196 



U. S. BUREAU OF FISHERIES 



aged 3.36 inches (8.4 centimeters) in length and attained an average 

 weight of 9.61 grams b}' October 3. In 1929 a few fingerlings were 

 raised under conditions that were somewhat superior to the average. 

 These fingerlings (1.290) reached an average length of 4.28 inches 

 (10.71 centimeters) and an average weight of 17.3 grams; 87 finger- 

 lings in the same pond did slightly better and reached an average 

 length of 5.5 inches (13.83 centimeters) and an average weight of 

 44.9 grams. These data, though incomplete, gives some idea of the 

 rate of growth during the 4-month season at Fairport. This is also 

 shown graphically by means of growth curves in Figure 6. 



The variations in the growth rate from time to time are probably 

 due primarily to variations in the food supply. The sharp rise in 



8 



CO 



1. 1 «J 



DC 



a: ^ 

 o 



22 



23 



JUNL 



JULY 



AUG. 



4 24 

 SLPT. 



Figure 6. — Growth curves of larscmcutli black bass fingerlings in 

 1928. The two lower curves represent weights in grams ; the two 

 upper, lengths in centimeters 



the weight curve for E 1 illustrates what happens when the food 

 supply becomes exhausted and the large bass feed on the smaller. 

 This condition is accompanied by a low percentage of survival. 



SMALLMOTJTH BLACK BASS 



Conditions in the ponds at Fairport are very different from those 

 usually associated with the smallmouth bass {Microptei^us dolo- 

 niieu). The warm turbid water and bottoms covered with black mud 

 are so unlike the natural environment of the smallmouth that it was 

 at first thought inadvisable to attempt to propagate this species. 

 However, in the fall of 1927 an opportunity arose to obtain a number 

 of smallmouth bass from the Rock River (111.) and it was decided 

 to stock one pond, even though it was doubtful if the venture would 

 prove a success. Accordingly, 11 adults were obtained from the 

 river and wintered in the station ponds without loss. In the follow- 

 ing spring 9 more adults were obtained from the same source making 

 a total of 20 fish which were placed in D 8 on May 1. This stocking 



