PHYSIOLOGICAL-RESPONSES OF THE GILTHEAD SEA BREAM SPARUS-AURATA TO HYPOOSMOTIC SHOCK

Physiological responses are studied in sea bream after quickly reducing water salinity from seawater (3.7%) to approximately plasma isosmotic salinity (1.3%) and to near freshwater (0.3%), Cardiorespiratory variables do not show clear differences after salinity changes except when considering the immediate response in which compensatory mechanisms are observed. Slight changes in haematological parameters and important variations of cortisol are also found. These results are discussed in relation to the specific physiological adaptations to salinity and the non-specific response to environmental changes.