Table 1.

Kinematic and hydrodynamic measurements for pectoral fin maneuvers by rainbow trout

Angular velocity of body (degrees s-1)Mean jet angle (degrees)Mean jet velocity (cm s-1) Wake force (mN)
Turning13.5±2.4121.4±5.05.9±0.42.7±0.9 (0.8±0.3)1.1±0.2 (0.4±0.1)-
Braking11.4±2.4116.3±2.06.1±0.3-2.5±0.6 (0.7±0.1)4.7±1.5 (1.5±0.2)
  • Values are means ± S.E.M. (N=12-22 events from two individuals per measurement).

    Measurements for hovering and turning were made in ventral view (frontal-plane velocity field, XZ), and for braking in lateral view (parasagittal-plane velocity field, XY).

    Angular velocity of body data report the rate of yawing rotation and nose-down pitching of the longitudinal body axis during turning and braking, respectively (not measured for hovering). For turning and for the protraction half-stroke of hovering, tabulated jet angles indicate wake flow oriented anterolaterally; for the retraction half-stroke of hovering, the average jet angle represents posteromedial flow; and for braking, the jet is directed anterodorsally.

    Wake forces are stroke-averaged measurements reported per fin. Laterally, anteriorly and dorsally oriented components of force are reported for turning and braking, with force per unit pectoral fin area (mN cm-2) in parentheses.