Fig. 5. (A) Plasma osmolality, (B) [Na⁺] and (C) [Cl^-] in trout held in freshwater (Pre) and following transfer to freshwater (filled circles), 40% seawater (open squares) and 80% seawater (filled triangles). Vertical broken line represents the abrupt transfer. Symbols are offset for clarity where necessary. Data are means ± S.E.M. (N=5–8). Asterisks indicate significant difference from the control (freshwater) value.