Alex Mustard / Giant hogfish (Bodianus macrognathos) male yawning at a cleaning station run by juvenile Spanish hogfish (Bodianus rufus). Jardines de la Reina, Gardens of the Queen National Park, Cuba. Caribbean Sea...

Franco Banfi / Cuckoo wrasse (Labrus mixtus) male in front of Red sea fan, (Paramuricea clavata), Stupiste In dive site, Vis Island, Croatia, Adriatic Sea, Mediterranean

Tony Wu / Humphead parrotfish (Bolbometopon muricatum) shoal spawning in early morning, part of mass aggregation of thousands of fish. Caroline Islands, Palau.

SCOTLAND: The Big Picture / Cuckoo wrasse (Labrus bergylta) and Ballan wrasse (Labrus bergylta) on the wreck of Jayne, Shetland

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

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

Jurgen Freund / Shoal of Sergeant majors (Abudefduf saxatilis) with various Wrasses (Labridae) feeding on the Sergeant major fish eggs, Raja Ampat, Indonesia.

Tony Wu / Asian sheepshead wrasse (Semicossyphus reticulatus), male in white breeding colouration. Niigata Prefecture, Honshu, Japan. June.

David Fleetham / Cleaner wrasse (Labroides dimidiatus) eating parasites off Coral grouper (Cephalopholis miniata) with Shrimp (Lysmata amboinensis) Mabul Island, Malaysia.

Alex Mustard / Napoleon wrasse (Cheilinus undulatus) super male, patrolling coral, Ras Mohammed Marine Park, Sinai, Egypt. Red Sea

Alex Mustard / Group of predators hunting together, in an example of 'Nuclear foraging'. The Moray eel (Gymnothorax javanicus) flushes out prey, and is followed by a Napolean wrasse (Cheilinus undulatus) and a Bluef...

Alex Mustard / Harlequin sweetlips (Plectorhinchus chaetodonoides) cleaned by a pair of bluestreak cleaner wrasse (Labroides dimidiatus). South Atoll, Tubbataha Atolls, Tubbataha Reefs Natural Park, Palawan, Philipp...

Alex Mustard / Portrait of Bandcheek wrasse (Oxycheilinus digrammus) taken during the day. Anemone City, Ras Mohammed Marine Park, Gulf of Aqaba, Red Sea. Sinai, Egypt.

Alex Mustard / A portrait of a male Ballan wrasse (Labrus bergylta), showing his bright mating colours. Plymouth, Devon, England, Great Britain. Wreck of the Glen Strathallan, Plymouth Sound, English Channel. Highly...

Brandon Cole / Giant Barrel Sponge (Xestospongia muta) on top of reef is a fish cleaning station. Small yellow fish in background (juvenile Bluehead Wrasses, Thalassoma bifasciatum) swarm about, remove parasites and...

Jurgen Freund / Manta rays (Manta birostris) at cleaning station being cleaned by wrasses, Moluccas Islands, Indonesia.

Jurgen Freund / Sergeant major damselfish (Abudefduf vaigiensis), Parrotfish and Wrasses in the house reef of Miniloc Island Resort, El Nido, Palawan, Philippines. These fish come together densely when bread is throw...

Nick Upton / Rock cook / Small mouthed wrasse (Centrolabrus exoletus) caught in a rock pool on a low tide, being taken out of a fishing net. Cornwall, UK.

Georgette Douwma / Elongate surgeonfish (Acanthurus mata) at a cleaning station with Bluestreak cleaner wrasses and sweepers in the background. Andaman Sea, Thailand

Gary Bell/ Oceanwide / Whitemouth Moray (Gymnothorax meleagris) being cleaned by Cleaner Wrasse (Labroides sp) juvenile, Christmas Island, Australia

Shane Gross / Cunner (Tautogolabrus adspersus) pair in Eelgrass (Zostera marina) bed. Newfoundland, Canada. September.

Shane Gross / Cunner (Tautogolabrus adspersus) fish in Eelgrass (Zostera marina) bed. Newfoundland, Canada.

Shane Gross / Atlantic cod (Gadus morhua) juveniles sheltering in Eelgrass (Zostera marina) bed alongside Cunner (Tautogolabrus adspersus) fish. Once the most caught fish in the world, the cod fishery collapsed in...

