It's a male Pseudanthias squamipinnis - or at least a member of that species complex. Rudie Kuiter recently split this species (as usually understood) into a number of species. However, I'm not sure whether these will withstand scrutiny by other ichthyologists (though I have little doubt that P. squamipinnis should be split up - there's a lot of variation in male coloration between localities). Unfortunately, I don't have a copy of Rudie's book, so I can't tell you what name he would apply to it. It matches closely with photos I have of individuals from the Western Indian Ocean.
Tony