TIME OF SPAWNING 



In 1975, the first sturgeon was collected on May 9, with large concen- 

 trations appearing around May 21 (figure 12). The last sturgeon was 

 collected on August 7, although sampling continued until August 10. The 

 first ripe male (one from which milt could be stripped) was taken on June 3; 

 no ripe females were caught in 1975. Internal examination of two sturgeon 

 on July 10 revealed a few black eggs remaining in. the body cavity. It was 

 assumed that these fish had spawned in the Tongue River. 



7000-1 



6000- 



5000 



^ 4000- 



_ 3000- 



2000- 



1000- 



1000 2000 3000 4000 5000 

 Weight at Tagging (g) 



6000 



7000 



Figure 11. Linear regression analysis of the weight at 

 tagging (before spawning) compared with the weight at recapture 

 (after spawning) of shovelnose sturgeon in the Tongue River. 



35 



