Age, growth and mortality estimates of Sillago suezensis from Iskenderun Bay, northeastern Mediterranean Sea

Abstract

The age composition, growth parameters, size distribution and sex ratio of Sillago suezensis caught from Iskenderun Bay in Northeastern Mediterranean Sea were investigated. Female and male composition of the population was determined as 40.37 and 59.63%, respectively. Total length of females ranged between 12.30 and 24.20 cm, while it was between 11.50 and 22.50 cm for males. The length (L)-weight (W) relationships for males and females were estimated as W = 0.0071 x L-3.014 and W = 0.0070 x L-3.020, respectively. Age data derived from otolith readings were used to estimate the growth parameters of the von Bertalanffy equation. The estimated parameters for all individuals were: L-infinity = 35.65 cm, K = 0.299 year(-1) and t(0) = -0.288 year. Asymptotic length L-infinity revealed greater growth for males than females. Growth constant K was slightly higher in females than in males. The maximum age was 5 years for females and males. The 1-year-old group was dominant amongst males whereas the 2-year-old group was dominant within females. The condition factor was 0.739 +/- 0.005 for females and 0.742 +/- 0.004 for males. Spawning period of S. suezensis determined to be between April and August. Overall total mortality was estimated as 0.96 year(-1), natural mortality was 0.85 year(-1) and fishing mortality was 0.11 year(-1).