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    Age, growth and reproduction of the Shabut Barbus grypus (Cyprinidae) in Ataturk Dam Lake (Euphrates River), Turkey
    (Soc Francaise D Ichtyologie, 2008) Oymak, S. Ahmet; Dogan, Necmettin; Uysal, Ersin
    Age, growth and reproduction of 243 shabut Barbus grypus Heckel, 1843 in Ataturk Dam Lake in Turkey were studied from June 2004 to July 2005. The population was composed of 13 age classes. Age groups, 4-6 for females and 2-4 for males, were dominant. The total length and weight of the individuals ranged from 145 to 960 mm in length and from 40 g to 11kg respectively. The regression model fitted to the relation between length (FL) and weight (W) of fish was Log W = -4.6112 + 2.8835 Log FL (r(2) = 0.989) for females, and Log W = -4.8607 + 2.9679 Log FL (r(2) = 0.990) for males. The von Bertalanffy growth equations for females and males were found as Lt = 134.65 [1 - e(-0-10038) ((t + 1.85731))] for females and Lt = 106.77 [1 - e(-0-13649(t+ 1.095))] for males. The total observed sex ratio was: 1.34 (females/males). The spawning period extended from May to July. Fecundity ranged from 16,000 to 235,784.
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    Heavy metal in tissues of Tor grypus from Ataturk Dam Lake, Euphrates River-Turkey
    (Springer, 2009) Oymak, Seyit Ahmet; Karadede-Akin, Huelya; Dogan, Necmettin
    Ataturk 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 Ataturk 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.
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    Reproductive characteristics of an invasive species Carassius gibelio (Bloch, 1782) in Ataturk Dam Lake, Turkey
    (Central Marine Fisheries Research Inst, 2017) Parmaksiz, Arif; Oymak, Seyit Ahmet; Dogan, Necmettin; Naim, Darlina Md; Unlu, Erhan
    In this study, sex composition, spawning period, fecundity and sexual maturity of the gibel carp, Carassius gibelio (Bloch, 1782), an invasive species in the Ataturk Dam Lake, on Euphrates River, Turkey were studied. C. gibelio specimens were analysed from Ataturk Dam Lake and the percentage of the males and females was 45.55% and 55.45% respectively out of the 110 specimens studied, ranging between age groups I - VI. The age at first maturity was three years for both females and males. The diameter of the egg was smallest in September, with a mean of 0.62 mm, while the mean egg diameter in June was greatest, at 1.54 mm. The absolute fecundity ranged from 1054 to 22548. Reproduction of gibel carp in Ataturk Dam Lake in Turkey was characterised by a young age at first maturity and high spawning capacity that would facilitate population expansion in aquatic environments.
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    Select biological characteristics of the mossul bleak Alburnus mossulensis Heckel, 1843 (Actinopterygii: Cyprinidae) in the Ataturk Dam Lake, Turkey
    (Central Marine Fisheries Research Inst, 2018) Parmaksiz, Arif; Oymak, Ahmet; Dogan, Necmettin; Unlu, Erhan
    Maturity, growth and reproductive characteristics of the mossul bleak Alburnus mossulensis, from Ataturk Dam Lake (Euphrates) were assessed. Maturity composition of the analysed samples varied between age groups I and VII. The ratio of females to males was 1.047:1. Fork length of the samples varied between 40-198 mm and weights were in the range of 0.45-68 g. The regression equations derived for the length-weight relationship was Log W = -5.5531+3.2958 Log FL (r2=0.9593) for females and Log W=-5.3695+3.2112 Log FL (r2=0.9487) for males. Mean condition factor was determined as 1.069 for females and 1.062 for males. Absolute fecundity was established to be between 288 and 3380. The age of sexual maturity was 3 years in females and 2 years in males.
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    A Study on the Age, Growth and Reproduction of Aspius vorax (Heckel, 1843) (Cyprinidae) in Ataturk Dam Lake (Euphrates River), Turkey
    (Central Fisheries Research Inst, 2011) Oymak, S. Ahmet; Unlu, Erhan; Parmaksiz, Arif; Dogan, Necmettin
    In this study, the age, growth and reproduction characteristics of Aspius vorax, which were caught from Ataturk Dam Lake (Euphrates River) between September 2007 and August 2008 were determined. The age composition of the specimens ranged between II and IX age groups. The observed sex ratio was 1:1.75 (females/males). The fork length and weight of the individuals that were examined ranged from 184 to 863 mm and from 54 g to 4,317 g, respectively. The relationship of fork length (L-F) and scale radius (S) was estimated as: L-F=-95.6669+172.254 S, (r(2) = 0.669). L-infinity values were calculated to be 158.36 cm for females and 218.47 for males. Length - weight relationships were Log W =-3.4242+2.4297 Log L-F; (r(2) =0.8686) for females, and Log W =-4.7247+2.9051 Log L-F (r(2) =0.9549) for males. Mean somatic condition of females and males were estimated as 1.069 and 1.062, respectively. The highest values of the somatic condition were determined in the November for females (K=1.23) and in the September and October (K=1.13) for males. Males matured during their third year of life in the studied samples, but due to lacking of young female specimens, the first maturity age for female was not determined. However, all those females examined at age 4 and over were seen to reach mature.