Cadmium accumulation and its effect on calcium metabolism in the girella Girella punctata during a long term exposure.

Abstract

Cadmium accumulation and its effect on calcium metabolism in girellas were studied during 24 weeks of exposure to sublethal cadmium levels (25 to 250μg Cd/l) in filtered sea water. After the 24 weeks of exposure, the fish were reared in clean sea water for 10 weeks and the removal of cadmium from the bodies was investigated. A large amount of cadmium was accumulated in the livers and kidneys during the exposure. Cadmium levels in the gills and intestines reached to the maximum amount within 8 weeks and remained constant thereafter. Cadmium contents in the gills and intestines decreased remark-ably after the end of the exposure period. The 4 week exposure of girellas to cadmium caused a depression of the serum calcium concentrations in proportion to the cadmium levels in the test water. However, there was no difference between the serum calcium concentrations of the ex-posed fish and those of the control after 16 weeks. Calcium contents in the kidneys after the 24 week exposure showed a tendency to decrease in proportion to the cadmium levels in the test water. The exposure to cadmium had no effect on the calcium contents in the livers, intestines, gills, muscles and vertebrae.