Investigation of asymmetry in some morphological characteristics of two freshwater fishes from Iraq

This research aims to investigate the levels of fluctuating asymmetry (FA) in six external morphological traits, along with four meristic traits in two commercially exploited fish species, Cyprinus carpio and Leuciscus vorax. Additionally, the data for this study were collected as part of a broader project on these two species. The bilateral symmetry index employed to measure this variation showed large departures, as confirmed by the results obtained. Of those considered traits, snout length (SnL) was the best predictor of FA in both C. carpio and L. vorax. The remaining nine traits had asymmetry indices of different signs, indicating a species-specific response to habitat degradation. Finally, the possible link between bilateral asymmetry and fish taxonomy was also investigated; however, future research is needed to assess this relationship.