Shape Analysis of Otoliths of the Round goby, Neogobius melanostomus (Gobiiformes, Gobiidae), from the Black Sea Basin

Abstract

This study aims to assess the round goby Neogobius melanostomus stocks discriminability based on the shape of its otoliths. Recent otolith-shape-based species and stock discrimination studies have been using otoliths’ contours in sagittal plane and we are following this approach. We hypothesized existence of several geographically separated populations of the round goby. Round gobies have been sampled in different localities of the North-Western Black Sea, otoliths were removed in course of the full biological analysis and photographed in sagittal plane. Principal components of the otolith contour were processed by linear discriminant analysis aiming to cross-validate the discriminability of round gobies of different geographical locations, which would allow for showing different stocks or populations. This research allows for the conclusion of limited applicability of otoliths’ contours for discrimination of stocks or populations of round goby based on multiple annual samples. However neither classification matrices of discriminant analysis nor cluster analysis dendrograms show some single pattern except for the high year to year otoliths variability, which allows for a hypothesis of a strong response of contour formation to habitat and feeding conditions. This assumption has to be definitely verified by further research.

Keywords

• morphology
• ear stones
• bony-fishes
• ponto-caspian gobies