Growth characteristics of the chub mackerel (Scomber japonicus Houttuyn, 1782) in Izmir Bay (Aegean Sea, Turkiye)

Age and growth of chub mackerel, Scomber japonicus, were studied in the Izmir Bay (Aegean Sea). A total of 520 specimens were collected during the period November 1997 to October 1998 from purse-seine boats operating in the Izmir Bay. Fork lengths ranged between 12.5 and 27.2 cm. Overall female: Male ratio was 1:1.13. Age distribution of the samples ranged from I to IV years (otolith readings). Chub mackerel grew positive allometrically (b = 3.40+/-0.05 at 95% confidence level). Growth parameters of the population were: L-infinity = 27.15 cm, K = 0.20 year(-1), t(0) = -0.48 years for females; L-8 = 29.64 cm, K = 0.23 year(-1), t(0)= -0.39 years for males and L-8 = 29.87 cm, K = 0.20 year(-1), t(0)= -0.36 years for both sexes. Growth index (Phi') was calculated as 2.29, 2.31 and 2.25, respectively for females, males and sexes combined.