My guess is a gall crab. Not really much of a problem for the coral but if it bothers your aesthetic yo could CAREFULLY squirt some H202 into the opening with a syrenge and needle. I would leave it myself.
My guess is a gall crab. Not really much of a problem for the coral but if it bothers your aesthetic yo could CAREFULLY squirt some H202 into the opening with a syrenge and needle. I would leave it myself.