Skip to main content
Fig. 10 | BMC Zoology

Fig. 10

From: Ultrastructure and functional morphology of the appendages in the reef-building sedentary polychaete Sabellaria alveolata (Annelida, Sedentaria, Sabellida)

Fig. 10

S. alveolata. Branchial coelom and blood vessels TEM. a Somewhat oblique section through middle region of branchia showing inner and outer branchial vessel (ibrv, obrv) and circular connecting blood space (bs, arrows), note blood cell (hemocyte) (bc) in obrv, peritoneum (pt) formed by cells of varying thickness reaching their maximum thickness around the nuclei (nc), b Blood cell with nucleus (nc) and branched sheet-like extensions (arrows), arrowheads point to coated pits, c Enlargement of hemocyte process with numerous endosomes, coated vesicles and a few coated pits (arrowheads), d Coelomic lining or peritoneum (pt) of inner branchial vessel (ibrv) formed by granulocyte-like cells with numerous electron-dense granules and lysosomes (ly), inset: basal part of granulocyte-like cell facing to blood vessel with bundle of myofilaments (arrow), e ECM (ecm) forming wall of blood vessel (bv) covered by extremely thin coelomic lining (pt), arrow points to zonula adherens, arrowhead to septate junction between adjacent peritoneal cells, f Coelomic lining (pt) covering blood vessel (bv) composed of myofilament-free and myofilament-containing cells (arrows), g Tangential section through several basal regions of blood spaces (bs) and branchial coelom (brcoe); peritoneal cell with myofilaments (mf) and intermediate filaments (if), peritoneal cells followed by ECM (arrows) and blood space (bs), ECM covered by a loose meshwork of collagen-like fibers (arrowhead). Abbreviations: bc - blood cell (hemocyte), brcoe - branchial coelom, bs - blood space, bv - blood vessel, cu - cuticle, ecm - ECM, ibrv - inner branchial vessel, if - intermediate filaments, ly - lysosome, mf - myofilaments, mi - mitochondrion, nc - nucleus, pt - peritoneum, suc - supportive cell

Back to article page