Otolith Shape Analysis of the Mediterranean Horse Mackerel, Trachurus mediterraneus (Steindachner, 1868) (Perciformes: Carangidae) from the Coastal Waters of Sevastopol and Balaklava (the Black Sea)

— Otolith shape analysis was conducted with two methods on nine samples of the Mediterranean horse mackerel Trachurus mediterraneus (Steindachner, 1868 ) caught in Sevastopol and Balaklava bays in 2017–2018. The first method was based on morphometric measurements: length, width, perimeter, and area, which were adjusted to the average fish length from all studied samples; six otolith shape indices were obtained for the analysis: aspect ratio, circularity, rectangularity, roundness, form factor, and ellipticity. The second approach used coefficients of the elliptical Fourier analysis of otolith contours. No significant differences were found between the left and right otoliths as well as between otoliths of males and females. The results of discrimination between the samples were different for these two methods, but in general, otoliths of the horse mackerel from all studied bays did not differ significantly in both shape indices and Fourier coefficients.