Shim. — Rearing the Channel Catfish 87 



larvae were not available. The fact that such a large per 

 cent (17.9) of ooze, or silt and debris, was taken is very 

 interesting and brings up the question whether it was 

 taken by selection, or incidently with the other items. 

 The first appearance of the ooze was noted in the fishes 

 taken August 12, a total absence having occurred in the 

 two previous collections. 



With few exceptions the food taken by the fish in Pond 

 4 E was very similar in kind and amount to that obtained 

 in 1 E. 



In Pond 9 D, also, the greater part of the food taken 

 by the fish consisted of insect larvae, but in this pond 

 the EphmeHda larvae made up the largest single item, 

 forming 34.5 per cent of the total food taken. This is a 

 striking difference as compared with the much lower per- 

 centages of these forms in the fishes from the other two 

 ponds. Collections of the animal life in the pond re- 

 vealed the fact that Ephmerida larvae were quite abun- 

 dant and Chironomus larvae much less so. The fact that 

 Chironomus larvae made up 28 per cent of the food of the 

 fishes in a pond in which they occurred in much less num- 

 bers than the Ephmerida larvae which made up 34.5 per 

 cent of the food, would seem to indicate that, when ob- 

 tainable, Chironomids are the favorite food. The large per 

 centage (7.8) of filamentous algae taken in the food of 

 fishes from this pond, is no doubt accounted for by its 

 great abundance in this pond, and its almost complete ab- 

 sence in the other two ponds. Though considerable algae 

 would undoubtedly be taken incidentally with the other 

 items of food, there is perhaps little doubt that it is di- 

 rectly taken to some extent by the fish as food. Dragon- 

 fly larvae made up 3.5 per cent of the food in this pond, 

 while they were merely represented in the food of fishes 

 from Ponds 1 and 4 E. 



Briefly comparing the food taken by the fish in the 



three ponds, it will be noted that the food of the fishes 



(from Pond 9 D differed from that of the other fishes, 



'principally in the larger amount of Ephmerida larvae 



taken, with corresponding decrease in Chironomus lar- 



