Fig. 6

Schemes of the lophophore innervation in Crisia eburnea. a Organization of the serotonin-like immunoreactive nervous system of the lophophore, viewed from the top. b Innervation of tentacles. c The main nerve tracts of the lophophore and the body; lateral view. d Top view of the nerve elements after staining for tyrosinated α-tubulin. Abbreviations: afn – abfrontal tentacle nerve; cg – cerebral ganglion; cns – circular nerves of atrial sphincter; con – circumoral nerve ring; cpr – circumpharyngeal nerve ring; laf – latero-abfrontal tentacle nerve; lan – latero-anal nerves; ldl – lophophoral anal nerve; lf – laterofrontal tentacle nerve; lln – longitudinal lateral nerve of the digestive tract; lnw – longitudinal nerves of the body wall; mf – mediofrontal tentacle nerve; mo – mouth; mvn – medial visceral nerve; on – outer nerve ring; rn – radial (intertentacular) nerve; sap – anal serotonin-like immunoreactive perikarya; sbln – small branches of the longitudinal nerves of cystid; sop – oral serotonin-like immunoreactive perikarya; t – tentacle; vr – vestibular nerve ring