Melanurus Wrasse

Snapshot: This fish flaunts a vibrant blue-green body adorned with striking horizontal pink or yellow stripes.
 
Other tidbits: Can grow up to 12cm or so. Native to the tropical waters of the Western Pacific Ocean from Australia and Fiji to Indonesia, Japan, Samoa and Tonga. These wrasses are expert pest exterminators.
 
Bare bones must know: Live-rock fish only, fish-only system or reef aquarium. Thick, sandy substrate.