Differential detection of some commercial fish species of Anzali wetland based on their otoliths morphological characteristics

This study was conducted to investigate the shape and morphological characteristics of otolith in some of economic fishes in Anzali wetland and the possibility of using these characteristics to identify species. In this study, Sajita otolith was extracted from 5 species of fishes and their morphological characteristics were investigated. These species belong to the families of Esocidae (Esox lucius), Leuciscidae (Abramis brama), Xenocyprinidae (Hypophthalmichthys mollitrix), Mugilidae (Chelon saliens) and Percidae (Sander lucioperca). The species were selected and their biometric characteristics and their otoliths were recorded and extracted. Then, the shape of the otoliths was studied and the biometric characteristics of the left and right otoliths of each sample were recorded by measuring their length, width and thickness. Also, the size, elongation and thickness indices of otolith were calculated and the relationship between the parameters was investigated. The results showed that the shape of otolith among these species and even species belonging to one family were different. The highest weight, head lengths and otolith lengths were not observed in the largest sample. There was a significant positive relationship between total lengths and otolith lengths in Chelon saliens and Sander lucioperca. Also, a positive and significant relationship was observed between the weight and thickness of otolith in Chelon saliens. So, the morphology of otoliths can play an important role in the taxonomy of fish.