Fig. 6 in Description of a new syllid species as a model for evolutionary research of reproduction and regeneration in annelids

Fig. 6 Confocal maximum projections of Typosyllis antoni n. sp. Phalloidin–rhodamine (gray) and serotonin labeling (red) of cross sections (a–c) and the proventricle (d, e) of adult specimens. Dorsal is up in a–c. Anterior is up in d and right in e. a Cross section of the midbody region, the prominent longitudinal muscle bundles are colored in yellow. The insert shows a detailed view of the parapodium, and major muscle bundles are color coded— parapodial retractor muscle in brown, acicular protractor muscle in green, acicular flexor muscle in violet, chaetal flexor muscle in pink, cirral muscle bundle in blue. b Cross section showing the distinct proventricle (pr) filling almost the whole body cavity. The longitudinal muscle bundles are color coded in yellow. c The proventricle (pr) and the ventral nerve cord (vn) show distinct serotonergic immunoreactivity. d The separated proventricle (pr) exhibits radial honeycomb-like muscle bundles (rb, dotted circle) and prominent circular muscle fibers (cf) surrounding the whole structure. e The separated proventricle (pr) is represented by an anterior circular muscle bundle (am) and suspending muscles (sm) terminating at the border between the anterior circular muscle bundle (am) and the radial muscle bundles (rb). am anterior circular muscle bundle, cf circular muscle fiber, dc dorsal cirrus, dv dorsoventral muscle fibers, in intestine, mm median muscle bundle, pa parapodium, pr proventricle, rb radial muscle bundle, sm suspending muscle fiber, vn ventral nerve cord. Scale bar=100 μm (color figure online)