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ORIGINAL RESEARCH article

Front. Mar. Sci.

Sec. Marine Conservation and Sustainability

Environmental effects on otolith morphology variability of European eel, Anguilla anguilla (Linnaeus, 1758), for subpopulation discrimination in Corsica

Provisionally accepted
  • 1UMS3514 Stella Mare, Biguglia, France
  • 2Aix-Marseille Universite, Marseille, France
  • 3Institut Mediterraneen d'Oceanologie, Marseille, France
  • 4Sciences Pour l'Environnement, Corte, France

The final, formatted version of the article will be published soon.

Otolith shape analysis is an efficient tool for fish stock identification. However, due to insufficient research, it remains still poorly understood concerning the European eel (Anguilla anguilla), a highly migratory catadromous and panmictic species. The aim of this study is to discriminate the subpopulations of A. anguilla from rivers and two lagoons (three sites) from Corsican continental waters using morphological variations in otolith shape. The otolith shape was described by indices of shapes and by geometric morphometric shape, to understand how otolith morphology changes with eel growth and across contrasting habitats. In this study, the shape of each otolith (N = 305) was described with one landmark and ninety-nine semi-landmarks and by eight shape indices (form factor, aspect ratio, ellipticity, circularity, roundness, rectangularity, squareness and solidity). Results indicate that otolith shape is highly marked for the larger compared to smaller sizes, particularly for the individuals from the lagoons. The slight differences in the small otoliths appear to be due to the acquisition of the shape during the glass eel stage in the marine environment whereas the difference marked in the shape of the large otoliths would be due to the variability of environmental conditions, underlying marked change in otolith shape during growth.

Keywords: Anguilla anguilla, European eel, Landmarks, otolith shape, Shape indices

Received: 02 Oct 2025; Accepted: 15 Dec 2025.

Copyright: © 2025 Millot, Esposito, Gerbaud, Aiello, Quilichini and Filippi. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Rémi Millot

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