50 



THE GAME BREEDER 



more deeply indented than in mature, 

 large specimens. All big Rainbows I 

 have seen show a "square" or nearly 

 right line along the margin of the tail 

 when fairly extended. This is so notice- 

 able a feature that in many places this 

 trout is commonly called "square-tailed 

 trout." 



Certainly the shape of the Rainbow's 

 tail distinguishes him easily from Clark 

 trout, which has a rounded hollow in the 

 mid-margin, and the corners or lobes 

 gracefully rounded. In the Rainbow 

 the points are sharply angular, as in the 

 Steelhead. The difference between the 

 tails of all the salmon is easily learned, 

 but is so little as to confuse Steelhead 

 and Rainbow. 



One of the characteristics given by 

 Doctor Jordan is : "Head obtusely ridged 

 above."' Several other writers copy this 

 description exactly. It is plain that 

 they have taken the Doctor's statement 

 without question, permission or exami- 

 nation. Look for the "obtuse ridge," 

 and see if there's any such feature. 



Doctor Jordan says, "the mouth is 

 smaller than in Cutthroat," and so it is. 

 This difference is evident. The gape of 

 the Rainbow from tip of jaw to corner 

 of the mouth is about one-fourth less 

 than in Cutthroat. The angle of the 

 open mouth in Rainbow is just in line 

 with front edge of eye-pupil. In Cut- 

 throat the mouth extends back to middle 

 of pupil or farther. 



In young and medium size fish the 

 Rainbow's head is distinctly more blunt 

 and rounded than in any other of our 

 trouts. In this feature there is a notice- 

 able difference from the adult Steelhead, 

 which has a more pointed upper jaw. 



Comparison, I believe, will establish 

 this difference as one certain mark of 

 recognition. There is an "innocent" air 

 in the profile of the Rainbow, due to this 

 roundness of the front of the maxillary. 



The eye seems to be a very notable 

 point too. In recent examinations I have 

 observed the eye of Rainbows to be 

 peculiar by reason of its larger size — 

 one-fifth greater diameter than that of 

 Clark trout — and by a staring look which 

 the latter has not. The iris in Rainbow 



is broader than the Clark and of a clear, 

 pale yellow, with rarely any spots in or 

 on the iris, while the eyes of many 

 Clark trout examined recently show the 

 iris to be almost covered by dark spots 

 resembling the spots of the surrounding 

 skin. The narrow band of iris surround- 

 ing pupil is also of a darker, rich gold. 



My opportunity for observation of 

 Rainbow is rare, and I do not venture to 

 be dogmatic concerning him; but I hope ^ 

 this peculiar difference in sizes and 

 marking of the eye may prove to be dis- 

 tinctive. 



One other peculiarity marking the 

 Rainbow is the usual presence of spots 

 on the cheek or opercle, black and round 

 Color and shape of these spots, as well 

 as the peculiarity of their placing, seems 

 a distinct trait. 



The general color of the Rainbow, ex- 

 cept in breeding season, differs little 

 from Clark trout, except the red bar. 

 Sometimes a Rainbow is very profusely 

 ■ spotted, but usually the Clark trout is 

 more numerously speckled. 



There is, I believe, a real dift"erence in 

 the majority of the spots, in shape. I 

 thought two years ago that in the spots 

 was a sure mark. Specimens of Rain- 

 bow then seen were marked mostly by 

 little crescent-shaped spots, sometimes 

 joined together making a "3," and with 

 occasionally a third crescent attached to 

 the "3" ; but I found some Clark trout 

 with the same marks. However, the 

 spots of the Clark are mostly larger, and 

 are of an irregular circular or hexagonal 

 type. The spots on base of tail are 

 larger and blacker in the Clark trout. 



The variation of spots and colors in 

 all trout, at certain times, is so great 

 that few naturalists would risk an opin- « 

 ion on these alone. The Rainbow fre- f 

 quently has red stripes under the mandi- 

 ble, but they are narrow. The Clark 

 trout is sometimes almost without these, 

 but where present they are twice as 

 broad as in a Rainbow of the same size. J 

 Both fish return from the sea with " 

 hardly a trace of this throat mark. 



Authorities referred to above state ■ 

 that the Rainbow is the typical trout of I 

 coastwise streams, and that it is not 



