Bilateral Asymmetry in Asterisci Otoliths of Cyprinion kais and C. macrostomum (Cypriniformes, Cyprinidae) collected from Tigris River, Şirnak Region, Türkiye

Abstract

Otolith traits such as size and mass were investigated in 60 fish specimens of C. kais and C. macrostomum collected from the Tigris River, Şırnak region, Türkiye collected from September 2015 to December 2015. The purpose of this work was to determine the asymmetry level in the otolith length (OL), otolith width (OW), and otolith mass (OM). OL's rate of asymmetry was greater than OW’s and OM's. The asymmetry in the three otolith traits rose with the fish length. The plausible reason for asymmetry in the otolith features explored has been considered relative to the inconsistency of growth triggered by ecological influence associated with the inconsistency in water temperature, salinity, depth, and contaminants occurring in the Tigris River System.