Figure 4. The effect of elevated water pCO₂ (10 (•[blue]), 30 (▼[yellow]) and 50 (■[red]) mm Hg pCO₂) on plasma.

A) [HCO₃⁻], B) [Cl⁻], D) [Na⁺], E) [Ca²⁺], and F) [Mg ²⁺] in Pacific hagfish (mean ± SEM). In C), bars represent the change (relative to controls) in [HCO₃⁻] (hatched), [Cl-] (cross hatched) and net difference between HCO₃⁻ - Cl⁻(open) during exposure to a water pCO₂ of 10 (blue), 30 (yellow) and 50 (red) mm Hg (approximately 1.5, 4 and 6 kPa). “*” indicates a statistically significant difference from time 0 values (p < 0.05).