Macaron Sponge

Symphon macaron. A sponge that has developed a disc of flagellated feeding cells. Named for the dessert sandwich cookie (not available in current fabricator settings).

1. Hardened plates Instead of a sponge's normal inner and outer layers, the macaron develops two hard plates of pinacoderm. These anchor the feeding disc to a holdfast.

2. Feeding disc The sponge's mesohyl (internal jelly) has specialized into feeding disc, with tentacled cells that pull particles from the surrounding seawater. This leaves the delicate jelly vulnerable to predators and parasites.

3. Hostage exchange The feeding disc hosts the larvae of sponge-eating organisms in its pores. By providing a shelter and habitat for their young, the macaron may buy itself a degree of safety and defense. (These larvae are themselves tempting prey for many species.)

4. Unusual protein expression Many of the cells in the feeding disc express proteins also found in the hosted larvae. This may be a recognition signal to attract the desired species.

ASSESSMENT: Inedible despite name. Await further updates.