Coral or pest?

[Lacrette1991]

I noticed these little things growing just on the rock my green star polyps are on. Any idea what they are? Doesn’t look like aptasia and can’t find anything online.

 

[tbrown]

Hard to tell but kind of look like miniature feather dusters.

 

[Jekyl]

Pics in blue light isn't much help.

 

[Lacrette1991]

Pics in blue light isn't much help.

I got out my flash light but as soon as I put it on them they shoot inside the rock

 

[GaryE]

They look like clove polyps

 

[vetteguy53081]

Hydroids. These are capable of stinging coral but not like aptasia. The best defense is to starve them by preventing food from reaching them. They favor brine shrimp. Simply direct water flow towards them, not at them and they will starve to death.