What is this stuff?

[wsurf4me]

I've done a little searching and can't seem to find an id on this stuff. It started on a piece of tonga branch and is slowly spreading to other rocks. What is it and better yet what eats it, I have a several tangs and a scribbled rabbitfish and they won't touch it.

[ClamIAm]

Definitely a calcareous green alga, maybe Udotea? I've never heard of it growing to such proportions as that though.

[wsurf4me]

I don't think it's calcareous, it's not like halimida anyway. This stuff appears to be like lettuce or spinach, I thought maybe it was some type of caulerpa. I was hoping once I had an id I could look into what eats it.

[wsurf4me]

This stuff also has hairlike strands that float freely in the water, it seems as if it spreads with runners like caulerpa. ID anyone?

[graveyardworm]

I agree with the ID of Udotea.

[Plantbrain]

another vote for Udotea here as well, it does not have to be hard feeling to the touch etc, it can be fairly soft, and it does spread via runners.

No clue what will eat it.

Regards,
Tom Barr

[piercho]

Pacific diadema urchins and tuxedo urchins both ate Udotea (Caribbean mermaid fan) in my tank. My Udotea was thicker, stiffer, and grew by runners though the sand unlike this stuff.