PLANTS OF IMPORTANCE IN POND FISH CULTURE. 



By Dr. Emmeline Moore. 



State Conservation Commission, 



Albany, N. Y. 



In the brief time at my disposal, I shall stress the need of 

 conserving certain pond plants which contribute to the food supply 

 of the young fish. 



The Bureau of Fisheries has given me the opportunity to make 

 some investigations along this line, and the directors and super- 

 intendents of fish cultural stations have facilitated my work in 

 every way with results which indicate a more efficient treatment 

 of the natural forage supply in the ponds. 



The problem thus far has centered around observations of 

 the food taken by the advanced fry and fingerlings of bass, sunfish, 

 buffalo-fish and other pond fish. My point of attack has been to 

 make a botanical survey, as it were, of the contents of the fish 

 stomachs, a survey which had for its object the determination, 

 not only of the table of contents, but of the actual plant materials 

 which supply food for the organisms on which the fish feed; that 

 is, by working back to the plant substance which is drawn upon 

 either directly or indirectly by the organisms upon which fish 

 feed. In the last analysis it is always plant substance. 



A natural food is required by the young pond fish. As you 

 know, they will not accept artificial food. For this reason, then, 

 the necessary first step has been to reduce the actual food taken 

 to its lowest botanical terms, so to speak, and thus to study the 

 forage substance which the ponds contribute in building up the 

 large supply of natural food for the young fish.* 



The tables were compiled from examinations of the food content 

 of fish which were taken at weekly intervals during the early 

 growth period, that is, of the advanced fry and fingerling stages. 

 The tables show a preponderance of chironomid or midge larvae, 



* At this point Dr. Moore displayed tables which showed the food 

 content of young pond fish examined at the U. S. Biological Station, Fairport, 

 Iowa. Since the Louisville Meeting these tables have been published, 

 appearing as a part of the report of the U. S. Commissioner of Fisheries for 

 1919. See Appendix IV, Bur. of Fisheries Doc. No. 881. 



