Fig. 6
Light micrographs of cross sections of all oral sensory organs (oso) in a specimen of Bathochordaeus stygius. osoar/l: anterior oral sensory organ of the right/left side, osolr/l: lateral oral sensory organ of the right/left side, osoir/l: inner oral sensory organ of the right/left side. Note that osoal contains three clusters of sensory cells, osoal1-3. The apical openings in the epidermis covering of osoal1-3 are depicted in Additional file 2: Figure S2. aj—apical junctions, ec—epidermis cell, ep—epidermis, hr—house rudiment, icm—intracellular matrix, ne—neurites, nu—nucleus, sc—sensory cell