NATURAL HISTORY OR THE QUINNAT SALMON. 
71 
below Redding. Farther downstream the channel becomes deeper, gravel ban Its 
disappear, sand banks become less frequent, and rapids are wanting. Such is the 
character from Colusa to Sacramento. Below Sacramento it runs through a level 
country and for most of the distance is affected by tides. There are many sloughs, 
some connecting it with the San Joaquin. The Sacramento and San Joaquin rivers 
join as they empty into Suisun Bay. 
The water of the upper part of Sacramento River and the upper tributaries is 
quite clear, and continues so until the mouth of Feather River is reached, from 
which point to the mouth it is very muddy. It is in the muddy water between the 
mouth of Feather River and Vallejo that the salmon for the markets are taken. 
The only species of salmon regularly frequenting the Sacramento River is the 
quinnat. The dog salmon is found occasionally, four specimens having been seen 
during this investigation. Mr. Chamberlain reports finding single specimens of the 
blueback and humpback at Baird in 1899. The humpback has also been reported 
by others. The only record of the silver salmon from the Sacramento River is that 
given by Jordan & .Touy (Proc. U. S. National Museum 1881). 
THE GENERAL LIFE-HISTORY OF THE PACIFIC SALMONS. 
The salmon under consideration in this report is the Sacramento or quinnat 
salmon ( Oncorhynclius tschawytscha ) , also known as Columbia River salmon, king- 
salmon, and chinook salmon, and is the largest and most important of the five species 
of Pacific salmons. The others, in the order of their importance, are (1) blueback 
(O. nerJca), also called red salmon, redfish, and sockeye; (2) silver salmon (O. 
kisutch ); (3) humpback salmon (O. gorbuscha), and (4) dog salmon (O. keta). 
The Pacific salmons, as above named, are different from the Atlantic salmon, 
which is related to the steelhead or salmon trout of the Pacific coast. One of the 
important characters that separate the Pacific salmons from the steelhead and its 
relatives, the Atlantic salmon and the rainbow and cut-throat trouts, is the larger 
number of rays in the anal fin — the unpaired fin on the under side of the tail. The 
steelhead and its allies have fewer than 13 rays (usually 11) in this fin, while the 
Pacific salmons have more than 13, the number for the quinnat being 16.“ 
An equally fundamental, though physiological, difference lies in the fact that 
the Atlantic salmon and steelhead trout spawn several times while the Pacific 
salmon, of whatever species, dies as soon as it spawns once. This is a very striking- 
difference and its importance can hardly be overestimated. A further difference 
lies in the habits of the young. The young of the Pacific salmon seek the ocean as 
soon as they are able to swim ; their migration is accelerated by high water and 
retarded by low water, and they do not return to fresh water till mature. On 
the contrary, young trout do not seek the ocean for several months after they are 
able to swim, low water is an incentive to migration, and they run back and forth 
between fresh and salt water seeking food. 
The quinnat salmon is found throughout the Pacific coast from Monterey Bay 
northward, but is less abundant north of Puget Sound. At spawning time it fre- 
quents the larger streams, especially those with estuaries. The blueback salmon 
is the most abundant of the Pacific salmons, and is most numerous in Alaska. Its 
favorite spawning streams are those tributary to lakes. The silver salmon prefers 
« For other anatomical characters, see Jordan & Evermailn, Fishes of North and Middle America, Bulletin 47, 
United States National Museum. 
