182 



BULLETIN OF THE BUREAU OF FISHERIES 



Table 4. — Maximum temperatures, in degrees centigrade, tolerated for various lengths of time by normal 

 individuals and by those that had been acclimatized for different lengths of time at 10° and 30° C. 

 The signs +? or — ? indicate that the limit of tolerance was shown to be as high (or low) as the 

 figure given and was possibly higher (or lower) 



Temperature and duration of acclimatization 



24-hour 

 tolerance 



4-hour 



tolerance 



1-hour 



tolerance 



15-minute 

 tolerance 



Perch: 



30°, 1 day- 

 Normals 



10", 1 day... 

 10°, 4 days.. 



Bass: 



30°, 4 days.. 

 30°, 1 day- 

 Normals 



10°, 1 day... 

 10°, 4 days.. 

 10°, 16 days 



Bluegills: 



30°, 4 days.. 

 30°, 1 day- 

 Normals 



10°, 1 day... 

 10°, 4 days.. 

 10°, 16 days 



Sunfish: 



30°, 4 days.. 

 30°, 1 day.. 



Normals 



10°, 1 day... 

 10°, 4 days.. 

 10°, 16 days 



Toad tadpoles: 

 30°, 4 days.. 

 30°, 1 day... 



Normals 



10°, 1 day... 

 10°, 4 days.. 



30.3 

 29.6 

 29.0 

 29.0 



35.2 

 36.0 

 32.2 

 31.5 

 30.0 

 28. 0-? 



35.6 

 34.3 

 34.0 

 30.0 

 30.6 

 28. 0-? 



34.3 

 34.2 

 34.0 

 32. 0+? 

 30.0 

 28. 0-? 



37.6 

 36.0 

 36.3 

 35.7 

 34.4 



32.0 

 31.5 

 30.3 

 29.4 



36.0 

 36.0 

 32.4 

 31.8 

 30.0 

 28.3 



36.3 

 35.7 

 34.0 

 30.0 

 31.1 

 28.0- 



35.7 

 34.8 

 34.0 



30.4 

 29.4 



38.0 

 37.7 

 37.3 

 36.3 

 35.6 



32.0 



34.0 



34. 0+? 



32.0 



32.0 



34.0 



32.0 







31.3 



31.7 



31. 7+? 



36.9 



37.4 



39.0 



36.0 



36.7 



38.0 



33.4 



33.7 



36. 0+? 



32.0 



32.3 



34.0 



31.0 



32.8 



34.0 



29.0 



29.8 



30.0 



36.3 



38.0 



38. 0+? 



36.0 



36.7 



38. 0+? 



34.3 



35.7 



36.4 



30.7 



32.6 



34. 0+? 



32.7 



33.5 



34. 0+? 



28.3 



30. 0+? 



30. 0+ ? 



38.0 

 36. 0+? 

 35.3 



38.0 

 36.0 



31.2 

 30. 0+? 



39.8 

 38.0 

 37.4 

 37. 1 

 36.7 



33.4 



40. 0+? 



38.0 



38.6 



37.1 



37.0 



Table 5. — Numbers of degrees centigrade by which tolerances of different species were modified by 

 acclimatization at 30° and at 10° C. The data in this table represent the differences between the 

 temperatures tolerated by normal and acclimatized individuals, as shown in Table 4 



Temperature and duration of acclimatization 



24-hour 

 tolerance 



4-hour 

 tolerance 



1-hour 

 tolerance 



15-minute 

 tolerance 



Perch: 



30°, 1 day... 



10°, 1 day... 



10°, 4 days.. 

 Bass: 



30°, 4 days.. 



30°, 1 day... 



10°, 1 day... 



10°, 4 days.. 



10°, 16 days. 

 Bluegills: 



30°, 4 days.. 



30°, 1 day— 



10°, 1 day... 



10°, 4 days.. 



10°, 16 days 

 Sunfish: 



30°, 4 days.. 



30°, 1 day... 



10°, 1 day... 



10°, 4 days.. 



10°, 16 days 

 Toad tadpoles: 



30°, 4 days.. 



30°, 1 day— 



10°, 1 day... 



10°, 4 days.. 



0.7 

 -.6 

 -.6 



3.0 

 3.8 

 -.7 

 -2.2 

 -4.2 



1.6 

 .3 

 -4.0 

 -3.4 

 -6.0 



. M 

 .2 



(?) 

 -4.0 

 -6.0 



1.3 

 -.3 

 -.6 

 -1.9 



0.5 

 -1.2 



3.6 

 3.6 

 -.6 

 -2.4 

 -4.1 



2.3 

 1.7 

 -4.0 

 -2.9 

 -6.0 



1.7 



-3.6 

 -4.6 



.7 

 .4 

 -1.0 

 -1.7 



0.0 

 .0 

 -.7 



3.5 

 2.6 

 -1.4 

 -2.4 

 -4.4 



2.0 

 1.7 

 -3.6 

 -1.6 

 -6.0 



2.7 

 .7 



-4.1 

 -5.3 



2.4 



-.3 

 -.7 



2.0 



-."§" 



3.7 

 3.0 

 -1.4 



-.9 

 -3.9 



2.3 

 1.0 

 -3.1 

 -2.2 

 -5.7 



1.4 

 -.6 

 -1.5 

 -1.6 



