V4 
and that the variation was mainly an expression of cycles activity were in the months following spawning (July and 
in insect populations. August) and in the colder months (November, Febru- 
The heaviest feeding occurred in May as the spawn- ary, and March). 
ing season approached. ‘The periods of least feeding As the darters increased in size, the over-all diet 
100 
Fig. 9—Seasonal variation in 
the diet of Percina phoxocephala 
specimens of all sizes. The per- 
centage of each food item repre- 
sents its contribution to the total 
number of items found in all fish 
examined each month. 
PERCENT OF FOOD ITEMS 
oO 
FEB. MAR. APR. MAY JUNE JULY AUG. SEPT. OCT. NOV. 
,MIDGE 
NN & MAYELY [__] caDDISFLy 
BLACKELY 
PERCENTAGES 
31-40mm 
(10) 
Fig. 10—Composition of the diets of five 
size-classes of Percina phoxocephala. Numbers 
in parentheses are specimens examined. 
