“…Although trout have been described as stenothermal (Varley, 1967), aspects of their metabolism have been shown to adapt to temperature (Peterson & Anderson, 1969). Exposure to cold has been shown to cause increases in activity of proteolytic enzyme activity (Owen & Wiggs, 1971;Milanesi & Bird, 1972;Whitmore & Goldberg, 1972), fatty acid utilization (Dean, 1969), glucose metabolism (Hochachka & Hayes, i 962) and some mitochondria1 enzymes (Hazel & Schuster, 1976) for a variety ofspecies oftrout.…”