Baby bristlestar or aiptasia?

[Picassoclown]

Hey everyone. I just received blue hypnea from Topshelf and while observing it, I noticed there was a huge colony of bristlestars, which I do not mind, but i found these right after I put it into my tank. I do not know for sure if this is aiptasia? The dark spot on it looks like the body of the bristleworms I found. Weird thing is, they move on their own, I have not seen baby aiptasia do this, but a part of me doesn't know for sure, so I removed instantly. What are these?

 

[Picassoclown]

Sorry, forgot to add a picture of the bristlestar. Here it is.