Cleaning on the reef

cleaner fish on the reef malapascua

Some of the ocean’s most spectacular sightings revolve around the rather mundane activity of ‘cleaning’.  Incredible creatures such as sharks and rays visit cleaning stations around the world to allow smaller creatures to nibble at, or ‘clean’, their bodies.

Thresher sharks roam all around the world but live so deep that sightings are infrequent and rare.  However, here in Malapascua, the shallow cleaning stations of Monad Shoal bring sharks up to recreational diving deths for their daily sunrise clean.

philippines reef fish cleaning stations

Many fish on the reef fulfil the role of a cleaner. The best known is probably the tiny electric blue cleaner wrasse, which can be seen cleaning anything from thresher sharks to puffer fish, and even bare skin exposed on a diver.  The job of cleaner is also not exclusive to fish; many tiny species of shrimp can be found cleaning other creatures as well.

Since there is an obvious benefit to all involved, usual predator/prey rules are often suspended in return for this favour.  Cleaner fish on the reef can attract clientele by dancing or waving their antennae, and those coming in for servicing might change position to hang upside down in the water or even change colour.  It is thought that these behaviours demonstrate a non-threatening intent, although other theories suggest that changing colours allows cleaners to better identify parasites and dead skin on the body.

reef fish cleaning stationsphilippines fish cleaning stations


While most aquatic life respects the non-predatory rules of the cleaning relationship, the Sabretooth Blenny has evolved to take advantage of this truce.  Similar in appearance to the cleaner wrasse, this sneaky fish will mimic the cleaning dance to attract a customer, and once they’re close enough they’ll bite off a chunk of flesh to dart away with!

So next time you’re on a dive, stop and pay attention to unusual fish behaviour.  It’s fascinating to watch and you never know what might come along for a spa session!

Thanks to Klaus Stiefel for the beautiful photographs!

fish cleaning stations

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