Otolith Shape and Characteristics as a Morphological Approach to the Stock Identification in Barbus Tauricus (Cyprinidae)

Abstract

This study is aimed to discriminate Barbus tauricus stocks using otolith shape indices and morphometrics. B. tauricus samples were obtained from some inland waters of Black Sea basin (Streams Akcay, Engiz, Terme, Karadere and Degirmenagzi), and also Luciobarbus sp. samples from Sakarya River were used as an outgroup. Utricular and lagenar otoliths were removed by making left and right distictions. Otolith width, length, perimeter and area were determined by Imaging Software. Power model was applied to estimate the relationships between the otolith measurements and total length. Form Factor, Circularity, Roundness, Rectangularity, Aspect Ratio and Ellipticity were used for otolith shape analyses. A standardized model was used to remove size effect on otolith measurement. Discriminant function analysis were performed to detect differences in otolith shape variations. The discriminant function analysis performed for otolith shape indices and measurements explains the intraspecific variability among localities. According to discriminant function analysis, 75.3% of B. tauricus stocks were correctly classified. The results of this study provide the first comprehensive data regarding the otolith shape analyses and relationship between the otolith morphometrics with total length of Crimean barbel.