Fig. 5. The effects of a bolus injection of CO₂-enriched saline (5% CO₂; open circles; N=8) or air-equilibrated saline (controls; filled circles; N=8) into the caudal vein on (A) cardiac frequency (fH), (B) arterial blood pressure (Pa), (C) ventilation amplitude (V_AMP), (D) systemic vascular resistance (R_S), (E) cardiac output (Vb) and (F) ventilation frequency (fG) in intact rainbow trout (Oncorhynchus mykiss). Values are means ± 1 S.E.M.; significant differences (P<0.05) from pre-injection values (time=0) are denoted by asterisks. There were no significant differences between the control and treatment groups at any measurement time. 1 mmHg=0.133 kPa.