THE SACRAMENTO SALMON. 



209 



the bay. After reaching the shoals in the middle portion of the river 

 they move slowly, having already found pretty good spawning grounds. 

 They are about two months reaching their spawning grounds (between 

 stations 17 and 8 of the accompanying map), which are but little more 

 than half as far up stream as those of the spring run. 



In September, 1901, over a hundred salmon were weighed and 

 branded with serial numbers and released in the river at Eio Vista. 

 Three of these were taken later upon their arrival at the spawning 

 grounds. The following is a tabular statement of the data concerning 

 I hem, the loss in weight being due to migration alone. No. 34 was 8 

 days in spawning, extruded all but 20 ova, and lost thereby 21 per cent, 

 more of the Eio Vista weight. 



The salmon of the spring run reach their spawning grounds from 

 two to six weeks, or even longer, before spawning, which time they 

 spend lying quietly in the pools. The fall salmon are more nearly ripe 

 when they arrive at the spawning grounds, many of them ceasing to 

 ascend only when ready to spawn. 



Spawning and Death. 

 Salmon are in fairly good con- 

 dition when they begin spawn- 

 ing, notwithstanding the fact that 

 they have been without food for 

 several weeks or even months, 

 and have traveled several hundred 

 miles in the meantime. The male 

 has changed his appearance. His 

 snout has grown longer and much 

 hooked; large, conical, hooked 

 teeth have appeared in his jaws ; 

 his body has grown thinner and 



apparently deeper, though the latter point has not been determined yet 

 by measurements; his skin has thickened and embedded the scales. 

 The larger males become somewhat reddish in color as spawning time 

 approaches. The female has changed less. The abdomen is somewhat 

 distended from the ripening ova, the skin thickened as in the male, and 

 the color has become more or less of a dull olive. 



VOL. LXI. 14. 



Head of a Salmon with the Opercle cut 

 away, showing the gills attacked by fun- 

 GUS and Parasitic Copepods. Yet alive 



WHEN TAKEN. 



