(Downloading may take up to 30 seconds.
If the slide opens in your browser, select File -> Save As to save it.)
Click on image to view larger version.

Fig. 3. Particle imaging velocimetry images of currents generated by a male crab,
with and without courtship stationary paddling. (A) Side view of the crab when
it is not performing courtship stationary paddling. The gill current generates
flow upwards toward the water surface. (B) Side view of the crab performing
courtship stationary paddling, which generates a forward current. (C) View
from above of the crab performing courtship stationary paddling, which
generates a forward current. The mean velocity for current generated by the
paddling was 3.1 cm s–1.