I have slowly begun to stock my tank. Last week I picked up a really nice piece of rock with a mushroom coral on it and a few other things like feather dusters. The coral adjusted quickly and it looks nice and healthy but this morning I noticed a tear on the mushroom. Despite the tear, the coral doesn't appear unhappy.
I don't have much in my tank at the moment. I have an emerald crab, a tuxedo urchin and a peppermint shrimp. I also have some snails and a few blue legged hermit crabs. None of these animals seem interested in the mushroom and I don't know how it got injured. I did notice 2 clear/white tentacles coming out of a crevice in an adjacent rock. These tentacles could reach the area where the rip was - I think. I don't have a picture. I didn't see it today and lights are off now. If these tentacles sting, what would the injury look like? Or, does the damage depend on what it is? When I was looking at the tentacles, it seemed like they were trying to zap the mysis shrimp that swam by. There are only 2 tentacles and they are about an inch long. How do you extract something from a crevice, anyway? This particular rock is holding up other rocks and is a key piece in the stability of the aquascape. It might be simpler to move my new rock with the mushroom coral...
Or, could the hermits/emerald crab have injured the coral by walking on it? They seem to ignore it but I don't know what happens in the dark