How's this?
1. Small feather duster tube that the Goni has grown around (still alive).
2. This is part of an old tunnel that is healing over.
3. Fresh exit hole. The grayish looking material comes from the Goni. The gray stuff acts as a filler in the wound to rebuild tissue over the old skeleton; it probably is an infection fighter too.....In one of my other specimens, in which a polyp was torn off (no worm), the stuff is not originally gray, but more of a greenish color with a sticky cotton-like texture when it is fresh. The stuff collects debris as it accumulates, turns into dead tissue, and then turns gray. As the wound closes, it comes out and falls away. The worm has already caused the damage, the coral is trying to heal itself, and the worm is burrowing through the stuff. I have older photos where the worm has burrowed, but before the coral started healing itself.
4. Another old burrowing area, which is healing over.
It appears as if the worm moves or burrows along the tops of the corallite ridges. I imagine the feather duster is putting out offspring underneath the coral tissue and then the offspring has to burrow out. It doesn't appear to be eating polyps, just burrowing. If the tissue connected to the corallite ridge is damaged enough, it will cause the whole polyp to die.
Solution: Kill the feather duster, leave the tube and close it with super glue, the offspring burrows out (if that's what it is and if it leaves the goni), goni heals itself.
