Comparison of some morphological characteristics of three sparid fishes (Perciformes: Sparidae) otoliths (Sagitta) from Shatt Al-Arab River, Basrah (southern Iraq)

Abstract

The otoliths (ear stones) of sparid species (Acanthopagrus berda (Forsskal,1775), A. latus (Houttuyn, 1782) and Sparidentex hasta (Valenciennes,1830)) sagittae were studied. Fifty specimens of each species with different sizes were collected from local markets since December 2014 to March 2015. The largest otolith pair of each specimen (sagitta) was extracted and used to differentiate among the three species. The results revealed that the sagittae of these three species differ from each other, especially from posterior, that it is almost straight in A. latus, whereas there is a notch in A. berda, in S. hasta the posterior of sagitta regularly pointed. A linear relationship between total length-otolith length and body weight-otolith weight are found for the three-studied species. The otolith weight correlated with fish body weight was stronger than the correlation of otolith length with fish total length. The form factor of A. latus is higher than the other two species so as to roundness, but S. hasta has the highest aspect ratio. The results suggest that otolith (sagitta) morphology of the three sparid species differs from each other, thus, sagitta can be adopted to discriminate among these species, because it is species specific.