Figure 9 in Morphological perspective on the classification and evolution of Recent Pterioidea (Mollusca: Bivalvia)

Figure 9. Serial tissue fusion of filaments at ventralmost edge of demibranch margins. Transverse histological section of ctenidia (7 µm, Alcian Blue/Periodic Acid/Schiff's trichrome stain). A, extensive interfilamentar serial fusion of gill filaments, Malleus (Malvufundus) candeanus (AMNH 299406, 33.4 mm height); B, interfilamental serial fusion limited to a transient narrow bridge, Isognomon alatus (AMNH 298023, 43.41 mm). Abbreviations: ogf, ordinary gill filaments; tf, tissue fusion. Scale bar = 0.1 mm.