Age and growth of swordfish (Xiphias gladius L.) in the Aegean Sea


Abstract: Age and growth of swordfish, Xiphias gladius, were determined from 205 specimens (total n = 1408), collected from onboard a swordfish fishery fleet and from a wholesale fish market between June 2008 and July 2011. The length and weight distribution of all fish samples ranged from 51 to 242 cm and from 0.85 to 171.0 kg, respectively. The 70-80 cm lower jaw fork length range of swordfish had the highest ratio (approximately 57%). The length-weight relationship showed a positive allometric growth (b = 3.32; r^2 = 0.969). Age groups of swordfish in the Aegean Sea ranged between 0 and 4 years. Von Bertalanffy growth parameters were calculated as L_{\infinity} = 283.6 ± 56.6 cm, K = 0.15 ± 0.05 year^{-1}, and t0 = -2.09 ± 0.20 year^{-1}, and the index of phi-prime was \phi' = 9.4. The results show that there was overfishing of swordfish in the Aegean Sea.

Keywords: Swordfish, Xiphias gladius, age, growth, Aegean Sea, Turkey

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