Bluestreak cleaner wrasse
Bluestreak cleaner wrasse are active on coral reefs and provide a cleaning service to larger fish.
These busy little fish feed on the parasites and mucus covering their “clients”. The clients will even open their mouths and gill covers to allow the wrasse to clean.
Males are territorial and set up a cleaning station with several females. If the male dies or is removed, the dominant female will become a male within two to four days!
A small blenny, Aspidontus taeniatus, mimics the cleaner wrasse, but instead of cleaning, it tears pieces of flesh from surprised “clients”.