Fig. 14

Mantle margin of adult Nodipecten nodosus. Mantle margin as revealed by magnifying lens (a and b, ventral view, anterior to the left; c, posterior view, dorsal to the top) and histological cross sections (d–i). a Live specimen with valves slightly opened, showing the pallial tentacles and eyes. b Detail of the mantle margin in an anesthetized specimen, showing the large inner mantle fold with tentacles and the middle fold with tentacles and eyes. c Detail of the mantle margin at the auricular region where the inner folds from both mantle lobes are fused. d Adult pallial musculature composed of radial bundles (divided into outer and inner groups) and transverse bundles (arrow). Ventral to the top. Toluidine blue and basic fuchsin (TB). e Long pallial nerve connecting to the circumpallial nerve, the cortical region and the neuropil of which are shown in detail in the inset. Ventral to the top. TB. f Inner mantle epithelium with cells bearing tufts of cilia (arrows). Hematoxylin and eosin (HE). g Detail of neutral mucopolysaccharide secretion (magenta) in a gland cell from the inner mantle epithelium. Periodic acid-Schiff stain (PAS). h Outer mantle epithelium with long microvilli (arrows) covering the surface. HE. i Subepithelial secretory cells with acid mucopolysaccharide content (light blue) in the outer mantle epithelium. Alcian blue (AB). Abbreviations: cn, circumpallial nerve; co, cortex; if, inner mantle fold; ir, inner radial muscles; it, inner fold tentacle; ma, mantle; ne, neuropil; of, outer mantle fold; or, outer radial muscles; pa, pallial eye; pn, pallial nerve; te, middle fold tentacle