Fig. 11

Muscular system of the digestive tract of Stephanella hina. Confocal laser scanning microscopy stacks based on f-actin labelling. Volume renderings, projections or optical slices. F-actin in glow LUT. a Volume rendering of a dissected zooid showing the major areas of the gut. b Optical section of the data set in A showing the border between the esophagus and the cardia. c Volume rendering showing the fanned retractor muscle inserting into various sites of the oral digestive tract. d Detail of the smooth circular muscles of the caecum. e Detail of the circular muscles of the foregut showing cross-striation and the smooth hindgut, the intestine. f View of the circular muscles of the anus. Abbreviations: a – anus, ca – cardia, cae – caecum, cv – cardiac valve, es – esophagus, fg – foregut, int – intestine, lb. – lophophoral base, mo – mouth opening, or – orifice, ph – pharynx, phc – pharynx ciliation, rm. – retractor muscle, tm – tentacle muscles