Kelmen, Thanks very much for the link. That picture looks out of focus though. I think it could be Codium vermilara, of which a better picture is here:
http://www.saltcorner.com/sections/guest/algaepage/Green/calcareousalgae/Cvermilara.htm
That isn't what I've got however. Pictures that I've seen and descriptions I've read of Codium mostly point to irregular sponge-like lobes, as well as the fine hair-like branchlets. The stuff I've got definitely does not have the former, as the branches are quite cylindrical, with little sub-branching.
Right now, I think what I've got might be Bryopsis pennata. Univ. of Hawaii website, at
http://www.hawaii.edu/reefalgae/invasive_algae/chloro/bryopsis_pennata.htm
says:
1. Thallus filamentous, bushy, in tuft-like mats, to 10 cm high.
2. Fronds feather-like, 8 - 15 mm wide, pinnately branched
3. lateral branches of uniform length, constricted at base where joined to main axes.
4. Branchlets in two opposite rows on upper half of branch, lower half of branch is bare.
5. Rhizoidal system is fibrous, tightly interwoven.
6. Color is glossy dark green, often with light blue iridescence.
7. Main axes 240-360 Ã"šÃ‚µm diam; lateral branchlets 75-150 Ã"šÃ‚µm diameter.
8. Plants are dioecious, with male plants becoming yellowish-green and female plants turning dark green.
1,2,3,5 fit. The color is yellowish-green, so that accounts for 6,8.
4 only sort of fits because it looks to me that only about the bottom 10 to 20 percent of the branches is bare.
7 could be a major descrepancy. The hair-like branchlets do look about .1 mm thick (sorry, no microscope). But, I am sure that the main axes, while wet, have diameter 1 mm give or take 25% at most.
What's more, the picture they show on the page doesn't really look like what I've got (at least not to me).
The original post of the sticky on Bryopsis lists 3 varieties of Bryopsis pennata: leprieurii, secundata, secunda. I couldn't find any free info on them on the web. The last two names seem to imply some sort of asymmetry, which I do not see on my stuff. So maybe it is leprieurii. Or maybe I haven't even got the family right...
Anyway, one thing's for sure though. Bryopsis is widely regarded as a pest. No point taking a chance. So out that stuff goes.
