Believe it or not, some snails are pretty good swimmers. Richard Satterlie in his talk presented a lot of neurobiological data on the control of swimming speed in Clione. These animals have wings and use them to propel themselves very similarly to squid with sort of undulating movements. The wings can be made more or less stiff to change swimming speed. The swim interneurons controlling swimming speed are well characterized as are the muscles and motorneurons. It appears the different swimming states (fast, intermediate and slow swimming) in the nervous system are subject to serotonergic modulation.
Richard's lab is also obtaining 3D movement data from video cameras and software to fine-analyze the exact swimming motions on the computer. Thus, from behavior to muscles and neurons, the entire spectrum of the behavior can be studied very elegantly in this model.