ity when shrimp were transferred from 15 to 2 or 

 36%o S; osmotic stability was achieved in 2 h after 

 transfer from 15 to 5, 10, 15, or 25%o S. 



Highest catch rates for brown shrimp were de- 

 termined by Copeland and Bechtel (1974) to occur 

 in salinities from <4 to >35%o. This lower limit is 

 slightly less than the range of salinities (5-8%o) 

 suggested by Khlebovich (1968) at which ion ratios 

 change from typically freshwater to marine. 

 Therefore it appears that if juvenile or subadult 

 shrimp were acclimated to salinities that are typi- 

 cally marine (8-35%o), oxygen consumption rates 

 will not reflect any significant increased energy 



FISHERY BULLETIN: VOL. 78. NO. .3 



demands necessary for osmoregulation. Table 8 

 summarizes oxygen consumption rates of penaeid 

 shrimp that have been acclimated to and tested at 

 various salinity-temperature combinations. 

 Routine and standard rates vary from 0.14 to 0.75 

 mg O2 g wet m~^ h"^. 



Shrimp Size Effects on 

 Oxygen Consumption and Osmoregulation 



The effects of size on an animal's oxygen con- 

 sumption are apparent for individuals ranging 

 from 1 to 1,000 g (Zeuthen 1947). Generally a large 



Table 8. — Oxygen consumption of penaeid shrimps; some data converted to allow uniform reporting. Temperature (T) in degrees 

 Celsius, salinity (S) in parts p)er thousand, and mass (m) of live shrimp in grams. Genera Metapenaeus and Penaeus abbreviated as M. 

 and P. 



'Tested at 63% oxygen saturation. 



750 



