مرکز منطقه ای اطلاع رساني علوم و فناوري - Age, growth, fecundity and mortality of Aspius vorax (Heckel, 1843) in Karakaya Reservoir (in Euphrates River), Turkey

Abstract :

Population structure studies of Aspius vorax (Heckel, 1843) are insufficient despite the species’ commercial importance in Karakaya Reservoir. Thus, the main purpose of this study was to acquire data on some population parameters (age, length- weight relationship, growth, fecundity and mortality) to evaluate the current status of A. vorax for a successful management plan. A total of 249 specimens (102 female and 147 male) were caught and the sex ratio was 1:1.44 (female to male). The age data was estimated from vertebra and ranged between ΙΙ and VΙΙ. Weight increase was allometrical for both sexes. Mean condition factor was CF = 0.839 ± 0.005. The von Bertalanffy growth parameter estimates were L∞ = 93.114 cm, K = 0.153 yrs-1 and to = -1.132 yrs for females, L∞ = 86.494 cm, K = 0.173 yrs-1 and to = -1.078 yrs for males and L∞ = 92.675 cm, K = 0.151 yrs-1 and to = -1. 151 yrs for all individuals. The mean fecundity was 102873. It was found that the stock of A. vorax had been overexploited (E =0.56) in Karakaya Reservoir and the fishing pressure should be reduced to achieve a sustainable fishery.