There has been some debate about the identity of this fish. While it could be a new species, there is also a strong possibility that it is a hitherto unknown deepwater colour form of the Bicolour Cleaner Wrasse (Labroides bicolor). Neither idea has yet been confirmed, it will be interesting to see what this weird little wrasse ends up being!
Update on this: it seems that the most likely identity of this fish is a natural hybrid between the Bluestreak Cleaner Wrasse (Labroides dimidiatus) and Bicolour Cleaner Wrasse (L. bicolor). It also seems this is not the only known specimen - it was the only one to be collected, but a very similar fish has been photographed in the wild in Japan, in shallow water (this adds credence to the hybrid identity, as both putative parent species also co-occur in Japan).
Update: more specimens of this unusual fish have been found in Japanese museum collections - combined with the specimen photographed here (which has since been preserved), they total to at least six known physical specimens of this fish. Exciting!
