31 



must be planted in much greater numbers if an equal 

 production of bait-sized fishes is to be harvested. 

 Table 2 gives the recommended rates for the stocking 

 of fry in ponds operated by various management methods. 



Table 2 . -Recommended rates for stocking of fry and 



eyed eggs 



Many Minnesota dealers have had no return from 

 sucker fry planted in natural ponds. There are four 

 probable reasons for this. First, there may not have 

 been ample food for the fry at the time of planting. 

 A questionable pond should be fertilized with barnyard 

 manure about 2 weeks before the fry are planted. 

 Second, there may have been a large population of 

 aquatic insects in the pond at planting time. The 

 back-swimmer and the water tiger prey heavily on fish 

 fry and should be killed off 2 days before planting 

 time (p,6l). Third, the natural pond may have had a 

 population of predatory fish or minnows at planting 



