Figure 16.

Localization of ArPPLN1b immunoreactivity in the cardiac stomach, pyloric stomach, pyloric duct and pyloric caeca of A. rubens. (a) Transverse section of the central disk region showing immunostaining in the cardiac stomach and pyloric stomach. (b) High magnification image of the cardiac stomach showing immunostaining in bipolar‐shaped cells in the mucosa and in the underlying basiepithelial nerve plexus. (c) High magnification image of the pyloric stomach showing immunostaining in bipolar‐shaped cells in the mucosa and in the underlying basiepithelial nerve plexus. (d) Horizontal section of the arm of a juvenile starfish showing immunostaining in the pyloric duct and pyloric caeca. (e) High magnification image of a transverse section of pyloric duct showing immunostaining in bipolar shaped mucosal cells and in the underlying basiepithelial nerve plexus. (f) High magnification image of a transverse section through a lobe of a pyloric caecum showing immunostaining in bipolar shaped mucosal cells and in the underlying basiepithelial nerve plexus (arrowheads). Abbreviations: BNP, basiepithelial nerve plexus; CE, coelomic epithelium; CS, cardiac stomach; CT, collagenous tissue; Lu, lumen; Mu, mucosa; PC, pyloric caeca; PD, pyloric duct; PS, pyloric stomach. Scale bars: 200 μm in (a); 20 μm in (b), (c), (d); 100 μm in (e); 50 μm in (f)