Submit Manuscript | http://medcraveonline.com Introduction Fish is an important source of animal protein, which is cheap for humans that have very signifcant importance because of economic value and sensitivity against pollutants. Metals, exists in the environment normally and some of them play an important role in biologic processes. 1 Natural processes (Volcanoes, weathering and stone erosion, sediments, fring) and industrial progresses and technology causes the increasing the pollution of different natural resourcesin the environment like water and soil. Pollutants with infuencing on aquatic life create signifcant losses for them and subsequent consumers. 2-5 Heavy metals because of toxic effects and high accumulation power in many species of aquatics is considered signifcant. 6-7 Among Zinc (Zn) cupper (Cu) and Iron (Fe) are essential for body a little, but high amount of them create deleterious effects for creatures. There are other groups such as cadmium (Cd), lead (Pb) and Mercury (Hg) which is detrimental for body even a little. 3,8,9 The most important bad effect of cadmium consumption in human is decease of Itay-Itay or the disease of joints and bonds that consequently leads to death. 3,10 Cadmium in the fsh, affects the enzymatic routes of ascorbic acid synthesis. 10 In addition, accumulation of cadmium causes decreasing the size of liver and losing the glycogen resources of liver and muscle in the fshes. 10 Fishes in their environment cannot escape from these destructive harms of pollution and lead to polluting the food chain. 11–13 Age, length, weight, sexuality, food habits, ecologic requirements, the concentration of heavy metals in the water and sediment period of fsh shelf life in aquatic environment, fshing season, water chemistry (salinity, intensity and temperature) are the effective reason in accumulation of heavy metals in different organs of fsh. 14–16 Fishes are more sensitive to available pollutions in the water rather than humans. As a result, the sample of accumulation trend and elements accumulation in the fsh tissues can be used as a biological bio indicator to the changes in aquatic environments. 17–19 Caspian Marin shad (A.brashnikowi) from the family of clupeid that its length is 30 to 50cm. It is one of the bony fshes that because of having suitable length and weight is a commercial and economic species in the south area of Caspian Sea. 20,21 Several studies by researchers are done about amount of heavy metals in the fshes. In a research which was done by Yonesipour et al. on the Cyprinus fsh of Caspian sea (Cyprinusc arpio), the average amount of density in (SD) Fe, Cu, Zn, Ni, Co and Mn in the muscles of this fsh is 77/91±11, 12/11±17, 63/45±14, 121±14/3, 323/5±0/54µgr/gram of net weight respectively. Another research which was done by Akan et al., 22 the amount of Cu, Zn, Co, Mn, Fe, Cr, Cd, Ni and Pb maintained from 4species of Fishes (Clarias anguillaris, Tilapia zilli, Synodentis budgetti and Oreochronmis niloticus) from Beneu river of Nigeria. The highest amount of density was related to Fe in the gills of every 4 fshes and the lowest amount of Concentration of metals was maintained in the J Aquac Mar Biol. 2018;7(6):308‒312. 308 © 2018 Astani et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and build upon your work non-commercially. Studying the accumulation of heavy metals (Fe, Zn, Cu and Cd) in the tissue (muscle, skin, gill and gonad) and its relation with fsh (Alosa braschinkowi) length and weight in Caspian Sea coasts Volume 7 Issue 6 - 2018 Zahra Falahnejad Astani, 1 Hasan Taghavi Jelodar, 1 Hasan Fazli 2 1 University of Mazandaran, Faculty marine science, Iran 2 Member of the Institute of Ecology of the Caspian Sea, Sari, Iran Correspondence: Hasan taghavi Jelodar, Associate professor marine biology, Faculty of marine science, University of Mazandaran, Iran, Email Received: April 18, 2017 | Published: November 15, 2018 Abstract This research is done with aim of determining the accumulation of heavy metals (Fe, Zn, Cu and Cd) in different tissues of Caspian Marin shad (Alosa braschnikowi) in south area of Caspian Sea (Babolsar). Then 22 species of fshes were collected from commercial fshing, randomly. The density of samples’ heavy metals after biometry (length and weight) and tissue isolation and chemical digestion was measured by the Flame atomic absorption. The concentration of Fe in the tissues was such as, gonad> gills > skin > muscle, the Zn is such as muscle < gills < skin <gonad, the Cd is such as gonad> skin > gills > muscle and Cu was such as Muscle <gonad< gills < skin. The results of spearman correlation test have shown that in the tissue of gills between weight and the amount of Cd absorption (p<0.05), in the tissue of gonad between fork length and the amount of Cu absorption, there is a negative and strong correlation (p<0.01). However, in the tissue of muscles there isn’t any meaningful relationship. Also, the concentration of Zn in the skin and gonad was higher than FAO and UK (MAFF) standards and in all tissues the concentration of Cd was higher than all standards. Keywords: caspian marin shad; fork long weight; heavy metals; caspian sea; alosa braschnikowi Journal of Aquaculture & Marine Biology Research Article Open Access