• Purple Dive

What are underwater cleaning stations?

Updated: Oct 24, 2019




One of the most fascinating and entertaining activities that happens on the reef is at the cleaning station. Dive guides often make all sorts of funny signs to attract divers’ attention to the interactions happening there. These are locations where fish and other marine animals congregate daily to get parasites, dead skin, mucus and bacteria cleaned off their skin. The cleaners keep the reef and its inhabitants clean and healthy.


When fish pop to bed at night, snuggled up in their crevices and cracks, parasites come out and sneakily attach to their skin. These parasites are called ectoparasites and are cousins of our better-known fleas, lice and tics. These parasites latch on near the gills and fins. Lice combs not being an option, fish get rid of their parasites at the cleaning station. Smaller fish and other animals volunteer to pick off the parasites from the fish’s skin thus gaining a free meal and a certain level of immunity from bigger predators. They sometimes get a bite of flesh or mucus to boot.

The cleaning stations are often located at the top of a mound or large coral head or in a slot between two outcroppings.


One of the most famous and most loved cleaning stations near Bali, Indonesia is Nusa Penida’s Manta Point, where manta rays come every morning to get their parasites cleaned for the great pleasure of divers and snorkelers alike. It is one of the best sites in Indonesia for manta ray diving.

What is interesting about manta cleaning stations is that different species split the cleaning duties. Butterfly fish specialise in cleaning wounds the mantas may have, whereas the cleaner wrasse will clean inside the mouth and around and in the gills, the moon wrasse will take on picking off calagid copepods (sea lice) from the manta’s belly.


Many fish are willing to take on the job of cleaners, but some marine species have become famous for it.


The cleaner wrasse (labroides sp.)

The cleaner wrasse or blue streak cleaner wrasse is undoubtedly the most renowned of all the cleaners. It is found in the Indian and Pacific Ocean as well as in the red sea and south east Asia. It has an easily recognisable smallish (5.5 cm) body marked horizontally by a long distinctive black band from the tip of the head to the tail. The head is yellowish or light blueish whilst the rest of the Body is bright blue often with a white belly. This little fish survives solely on the free meals gleaned from its clients’ skin and invites larger fish and other marine species to get cleaned by performing a little dance.


The cleaner shrimp (lysmata amboinensis)

The second best known of the cleaner species and whose fame has reached a larger public with the film ‘Finding Nemo’ -remember the French barber shrimp in the aquarium- is the cleaner shrimp. This shrimp waves its antennae about to offer its excellent services as a teeth/mouth cleaner. Morays particularly seem to enjoy getting their mouth cleaned by these little red and orange shrimp marked with a distinctive white band down their body. Divers sometimes get a chance to use their services by taking out their regulator and letting the little shrimp go in for an inspection. These improvised dentists survive on bacteria, parasites and dead skin cells.


Butterfly fish (Chaetodontidae) and Angel fish (Pomacantidae)

These brightly coloured reef fish are less known as cleaners but often supplement their diet when juvenile by ‘working ‘at cleaning stations. Certain species carry on cleaning even into their adult life.




Surgeon fish (Acanthuridae)

Unexpectedly surgeon fish occasionally take on the role of cleaners, attending to other fish and even sea turtles removing algae from their shells.


Neon Goby (Elacatinus)

This little fish resembles the cleaner wrasse in its colouring and black band pattern. It also cleans ectoparasites, mucus and dead skin off passing larger fish and predators. It is mostly found in the Gulf of Mexico and Belize whereas the other species as more widespread around tropical waters Worldwide.


Albatrosses, sea gulls and other seabirds

Anecdotal evidence suggests that there is a relationship between the Albatros and the ocean sunfish (Mola mola). These bizarre deep-sea fish have certainly been witnessed popping up to the surface to have birds land on them and pick off their more tenacious parasites when fish cleaners simply don’t cut it anymore. In Nusa Penida, they come up to shallower waters with the cold currents to benefit from a thorough clean. They need it too; they can carry up to 40 different types of parasites. Their misfortune in that department brings them to shallow cleaning station depths where lucky divers can observe them on their spa day all along the coasts of Nusa Penida, Bali.


A few other species deserve a mention in our cleaner article though they do not tend to their counterparts, they still have a active role in keeping the reef clean and healthy. These are the ‘environmental cleaners and their job is all but negligible.


The sponge

Sponges filter the sea water, removing impurities and toxic elements. Certain species can filter up to 20 000 litres of water per kilo of tissue per day. They remove 95 percent of the bacteria and particles from the water and 90 of the dissolved organic carbon thereby converting suspended particles and dissolved matter into food for other animals. Certain tropical species contain photosynthesising organisms like coral and thus also produce three times the oxygen they consume..


The sea cucumber

These unremarkable reef inhabitants actually play an important role in cleaning the sand and sediments on the ocean floor. Indeed, they feed on the nutrients contained within the substrate by filtering the organic matter with its digestive tract. They can filter up to 45 kg a year and reportedly represent 90 percent of the deep ocean macro- fauna so they undoubtedly play an significant part in the sea bed purification.


The parrot fish

Parrot fish are grazers and spend about 90 percent of their time scrapping algae off of the reef. They have an essential role in reef ecology, keeping the algae in check and expelling coral sand which keeps beaches healthy. In places where parrot fish are over-fished, harmful algae can quickly take over leading directly to the decline in reef health.


cleaner species www.uw360.asiaspecies-that-clean

Many other species participate in reef health in various ways, it is the beauty of a well-designed system, a reef ecosystem designed by nature. If you have stories of other fish or marine species that are outstanding members of their community send us a message to our Facebook page Purple Dive Penida and we’ll publish them!

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