Precision of Age Estimates Obtained from Five Calcified Structure for Wels Catfish, Silurus glanis

Abstract

In this study, vertebrae, otoliths (asteriscus and lapillus), sectioned lapillus and pectoral fin rays were evaluated for age determination of Silurus glanis L., 1758 inhabiting Siddikli Dam Lake. All calcified structures showed the variable annual ring formation. Ages obtained from calcified structures were compared using the percentage of agreement (PA), average percentage of error (APE), and coefficient of variation (CV). Sectioned lapillus showed the clearest annulus formation and highest PA (76.4%) between readings, followed by asteriscus (43.9%), whole lapillus (40.5%), vertebrae (36.0%) and pectoral fin ray (33.3%). When sectioned lapillus compared to other structures, there were high ages obtained from this structure. Especially, the ages from the whole lapillus were lower than sectioned lapillus. Also, ages obtained from pectoral fin ray were the closer to sectioned lapillus ages than the other calcified structures. Owing to the highest PA, lowest APE and CV, sectioned lapillus was recommended as the most reliable calcified structure for age determination of S. glanis. Our findings can be used for effective fisheries management and determination of the biological characteristics of wels catfish.