Salmonidae 



103 



limited, will be small directly in proportion to these environing 

 restrictions. The trout of the Klamath Lakes, for example, reach 

 a weight of at least 1 7 pounds, while in Fish Lake in Idaho mature 

 trout do not exceed 8 to 9^ inches in total length or one-fourth 

 pound in weight. In small creeks in the Sawtooth Mountains 

 and elsewhere they reach maturity at a length of 5 or 6 inches, 

 and are often spoken of as brook-trout and with the impression 

 that they are a species different from the larger ones found in 

 the lakes and larger streams. But as all sorts and gradations 

 between these extreme forms may be found in the intervening 

 and connecting waters, the differences are not even of sub- 

 specific significance. 



Dr. Evermann observes: "The various forms of cutthroat- 

 trout vary greatly in game qualities; even the same subspecies 

 in different waters, in different parts of its habitat, or at different 



FIG. 64. FIG. 65. 



FIG. 64. Head of adult Trout-worm, Dibothrium cordiceps Leidy, a parasite oiSalmo 



clarkii. From intestine of white pelican, Yellowstone Lake. (After Linton.) 

 FIG. 65. Median segments of Dibothrium cordiceps. 



seasons, will vary greatly in this regard. In general, however, 

 it is perhaps a fair statement to say that the cutthroat-trout 

 are regarded by anglers as being inferior in gaminess to the 

 Eastern brook-trout. But while this is true, it must not by any 

 means be inferred that it is without game qualities, for it is 

 really a fish which possesses those qualities in a very high degree. 

 Its vigor and voraciousness are determined largely, of course, 

 by the character of the stream or lake in which it lives. The 

 individuals which dwell in cold streams about cascades and 

 seething rapids will show marvelous strength and will make a 

 fight which is rarely equaled by its Eastern cousin; while in 

 warmer and larger streams and lakes they may be very sluggish 

 and show but little fight. Yet this is by no means always true. 

 In the Klamath Lakes, where the trout grow very large and 



