Definition of cleaner wrasse
: any of a genus (Labroides) of small tropical wrasses found typically on coral reefs of the Indian and Pacific oceans that clean larger fish (such as surgeonfish) of parasites and dead tissue
- It has been known that a small fish called the cleaner wrasse eats parasites off larger reef fish and that it sometimes sneaks a nibble of skin mucus.
- —T. A. Frail et al., Smithsonian, September 2011
- Customers respond by suspending their normal predatory instincts and hanging almost in a trance, mouths and gills open, while the cleaner wrasses work—often swimming inside the mouths of larger fishes to find the parasites.
- —John Vandenbeld, Nature of Australia, 1988
