Age, growth, Mortality and Exploitation of the Axillary seabream, Pagellus acarne (Risso, 1826) (Sparidae) from the Syrian marine waters

Abstract

The Axillary seabream, Pagellus acarne is considered as one of the main target species of the commercial fishery in the Syrian marine waters, and there is no study yet on its biology in the Syrian coast. As the growth biology is of great importance in the good management of fishing of this species and increases opportunities to optimally exploit its stock. A total of 1494 individuals of P. acarne were collected from the Syrian coast between May 2019 and April 2021. The age composition consisted of five age groups. The length-weight relationship revealed a positive Allometric growth (b= 3.292, 3.263, 3.29) for all population, males and females, respectively. The Von Bertalanffy growth parameters and growth performance index φ‏‎` were calculated: L<sub>∞</sub>= 19.78 cm, 21.5 cm and 22.97 cm; K= 0.23, 0.32 and 0.18; t<sub>0</sub>= -0.044 years, -0.238 years and -0.239 years; φ<sub>L</sub>‏‎`= 1.95, 2.17 and 1.97 for all population, males and females, respectively. The resilience / productivity of P. acarne was medium (0.16 ≤ K < 0.30), and depending on the concept of maximum age T_max (13 years), it has low value (T_max = 11 – 30 years). The age and length at first capture and

recruitment were: T_c= 1.78 years, T_r= 1.07 years, L_c= 6.78 cm and L_r= 4.48 cm. The total and natural mortality, survival and exploitation rates were:     Z= 0.92 year^-1, M= 0.703 year^-1, S= 0.4 year^-1 and E= 0.14 year^-1.