What can otolith examination tell us about the level of perturbations of Salmonid fish from the Kerguelen Islands?

• Published in: Ecology of Freshwater Fish
• Main Authors: Morat, F., Betoulle, S., Robert, M., Thailly, A.F., Biagianti-Risbourg, S., Lecomte-Finiger, R.
• Other Authors: Biologie et écologie tropicale et méditerranéenne 2007-2010 (BETM), Centre National de la Recherche Scientifique (CNRS)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Perpignan Via Domitia (UPVD)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2008
• Subjects: [SDE.MCG]Environmental Sciences/Global Changes; Kerguelen; Kerguelen Islands
• Online Access: https://hal.archives-ouvertes.fr/halsde-00371926; https://doi.org/10.1111/j.1600-0633.2008.00313.x

International audience Otoliths preserve a continuous record of the life cycle from the natal through the adult stage. For that reason, the morphological and chemical characteristics of otoliths of two nonnative Salmonids, brown trout (Salmo trutta) and brook charr (Salvelinus fontinalis) from populations on the Kerguelen Islands were compared. Several approaches were used to study the relationships between otolith morphometry, crystal morph and chemical elemental composition. These salmonids sampled in Kerguelen are well differentiated in terms of species through their otolith shape. The results indicate that ecotypes and river populations can be reasonably well differentiated on the basis of otolith shape. The crystallisation study has revealed the presence of a particular form: the vaterite, present at a high rate: 45% of S. fontinalis and 18% from Salmo trutta fario. Moreover, vaterite and aragonite otoliths presented differences in chemical composition.