REPORT OF COMMISSIONER OF FISH AND FISHERIES. CXXXVII 



cau not be found iu the luaiu stream. By the time the later rim reaches 

 the middle section of the river, that is to say, from Chico to Redding, 

 the water is so low that many fish are obliged to spawn in the main 

 river, where numerous spawning-beds are found. The salmon of the 

 later run, therefore, rarely go beyond Eedding. 



(3) The spawning period of the early run is between July and Sep 

 tember, of the later run during November and December, though occa- 

 sional spawning fish may be found any time from April to January. 



(4) Shallow water with gravelly bottom and swift current is usually 

 selected for the spawning-beds. The female selects a place, extrudes a 

 few eggs, and moves away; the male immediately takes the same posi- 

 tion, or sometimes a few feet farther downstream, and emits a small 

 quantity of milt. These acts are repeated at short intervals for 10 days 

 or 2 weeks, continuing day and night. The few eggs that are not at 

 once devoured by small fishes float several feet or yards downstream 

 and lodge among the gravel, where they hatch in 40 to 70 days, accord- 

 ing to the temperature. 



(5) The so-called "nests" of spawning salmon are not nests in any 

 sense of the word, as they are not intended for eggs and do not receive 

 eggs. These excavations, several feet in diameter and often 6 or 8 

 inches deep, are made by the female turning on her side and digging 

 her tail in the gravelly bottom; the movement is probably for the pur- 

 •pose of loosening the eggs from the ovarian sac. Incidentally, some of 

 the eggs may thus be covered by fine sediment, which drifts downstream. 



(6) The alevins hide among the rocks about six weeks. As soon as 

 they are able to swim, they begin feeding and moving downstream. At 

 first they travel more at night, but as they get older and reach the lower 

 part of the river, they migrate mostly by day. They require about 

 three mouths to pass from liedding to San Francisco Bay. 



(7) There are two runs of salmon fry down the river, one passing the 

 vicinity of Redding during October, November, and December, the other 

 during the latter part of January, February, and March, Practically 

 all the young salmon have left the region by the 1st of April, although 

 a few remain in the headwaters all summer. 



(8) Most of the salmon return to fresh water at the age of 2^ years, 

 and spawn 36 months after the spawning of the parents. Some, 

 however, are a year older when they leave the sea. 



The planting of salmon fry near the ocean, in order that they may 

 not have to run the gauntlet of enemies in their long journey to the 

 salt water, has from time to time been suggested. To test the feasibility 

 of this project, Mr. Rutter took 50,000 salmon eggs from Battle Creek 

 to Pacific Grove, on Monterey Bay; the eggs reached the coast on 

 December 12 and were hatched December 19. The experiments con- 

 cluded February 15. It was shown that salmon fry can not go directly 

 from fresh to salt water, but need to pass through an estuary of brackish 

 water. An alternation of density, such as is secured by the tides, 

 appears to be beneficial. It was further shown that under the age of 

 two months salmon can not live in i>ure salt water. 



