Paracheilinus rubricaudalisis commonly referred to as Red-tailed Flasher Wrasse. Difficulty in the aquarium: Only for advanced aquarists. A aquarium size of at least 400 Liter is recommended. Toxicity: Toxic hazard unknown.
This species is not well known yet. Is common in Australia and Fidji. Surely they are to be kept like other Paracheilinus. They are tender, skittish fish, that should not be kept as singles.
The photo from Hiroyoko Tanaka shows a mail one with about 8 cm from Vanatu.