something living inside in my blasto frag

[dmitriy loos]

so i got this blasto and at first i suspected something was living on it, yet i wasn’t sure. this feeding confirms it. it will slowly come out and then shoot back into its little hole. anyone have ideas or know if it’s harmful? it doesn’t live inside the coral, but on the rock that the coral lives on. concerned that in the future it will prevent growth and possibly harm the blasto. couldn’t upload the video because it is too big, but here is a picture of it od up and closed. 

[Tired]

I can't see it in either picture. Can you take another picture like the white one, and circle it in the picture? 

 

Look up fanworms and barnacles. Those are my two guesses. Both are harmless, and the coral will just grow around them. It'll grow around most rock-inhabiting organisms without any serious harm, though may find them minorly annoying in that immediate area.