Energy and migratory behavior in glass eels (Anguilla anguilla)

• Main Authors: Bureau Du Colombier, Sarah, Bolliet, Valérie, Lambert, Patrick, Bardonnet, Agnes
• Other Authors: Ecosystèmes estuariens et poissons migrateurs amphihalins (UR EPBX), Centre national du machinisme agricole, du génie rural, des eaux et forêts (CEMAGREF), Institut National de la Recherche Agronomique (INRA)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2007
• Subjects: [SDE]Environmental Sciences; Anguilla anguilla
• Online Access: https://hal.inrae.fr/hal-02589896

International audience The influence of energy content of glass eels (Anguilla anguilla) on their migratory behavior was investigated in November 2004 and February 2005 under laboratory conditions. Fish were sorted according to their response to a decrease in light intensity: Glass eels becoming active at dusk and using water flow to move with the current were considered as active, whereas those remaining in the substratum throughout the catching period (24 h) were categorized as inactive. Active glass eels exhibited higher energy content than inactive ones, whatever the catching month, and were more pigmented. Differences in percentage dry weight between active and inactive fish were already significant in the first pigmentary stages, suggesting that energy content plays a causal role in the estuarine migration of glass eels. The possible impact of energy state on the development of different migratory tactics in glass eels is discussed.