Fig. 17.

Neuromuscular system of the membranous sac in Cinctipora elegans. CLSM, staining of f-actin (phalloidin, glow-LUT) and acetylated alpha-tubulin (green). a Optical section showing the membranous sac surrounding the proximal area of the caecum. b Volume rendering showing the musculature of the membranous sac in the proximal area similar to A. Several fibers are highlighted in pink. Longitudinal and circular muscles of the caecum are seen beneath the membranous sac. c Musculature of the membranous sac in a more distal area, at the lophophoral base. Several fibers over the retractor muscle are highlighted in pink. Volume rendering. d Innervation of the membranous sac. Volume rendering. e Optical section showing muscles and nerve fibers in the same bundle. Abbreviations: cae – caecum, ep – esophagus, es – endosaccal space (coelom), mp – multipolar neurons, msm – membranous sac muscles, msn – membranous sac neurite bundles, rm – retractor muscle