Fig. 7. Effects of bolus infusions of adrenaline, phenylephrine, and isoproterenol (2 µg kg^–1) on haemodynamic variables in S. marmoratus in aerated water (P_O2>130 mmHg). Black bars represent control values and grey bars represent values after infusion of the adrenergic agonists. , cardiac output; V_S, stroke volume; f_H, heart rate; P_CV, central venous blood pressure; MCFP, mean circulatory filling pressure; P_DA, dorsal aortic blood pressure. Values are mean ± s.e.m.; N=4–9. *Significant difference relative to control values (1 cmH₂O=0.098 kPa).