Otolith shape analysis and relationships between total length and otolith dimensions of European barracuda, Sphyraena sphyraena in the Mediterranean Sea

Abstract

Aims of the present study were to evaluate otolith shape and estimate the relationships between total length and otolith dimensions of S. sphyraena from the Mediterranean coast of Turkey. Two shape analysis methods were used for otolith shape and also two regressions models were used to estimate total length-otolith dimensions relationships. In the present study, 97 fish were examined during 2020-2021 fishing season. Otolith shape indices such as form factor, aspect ratio, ellipticity, circularity, rectangularity, and roundness were calculated for each S. sphyraena sample. Otolith contours were obtained using wavelet functions and ten otolith morphological characters for S. sphyraena. Morphological characteristics of S. sphyraena otoliths were variable both between left and right side of the otolith and total length groups. Otolith width and area measurements differed statistically between left and right otoliths (p<0.05). High-level morphological differences in anterior, posterior and dorsal part zones of the otoliths of S. sphyraena were detected between right and left otoliths. The relationships were determined between total length and otolith dimensions. The highest correlation value was calculated between otolith length and total length (r(2): 0.876). This is the first study to determine the otolith shape and relationships between total length and otolith dimensions of S. sphyraena from the Mediterranean coast of Turkey.