Alex Mustard / Reef manta (Mobula alfredi) female swimming close to a coral reef, while cleaner wrasse (Labroides dimidiatus), tiny by comparison, pick parasites from her lips. Misool, Raja Ampat, West Papua, Indone...

Shane Gross / Pelagic thresher shark (Alopias pelagicus) cleaned by Bluestreak cleaner wrasse (Labroides dimidiatus) at Monad Shoal off Malapascua Island, Philippines.

Gary Bell/ Oceanwide / Blue-streaked Cleaner Wrasse (Labroides dimidiatus) cleaning gills of Semicircle Angelfish (Pomacanthus semicirculatus), Great Barrier Reef, Australia

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.

Alex Mustard / Bluestreak cleaner wrasse (Labroides dimidiatus) attends to a Clark's anemonefish (Amphiprion clarkii) at a cleaning station on a coral reef. It is unusual to see an anemonefish at a cleaning stat...

Alex Mustard / Reef manta (Mobula alfredi) at a cleaning station with Cleaner wrasse (Labroides dimidiatus). South Ari Atoll, Maldives. Indian Ocean.

Richard Robinson / Orbicular damselfish (Amblyglyphidodon orbicularis) cleaned by the Striped Cleaner Wrasse (Labroides dimidiatus) at Yagasa Lagoon, Lau Island Group, Fiji.

Richard Robinson / Egghead Parrotfish (Scarus oviceps) cleaned by a Striped Cleaner Wrasse (Labroides dimidiatus) Vatoa Island / Turtle Island by Captain Cook, Lau Island Group, Fiji.

Georgette Douwma / Orbicular burrfish or Shortspine porcupinefish (Cyclichthys orbicularis) with a Bluestreak cleaner wrasse ( Labroides dimidiatus) Ambon, Indonesia.

Bert Willaert / Midnight snapper (Macolor macularis) being cleaned by Bluestreak cleaner wrasse (Labroides dimidiatus), Kimbe Bay, West New Britain, Papua New Guinea