Comparative bilateral asymmetry of six Barbus species collected from the rivers in western Anatolia, Republic of Türkiye

Abstract

ABSTRACT The bilateral asymmetry was analysed on 259 fish specimens comprising six Barbus species collected in June-August 2010 from rivers in western Anatolia. The goals of this study are: (1) to check for the levels of bilateral asymmetry amid the ten morphological features of the six Barbus species and (2) to compare the levels of this asymmetry among the ten localities in western Anatolia. The possibility of applied investigations using bilateral asymmetry and fishes as an indicator of the health of the freshwater systems was also conducted. Statistical analyses have shown that the ten morphological traits chosen for this study exhibit variable levels of bilateral asymmetry in the six Barbus species collected from the ten localities studied. The asymmetry value was highest for snout length and lowest for the prepectoral fin length observed in B. pergamonensis. An increasing tendency in asymmetry levels was exhibited for each of the ten morphological traits in the fish length groups selected for each Barbus species assessed. The result of the individuals being right-handed or left-handed has shown that specific morphological characteristics are either dextral or sinistral or showed no bilateral asymmetry in different Barbus species studied.