Syllis sp.02is commonly referred to as unknown Syllid. Difficulty in the aquarium: There are no reports available yet that this animal has already been kept in captivity successfully. Toxicity: Toxic hazard unknown.
Leslie Harris : "
I'm sure the worm had nothing to do with the closure of the mussel. Syllids tend to be predators on sessile organisms like bryozoans and sponges, some eat algae & detritus, and a couple of species are known to prey on soft corals. The normal mode of feeding is to puncture cell walls & suck out the contents so with a few exceptions they do little damage to their prey. One big exception is Syllis onkylochaeta Hartmann-Schroder which eats soft corals."