Not sure what this is ti the left of the coral frag. It has a fan type top on it much like a feather duster. It retracts into the tube when I get even close to it.
It kinda looks like a mini featherduster/fan worm?
Otherwise hydroid... hopefully feather duster. I don’t know how to identify hydroids as never had them but my mini feathers had hard tubes that they would retract into.
A description would help