Survey of relationship between fork length, weight, age and the uptake of heavy metals in muscle and skin tissues of Caspian Roaches (Rutilus rutilus caspicus) in the southern part of Caspian Sea

This work investigates the relationship between fork length، weight، age and the uptake of heavy metals such as iron، zinc، copper and cadmium in muscle and skin tissues of fish (Rutilus rutilus caspicus) in two sites in Sari and Turkmen Seaport of Southern part of Caspian Sea. Samples were collected in autumn 2013 and winter 2014. After measurement of fork length، weight، age by squama of 37 samples and preparation and parting of tissues، concentration of heavy metals were determined following wet digestion using Flame Atomic Absorption Spectrophotometry. Spearman correlation test results showed that fork length and weight and uptake of copper in the muscle tissue have negative correlations (p<0. 05). However this correlation between the weight and the uptake of iron is positive (p<0. 05). In the skin، there is a positive correlation (p<0. 05) between fork length and extent of absorption of iron and cadmium، unlike those between the weight and the absorption of zinc. The importance of the findings of this study due to the presence of heavy metals in tissues of fishes، especially muscle tissue، which is due to the consumption of oral tissue، heavy metals have the ability to transfer to humans in terms of public health and the health of people is a special place. These values were compared with the WHO and the FAO and UK (MAFF) safety standards regarding the amount of the above mentioned heavy metals in fish tissues. Based on the results of this study، The average concentrations of cadmium in the muscle and skin tissues proved to be higher than international standards. It is recommended not to use these fish due to the toxicity and high levels of cadmium in their muscle tissues.