Fig. 14

Schematic overview of the neuroanatomy of the lophophore base of Asajirella gelatinosa. A From the cerebral ganglion several projections extend: two ganglion horns into each lophophoral arm and the circumoral nerve ring around the foregut. Ultimately, two epistomial horns ascend distally and project as epistome neurite bundles into the epistome. B Schematic detail of the innervation of a single tentacle shows neurite bundles branching along the fronto-abfrontal axis: The radial nerve projects from the ganglionic horn/circumoral nerve ring abfrontally. Along the radial nerve, two laterofrontal neurite bundles branch off. Abfrontally, a pair of lateroabfrontal and abfrontal neurite bundles split off. Most abfrontally, the additional radial nerve branches off. Each tentacle is supplied from two adjacent radial nerves (lined circles). Frontally, a single mediofrontal tentacle neurite bundle project from the ganglionic horn/circumoral nerve ring into each tentacle. afm abfrontal tentacle muscle, afn abfrontal neurite bundle, arn additional radial nerve, cg cerebral ganglion, con circumoral nerve ring, drn distal radial nerve, eh epistomial horns, enb epistome neurite bundles, ep epistome, fm frontal tentacle muscle, gh ganglion horns, la lophophoral arm, lan lateroabfrontal tentacle neurite bundle, lfn laterofrontal tentacle neurite bundle, mfn mediofrontal tentacle neurite bundle, ph pharynx, rn radial nerve, t tentacle, tc tentacle coelom