Table 8b. --Winter lethal values of oxygen for iao 



Table 8c. --Analysis of variance of the data 

 from the above two tables 



♦Significant at 5-percent level (P < 0.05). 



Lethal Values of Oxygen for Iao: Experiments Using Several Fish 



Procedure. --In these experiments, 10-15 fish (usually 14) were placed in a 1 -liter 

 aspirator jar with a side-opening close to the bottom for withdrawing water samples. Water was 

 circulated through the container for 1 hour, at which time the fish were quiescent and appeared 

 to be schooling normally. Circulation was then stopped, about 100 ml. was run out and replaced 

 by mineral oil, after which the jar was securely stoppered. Three samples were taken in each 

 experiment, after approximately one-third, one-half, and all of the fish had died. At the end of 

 the experiment all fish were nneasured to the nearest millimeter. The tests were run in Decem- 

 ber 1951 and January 1952. 



