Age, growth and mortality of the comber, Serranus cabrilla (Serranidae) in the Edremit Bay (NW Aegean Sea, Turkey)

Abstract

Age, growth and mortality of comber, Serranus cabrilla (L., 1785) were determined from 595 specimens collected on the northwestern Aegean coasts of Turkey from September 1997 to September 1998. Fork length ranged from. 8.6 to 22.3 cm, while weight varied between 10.5 and 163.7 g. The von Bertalanffy growth equation was fitted on the basis of mean length-at-age data resulting in parameters values of Linfinity = 33.6 cm (S.E. = 0.46), K = 0.111/y (S.E. = 0.03), t(0) = -3.17 (S.E. = 0.030). Weight increased allometrically for both sexes together with b = 2.67 (S.E. = 0.226). The comber is a relatively short-lived species. The oldest male and female were estimated to be 4 years old. The total (Z) and natural (M) mortality were 0.49 and 0.32 per year, respectively. The exploitation ratio E = 0.35 indicated that the population was slightly exploited. The sex ratio was skewed in favour of females (1.26:1). The monthly values of gonadosomatic index (GSI) of females indicated that spawning occured mainly in April and May.