Determination of some biological characteristics of the chub (Squalius orientalis Heckel, 1847) in Borçka Dam Lake

In this study, some biological characteristics of the chub (Squalius orientalis Heckel, 1847) in Borçka Dam Lake were investigated. A total of 392 samples were obtained during the study. The lengths of all samples examined were between 14.1 cm and 53.2 cm and their weight ranged from 28.08 to 22267.00 g, the mean length was 28.3 ± 7.83 cm and the mean weight was 364.35 ± 353.86 g. The total length and weight of males varied from 14.1 cm to 46.0 cm and from 28.08 g to 1325.98 g, also the mean length and weight were calculated as 24.7±6.65 cm and 229.29±221.62 g, respectively. The total length and weight of females were ranged from 15.4 cm to 53.2 cm and from 37.84 g to 2267.00 g, also the mean length and weight of females were calculated as 30.1±7.73 cm and 432.08±386.25 g, respectively. The length-weight relationships of the examined samples were determined as W = 0.0035L3.369 for females, W = 0.0058L3.216 for males and W = 0.0043L3.306 for all individuals. It was determined that growth type was positive allometric (b> 3) in examined females, males and all individuals. As a result of age readings made from scales, it was found that age distribution ranged between 3 and 16 years in all individuals. The smallest fish caught was 14.1 cm in length and 3 years old, while the largest fish caught was 53.2 cm in length and 16 years old. The length at first maturity were estimated as 20,6 cm for males and 21,3 cm for females. It was determined that the reproductive period of S. orientalis in Borçka Dam Lake was between April and July.