FIGURE 12 in Morphology and taxonomy of Isognomon spathulatus (Reeve, 1858), a cryptic bivalve from the mangroves of Thailand

FIGURE 12. Morphology of ctenidia of Isognomon spathulatus (transverse histological section, 5-µm, PAS stain of single inner demibranch; AMNH 319258; 52 mm). A—Section at distal-most edge of demibranch margin showing absence of serial interfilamentar tissue fusion; B—Section slightly proximal to that of A showing limited extent of interfilamental serial fusion restricted to narrow, median bridge; C—Section at mid-height of demibranch; D—Closeup of single lamella showing ciliation of ordinary filaments; E—Section though row of ciliated disks showing interfilamental junctions. Abbreviations: ac, apical cilia; cd, ciliated disk; fg, food groove; lc, lateral cilia; lfc, laterofrontal cilia; ogf, ordinary gill filament; tf, tissue fusion. Scale bars: A−C: 150 Μm; D: 50 µm; E: 100 µm.