REPORT OF COMMISSIONER OF FISH AND FISHERIES. 87 



tbis part of the work, ;i number of new and important facts were dis- 

 covered respecting- the liabits of the three principal species of Sahnonidw 

 which spawn in these upper waters, namely, the chinook or quinnat 

 salmon [Oncorhynchus tscJunvytscha), the blneback salmon or redfish of 

 Idaho {Oncorhynchus nerJca), and the steelhead trout or salmon trout 

 {Salmo gairdneri). A preliminary report ujiou the investigations made 

 in Idaho has been i^ublished.* 



Important spawning-beds of the chinook salmon were found in 

 Salmon River and Alturas Creek near Sawtooth, in Payette Eiver just 

 below Big. Payette Lake, and in Snake liiver at Upper Salmon Falls, 

 while less important ones occur in the different tributaries of Weiser 

 River. It is also believed that large numbers of this species spawn 

 in other parts of Snake River and in other of its tributaries, but the 

 location of such grounds has not been definitely determined. The 

 spawning time of the chinook salmon which ascend to the colder waters 

 was found to be considerably earlier than in the case of those which 

 spawn in the Snake River. In the upper Salmon River it was over by 

 September 12, and in Payette River by September 27, but at Salmon 

 Falls it did not terminate until about November 1. This difference is 

 supposed to dei^end upon differences in the temperature of the water. 



The steelhead trout spawns extensively in the headwaters of Salmon 

 River, Payette River, and Weiser River, and in Snake River, but as 

 its spawning season is in the early spring nothing definite was learned 

 regarding its habits or abundance in the region examined. In Sep- 

 tember and October it was not found in any of the waters named except 

 the Snake River, in which it was quite common at Weiser during Sep- 

 tember, and a few were also seen at Upper Salmon Falls. 



The most interesting salmon which occurs in Idaho waters is the 

 blueback, known locally as the redfish. It was observed spawning in 

 September in the inlet of Alturas Lake near Sawtooth, and in that 

 of Big Payette Lake. The inhabitants of the region have long been 

 acquainted with these spawning grounds, but they had never been 

 visited by a naturalist until this year. The examinations were made 

 on September 12 and 13 at the inlets of Alturas and Pettit lakes, and on 

 September 27 at the inlet of Big Payette Lake, and individuals were 

 seen upon the beds on each of those dates. Many dead fish were found 

 at each lake and the spawning season of the species in these i)laces was 

 evidently about over. Nearly all the live fish observed were more or 

 less covered with sores, and their tins were frayed out. It is probable 

 that the redfish which spawn in these waters never return to the sea, 

 and that all die after accomplishing their reproductive functions. 



Two forms of the redfish are known to spawn in the inlets of the 

 lakes mentioned. One of these, known as the little redfish, measures 

 10 to 13 inches long and weighs almost invariably about half a i)ound 

 apiece. The other is very much larger, being from 20 to 25 inches 



* A preliminary report upon salnion iuvcstisrations in Idaho in 1894, by Barton W. 

 Evermaun, Bull. U. S. Fish Comm., xv, for 1895, pp. 253-284. 



