Morphometric parameters of the sagitta otolith among four carangids species in the Persian Gulf

Otoliths are considered as very useful structures of fishes for various studies. This investigation aimed to compare the morphometric parameters between the right and left otoliths of male and female specimens of four species of the fishes belonging to the family Carangidae from the northern Persian Gulf. The morphometric parameters such as weight, length, width, area and perimeter of sagittal otoliths were measured and compared between males and females. The relationships between otolith morphometric parameters (length, width, weight) and fork length were also examined. According to the results from independent sample t-test, significant differences were found in length, width, and area of otoliths between males and females of Carangoides malabaricus, whereas no significant differences were found for three other species. The otolith weight of Carangoides coeruleopinnatus and Megalaspis cordyla were significantly different between left and right otoliths (p<0.05).  Likewise, significant differences were found in the otolith area of the right and left otoliths of Carangoides. coeruleopinnatus (p<0.05). Furthermore, no significant differences were found in the shape indices including form factor (FF), roundness (RD), aspect ratio (AR), circularity (C), rectangularity (R) and elipticity (E) between the right and left otoliths. The results suggest that the length and weight of sagittal otoliths are likely suitable indicators for fish fork length in all studied species.