i 



Figure [i9. — Raceway used in Ocqueoc River to determine length of 



hatching period and production of larvae from the redds. 

 Left hand of attendant is on funnel from which plankton 

 net extends downstream. 



departure from the nests were occuring (June 25-July 21), mean daily 

 water temperatures varied from 65.5 degrees F, to 75.5 degrees F.; 

 the average temperature for the period was about 71 degrees F. 

 Daily extremes ranged from 6l degrees F. to 79 degrees F. 



Data obtained from each spawning pair and nest were as follows: 



Nest No. 1 (in raceway): — Spawning was completed in this nest 

 on June 257~'l9li7. The female, l6.7 inches in total length, had a 

 potential egg production of 56, 600 eggs (estimated from a curve 

 based on egg production data which is presented elsewhere in this 

 study) . The following numbers of larvae left the nest and were taken 

 in the trap on the following dates: 119 on July lU, ii69 on July 15, 

 and 3h on July l6; total — 622 individuals. The production of larvae 

 constituted 1.1 percent of the reproductive potential of the female. 



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