REPORT OF STATE BOARD OF FISH COMMISSIONERS 83 



almost as much spotted as the Rainbow trout. It reaches a weight of 

 sixteen to twenty pounds. From the market point of view, the Steel- 

 head is the most important of American trout, being, usually, the 

 largest and one of those most easily reared artificially. It is a fine 

 game fish, taking the hook freely and vigorously. The large trout of 

 Fraser River, known as Stitse, or Kamloops trout, is a Steelhead. It 

 probably resides in the large lakes of Washington and British Columbia, 

 never descending to the sea. 



There has been much discussion as to whether the Steelhead is a 

 species really distinct from the Rainbow trout, and on this question 

 the writer lias at different times held different opinions. 



Very careful comparison of specimens leaves no doubt that the two 

 are distinct. The Steelhead usually is slenderer than the Rainbow trout, 

 less spotted, has less red on the side, and reaches a larger size. But 

 these distinctions are all deceptive. The best characteristic of all is 

 the short head, shorter in proportion than in any other trout. The head, 

 as in fishes generally, is proportionately shorter in the adult than in the 

 young. 



The dorsal fin of the Steelhead is never, in my experience, as large 

 or as much spotted as in the Rainbow trout, or even as in the Cut-throat 

 trout. The scales are always larger than in the Rainbow, and smaller 

 than in the Cut-throat. By these marks even young fish, like the one 

 represented in our figure, can be readily distinguished. The Steelhead 

 finds its center of distribution in the Columbia. The Kamchatka trout, 

 Salmo mykiss, which we once wrongly supposed to be the same as the 

 Cut-throat trout, is more like the Steelhead. 



HA IX I'.OW TROUT. 



The trout par exa ll< nc< of < lalifornia, found in almost every perma- 

 nent brook, is the one to which I gave, in 1878, the name of Rainbow 

 trout, this name being a translation of Salmo ir'idia, given it in 185-1 

 by Dr. W. P. Gibbons, of Alameda. Gibbons wrote the name "iridia," 

 and perhaps that form of the word ought to stand, but irideus, as it is 

 usually spelled, is better Latin. Gibbons 's specimens came from San 

 Leandro Creek, near Alameda. 



The Rainbow trout has larger scales than the others, usually one 

 hundred and twenty-five to one hundred and thirty, in a lengthwise 

 row. The dorsal fin is high, having usually seven to ten rows of black 

 spots. The old males show a good deal of bright red along the side. 

 There are no teeth on the middle line of the tongue. The head is 

 larger than in any other of these trout, its length being contained 

 from three and one half to four times in the length of the bodv. 

 measured along the side from the tip of the snout to the base of the 



