BLACK BASS CULTURE 



191 



The optimum number of fry per acre for stocking nursery ponds 

 remains to be determined. This number will, of course, depend on 

 the abundance of food and the size which it is desired to have the 

 fino:erling reach in one season. Another very important consideration 

 is the relative cost of production of fry and fingerlings. This cost 

 must determine whether we should aim at a high percentage of 

 survival or at a large number of fingerlings per acre. For instance, 

 the cost of production should determine whether it is better to stock 

 with 10,000 fry to the acre and have 60 per cent survival with G,000 

 fingerlings, or to stock wath 20,000 fry and get 8,000 fingerlings 

 per acre with a survival rate of 40 per cent. On tlie basis of our 

 experience we believe that 8,000 fingerlings at the lower rate of 

 survival would be the more economical practice. The following 

 experiments may be of interest in this connection : 



In 1926 two small ponds, F 2 and F 3, were stocked with bass 1.5 

 inches in length at the rate of 1,500 to the acre. These bass made 



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Figure 5. — Removinu liiij;iiliiig bass from the ponds at Fairport 



a very good growth, but in spite of the fact that they were well ad- 

 vanced before they were placed in the pond, only 67.5 per cent sur- 

 vived in the fall. The fingerling production amounted to 1,024 per 

 acre. The percentage of survival is high as compared wdth the rest of 

 our results but the production per acre is ver}^ low. In the same year 

 some ponds w^ere stocked wdth small fry at the rate of 26,000 and 

 36,000 to the acre. The fingerling production amounted to 4,610 

 and 6,253 per acre, respectively. The percentage of survival in the 

 last two cases was only 17 per cent. In view of our later experiments 

 w^e do not favor either of these extremes. Our results for D 7 

 show that from 20,000 to 25,000 fry per acre — if not the optimum 

 number — produce good results. In 1927 this pond was stocked at the 

 rate of 25,000 to the acre ; the rate of survival was 33.7 per cent, the 

 fingerling production being 8,018 per acre. In 1928 the same pond 

 was stocked with 22,000 fry to the acre; the rate of survival was 

 45.8 per cent, and the fingerling production reached 9,963 per acre. 

 In 1929 the pond was again stocked at the rate of 25,000 fry to 



