58 tr. S. BUREAU OF FISHERIES, 



throat trout and its different derived forms vary greatly in the sizes at which 

 they reach maturity, the chief factors being, of course, the size of the body 

 of water they inhabit and the amount of the food supply. 



Those species or individuals dwelling in lakes of considerable size, where 

 the water is of such temperature and depth as to insure an ample food sup- 

 ply, will reach a large size, while those in a restricted environment, where 

 both the water and food are 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 17 pounds, while in Fish Lake in Idaho mature 

 trout do not exceed 8 to 9i 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 

 under the impression that they are a species different from the larger ones 

 found in the lakes and larger streams, but as all sorts of gradations between 

 these extreme forms may be found in the intervening and connecting waters the 

 differences have not even subspecific significance. 



The various forms of cutthroat trout vary greatly in game qualities. Even 

 the same species in different waters, in different parts of its habitat, or at dif- 

 ferent seasons will vary greatly in this regard. In general, however, it is per- 

 haps a fair statement to say that the cutthroat trout are regarded by anglers as 

 being inferior in gameness 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 marvellous strength and will 

 make a fight which is rarely equalled by its eastern cousin, while in warmer 

 waters and larger sti'eams 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 where they are often very loggy, one is occa- 

 sionally hooked which tries to the utmost the skill of the angler to prevent his 

 tackle from being smashed and at the same time save the fish. An in- 

 stance is on record of a most enthusiastic and skilful angler who required one 

 hour and three-quarters to bring to rest a 9i-pound fish in Pelican Bay, Upper 

 Klamath Lake. * * *. The typical cutthroat trout (Salmo clarkii) may be 

 described as follows: 



Head 4; depth 4; D 10; A 10; cceca 43; scales small, in 150 to 170 cross 

 series. Body elongate, compressed ; head rather short ; mouth moderate, the 

 maxillary not reaching far beyond the eye ; vomerine teeth as usual set in 

 an irregular zigzag series ; teeth on the hyoid bone normally present, but often 

 obsolete in old examples; dorsal fin rather low; caudal fin slightly forked 

 (more so in the young). Color, silvery olivaceous, often dark steel color; back, 

 upper part of side and caudal peduncle profusely covered with rounded black 

 spots of varying sizes and shapes, these spots often on the head and sometimes 

 extending on the belly ; dorsal, adipose, and caudal fins covered with similar 

 spots about as large as the nostril; inner edge of the mandible with a deep 

 red blotch, which is a diagnostic mark ; middle of side usually with a diffuse 

 pale rosy wash, this sometimes quite bright and extending on to side of head ; 

 under parts silvery white. The red blotches or washing on the membrane 

 joining the dentary bones of the lower jaw are usually constant, probably al- 

 ways present in the adult, and constitute a most important character. This 

 species has been called Salmo mykiss in various publications by the writers 

 and others, but the true Salmo mykiss is allied to Salmo gairdnerii and has 

 never been taken outside of Kamchatka. 



GROWTH AND EGG PRODUCTION. 



The superintendent of the Bozeman (Mont.) hatchery gives the 

 following information regarding the growth and egg-production of 

 the black-spotted trout of the Yellowstone National Park waters: 



Even with domesticated trout on the hatchery grounds, fed and reared in 

 the same ponds and with the same opportunity for growth, there is a very wide 

 range of development. In the case of wild fish we have reason to believe that 

 this development presents even a greater range owing to food conditions, range, 

 and number of fish in proportion to the previously named conditions. From 



