is iDrovided by the body fats and 

 tissues, which also provide ma- 

 terials for the development of 

 rej)roductive products — the eggs or 

 ova of the female and the 

 spermatozoa of the male. The lat- 

 ter, however, are usually fully de- 

 veloped when the fish enters fresh 

 water, whereas the eggs of the fe- 

 male become "ripe" or mature at 

 about the time the fish arrives at the 

 spawning area. The flesh of the 

 adult salmon deteriorates rapidly 

 after the fish enters fresh water, as 

 the body is being drained of its sus- 

 taining materials for the survival of 

 the fish and the development of re- 

 productive products, while there is 

 no intake of food for conversion to 

 energy. Thus, the salmon taken at 

 the mouths of the rivers, or offshore 

 in the ocean, are much more desir- 

 able for human consumption than 

 are those taken uj)stream in the 

 rivers. Fish taken offshore or at 



the mouths of rivers have firm flesh 

 of good color but the fish taken up- 

 stream have flesh that is soft and off 

 color. There is variation among 

 and within the species in this 

 respect. 



Durmg the spawning migration 

 in fresh water, the adult salmon will 

 proceed quite rapidly upstream. 

 The rate of progress usually is from 

 3 to 10 miles or more a day. Chi- 

 nook and red salmon in the larger 

 streams of Alaska may spawn at the 

 extreme headwaters 1,500 or more 

 miles from the ocean, and the same 

 was true in the Columbia River be- 

 fore the construction of dams. 

 Chum and pink salmon usually 

 spawn within a few miles of the 

 ocean and often just above the reach 

 of the tides. Here, too, there is con- 

 siderable variation among and 

 within species. 



Despite the much-publicized abil- 

 ity of adult salmon to leap vertical 



"\ 



Figure 3. — Salmon leaping at falLs. 



