Need Help Identifying this Macro Algae

[magnetar68]

A clear, crisp photograph

I did my best. See Below


A description of the texture of your algae (is it brittle? soft? fleshy? does it break easily?)

The round disk-like petals are soft, the branches are more like twigs: quite firm and hard to break.


A good reference for the size of the algae (try for something in the photograph that shows the scale)

The horizonal width of the whole strand is about 12-15cm (bottom pic), but each little disk-like petal is about 4mm (~1/2 cm or 1/4 inch) in diameter.


The location of your live rock or collection spot (Caribbean, South Pacific, Pacific, etc.)

Not sure.


A description of the growth habit of your alga (growing on rock, on/in the sand, in the water column, etc.)

Seems free floating in the water column like a Chaeto. I have wedged it between some rocks to keep it from moving around.

http://i788.photobucket.com/albums/yy163/rletulle/003.jpg

http://i788.photobucket.com/albums/yy163/rletulle/002.jpg

http://i788.photobucket.com/albums/yy163/rletulle/001.jpg

[Sugar Magnolia]

Caulerpa nummularia.

[magnetar68]

I did find C. nummularia when I was doing my google image search, but this seemed to have thinner branches and smaller diameter tubes than the pics I found. Perhaps this is less mature? Also, this algae was free floating rather than crawling along a rock.

E.g here:

http://www.melevsreef.com/id/caulerpa_nummularia.html

[Sugar Magnolia]

Mermaid's cup? Acetabularia.

[magnetar68]

I think C. Nummularia is the better guess. Actebularia does not seem to have the vine-like branching and has a well defined petal shape that I don't see here. I removed it from my system in the event it is C. Nummularia.