Age determination and morphology of otolith in Alburnus chalcoides (Guldenstaedt,1772) in the southern Caspian Sea

Abstract

The aim of this study was to provide necessary information on the age, growth and sex ratio of one of commercially important cyprinid species, Alburnus chalcoides in the southern Caspian Sea (North Iran) from 2010 through 2011. 53 specimens of both sexes (males and females) were collected monthly. The samples were transported tothe laboratory for further biological measurements and otolith extraction. The maximum and minimum age of A.chalcoides was 4+(FL=26.0 cm) and 1+ (FL= 18.1 cm), respectively. The mean fork length of A. chalcoides was 20.21?0.287 cm; and the sex ratio was 1.0: 2.12. The length-weight relationshipscalculated for all individuals were as W=0.141TL2.199 (R2= 0.648). Different regressions were prepared between age and morphological measurements of fish and otolith, of which the highest correlation was between age and body length as a linear regression of TL=1.959Age+16.32 (r= 0.66). There was no significant correlation between morphometric measurements ofotolith and fish morphological parameters (p> 0.05), and an allometric growth was found with a slope of b=1.926 for the study area.