Some Biological Characteristics of Silurus triostegus Heckel, 1843 from Atatürk Dam Lake (Turkey)


Abstract: In this study, some biological characteristics such as age and sex composition, growth in length and weight, age-length, age-weight and length-weight relationships, condition factor spawning time, age of sexual maturity, and fecundity of Silurus triostegus in Atatürk Dam lake were investigated. The percentage of females was 48.3% and that of males 57.7% out of 623 specimens belonging to age groups I-XI. Isometric growth patterns were proved from the length-weight relationships. It was estimated that the females had higher Lo (202.85 cm) and lower low K (0.046871) values than males (Lo 113.98 cm and K = 0.101972). Mean condition factors of females and males were calculated to be 0.99055 and 0.95625 respectively. The highest condition factor values were found in April, and the lowest in December. The age of sexqual maturity IV in females and age III in males. The diameter of the egg was smallest in July, with a mean of 1.035 mm, while the mean egg diameter in May was greatest, at 1.937 mm. The fecundity ranged from 6.800 to 120.300. Fecundity was significantly correlated with fish length, fish weight and gonad weight.

Keywords: Silurus triostegus, growth, condition factor, reproduction, Atatürk Dam Lake.

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