The spawning season also varies with the locality, and 

 ranges from the latter part of July to the middle of 

 November. The date of spawning seems to be deter- 

 mined by the temperature of the water, for It is said 

 that the salmon will not spawn, even if on the spawn- 

 ing grounds, until the water has fallen to a temper- 

 ature of 54 degrees Fahrenheit. 



The chinook salmon is the largest of the family, 

 specimens having been taken in Alaska waters that 

 have weighed 100 pounds, while 50 to 60 pound fish are 

 common. Those taken in the Columbia river are said 

 to average 22 pounds, while the average of the Sacra- 

 mento river catch is 16. 



Head, rather pointed; eye, small and situated a little 

 in front of the back of the mouth; body, rounded and 

 full, the deepest part being about midway of its length; 

 pectoral fins, short and situated low and just behind 

 the gills; dorsal fin, nearly midway of the back; ven- 

 tral fins, a little behind the center of the dorsal; anal 

 fin about half way between the ventral and the tail; 

 adipose fin, a little in front of the rear of the ventrals; 

 caudal fin, or tail, slightly forked. 



The back, dorsal fin and tail are generally well cov- 

 ered with dark brownish black spots. There are few 

 spots as a rule on the head, and those are of a slaty 

 color. 



There is always some variation in color, but usually 

 the back is quite dark, turning to bluish on the sides 

 and light silver below. As the spawning season ap- 

 proaches, the jaws of the males become lengthened and 

 badly distorted and the color changes to more of a pink- 

 ish hue and blotched in appearance. The gills are nev- 

 er alike on both sides, varying from 15 to 19 in num- 

 ber. (See plate giving names of all parts mentioned.) 



BLUEBACK, OR SOCK-EYE SALMON, 

 REDFISH 



(Oncorhynchus nerka) 



This species is next in commercial value to the 

 chinook. It has been taken occasionally in the Sacra- 

 mento river but it is not common south of the Columbia 

 river. The run of this species begins about the first of 

 April and the fish go as far as Salmon river, Idaho, 

 fully 1000 miles from the sea to spawn. By a peculiar 

 instinct this species only run up such rivers as have 

 lakes at their heads, and spawn in the lakes or at tn 

 mouths of little streams emptying into them, in many 

 133 



