Gary Bell/ Oceanwide / Scarlet Cleaner Shrimp (Lysmata amboinensis) cleaning mouth of Tomato Grouper (Cephalopholis sonnerati), Great Barrier Reef, Australia

Gary Bell/ Oceanwide / Scarlet Cleaner Shrimp (Lysmata amboinensis) cleaning mouth of Tomato Grouper (Cephalopholis sonnerati), Great Barrier Reef, Australia

David Fleetham / Cleaner wrasse (Labroides dimidiatus) swimming alongside Golden damsel (Amblyglyphidodon aureus) looking for parasites, Fiji, Pacific Ocean.

Alex Mustard / Colourful reef scene with Coral grouper (Cephalopholis miniata), map puffer (Arothron mappa) and Panda butterflyfish (Chaetodon adiergastos). Tank Reef, Fiabacet Islands, Misool, Raja Ampat, Indonesia...

Jeff Rotman / Jewel Grouper / Coral hind (Cephalopholis Miniata) with mouth open, Red Sea, Egypt

Fred Bavendam / Scarlet Cleaner Shrimp (Lysmata amboinensis) working on a Tomato Grouper (Cephalopholis sonnerati), Milne Bay, Papua New Guinea

Pascal Kobeh / Graysby seabass (Cephalopholis cruentata) on the reef, Yucatan peninsula, Mexico, Caribbean.

Gary Bell/ Oceanwide / Blue-streaked Cleaner Wrasse (Labroides dimidiatus) cleaning mouth and gills of Tomato Grouper (Cephalopholis sonnerati), Great Barrier Reef, Australia

Alex Mustard / Coral grouper (Cephalopholis miniata) waits in ambush, hiding against a seafan (Annella sp.) hunting silversides (Atherinidae), with schooling bigeye snapper (Lutjanus lutjanus) behind. Misool, Raja A...

Alex Mustard / Large reef scene on the current exposed face of a coral reef, with seafans (Melithaea sp.), soft corals (Dendronephthya spp.), sponges, coral grouper (Cephalopholis miniata), anthias, damselfish and m...

Alex Mustard / Schools of baitfish including Cardinalfish (Apogon spp) and Silversides (Atherinidae) mass on a coral reef, with Giant barrel sponge (Xestospongia sp.) and predatory coral grouper (Cephalopholis minia...