Lydell. — Fresh-Water Mussels as Fish Food 25 



Other experiments were then tried in regard to feeding the 

 meal to our adult fish. This we accomplished by making a thick 

 mush, similar to a corn-meal mush, simply by stirring the meal 

 into boiling water slowly until the mush was as thick as it could 

 possibly be stirred. This was set away to cool and then run 

 through a grinding machine or a press, with holes in it the size 

 of the food required. The food came through the press or grinder 

 in wormlike masses. We found our adult fish would take this a 

 great deal more readily than they did the ground up clams. 



REDUCING THE DEATH RATE AMONG OUR STOCK FISH. 



During the summer of 1918 and 1919, clam meal was the 

 only food used to feed all of our fish at the Mill Creek Station, 

 and the death rate has been reduced to a minimum. Not enough 

 fish died in 1919 to justify us in keeping a record of them. Prior 

 to 1918 the death rate among our stock fish, such as bass, blue- 

 gills and perch, was always about 25%. From the Drayton 

 Plains Hatchery, in Michigan, comes the following report: 



"I have lost less than 20% of my blue-gill breeders this season, 

 where every season before we have lost 75% and I firmly believe 

 that it is all due to clam meal diet. We have fed it almost clear 

 to both the large and small fish, and they have certainly done well 

 on it. J. L. Brass, Overseer." 



At Mill Creek Station this season 89,000 blue-gills and 57,000 

 perch were raised to the fingerling stage. The last of these were 

 distributed on October 4th, when they ranged from 13^ to 5 

 inches in length. At first they were fed five times a day, but later 

 only one feeding was given each day. 



CLAM MEAL AS A NATURAL FISH-FOOD PRODUCER. 



During the season of 1918, when our ponds were drawn down 

 and being cleaned, I scattered about 25 pounds of clam meal 

 around the shores of one pond. Several days after the ponds were 

 re-filled with water, I noticed large quantities of Crustacea, which 

 seemed to be more abundant in this particular pond. Whether 

 this was due to the clam meal, of course, we do not know. 



During the season of 1919, this experiment was carried further, 

 part of our ponds were treated and the others were not. The 



