Bluestreak Cleaner Wrasse

Snapshot: A bold blue stripe pops against its snowy white back and belly, maybe tinged with a hint of yellow.
 
Other tidbits: Can grow up to 11cm or so. Range extends from the Red Sea through the Indo-Pacific region to Japan and eastern Australia, extending into Oceania. This extraordinary fish sets up shop as a personal spa for other species, offering a VIP treatment to rid them of pesky parasites. It even dares to tidy up inside larger fish's mouths and gills!
 
Bare bones must know: Live-rock fish-only system, fish-only system, or reef aquarium. Mature and well established aquarium. Expert aquarists only.