Are they solitary or are there a number of worms in each hole? If there are a lot of worms colonizing a shared hole, it may be a spaghetti polychaete worm. I have never heard of digitate hydroids being parasitic. They are reef-safe filter feeders to my knowledge.
Digitate hydroids sway and retract when they collect food, while spaghetti worms creep around, stretching out in all directions and retract in the same fashion.
Last edited by mr.wilson; 03-15-2010 at 04:51 AM.
|