Electrophysiological and behavioural responses of turbot (Scophthalmus maximus) cooled in ices water

• Published in: Physiology & Behavior
• Main Authors: Lambooij, E., Bracke, M.B.M., Reimert, H.G.M., Foss, A., Imsland, A., van de Vis, J.W.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2015
• Subjects: fish; l; pain; stress; system; welfare; Slaughter; Scophthalmus maximus; Turbot
• Online Access: https://research.wur.nl/en/publications/electrophysiological-and-behavioural-responses-of-turbot-scophtha; https://doi.org/10.1016/j.physbeh.2015.05.019

Behavioural, neural and physiological aspects related to pre-slaughter cooling of turbot habituated to two environmental temperatures (18.7 and 12.0 °C) were investigated. Six fish in both treatments were immersed in ice water for 75 min. For control, four fish were immersed in water under their habituated environmental temperature. Turbot did not show a quick reduction of overall power in the EEG (electroencephalogram) to less than 10%, nor did the turbot show a shift in brain wave predominance from high to low frequency waves. At 15 min after immersion in ice water at least 7 out of 12 fish still showed total power values over 10% of pre-immersion values. Significant reductions in responsiveness to needle scratches and reduced breathing after immersion in ice waterwere observed, but none of these parameters had dropped to 0 even after 75 min in icewater. A significant reduction in gill score was found at 2 and 5 min after immersion in ice water compared to the control fish (p