Comparison of Heavy Metal Uptake of Cd in Liver of Zebra fish in Saltwater and Freshwater Environments

The purpose of this study was to compare the heavy metal uptake of Cd in liver tissue of endemic fish Aphanius sophiae in the saltwater Eshtehard of Karaj and fresh water in laboratory conditions، the relationship between cadmium accumulation in the liver، the effect of salinity and different concentrations of Cd uptake. Sampling did randomly from Salt River in the spring and summer 2011. After 18 days storage and feeding in 4 aquarium tank with concentrations ppm (20، 10، 5، 0) cadmium، the fish were sampled. After biometry and sex determination، liver tissue was isolated and were dissolved with the wet acid digestion method، thus The concentrations of the Cd were measured using ICP-OES. In the analysis of samples taken from tanks containing salt water aquarium 24 percent were male and 76 percent of the samples were female and in fresh water aquarium 35% of the sample were male and 65 percent were female. The average length of fish in salt water 3/4 ± 0/3 and in fresh water 2/77 ± 0/17. Mortality percent after exposure to fresh water Aquarium was 56% and Mortality in salt water water did not observed during the test period. Regression analysis don''t show، the relationship between cadmium concentrations in liver and fish body length and age in saltwater and freshwater. The accumulation of cadmium in the liver in fresh water 1/47 more than the concentration in the saltwater. To examine differences in Cd accumulation in both freshwater and saltwater environments، T-test was performed، results showed no significant difference in Cd concentrations in the two environments. Environmental impact by using Split plot analysis in completely randomized design and Duncan test were investigated. Table Analysis of variance showed that there is no interaction between cadmium and salinity. Cadmium accumulation in fresh and salt water at all concentrations (except 20 freshwater) increased with increasing concentrations of cadmium.