The Cleaner Fish of Bohol: A Guide to the Reef’s Unsung Heroes
You’re hovering peacefully over a coral garden in Bohol, watching the gentle rhythm of the reef. A large, formidable-looking grouper, a powerful predator, hangs motionless in the water. Its mouth is agape, its gills are flared, and it looks completely vulnerable. You might think it’s a threat display, but then you see it: a tiny, electric-blue fish, no bigger than your little finger, darts confidently in and out of the grouper’s mouth and gills, completely unharmed.
You’ve just stumbled upon one of the most fascinating and vital social interactions in the entire ocean: a coral reef cleaning station.
This is not a strange and fleeting truce; it’s a highly organized, essential service. These cleaning stations are the health clinics of the sea, run by a dedicated crew of tiny, hardworking fish and shrimp. At Sierra Madre Divers, we believe that learning to spot and understand these interactions is one of the most rewarding parts of diving. Let’s introduce you to the unsung heroes of Bohol’s reefs.
The Health Clinic of the Sea: What is a Cleaning Station?
A cleaning station is a specific location on the reef—a prominent coral head, a small cave, or a rocky outcrop—where marine animals come to be cleaned. This is a perfect example of a symbiotic relationship called “mutualism,” where both parties receive a significant benefit.
- The “Client”: Fish, turtles, and even rays will visit these stations to have ectoparasites, dead or infected skin, mucus, and leftover food particles removed from their bodies, gills, and even the inside of their mouths. This service is crucial for their health, reducing irritation and preventing disease.
- The “Cleaner”: For the smaller cleaner fish and shrimp, these parasites and dead tissues are a reliable and nutritious food source. They get a free meal, and in return, their clients stay healthy.
The etiquette of a cleaning station is a marvel of inter-species communication. A client fish will signal its desire to be cleaned by adopting a specific, often strange-looking, pose—hanging vertically, tilting its head up, or opening its mouth and gills wide. This is a sign of trust and an invitation for the cleaners to begin their work.
Meet Bohol’s Hardest Workers: The Cleaners
Our reefs are home to a dedicated crew of these underwater doctors. When you’re diving with us, keep an eye out for these key players.
The Doctor is In: The Bluestreak Cleaner Wrasse (Labroides dimidiatus)
This is the undisputed star of the cleaning world. The Bluestreak Cleaner Wrasse is the most famous and widespread cleaner on Indo-Pacific reefs. Its bold, electric-blue stripe on a black background is like a universal neon sign that reads, “Open for Business.” To attract clients, this energetic little fish performs a unique, hypnotic “dance” in the water column. Once a client has assumed the position, the wrasse will meticulously move over its entire body, using its specialized, tweezer-like mouth to pick off parasites with surgical precision. It’s an incredible sight to see these tiny doctors servicing clients a hundred times their size.
The Antennae-Waving Crew: Cleaner Shrimp
Not all cleaners are fish. Some of the most dedicated hygienists are crustaceans that operate from a fixed location.
- Scarlet Skunk Cleaner Shrimp (Lysmata amboinensis): You’ll often find these beautiful shrimp in pairs or small groups, living in a sea anemone or on a prominent coral head. They are easily identified by the striking red stripes on their body and the single white stripe running all the way down their back. To advertise their services, they will wave their long, white antennae enthusiastically to attract passing fish. A fish will then settle near the shrimp’s home, allowing the nimble crustaceans to climb aboard and begin their work.
- Banded Coral Shrimp (Stenopus hispidus): Also known as the Boxer Shrimp, this striking creature with its red and white banded body and long white antennae is another common cleaner. They are often found in pairs, peeking out from a crevice in the reef. They are a bit more shy than the Skunk Cleaner Shrimp but are equally important members of the reef’s sanitation team.
The Apprentices: Juvenile Fish Cleaners
One of the most fascinating facts about cleaning behaviour is that it’s not always a full-time job. Many species of fish, particularly some angelfish, sweetlips, and wrasses, will act as cleaners only when they are juveniles. Their distinct, often brightly coloured juvenile patterns act as a temporary uniform, signaling to other fish that they are offering cleaning services. As they grow into adults, they lose this colouration and graduate to their adult roles on the reef.
The Importance of a Good Scrub: Why Cleaners are Crucial
Cleaning stations are far more than a quirky novelty; they are cornerstones of a healthy reef ecosystem. Scientists have conducted experiments where they have removed all the cleaners from a patch of reef. The results were dramatic and swift: the number and diversity of fish on the reef plummeted. The remaining fish showed clear signs of disease, stress, and heavy parasite loads.
Cleaners are a “keystone species.” Their impact on the health and stability of the entire community is disproportionately large compared to their small size and number. They are the doctors and sanitation workers who prevent epidemics and keep the entire city of the reef thriving.
A Diver’s Guide to Observing Cleaning Stations
Witnessing this incredible behaviour is easy if you know how.
- Slow Down and Find a Spot: Cleaning stations are fixed locations. The key is to stop swimming from place to place and instead, find a prominent coral head and simply watch. Patience is your best tool.
- Give Them Space: This is the golden rule. If you get too close to a cleaning station, the often-large client fish will be spooked and swim away, ending the interaction. Find a comfortable, neutral spot a respectful distance away and observe from there.
- Look for the Signs: Watch for fish behaving strangely—hovering in odd positions, opening their mouths wide, or twitching. This is often the signal that a cleaning is in progress or about to begin.
- Ask Your Guide: The best and easiest way to witness this is to ask your Sierra Madre Divers guide. They have spent thousands of hours on our local reefs and know the location of the busiest “health clinics” on every dive site. They can position you for the perfect, non-intrusive view.
The next time you dive, take the time to look for these bustling hubs of activity. It’s a chance to see the intricate social fabric of the reef in action and appreciate the small, unsung heroes that make this entire vibrant world possible.
