What's this?

[Timbo13]

Hi all,

These purple soft things have been on my hammer coral skeleton for a while now. They don't really seem to be bothering it. They're soft and I can scrpae them off easily. Does anyone know what they are? These photos were taken in the morning before the lights came on. Ignore the little vermatids, they are a separate battle. I thought mybe sponges or I have some mushroom coral that is constantly growing in weird places in the tank.
Thank you

 

[JoJosReef]

Do they move or are they stationary? The ones on the left look like they have a siphon type hole in them, is that correct? possibly a purple sponge, less likely tunicate, but some sponges can be problematic if they are spreading across your coral.

 

[mermaid_life]

Agree... Tunicate or sponge.

 

[Koty]

Flatworms? A wrasse can take care of them.

 

[Timbo13]

Thanks for your replies everyone. I’m not sure if they move, once the hammer opens they’re hidden from sight. I guess I’ll wait a few days and compare the photo from today then. I’m pretty sure they’ve been there for months. If they don’t move should I leave them? If they move what is the best course of action?

 

[mermaid_life]

If they don't move and are not bothering the coral, it's no harm and you can leave it. Tunicates/sponges just filter the water.