STATOMOTOR SYSTEM IN THE MARINE MOLLUSK CLIONE-LIMACINA

1. In the marine mollusk Clione limacina the ''statomotor system'' (na med by analogy with the oculomotor system) has been found. This system includes a muscle that is directly attached to the statocysts connect ing them with each other and with the inner surface of the body. 2. Th e statocyst muscle consists of four electrically coupled, mononuclear cells. Statocyst muscle cells do not generate spikelike potentials but only excitatory junctional potentials. 3. The motor input to the stat ocyst muscle correlates with the activity of the locomotor generator. This suggests that in the soft-bodied Clione contraction of the statoc yst muscle stabilizes the statocysts into a standard ''working'' posit ion in relation to coordinates of the body. This statocyst stabilizati on is important for Clione's spatial orientation during swimming.