Fig. 7
Postmetamorphic Nodipecten nodosus scallops. Ventrolateral view in a–c (anterior to the left), cross-section in d and e (ventral to the top and left), and lateral view in f and g (anterior to the left and ventral to the top). a Light micrograph with differential interference contrast. b Detail from the same individual showing the inner curtain-like fold, with cilia on its edge. c Mantle margin with inner fold and row of cilia on the periostracal groove, scanning electron micrograph (SEM). d Cross section of an entire specimen showing extension of the mantle and pallial cavity where gill filaments are developing. Toluidine blue and basic fuchsin (TB). e Detail of the same region of the inset indicated in d, showing the pallial cavity and the two-folded mantle margins. TB. f Postmetamorphic musculature stained with phalloidin and reconstructed based on confocal micrographs. Mantle muscles are presented in yellow and other muscular groups (i.e. foot retractor and adductors) are in red. g Detail of the pallial musculature from f showing retractor and margin-parallel muscles. Abbreviations: aa, anterior adductor; ci, cilia; fo, foot; gf, gill filaments; if, inner mantle fold; mm, mantle margin; mp, margin-parallel muscles; of, outer mantle fold; pa, posterior adductor; pe, periostracum; pg, periostracal groove; rm, retractor muscles