258 



BUTJiETIN OF THE BUREAU OF FISHERIES. 



Food of fish in fishponds at Fairport, Iowa, by H. E. Schradiech. 

 [In the last five columns the figures are percentages, the entire food 100.] 



Length 

 of fish 

 eating 



beetles, 

 milli- 



meters. 



Uniden- 

 tified 

 beetles, 

 d6brls. 



Hydro- 

 philid 

 beetles, 

 adults. 



H dro- 

 philid" 

 beetles, 



Dytis- 



cid 

 beetles 

 larvse. 



HaU- 



plid 

 beetles 

 adults. 



14 



26 

 98 



108 

 93 

 98 



110 



in 



8 

 22 

































4o 













12 









3 

























































135 







50 















76 









6 













41 



45 

 45 

 48 

 52 

 54 

 55 

 56 

 62 

 50 







25 



25 

 5 

 25 

 30 







































20 











15 







lo 



10 











10 



10 











45 







lU 



8 











22 

 24 

 24 

 24 

 28 

 28 

 35 

 37 

 39 

 41 

 41 

 42 

 42 

 42 

 45 









20 

 25 





















12 











15 

 15 

 35 

 50 

 30 

 55 

 70 

 50 

 7 

 20 



















































































20 











Fish- 

 pond 

 from 

 which 

 taken. 



Number 

 of fish 



Ex- 

 treme 

 lengths 

 of fish 



ex- 

 amined, 

 milU- 

 meters, 



Eupomotis gibbosus, common sunfish 



Ictalurus punctatus, channel catfish 



Ictiobus bubaUs, smaU-mouthed buflalofish 



Lepomis paUidus, bluegill.. 



Micropterus salmoides, large-mouthed black bass.. 



4D 

 16B 

 5D 

 7D 

 2D 



This table is of considerable interest for several reasons in spite of tbe fact that 

 it contains but five different kinds of fish. In the first place, these fish are widely 

 distributed and represent 10 different ponds, whose contents of animal and vegetable 

 life are very diverse. In consequence the record has a broader significance than it 

 would otherwise possess. Again, three of these fish — the common sunfish, the chan- 

 nel catfish, and the small-mouthed buffalofish — appear only in Forbes 's record, 

 where there were no data as to the size of the fish or the amount of food. A fourth, 

 the large-mouthed black bass, appears only in Pearse's record, where the amount 

 of beetles consumed was insignificant. 



The present record supplies these missing details and, so far as the bass is con- 

 cerned, entirely changes the diet statistics. Of the small-mouthed buffalofish 

 the examination of two lots from separate ponds, totaling 78 fish, none of which 

 ate any beetle food, have been included for the sake of the contrast in size. The 



