108 NORTHERN FISHES 



many of the streams tributary to Lake Superior. Those ascending the 

 French River near Duluth are numerous. An example from this stream 

 measured 22 inches in length. 



Brown trout are not nearly' so delicately flavored as the native brook 

 trout, but they grow to a much greater size, often reaching a weight of 

 12 pounds. Surber has seen one weighing slightly over 11 pounds, caught 

 in Willow River a short distance from Hudson, Wisconsin. They rise 

 freely to the artificial fly and put up a strenuous fight when once hooked, 

 but the large ones are seldom taken except at twilight and sometimes 

 after dark. The hybrid produced by crossing this species with the native 

 brook trout is an extremely handsome fish, marked like a zebra, and 

 apparently immune to many of the diseases that at times destroy whole 

 stocks of brook trout. However, it is a "mule"; all attempts to breed it 

 have proved futile. 



YELLOWSTONE CUTTHROAT TROUT (Yellowstone Trout) 

 Salmo clarkii lewisi (Girard) 



The cutthroat trout has a silvery-gray color, with black spots pro- 

 fusely scattered over the back and sides. The lower jaw is streaked 

 with red in the crease along the jaw bone. The middle of the side has a 

 rosy tinge. The scales are of moderate size and number 140-190 in the 

 lateral line. The dorsal and anal fins each have 10 rays. The tail is 

 slightly forked. This fish is native to streams of the Rocky Mountains. 

 Various attempts have been made to introduce it into Minnesota 

 streams, but without apparent success. Hubbs and Lagler (1941) 

 state that there is one record of at least temporary establishment in 

 Michigan. 



LAHONTAN CUTTHROAT TROUT (Silver Trout, 

 Tahoe Trout, Redfish) 



Salvio clarkii henshaivi Gill and Jordan 



The silver trout has a green back and coppery silver sides. It is en- 

 tirely covered by spots. The dorsal fin has 11 rays, the anal fin 12. The 

 scales are of moderate size and number 160-170 in the lateral line. This 

 fish is native to streams and lakes of the eastern slopes of the Sierras. 

 Several hundred thousand small fingerlings of this species were planted 

 in Big Trout Lake, St. Louis County, Minnesota, in 1921-23, but there 

 is no record of any survival. 



COAST RAINBOW TROUT (Steelhead Trout) 

 Salmo gairdnerii irideus Gibbons 



The color of the rainbow trout (Figure 12) is either bluish or olive 

 green above and silver on the sides, with a broad, pink lateral band. The 

 back and sides and the dorsal and caudal fins are profuselj^ spotted. The 



