Barberfish – The Best Supporting Actor of Cocos Island

Photo courtesy from Ryan Photographic

Barberfish (Johnrandallia nigrirostris)

Common Name: Blacknosed Butterflyfish
Max. Length: 20 centimeters
Length at 1st Maturity: 12.9 centimeters
a value: 0.02100
b value: 3.215
Depth Range: 6 – 40 meters (20 – 132 feet)
Frequency: Common, usually found in coral reefs around the Eastern Pacific Ocean

If we consider Hammerheads and other species of sharks as the main actor when you go diving in Cocos Island, then it cannot be argued that the Barberfish are the supporting actors . . . even without a script.

We have mentioned barberfish several times in our previous articles as the fish primarily responsible for cleaning Hammerhead Sharks and other big pelagic species in established cleaning stations around Cocos Island, so we might as well talk about them. After all, if not for barberfish, then Hammerhead sharks might go somewhere else where other fish can take care of them.

Photo courtesy from

During your underwater adventures in Cocos Island, we are sure you will be having a hard time catching up all the names of the fish you see where you can easily find a hundred variety in just one setting. But allows us to share with you some easy and quick identifying marks of a barberfish. They have a small compressed body with a distinct silver yellow color and a single black band at the base of the dorsal fin. Aside from this, it has a small mouth that can be extended forward. May we warn you though that barberfish has a striking resemblance with the Southern Scythe Butterflyfish (Prognathodes carlhubbsi) and the Scythemarked Butterflyfish (Prognathodes falcifer)

How do Barberfish clean Hammerhead sharks?

First, positioning before sunrise is very important where you can see barberfish positioned near a reef ledge where they can easily be spotted from the deep and that hammerhead sharks have an easy access to them. Second is grouping where barberfish aggregates in several small groups establishing multiple cleaning station in just a single reef. Just imagine an entire street block lined-up with several car wash stations.

Photo courtesy from Matthew Meier – PhotoShelter

Once a hammerhead shark maneuvers and comes in to a motionless state, barberfish can now perform their job bringing with them their huge appetite for bacteria, parasites and dead skin from the shark. If not for their brush-like teeth, then cleaning a single shark would take hours to finish where in reality only takes 5 – 10 minutes. After the cleaning process is done, the shark leaves and the barberfish takes position again for its next client. A full day of cleaning sharks completely satisfies the appetite of a barberfish where they are ready to take refuge at cracks and crevices during night.


Well, there might be other contenders for the Best Supporting Actor Award as there are other cleanerfish doing their jobs in a car wash station like the cleaner wrasse (Labroides dimidiatus) and some species of angelfish. But so far, popularity and fame of the barberfish surpasses the competition where it might hold the title for a lifetime.

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Video courtesy from Taeyoung Lee

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