368 American Fisheries Society 



ranged in number from 1 to 85 ; twelve bass ate them exclu- 

 sively. Midge larvae are important in the food of the bass 

 throughout the period they were examined, although they are 

 less important in the 8^/^ to 15 and 41-45 mm. stages than 

 the others. They are particularly abundant between 16-40 mm. 

 The most important larvse are: Chironomiis, Tanytarsus, Or- 

 thocladiiis, Cricotopiis, and Tanypus. 



Fish are not important in the food of the very young bass 

 between 8^^ to 15 mm. but increase as the bass grow older. 

 Above 16 mm. they are common in the diet of the bass, and 

 gradually increase except in the 36-40 mm. stage. The young- 

 est bass to eat a fish was 12 mm. long and 25.4 per cent of the 

 bass eating fish ate them exclusively. Fish were found in 17.8 

 per cent of the bass. The fishes eaten were the ones most often 

 associated with the bass, except in the case of the perch. Those 

 eaten, in order of their importance, are: Minnows (spot-tail, 

 most important), stone rollers, fan-tailed darters, carp and the 

 darter Cottogaster copelandi. One young bass was eaten, 

 which points to a slight amount of cannibalism. 



Mayfly nymphs rank last of the seven important foods of 

 the young bass, being found in 12.1 per cent of the fish. They 

 are unimportant up to 15 mm., as they were found in only 

 1 bass below that length. They are very important between 

 16 and 45 mm., and are not found after the 45 mm. stage. 

 The number eaten varied from 1 to 41, and three bass ate 

 mayfly nymphs exclusively. The most common mayflies were 

 Hexagenia, Ephemerella, and Bcetis. 



The 29 remaining articles of diet will be grouped together, 

 as they are found in from one per cent to 5.7 per cent of the 

 bass, and are unimportant. 



Caddis pupae were found in 5.7 per cent of the bass, about 

 equally distributed between the 21-45 mm. stages; none was 

 found above or below these stages. Ostracods were in 3.8 per 

 cent of the bass ; like the copepods and cladocerans they are more 

 abundant up to the 25 mm. stage, and after that decrease in 

 importance. Seven bass between 21-45 mm. ate caddis larvae. 



