Asymmetry in certain morphological characters of the carangid species Decapterus russelli, collected from the Lemah coastal area, on the northern part of Oman Sea

Asymmetry analysis has been carried out for some bilateral characters of Decapterus russelli (Family: Carangidae) collected from Oman Sea. The results showed that postorbital length demonstrated the highest incidence of asymmetry among the characters studied. The lowest asymmetry value was for the number of pectoral fin rays. An increasing trend in the asymmetry value with fish length is also obtained for preorbital length, number of pectoral fins and number of lateral line scutes. A similar trend is also evident in the postorbital length and eye lens diameter of individuals with body sizes <160 mm. The possible causes of asymmetry in this species are herein discussed in relation to different pollutants and their presence in the area.