Research Product

Pink shrimp (Penaeus duorarum), exposed for 30 to 50 days to 3 µg of polychlorinated biphenyls (PCB) per liter in flowing sea water, accumulated up to 40 mg of PCB per kg in hepatopancreatic tissue. Fifty per cent or more of the experimental shrimp died after 20 to 30 days exposure. Light and electron microscopy of shrimp surviving 30-day exposure revealed two forms of hepatopancreatic cellular alterations that may reflect toxic responses. The most prevalent cytopathic alteration was the occurrence of small (20 to 50 nm.) and large (100 to 700 nm.) vesicles in nuclei of absorptive cells. Such vesicles were observed in 30 to 80 percent of cell profiles from exposed shrimp. These cells also presented abnormally proliferated endoplasmic reticulum and high numbers of free and attached ribosomes. The other significant difference between exposed and control shrimp was the presence of a baculovirus in 5 to 8 percent of the hepatopancreatic nuclei of exposed shrimp. This virus was associated with several nuclear and cytoplasmic alterations, and is the first Baculovirus to be reported in animals other than insects or mites. The significance of the virus infection and PCB exposure of the infected shrimp will be discussed.