Growth Rate of Yearling Colorado Squawfish at Different Water Temperatures

Abstract
Growth rate of yearling Colorado squawfish, P. lucius, over a 12-wk period, was determined for fish held at 15, 20, 25 and 30.degree. C with excess food. The effect of temperature on growth rate was highly significant; fastest growth occurred at 25.degree. C. Fish gained about 0.3 g at 15.degree. C, 0.9 g at 20 and 30.degree. C, and 1.7 g at 25.degree. C during the 12-wk period. Results suggest that 25.degree. C, the final thermal preferendum, is the temperature at which Colorado squawfish grow fastest with abundant feed. Future water shortage and development projects should be designed to provide summer water temperatures as near this level as feasible.