Comparing bioaccumulation of cadmium chloride in different tissues and organs of freshwater crayfish (Astacus Leptodactylus) of Aras dam under aquaculture conditions

The freshwater crayfish of Aras (Astacus Leptodactylus) belong to the order of Decapoda. In polluted environment crayfish are able to accumulate a considerable amount of heavy metal in their tissues and to excrete some of them. Freshwater crayfish species are considered to be biological indicators of clean water. The aim of this research was to evaluate the amount of cadmium in the tissue of A. Leptodactylus especially in their muscle, which is the consumed part of their body. In this study the crayfish was exposed to intermediate concentration of cadmium chloride (500μg/ L) for periods up to 3 weeks. In the first, second and third weeks bioaccumulation in various tissues was under investigation. The data of toxicological analysis obtained by the method of atomic absorption revealed that the levels of bioaccumulation of metal are different in various tissues of the crayfish. The accumulation of cadmium in exoskeleton was the highest (76.6 μg/g) and in muscles was lowest (3.105 μg/g) degree. The amount of heavy metal in the tissues of crayfish was as follow: Exoskeleton> gills> digestive tract> hepatopancreatic > testis and ovary> muscles. The amount of accumulation in the muscle was lowest and this can be indicative of the health of this aquatic environment with commercial value. And most importantly, the larger crayfish are less crowded and this can be in the interest of consumers and breeders of this aquatic environment

Keywords:

Crayfish , Cadmium , Aras dam , Bioaccumulation