What is this on my rock?

[DannyB]

I don't have any idea what this stuff is but hopefully someone here will know.

 

[Retro Reefer]

Hard to tell by the pic are they tubes?

 

[Eckolancer]

Looks like dying Halimeda algae

 

[DannyB]

They don't look like tubes. Kinda star shaped calcium deposits.
I don't believe i have had any halimeda algae in my tank but I will be looking it up shortly.

 

[DannyB]

Definitely didn't have any Halimeda algae in my tank. Anyone else have any insight on what this could be? I can't get much better of a picture than that unfortunately.

 

[Eckolancer]

I still believe it is Halimeda algae that is dying. Pull some out and take a better picture of it. Halimeda grows in some different shapes if not properly taken care of.

 

[Lenny_S]

Can you pull a little out? Will help with better picture and description.

 

[DannyB]

It wouldn't be so much pulling some out as it would be scraping it off the rock.

Maybe the picture is being seen without a frame of reference. Look at the top left quarter of the picture and see a round whitish thing, that is a micro snail about the size of #2 pencil lead.

I hope that helps.

 

[McMullen]

Are they hard?

 

[DannyB]

yes and attached to the rock

 

[McMullen]

Could they be worms? Or used to be?

 

[DannyB]

Possible, but i never saw any of it alive. It is on the back glass as well around some coralline algae, and all over my rock only in the light though. It almost seems like it is dead coralline algae, but why would it turn skeletal?

 

[McMullen]

Hmm, I hope someone chimes in with an answer. It's hard to tell from the pic, I suppose it could be a hard algae like coraline. The growth pattern/structure just makes me think worms.

 

[DannyB]

It's possible some type of worms. They may have been so small I just didn't see them alive. It sure isn't moving now so if it was alive, it is dead now.

 

[KVYA]

I believe you have chondria