Life History of the Cutthroat Trout, Salmo Clarki Richardson, in Logan River, Utah

Abstract

Abstract This study of the cutthroat trout in Logan River, Utah, was based on 306 specimens collected during 1948 and 1949 with an alternating-current electric shocking machine. Cutthroat trout composed 24 percent of the anglers' catch during 1948 and 31.5 percent in 1949. The greatest numbers were found in areas with a high stream gradient. An estimated minimum number of 43.6 pounds of cutthroat per acre and 565 fish per mile was obtained from a series of shocking operations during 1949. Scale analysis was employed in determining the age of the fish. With a scale magnification of 50x, the body-scale (L/S) relationship of the cutthroat trout can be described as a curvilinear regression line, and expressed by the equation:L = 3.411 S1.2006The smallest average annual growth increment was 53 millimeters. This was based on a growing season of approximately 200 days. Growth began in the latter part of March and extended to early October. The relationship between standard length and weight was expressed mathema...