5 GEORGE V. 



SESSIONAL PAPER No. 39b 



A. 1915 



IX. 



SOME EXPERIMENTS ON THE FREEZING AND THAWING OF 



LIVE FISH. 



By W. H. Martin, B.A. 

 University of Toronto. 



The fishermen of the Bay of Fundy say that if, in very cold weather, a 

 herring be thrown out on the ground and frozen so that it is apparently quite 

 stiff, when thrown back into the water, it will swim off as soon as it thaws 

 out again. 



The following experiments were performed at St. Andrews, N.B., at the 

 Marine Biological Station, Summer of 1913, to determine how low a tem- 

 perature fish will stand and for what length of time they will survive such a 

 temperature. 



Methods. 



For the experiments the species Fundulus heteroclitus (the common mum- 

 michog) was used. They were easy to obtain in tide pools about St. Andrews. 

 They are of convenient size for experiments and are wonderfully hardy: 

 they are easily kept for several weeks in a tank, and were found to survive 

 sudden changes of Temperature much better than any other fish used. 



In the experiments a large carbide-tin was covered with felt and used as 

 a refrigerator. 



An inner tin vessel contained a mixture of ice and salt. The fish were 

 placed in an inner jar in water or in air as required. 



Results. 



Experiment I. A dozen fish were put into sea water at 6°C. and the jar 



was lowered into the freezins: mixture. The following; table gives the results: — 



396—6 



