However, in the process of salinity adaptation there was a relatively 

 high mortality in 2 and 36°/ooS, probably due to either salinity 

 stress or the process of molting. In this case where a single 

 test variable, i.e. salinity, was used the salinity adaptation 

 occurred within a day in the animals that survived. Also the mor- 

 tality rate was generally low. Besides there was good synchrony 

 between the steady respiratory responses and blood osmotic or ionic 

 regulation. The correlation between these two responses was dis- 

 turbed in experiments where two variables, i.e. salinity and tempera- 

 ture, were applied simultaneously. 



In animals acclimated to 25 °C and tested in 32 °C the salinity 

 related respiratory sequence was changed from 25°C test conditions. 

 Oxygen uptake levels were higher than in 25°C. Animals were hyper- 

 active from 1/2 hour in 15°/ooS to four hours in 2°/ooS; in 25 and 

 36°/ooS they appeared normal. Mortality was higher than in 25°C. 

 The decreasing oxygen consumption levels in 10, 15 Ccontrol) , and 

 25°/ooS after two or three days suggest the possible impact of 

 starvation. New steady-state levels appeared faster in osmotic or 

 ionic regulation than in the metabolic rates. At 32°C test conditions 

 the increased activity level apparently had influenced the respira- 

 tory rates and delayed the new steady-state metabolic levels. There 

 were no indications, however, that the behavioral responses could 

 directly influence the osmotic and ionic regulation as much as they 

 did the metabolic rates. 



The discrepancy between the two physiological responses was even 

 more pronounced in shrimp acclimated to 25°C and tested in 18°C. 

 Steady metabolic levels were obtained within six hours in all but 2 

 and 36°/ooS. There was a total mortality in 2°/ooS within four 

 hours. Steady-state levels were not seen in ionic or osmotic regu- 

 lation until three or four days although the initial changes in 15 

 and 25°/ooS were completed in two hours and in other salinities in 



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