SALMON AND TROUT IN ALASKA. 103 



eye or king. This, with the early arrival on the beds and conse- 

 quent high temperature of the incubating water, brings the hump- 

 back egg to a hardy stage early in the season and the fry to a stage 

 of development that sends them seaward with the opening of spring. 

 The small size and light color of the egg also ma}^ be advantageous. 

 In regions of larger rivers, such as Bristol Bay, the number of hump- 

 backs is much less in proportion to other species. The same is true 

 for more southerly regions. In the Bristol Bay region the average 

 size of humpbacks is considerably less than in Southeast Alaska, 

 Whether these facts are due to the character of the streams can only 

 be surmised. 



The limited number of cohos can not be attributed to scarcity of 

 spawning beds of the nature required. These are scarcely less 

 widely distributed than those suitable for the humpback. The 

 spawn incubates in about the same time, but is somewhat larger and 

 more brightly colored. The increased number of eggs, about 3,000, 

 should offset the disadvantage of size. The cohos coming last to 

 the beds, their eggs are undisturbed by other fishes, but since much 

 of the spawming is late the loss from physical causes may be greater. 

 The fry are probably less active, reach the sea later in the season, and 

 perhaps suffer greater loss from predatory enemies. 



The dog salmon, while widely scattered, occurs in numbers only 

 in selected streams. The eggs are very large, rather light colored, 

 and run about 3,000 to the fish. The incubation period probably 

 differs little from that of the humpback. The fry reach the sea 

 early, and there is no obvious reason why this should be one of the 

 scarcer species. 



The spa^^^ling habits of both king and sockej^e are obviously 

 advantageous. The king, resorting to large rivers, is able b}' its 

 strength to reach waters where the conditions are most favorable. 

 Other species do not work over its beds; and though limited in the 

 main trunks entered, the king secures extent of territory in the nu- 

 merous branches ; the habits of the young permit them to obtain the 

 necessary food in the streams, and the distance of the trip to be per- 

 formed insures their sufficient age and size for adequate protection 

 upon reaching the sea and its rapacious inhabitants. The summer 

 residence conserves the species to an extent, while the migration of 

 the main body as fry prevents overpopulation of the limited fresh- 

 water area. In this connection it is of interest to note that the fish 

 found in the Columbia headwaters in 1895 were of less than the aver- 

 age size for that stream, weighing only 10 to 14 pounds. Even allow- 

 ing for tissue expenditure during the ascent of the stream this does 

 not indicate that the stronger fish travel farthest, but rather the con- 

 trary. It seems possible that at a certain point the beds are occupied 

 by the stronger fish and that the less powerful go beyond in search 

 of unpreempted grounds. 



