Blue/Purple Invertebrate or Plant?

[scubadiverjackcook]

I took this photo of a bright blue branched plant or animal on the West Side of Santa Catalina Island in about 35 FSW with a water temp of about 64F. The color balance should be right because the surrounding reference species are the correct color. Is it animal or vegetable? I have been looking for the correct ID for a while with no luck.

 

[drbill]

It is a red alga whose name escapes me at the moment. I was filming it on my night dive last night since the colors are beautiful.