Age Determination of Shad (Alosa Pontica Eichwald, 1838) Inhabiting the Black Sea

Abstract

The most reliable bony structure and method were investigated for age determination of shad (Alosa pontica Eichwald, 1838) inhabiting the Black Sea. Therefore, five bony structures such as scale, vertebra, otolith, opercle and subopercle were removed from 240 individuals collected from April 1998 to April 1999. Each bony structure was prepared for age determination by different techniques, and examined by binocular microscope. Mean ages were estimated for each bony structure-reader combination and the precision of age estimated from multiple readings was evaluated. Furthermore, the error of ageing was calculated. Vertebra was the most reliable bony structure for ageing this species as it had the highest agreement and the lowest ageing error. Therefore, it is emphasized that the vertebra is the most accurate and reliable source of information in studies that require reliable age data about shad.