Algae ID please

[mike31154]

I had some in my system and was actually trying to encourage it to grow. Something kept nipping at it once it got a certain size though and I haven't seen any in a while. I suspect the nipper was a mithrax crab, but unable to confirm, never saw the dirty deed being done. Happened overnight to the best of my knowledge.

I also have a scrap of Halimeda trying to make a go of it, but my female Maroon Clownfish seems to have an issue with it. As soon as one or two of the branches reach a certain size, she tears it up.