International eel symposium, 2003 - Quebec August 11, 2003
Poster Session

A Stage-Structured Model to Predict the Effect of Temperature and Salinity on Glass Eel Anguilla anguilla Pigmentation Development

Briand, C. Institution Aménagement Vilaine 56130 La Roche Bernard France
Fatin, D. Institution Aménagement Vilaine 56130 La Roche Bernard France
Lambert, P.* Cemagref, Unité Ressources Aquatiques Continentales, F-33612 Cestas Cedex France.

Presenter email address: Patrick.lambert AT Bordeaux.Cemagref.fr

Abstract Text: The pigmentation of European glass eel Anguilla anguilla was studied experimentally. Samples were kept in net cages in estuarine and fresh waters and in aquaria at controlled temperature. The pigmentation kinetic from stage VB to VIA3 was modelled by gamma cumulative functions. These functions varied with respect to the couple temperature-salinity whose effects were adjusted by beta functions. The model could be used to predict the evolution of pigment stages in the Vilaine estuary, and used as a tool to explicit the glass eel population dynamic. However, it failed to predict pigmentation in groups collected in other localities in Europe, for example from the Mediterranean. The consequences are discussed in the light of the endocrine control of pigmentation, and the possible role of the endocrine state of the larvae reaching the continent.