Donut of Worms Creature Guide and Details | Subnautica 2

The worms go in and out of the central hole.

An organism (tentatively Raion donut) that resembles an Earthly anemone or ceriantherian, but is actually a sponge occupied by a colony of predatory worms.

[1] Raion
An organism defined as a sponge occupied by a colony of cloned predatory worms.

[2] Hunting strategy
The worms live in the sponge's jelly (called the mesohyl), protruding from its anus (the osculum) to sting passing prey with sticky cells and draw them into the sponge.

[3] Puzzling genetics
Spectrogenetic analysis indicates the host sponge and the resident worms contain partial copies of each others' genomes. This is a biological impossibility on Earth, and suggests that genetic inheritance functions differently on this world.

Assessment: minor sting hazard — do not insert fingers. Important scientific discovery.

They cannot be harvested.