Lydell. — Progress in Practical Fish Culture 225 



ural food supply. This was tried in 1920 at the Mill 

 Creek Hatchery in Michigan, with results which con- 

 firmed our former experiments. No doubt fish scrap meal 

 or any other form of meat or fish meal would serve equally 

 well. 



After several years of experimental work it has been 

 found that better results have been obtained in raising 

 bass in ponds with the adult fish than otherwise, provided 

 the adults are well fed every day. The reason is the im- 

 possibility of keeping out of the ponds during the breed- 

 ing and rearing season beetles, tadpoles and other forms 

 of aquatic life which naturally prey upon the food that the 

 fish culturist has provided for the young fry. Adult fish 

 in the pond eat these larger aquatic forms, and therefore 

 the minute Crustacea are saved for the little fish. If it 

 happens that too many fry have been released in a pond, 

 close watch is kept of the young fish and food conditions, 

 and before the food supply has become exhausted a num- 

 ber of the fish are removed to insure the remainder a food 

 supply sufficient to last until they reach the fingerling 

 stage. This is done from time to time, in fact, it is often 

 necessary to resort to this thinning-down operation four 

 or five times before the final cleanup of number one, two 

 and three fingerlings. 



REARING YOUNG BLUEGILLS IN PONDS 



The propagation of bluegills is as yet in its infancy, 

 especially in Michigan. Other states may have pro- 

 gressed further, but we find that the adult bluegills do 

 not live any too well in small or medium ponds, and for 

 some reason about two-thirds of the breeding stock is 

 lost each season. Good results have been obtained, al- 

 though it has been necessary to provide new stock each 

 year, which in a way is a drawback. We have been very 

 successful in the last two seasons in securing fingerling 

 stock of this variety without any breeders. We simply 



