Hole inside the skeleton?

[Notsolostfish]

Noticed the polyps were peeling on that hammer, took it out, and the i see a literal hole inside the skeleton in the middle? Why would that happen?



Alk:9.1
Cal:460
Mag:1410
Phosphate:0.11
Nitrate:15
Temp:77
Ph:8.2

 

[KrisReef]

Someone bored into it.
I think I might remove the head with the hole to protect the others from whatever bored in there.

Otherwise I would do a five minute potassium chloride bath 1/tbls gallon and hope that the invertebrate crawls out dying from the hole and hope that it didn’t lay eggs in there.