Acropora pest?

[chengtaotc]

While dipping this newly acquired Acropora tenuis coral, I noticed two strange cyst-like lumps. From the lower one, I actually saw a suspicious worm-like creature poking its head out—multiple times! Unfortunately, I didn’t have my tweezers on hand. By the time I grabbed them and kept watch, the worm never came out again. I increased the dip concentration (two little fish revive) and even gave the coral a 2-minute freshwater bath, but didn’t see the worm again. Worried about stressing the coral, I stopped and returned it to the tank. Could this be a pest? Any advice on what I should do next? Thanks in advance!

 

[SpSDrew]

Looks like just a barnacle to me. Mariculture acropora get them all the time. Harmless really.