First photo :
This 10 cm long worm stuck in the substrate of a soft coral. This worm has a cylindrical body.
Leslie Harris :" There are several syllid species known to live/ feed on soft corals. One of them which looks like this is Syllis onkylochaeta Hartmann-Schroder."
"Yes, they are. This particular type is one of the few known to eat corals. Most of the observations of the worm have been on leather corals. Julz should remove them and keep looking for new ones. "