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FISHERY BULLETIN: VOL. 76, NO. 1 







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36 



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Figure 36. — Electron micrograph of profile of hepatopancreatic 

 cell from pink shrimp exposed to 3 ppb Aroclor 1254 (PCB) for 52 

 days; note endoplasmic reticulum proliferation and beginning 

 formation of cytoplasmic whorls (arrow). ^ 14,400. 



Figure 37. — Membrane whorls (myeloid bodies) surrounding 

 lipid in hepatopancreatic cells of shrimp exposed to 3 ppb Aroclor 

 1254 (arrows). Control nonexposed shrimp did not produce profiles 

 with these configurations, x 28,500, 



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choices of clean or PCB-contaminated water. 

 These and other data suggest that PCB's, as pol- 

 lutants, could have influence on relative survival 

 and abundance of penaeid shrimps in natural wa- 

 ters. 



Organophosphates and Carbamates 

 Few organophosphate compounds have been 



tested in species of crustaceans. Howevei", those 

 tested have shown approximately 1,000 times 

 greater toxicity to shrimps than most other pes- 

 ticides tested (Butler 1966), and penaeid shrimps 

 have shown greater sensitivity than fishes or mol- 

 lusks (Table 4). 



Baytex ( Bayer 29, 493 ) was very toxic to penaeid 

 shrimp (Butler and Springer 1963) in the labora- 

 tory. Naled (1,2 dibromo-2,2-dichloroethyl-di- 

 methyl phosphate) had little effect in field tests on 

 shrimp. Fast dilution and instability without per- 

 sistence of compounds may be reasons for lack of 

 mortality of shrimps in field tests of organophos- 

 phates. In the laboratory, Dibrom is lethal to post- 

 larval brown shrimp at 2.0 ppb, and at 5.5 ppb it is 

 lethal to adult pink shrimp (5.5 ppb = LC^^ for 48 h 

 exposure). 



Malathion, at 14 ppb, caused hyperactivity, 

 paralysis, and death in penaeids, and parathion 



30 



