this period the respiratory rate of these animals was similar to the 

 shrimp tested in the control medium at 32°C. Steady metabolic level 

 at 25°C was also similar to the level in the control shrimp (15°/ooS 

 and 25°C, Fig. 121). 



Effect of reduced potassium on oxygen consumption 



Respiratory rates were determined at 18°, 25°, and 32 °C in 

 15°/ooS media with 30% K concentration (Fig, 124). 



At 18° and 25°C the immediate responses and stabilization pro- 

 cesses in 30% K solution took the same amount of time and followed 

 the same pattern as in the 0% Mg tests. In both test temperatures 

 the steady metabolic levels were maintained at the same levels as 

 in the control conditions (15°/ooS and 18° and 25°C, respectively; 

 Fig. 121). The steady-state level in 32°C was at a slightly higher 

 level than in the control (15°/ooS and 32°C, Fig. 121). The survival 

 rates at 18°, 25°, and 32°C were similar to the control test condi- 

 tions. 



Metabolic rates in relation to temperature 



Temperature effect on the metabolic rates is shown comparatively 

 in media with 25% Ca, 0% Mg, and 30% K concentrations (Fig. 125). 



In all these test conditions, the respiratory rates increased 

 with a temperature rise from 18° to 32°C. In 25% Ca and 30% K con- 

 centrations the oxygen consumption levels at 32°C were higher than 

 in control shrimp tested in 32°C. The respiratory rates in 0% Mg did 

 not increase at the same rate as in the other test conditions. The 

 temperature effect on the oxygen consumption was not significantly 

 different in 18° and 25 °C from the control shrimp tested at the 

 same temperatures. 



272 



