Figure 6

3D-reconstruction of the embryo of Saccoglossus kowalevskii at early kink stage (~ 96 h pf). Rows from left to right: dorsal, ventral, left and right view. Columns from up to down: The merge row (A-D) shows the embryo with all reconstructed structures. Note the asymmetric development of the anlagen of the gill pores (double arrowheads) in C and D and O and P. Epidermis row (E-H) shows the external shape of embryo. The telotroch is not shown. Endoderm row (I-L) reveals the transparent endodermal tissue (light green) revealing the subdivision into an anterior pharynx and posterior intestine region. The anlagen of the gill pores (gpA) can easily be discerned. The anlage of the stomochord (stA) is protruding shortly into the protocoel. Mesoderm row (M-P) shows the position of the anterior protocoel (blue) and the paired meso- (pink) and metacoelic (red) compartments. The pericardium (purple) is bulb-shaped and protruding into the protocoelic cavity. Download interactive 3D-PDF as Additional file5. co collar, mo mouth opening, stA anlage of the stomochord, tr trunk.