Figure 1

3D reconstruction and schematic representations of Loxosomatoides sirindhornae based on serial sections. (a) Overview showing the general shape of the animal divided into the stalk and calyx. (b) Oblique view into the internal anatomy, showing the U-shaped digestive tract, reproductive system including gonads and brood chamber and the terminal ducts of the nephridial system. (c) Lateral view; body of the calyx displayed transparently. (d) View on the retracted tentacle crown showing 17 tentacles, the terminal ducts of the protonephridial system and the ganglion. (e) Top view, tentacle crown and body of the calyx omitted. (f) Top view showing the aboral median carina on the calyx. Scale bar: 100 μm. (g) Schematic representation of the internal anatomy of L. sirindhornae in lateral view. Nephridial system with exception of the nephridiopore omitted. (h) Schematic representation of the internal anatomy of L. sirindhornae in frontal view. Tentacles are omitted for clarity. Colors: dark blue - stalk, red - body of the calyx, light blue - retracted tentacle crown, green - digestive tract, dark purple - terminal ducts of the nephridial system, light purple - brood chamber, orange - ovary + oviduct, yellow - central nervous system. Abbreviations: atc - atrial cavity, bc - brood chamber, btc - border of the tentacle crown, cns - central nervous system, es - esophagus, int - intestine, mo - mouth opening, np - nephridiopore, ov - ovary, rec - rectum rtc - retracted tentacle crown, sto - stomach, tc - tentacle crown, td - terminal duct.