Dec, 1921 FOOD of ohio darters 47 



Midge larvae and may fly larvae seem to furnish the main 

 articles of diet for both old and young. The very young show 

 a tendency to incorporate more of the entomostraca in their 

 diet and it is possible that specimens smaller than any of these 

 taken may eat still a larger percentage of entomostraca. In 

 the latter regard there is a slight resemblance to Percina 

 caprodes but the change from entomostracan food to insect 

 food is not nearly so well marked in Diplesion. Although 

 amphipods were abundant in the localities seined, few appear 

 in the food of Diplesion. Two specimens only from Buckeye 

 Lake had eaten more than fifty per cent of Amphipods. 



The specimens taken from the streams showed a more 

 varied diet than those from the lakes but the tendency to favor 

 midge and may fly larvae is still apparent. Silt and debris 

 appear in large quantities in the stream specimens but these 

 may have been taken accidentally while the fish were securing 

 other food. 



Summary of food habits in Diplesion hlennioides. 



1. The earliest stage, which is marked by the consumption 

 of entomostracan food in Percina caprodes, is poorly shown in 

 D. hlennioides. 2. May fly larvse and midge larvae constitute 

 the main articles of diet for both smaller and larger specimens. 

 3. Specimens from streams tend to show a more complicated 

 diet. 



C. Boleosoma nigrum Rafinesque. 



Specimens of this active little fish were taken in nearly 

 every stream and inland lake examined. Tables have been 

 prepared for those from the streams and for those from the 

 lakes, but the habits are so uniform that little of difi'erence is 

 offered in such tables. The younger specimens compare favor- 

 ably with those of Percina caprodes in their selection of ento- 

 mostraca and minute midge larva3 for food and in their gradual 

 relinquishment of this food to take up may fly larvae and larger 

 midge larvae. May fly larvae and midge larvae are the only 

 animals eaten by many and these forms are not wholly lacking 

 in the food of any. The constant occurrence and large quan- 

 tities of silt and debris indicate a selection of this material by 

 the fish for food. 



