David Fleetham / Hawaiian cleaner wrasse (Labroides phthirophagus) feeding on parasites on Crocodile needlefish (Tylosurus crocodilus) with coral reef below. Hawaii.

David Fleetham / Hawaiian cleaner wrasse (Labroides phthirophagus) cleaning Redlip parrotfish (Scarus rubroviolaceus) in coral reef. Kauai, Hawaii.

David Fleetham / Great barracuda (Sphyraena barracuda) with two endemic Hawaiian cleaner wrasse (Labroides phthirophagus) cleaning it. Hawaii.

David Fleetham / Eyestripe surgeonfish (Acanthurus dussumieri) laying on side with mouth open, a signal to attract Hawaiian cleaner wrasse (Labroides phthirophagus) Hawaii.

David Fleetham / Yellowfin goatfish (Mulloidichthys vanicolensis) with an endemic Hawaiian cleaner wrasse (Labroides phthirophagus) cleaning its mouth, Hawaii.

Alex Mustard / Crescent-tail bigeye (Priacanthus hamrur) portrait against blue water. Note there is cleaner wrasse in attendance (below mouth), Gubal Island, Egypt. Red Sea.

David Fleetham / Yellowfin goatfish (Mulloidichthys vanicolensis) and an endemic Hawaiian cleaner wrasse (Labroides phthirophagus) taking a close look in its mouth, Hawaii.

David Fleetham / Hawaiian cleaner wrasse (Labroides phthirophagus), an endemic to Hawaii, inspecting Orangespine unicornfish (Naso lituratus) for parasites, Hawaii.

David Fleetham / Hawaiian cleaner wrasse (Labroides phthirophagus), endemic, inspecting Long-jawed squirrelfish (Sargocentron spiniferum), Hawaii.

Doug Perrine / Indo-Pacific sergeant major fish (Abudefduf vaigiensis) being cleaned by Hawaiian cleaner wrasse (Labroides phthirophagus) in coral reef, Old Airport, Kailua-Kona, Hawaii, USA, Pacific Ocean.

David Fleetham / Ringtail surgeonfish (Acanthurus blochii) being examined by Hawaiian cleaner wrasse (Labroides phthirophagus), Hawaii, USA, Pacific Ocean.

David Fleetham / Orangeband surgeonfish (Acanthurus olivaceus) visiting cleaning station of Hawaiian cleaner wrasse (Labroides phthirophagus).They change colour to expose parasites, some turning black and others turni...