Rapid transfer of zander Stizostedion lucioperca to hypoosmotic brackish water (mean osmolality 230 mOsmol kg –1 , c. 8 psu) significantly increased plasma chloride concentrations after 24 h compared to those transferred to fresh water, although plasma osmolality was not significantly affected. After 6 days, plasma osmolality was slightly elevated but stable plasma glucose and cortisol concentrations and blood haematocrit and...