First record of Abnormal Otoliths in the Greater Weever Trachinus draco (Trachinidae) in the Black Sea

Abstract

The main objective of the study was to analyze the abnormal status in the sagitta morphology of the Trachinus draco in the Black Sea. For that, 118 individuals of T. draco are collected from Cape Jason in the Central Black Sea. Abnormalities in otoliths are investigated using Raman spectroscopy, scanning electron microscopy, and light microscopy. The otolith morphometric measurements and otolith shape indices are recorded for abnormal and normal sagittae of the T. draco. As a result of the analysis, abnormalities observed in T. draco otoliths is revealed several prominences on the distal and proximal surfaces of the left and/or right otoliths. The percentage of individuals with abnormal otoliths of the T. draco is calculated as 52.5%. While there is a statistical difference in weight, perimeter, and width measurements of abnormal and normal otoliths (p < 0.05), there is no difference in length and area measurements (p > 0.05). There is no correlation between the proportion of individuals with abnormal otoliths and total length. Otolith shape indices are not statistically different between normal and abnormal otoliths of the T. draco (p > 0.05).