Pascal Kobeh / Bluestreak cleaner wrasse (Labroides dimidiatus) cleaning Diagonal banded sweetlips (Plectorhinchus lineatus) New Caledonia. Pacific Ocean.

Pascal Kobeh / Bluestreak cleaner wrasse (Labroides dimidiatus) just swimming out of mouth of Oblique / Diagonal banded sweetlips (Plectorhinchus lineatus) whilst cleaning / feeding, New Caledonia. Pacific Ocean.

Pascal Kobeh / Bluestreak cleaner wrasse (Labroides dimidiatus) just swimming out of mouth of Oblique / Diagonal banded sweetlips (Plectorhinchus lineatus) whilst cleaning / feeding, New Caledonia. Pacific Ocean.

Sue Daly / Cuckoo wrasse (Labrus mixtus) female in process of changing sex to become male, Guillaumesse, Sark, British Channel Islands.

Sue Daly / Female Cuckoo wrasse (Labrus mixtus) with pair of parasites (Anilocra frontalis) L'Etac, Sark, British Channel Islands.

Sue Daly / Cuckoo wrasse (Labrus mixtus) male, Guillaumesse, Sark, British Channel Islands.

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

David Fleetham / Lined sweetlips (Plectorhinchus lineatus) with two cleaner wrasse (Labroides dimidiatus) inspecting its gills, Indonesia.

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