Aeroshell Sponge

*Shootroot cabbage*. A robust bottom-dwelling organism anatomically similar to a plastic starfish, or to an opened variety of Earth's extinct blastoids.

1. Animal anatomy The cabbage shootroot's upwards-facing mouth is surrounded by outstretched arms. These arms are hard, tightly grouped, partly calcified, and covered in a tough biopolymer characteristic of other shootroots (tentative name: polyproteovinyl). These arms produce the cabbage-leaf texture that gives the shootroot its name.

2. Seabed burrowing A second set of arms uses ribbons of the same tough biopolymer to dig into the seabed, stirring up sediment and expanding cracks in rock. This is a difficult and metabolically expensive process, but it is a niche with little competition.

3. Symbiote kiss The cabbage shootroot does not use its mouth to eat, or its hard leaflike arms to feed. These surfaces seem to be reserved for a symbiotic partner. The cabbage shootroot uses its mouth to transfer nutrients gathered by its roots to the symbiote, and to receive a trickle of food or chemistry in exchange.

4. Circular nerve cord Like all shootroots, the cabbage shootroot is notable for its expression of a circular nerve cord.

Assessment: do not sit. You may receive nutrients.