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We determined bioaccumulation of heavy metals (Cd, Pb, Ni and Hg) in the muscle, gill and liver organs of Barbus xanthopterus in summer 2009 in Karoon River, south west of Iran. Gill net was used to sample 48 random size fish specimens from Karoon River downward of Ahwaz city (Shekariyeh 3 village). The tissues were extracted and the elements were determined using atomic absorption spectrophotometer. Concentrations of heavy metals Cd, Pb, Ni , Hg in muscle tissue of Barbus xanthopterus were 1.679, 2.37, 1.16, 1.29mg/kg dry wt and in gill were 2.17, 2.92, 1.44, 1.34mg/kg dry wt and in liver were 1.92, 2.79, 1.31, 1.43mg/kg dry wt, respectively. All the results were statistically significant (P 0.05). The concentrations of heavy metals were higher than standards of the World Health Organization (WHO) in the muscle tissue of Barbus xanthopterus in Karoon River.

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Barbus sp. fish samples were collected during November 2007 to October 2008 from five landing stations in Karoon River: Gotvand, Shoshtar, Molasani, Ahwaz, and Darkhoin. During one year of study, more than 2000 specimens of B. grypus and B. barbulus were measured, mean±SD length values for this species were 37.94±8.18 and 43.62±10.27, respectively and maximum and minimum total length were 20-76cm and 20-94cm, respectively. Mean±SD of weight values for this species were 873.2±1092.45 grams and 778.59±725.97 grams, respectively and maximum and minimum weight were 52-11170 grams and 52-4675 grams, respectively. Growth and mortality parameters were calculated for B. grypus and B. barbulus as L∞: 86.64, 132.9 and K: 0.27, 0.17 and t0: -0.46, -0.66, M: 0.50, 0.33, F: 1.22, 1.04, Z: 1.72, 2.72, 'Ф: 3.31, 3.48, E: 0.71, 0.76, respectively. According to the exploitation coefficient, B. grypus and B. barbulus stocks are overfished hence we suggest a decrease in exploitation coefficient. Based on results and their comparison with the American Fisheries Society (AFS) indices, these species are classified in moderate to high vulnerable group fishes. *Corresponding author

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This study was conducted in order to determine the Iron levels in muscle, liver and gill tissues of Cyprinus carpio at the farmed ponds in Karoon river of three area, north (Shushtar), center (Ahvaz) and South (Khoramshahr) from Khuzestan Province of I.R. Iran in 2010. Fifteen fish were collected from each area. Iron was extracted and its concentration was measured using Atomic Absorption Spectrophotometer, Perkin Elmer. Data were statistically analyzed with SPSS14 at 0.05 confidence level. The order of Fe concentration in organs of Cyprinus carpio was gill> liver> muscle. The average of Fe levels in muscle, liver and gill were 0.82± 0.07, 6.18± 0.61 and 6.66± 0.45 mg/ Kg dw, respectively. The highest and lowest concentration of Fe in fish muscle were observed in Khoramshahr and Shushtar area, which were 0.98 and 0.54 mg/ Kg dw, respectively. According to the results of this study, accumulation of Fe in muscle of Cyprinus carpio was higher than FDA standards (0.5 ppm).