Trout and Lake Trout in Blue Mesa Reservoir, Colorado

Abstract

Published data concerning the standard weight in lake trout (Salvelinus namaycush) and brown trout (Salmo trutta) have been established. The standard weights were used to compute relative weights for data collected in the spring and summer of 2011 for brown trout and lake trout in the Blue Mesa Reservoir, Colorado. The mean relative weight of a sample of 100 brown trout ranging in length from 260 to 432 mm was 71.72 +/- 0.90, showing that the brown trout were in poor condition. The mean relative weight of a sample of 17 lake trout ranging in length from 387 to 689 mm was 86.57 +/- 2.40, showing that the lake trout were also in poor condition. Using least squares regression, a best fit curve was determined for weight (W) vs. total length (L) in the brown trout, W(L)=1000(L/517.49)^2.5746, where W is in grams, and L is in millimeters.