Shane Gross / Mediterranean rainbow wrasse (Coris julis) sheltering in Neptune seagrass (Posidonia oceanica) bed. Spain. June.

Claudio Contreras / Bluehead wrasse (Thalassoma bifasciatum) juvenile, Banco Chinchorro Biosphere Reserve, Caribbean region, Mexico, May

Claudio Contreras / Creole Wrasse (Clepticus parrae) male and female, Xkalac Reefs National Park, Caribbean region, Mexico, May

Claudio Contreras / Hogfish (Lachnolaimus maximus), Banco Chinchorro Biosphere Reserve, Caribbean region, Mexico, Vulnerable.

Claudio Contreras / Bluehead Wrasse (Thalassoma bifasciatum) juvenile cleaning Smooth Trunkfish (Lactophrys triqueter), Banco Chinchorro Biosphere Reserve, Caribbean region, Mexico, May

Alex Mustard / Portrait of a large male (sex determined by size) Ballan wrasse (Labrus bergylta) against green water. Farne Islands, Northumberland, England, United Kingdom. North Sea

Alex Mustard / Long exposure of a male Corkwing wrasse (Symphodus melops) by its nest. Swanage, Dorset, England, United Kingdom. English Channel. North East Atlantic

Alex Mustard / Corkwing wrasse (Symphodus melops) female carrying two large cymothoid isopod parasites (a large female and smaller male).. Swanage, Dorset, England, United Kingdom. English Channel. North East Atlant...

Alex Mustard / Pair of Broomtail wrasse (Cheilinus lunulatus) race upwards from the reef to spawn. Marsa El Shouna, Marsa Alam, Egypt. Red Sea.

Alex Mustard / Pair of a broomtail wrasse (Cheilinus lunulatus) spawning, the larger male is behind and smaller female is releasing her eggs. Marsa El Shouna, Marsa Alam, Egypt. Red Sea.

Sirachai Arunrugstitchai / Healthy Staghorn corals (Acropora sp.) with various reef fishes, including Moon wrasses (Thalassoma lunare), and Threespot dascyllus (Dascyllus trimaculatus) and a large school of Bigeye snappers (Lut...

Shane Gross / Pearly razorfish (Xyrichtys novacula) male at night. The Bahamas.

Jurgen Freund / Fish including Humphead wrasse (Cheilinus undulatus) feeding, tourists watching from Reef Magic pontoon. Great Barrier Reef, Queensland, Australia. 2019.

Jurgen Freund / Humphead wrasse (Cheilinus undulatus) feeding alongside other fish, tourists watching and taking photographs from Reef Magic pontoon. Great Barrier Reef, Queensland, Australia. 2019.

Pascal Kobeh / Green turtle (Chelonia mydas) feeding on the reef with a tarry or saddleback hogfish or blackspot wrasse (Bodianus bilunulatus) Kwazulu-Natal, South Africa.

Brandon Cole / Napoleon wrasse (Cheilinus undulatus). French Polynesia, Pacific Ocean.

Brandon Cole / Klunzinger's wrasse (Thalassoma rueppellii) swimming over Cabbage coral (Turbinaria cf. Reniformis). Egypt, Red Sea.

Brandon Cole / Mexican hogfish (Bodianus diplotaenia) swims overtop large sea star (Linckia sp.) along reef wall covered with barnacles, sponges and cup corals (Tubastraea coccinea). Baja, Mexico, Pacific Ocean.

Brandon Cole / Bignose unicornfish (Naso vlamingii) cleaned by Bluestreak cleaner wrasse (Labroides dimidiatus) at cleaning station next to coral head. Palau, Pacific Ocean.

Brandon Cole / Napoleon wrasse (Cheilinus undulatus), . Palau, Pacific Ocean.

Brandon Cole / Napoleon wrasse (Cheilinus undulatus). Palau, Pacific Ocean.

Brandon Cole / Napoleon wrasse (Cheilinus undulatus), and scuba diver, Palau, Pacific Ocean. Model released.

Brandon Cole / Napoleon wrasse (Cheilinus undulatus). . Palau, Pacific Ocean.

Brandon Cole / Napoleon Wrasse (Cheilinus undulatus), and scuba diver Palau, Pacific Ocean. Model released

Sergio Hanquet / Pearly razorfish (Xyrichthys novacula) Tenerife, Canary Islands.