Fig. 1.

The swim system of C. limacina. (A) Photos of C. limacina and C. antarctica. (Approximate magnification is 0.25× for C. limacina and 1× for C. antarctica.) (B) Cartoon circuit diagram of the swim system of C. limacina. D, elements involved in dorsal wing flexions; V, elements involved in ventral wing flexions. Excitatory synaptic connections are in red and inhibitory ones in blue. For simplicity, inhibitory connections between interneurons and motoneurons, and all connections to the contralateral pedal ganglion, have been left out. Elements that are reconfigured or recruited into activity during fast swimming are colored in yellow.