Unsure what is growing in my rainbow stylo

[Spare time]

They only grow in my rainbow stylo colony and I am not sure waht they are. They have a small soft tube with what looks like two little antennae sticking out you can see 2 pairs of those in the second picture on the top of the coral.

 

[35ppt]

Redacted

 

[Spare time]

Ah, I wonder why they popped up all of the sudden. I also wonder why they are growing only on the coral right there