ion concentrations (Table 26). The control medium was prepared with 

 synthetic sea salt. Tests were conducted at 18°, 25°, and 32°C. 



Behavior in control salinity 



The experimental shrimp were active in 25 °C for about 30 minutes, 

 possibly as a reaction to handling during the transfer to the contain- 

 ers. One shrimp died within the 24 hour observation period. Two 

 shrimp became stressed after three hours and the others resumed nor- 

 mal activity after one hour. 



The shrimp were hyperactive at 32 °C for almost two hours. One 

 shrimp died due to stress in seven hours; a second one died during 

 the night (ten hours later) after molting. The surviving shrimp 

 became quiescent for the duration of testing following the initial 

 hyperactivity. The shrimp were generally inactive in 18°C. They 

 walked or swam around the tank occasionally for about 30 minutes. 

 Later they were quiescent for the rest of the test period. The 

 behavior in the artificially constituted control medium did not 

 differ from that in the natural seawater in the three test tem- 

 peratures. 



Effect of deviated sodium 



Most shrimp survived in 25 °C except for deaths which occurred due 

 to molting in media with 85 and 120% sodium (Na) ion concentrations 

 (Table 26). The shrimp were hyperactive for two to three hours in 

 95% Na and for one hour in 85% Na before becoming quieter. The 

 animals were inactive in 120% Na throughout the test period. At 

 18°C all of the shrimp were quiet from the start and remained in- 

 active throughout. Two shrimp developed abdominal cramps in 95% Na 

 and died within 24 hours. 



More shrimp died at 32°C than in 25° or 18°C. The shrimp were 

 all hyperactive for one to two hours after transfer and later became 



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