Fig. 4 in Ophiomonas shinseimaruae Okanishi & Matsuo & Fujita 2021, sp. n.

Fig. 4. Vertical sections of the boundary zone stained with Picro-sirius red. a and b, Rejection reactions between two individuals. c and d, Fusion between two fragments of the same individual. a, Boundary formation between two individuals and a spicule stuck into another individual (arrowhead). b, Gathered mesohyl between two individuals (arrow). c, A collagenous structure (stained pink) formed at the contact interface. d, Fusion of the sponge tissue. Asterisks indicate the dermal-like layer to indicate the boundary region between two sponges.