Fig. 5

Organization of the coelom of the head of Owenia borealis. A Three-dimensional reconstruction of head (green) and trunk (yellow) coeloms. B Z-projection of head after staining with DAPI: dissepiment between head and trunk coeloms is indicated by arrowheads. C Z-projection of head and trunk cavity at sagittal optical section after staining with DAPI: dissepiment between head and trunk coeloms is indicated by arrowheads. D Three-dimensional reconstruction of blood vessels in head and part of trunk. Trunk and head coeloms are partly transparent. E Three-dimensional reconstruction of blood capillaries in tentacles. Abbreviations: bc – blood capillary; bw – body wall; dpr – dorsal protrusion; dt – digestive tube; dv – dorsal blood vessel; hc – head coelom; lbd – lateral branch of dorsal blood vessel; lbv – lateral branch of ventral blood vessel; lbp – lateral blood plexus; m – mouth; pgo – parapodial glandular organ; ph – parynx; t – tentacle; sb – setae bundle; trc – trunk coelom; vpo – ventral pharyngeal organ; vpr – ventral protrusion of the head coelom; vv – ventral blood vessel