No abstract

Atatürk Dam Lake is an important ecosystem located in south-eastern Anatolia in Turkey. In this study, concentration of Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn were determined in kidney, liver, gill and muscle of Tor grypus which has great economic value in Atatürk Dam Lake. Heavy metal levels in fish samples were analyzed by inductively coupled plasma spectroscopy (ICP). The metal accumulation in the liver, kidney and gill of Tor grypus was found to be quite high in comparison to the muscle. All metal levels detected in tissues were the limits for fish proposed by FAO/ WHO, EU and Turkish Food Codes and safe within the limits for human consumption in the edible parts of fish species in the region.

Concentration of some heavy metals (Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb and Zn) were determined in muscle, liver, kidney and gill of two barb, Barbus xanthopterus and Barbus rajanorum mystaceus, which have great economic values, in the Atatürk Dam Lake (Turkey). Heavy metal levels in fish samples were analyzed by inductively coupled plasma spectroscopy (ICP/OES). Heavy metal concentrations vary significantly, depending on the type of the tissue in fish species. The metal accumulation in the liver, kidney and gill of Barbus xanthopterus and Barbus rajanorum mystaceus was found to be quite high in comparison with that in the muscle. The mean concentrations of heavy metals in muscle tissues of Barbus xanthopterus were as follows: Co, 0.09; Cr, 0.12; Cu, 0.27; Fe, 5.26; Mn, 0.20; Ni, 0.08; Pb, 0.68; Zn, 1.39, whereas in muscle tissues of Barbus rajanorum mystaceus were as follows: Co, 0.11; Cr, 0.10; Cu, 1.07; Fe, 3.97; Mn, 019; Ni, 0.04; Pb, 0.66; Zn, 1.70 microg/g wet weight. Cd levels in gill and muscle tissues were below detection limits. All metal levels detected in tissues were safe for human consumption and within the limits for fish proposed by FAO/ WHO, EU and Turkish Food Codes.

Fatty acid (FA) compositions of total lipid, phospholipid (PL) and triacylglycerol (TAG) fractions have been determined in muscle tissues of Silurus triostegus. The distributions of saturated fatty acid (SFA), monounsaturated fatty acid (MUFA) and polyunsaturated fatty acid (PUFA) proportions were found to be different among total lipid, PL and TAG fractions from lipids in muscle tissues of the male and female S. triostegus in all seasons. Triacylglycerol contained a lower proportion of PUFA and a higher proportion of MUFA and SFA than PL while PL contained higher proportion of PUFA than proportion of MUFA and SFA compared to TAG. Triacylglycerol and PL fatty acid compositions in muscle tissues of the male and female fish species were found different. The most abundant fatty acids in the investigated seasons were palmitic acid (C16:0), stearic acid (C18:0), oleic acid (C18:1 n-9), palmitoleic acid (C16:1 n-7) and docosahexaenoic acid (C22:6 n-3). It was shown that the total lipid content and FA compositions in muscle tissues of the male and female S. triostegus were influenced by reproduction period and season.

Age at length, growth and reproduction of 220 Mastacembelus mastacembelus specimens from the Atatu¨rk Dam Lake were studied from July 2005 to July 2006. Total lengths and weights ranged from 7.0 to 85.0 cm and from 6 to 1100 g, respectively. Maximum age was 13 years. The regression model fitted to length and weight data was W = 0.0228 L 2.43 for males and W = 0.0029 L 2.95 for females. The von Bertalaffy growth equations for males and females were L t = 99.2 [1)e )0.11 (t)0.12) ] and L t = 69.2 [1)e )0.26 (t)0.35) ], respectively. Males dominated especially at an older age; the overall sex ratio was 1 : 0.63 (M:F). The breeding period was from May to July. Fecundity ranged from 2540 to 24 000 eggs per female.