What is this on my live rock?

[Brettdis]

So i’m New to saltwater. Yesterday we added some live rock. This morning I found this on one of them. I’m trying to learn as much as I can about what’s growing on them. I tried doing some search’s online and I found out what a few things might be, But this one I couldn’t find. Anyone know what it is? Thanks in advance.

 

[bribo12]

No picture

 

[Sniperhank]

Does it move? Can you describe it more? It's hard to see, it is sometimes hard to get a good picture of things in this hobby.

 

[Brettdis]

it doesn't move that i've seen. yeah its very hard to get a good picture. it took about 20 pictures to get that one. its very small i would say about a 1/4 of an inch long. its a deep purple colour. its in a hole in the rock. doesn't look soft or fuzzy. looks like its hard. almost like someone dipped that part of rock in paint but its coming up off the rock not around the rock if that makes sense.

 

[Sniperhank]

Looks like maybe a type of sponge.

 

[Brookster123]

I think sponge as well. I have similar looking sponges in my rock. They're beneficial I believe.

 

[Sniperhank]

They can be. But sponges can also be invasive. If they encrust over large amounts of rock they can filter a lot out of the water column but also can be toxic. Sponges are cool, but I always keep an eye on them if they aren’t pineapple sponges.

 

[Brettdis]

Thanks. Being new t salt water its exciting to find stuff growing on the rocks. Hopefully it keeps growing so I can post a better picture.

 

[54seaweed]

if it's hard it just may be coraline hard to tell in that picture