Looks like halimeda sp. macroalgae.
Either: Halimeda macroloba or
Halimeda tuna
My guess is Halimeda tuna.
Take a look at post # 5
https://forums.saltwaterfish.com/forum/thread/373943/algae-identification-thread
Ah yes it is halimeda, thanks for the great info!
But what I meant was, I think my wrasse was asking "hey what is this plant thing?" as he swooped in for a closer look..