STARVATION AND THE RESISTANCE OF FISHES 

 TO LACK OF OXYGEN AND TO KCN. 



MORRIS M. WELLS. 



PAGE 



I. Introduction 441 



II. Material and General Methods 441 



III. Experimental Methods 443 



IV. Presentation of Data 443 



1. Seasonal Resistance of the Fishes 443 



2. The Process of Starvation 445 



3. Resistance to Lack of Oxygen 445 



4. Resistance to KCN 446 



5. Comparison of Species 448 



V. Discussion 448 



VI. Summary 451 



VII. Acknowledgments and Bibliography 452 



I. INTRODUCTION. 



The following paper is a report on experiments that were car- 

 ried on at the University of Chicago during the fall and winter 

 of the years 1913 and 1914. The object was to determine the 

 effect of starvation upon the rate of metabolism in fresh-water 

 fishes. The work is still in progress, but it has seemed best to 

 record briefly at this time some of the results thus far obtained. 



II. MATERIAL AND GENERAL METHODS. 



Practically all of the experiments reported here were performed 

 with the rock bass (Ambloplites ntpestris Raf.). To confirm the 

 apparent similarity of the effects of the low oxygen and the KCN 

 treatments, experiments with tadpoles and three or four other 

 species of fishes were performed. 



All of the animals used were collected in the streams and ponds 

 in the vicinity of Chicago. The collections were made during 

 the months of October, November and December. The animals 

 were brought into the laboratory at once and with a minimum 

 amount of handling. They were weighed immediately and those 

 that were to be starved were placed in compartments in aquaria 

 through which tap water coming from Lake Michigan was 



441 



