Fig. 1. (A) Swimming larva of Ciona intestinalis. In the trunk the two pigmented organs are visible within the sensory vesicle. Scale bar, 100 µm. (B) Diagram of motor neurons of the visceral ganglion and of the innervation pattern of muscle cells in the tail, dorsal view (modified from Bone, 1992; Cole and Meinertzhagen, 2004; Brown et al., 2005). Neurites connecting motor neurons to the muscle cells in the tail present some varicosities (arrow). ap, adhesive papillae; mc, muscle cell; mn, motor neurons; ne, neurites; N, neck; NT, neural tube; oc, ocellus; ot, otolith; SV, sensory vesicle; tr, trunk; t, tail; VG, visceral ganglion).