nonsignificant differences between the adjacent means and the state of 

 the experimental animals. The state of the animals was recognized 

 from their activity level and other behavior. The new steady-state 

 levels were usually higher than in 15°/ooS. In 10, 15, and 25°/ooS, 

 where the animals apparently experienced relatively less salinity 

 stress, there was a slight decline in the respiratory rates after the 

 fifth day. This may reflect a possible starvation effect which was 

 higher in 32°C than in 25°C but was not observed at 18°C. 



Within six hours stabilization started at 32° and 18°C. The 

 shrimp at 32°C reached a steady state from the third day in 10 and 

 15°/ooS and from the fifth day in 25°/ooS (Fig. 101). After the 

 third day the shrimp were apparently under the influence of hunger. 

 Comparison of the oxygen means between the first and third days 

 showed significant differences in 10 and 15°/ooS and to a lesser 

 extent in 25°/ooS (Table 8). Therefore, the conclusion about the 

 new steady state was inconclusive and was based solely on the flat- 

 ness of the metabolic curve. The starvation effect was not noticed 

 in 2, 5, and 36°/ooS where the animals were under both salinity and 

 temperature stress. There was a high mortality rate in these con- 

 centrations. The possibility of reaching a new steady state in 

 these conditions was doubtful. 



In 18°C the respiratory rates dropped to very low levels within 

 a few hours after transfer and remained so in all salinities (Fig. 

 102). After some days the respiratory rates, however, tended to 

 return toward the level in 15°/ooS and 25°C in 10 and 15°/ooS but 

 not in other media. All shrimp in 2°/ooS died within four hours. 

 In 5°/ooS there was also a high mortality. The shrimp at 18°C were 

 obviously less affected in 25 and 36°/ooS. In 18°C steady-state 

 metabolic levels were reached in 5, 10, 15, and 25°/ooS within six 

 hours. 



199 



