Barberfish

Approaching barberfish requires a masterclass in static buoyancy and patient positioning, especially when they are servicing skittish pelagic clients like hammerhead sharks or manta rays. Settle downcurrent and slightly below the cleaning station on an exposed rock ledge, taking care never to damage marine growth or obstruct the incoming swim lanes of approaching megafauna. Rapid movements, loud bubble bursts, or aggressive finning will cause large hosts to veer away and send the cleaner school retreating into the reef. For underwater photographers, a wide-angle or fisheye lens is recommended to capture the dramatic contrast between the brilliant yellow barberfish cluster and the dark, imposing profile of a host shark. Use gentle fill-flash or dual strobes angled outwards to illuminate the silver-and-yellow scales without blowing out reflective shark skin or backscattering suspended oceanic particles.

Encountering the barberfish is possible year-round throughout its Eastern Pacific range, but peak liveaboard seasons offer the most dramatic cleaning station action. In the Galapagos Islands, the dry, cool season from June to November brings rich nutrient upwellings and massive schools of scalloped hammerheads to northern outposts like Darwin and Wolf, triggering non-stop cleaning displays. For Cocos Island, diving is spectacular throughout the calendar, yet the calmer seas from December to May provide superb visibility to observe mid-water cleaning aggregations. If heading to Socorro and the wider Revillagigedo Archipelago, the prime liveaboard window spans November to May, when pelagic life is at its densest and the resident barberfish are in high demand servicing giant manta rays and visiting pelagic sharks.

The barberfish is native exclusively to the tropical and warm-temperate waters of the Eastern Pacific Ocean, occurring from the Gulf of California (Sea of Cortez) and the southern coast of Baja California southwards to Panama, the Galapagos Islands of Ecuador, and Malpelo Island in Colombia. It also thrives across oceanic outposts including Cocos Island and the Revillagigedo Archipelago (Socorro). This species primarily inhabits rugged, current-swept rocky reefs, volcanic boulder slopes, offshore pinnacles, and drop-offs. While occasionally sighted in shallow bays around 3 metres, it is most prolific at depths between 6 and 40 metres, often hovering in the mid-water columns above vertical walls where upwelling currents attract pelagic megafauna to cleaning stations.

The barberfish is an opportunistic carnivore and specialised cleaner whose diet consists predominantly of ectoparasitic crustaceans, including copepods, isopods, and sea lice picked directly from the dermis, gills, and mouths of host fishes. In addition to servicing pelagic visitors and resident reef fish, *Johnrandallia nigrorostris* feeds actively on small benthic invertebrates such as hydroids, bryozoans, small polychaete worms, and exposed mollusc tissues. During periods between large cleaning events, individuals browse over rocky surfaces and algae-covered boulders, using their precise, plier-like jaws to snatch tiny organisms sheltering in rock crevices. Feeding occurs exclusively during daylight hours, with cleaning activity peaking during mid-morning and early afternoon when ambient light is strongest and pelagic megafauna frequent shallow cleaning stations along outer reef ridges.