invertebrates. He considered this as an important adaptation for 

 using the metabolic reserves during periods of stress. 



There were discrepancies observed between the mortality rates 

 of brown shrimp in the oxygen studies and those in the osmotic and 

 ionic regulation studies. There are two possible reasons for this 

 outcome. In the metabolic studies, fewer shrimp (11 or less) were 

 used in each test condition than in the osmoregulation and ionic 

 regulation where up to 200 were used. Also in the oxygen studies, 

 the shrimp were confined to narrow respiratory chambers with just 

 a small amount of sand in the bottom. In the other studies shrimp 

 were able to swim about or bury freely which probably contributed 

 to their better survival rates in unfavorable test conditions. 



Irrespective of test temperature the shrimp acclimated to 

 32°C attained new steady-state levels in the metabolic, osmotic, 

 and chloride regulation in 10 and 15°/ooS within the first day. 

 At 32 °C test temperature steady-state metabolic levels appeared 

 in 5°/ooS on the first day but not in 25°/ooS. In 25°/ooS there 

 was a gradual drop in the oxygen consumption. However in 25°/ooS 

 steady-state osmotic and chloride levels did appear. Between the 

 first and fourth day large osmotic fluctuations occurred in 2, 5, 

 and 36°/ooS and slowed the rate of adaptation process. Chloride 

 ion reached steady state on the first day in 10, 15, 25, and 36°/ooS 

 and after two days in 2 and 5°/ooS. 



In shrimp acclimated to 32°C and tested at 25°C steady metabolic 

 rates appeared on the first day in 10, 15, 25, and 36°/ooS and on the 

 third or fourth day in 2 and 5°/ooS. Steady-state levels in osmotic 

 and chloride regulation in 2 and 5°/ooS appeared on the fourth day 

 more or less at the same time as in the metabolic rates. The osmotic 

 and chloride ion regulation in 36°/ooS was still in the process of 

 stabilization by the end of one week. 



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