Gavin Hellier / Anakena beach, monolithic giant stone Moai statues of Ahu Nau Nau, four of which have topknots, Isla de Pascua / Easter Island, Rapa Nui, Chile 2008

Sue Daly / Norwegian topknot (Phrynorhombus norvegicus), Trondheimsfjord, Norway, July.

Sue Daly / Topknot (Zeugopterus punctatus), swims out of the frame, Sark, British Channel Islands, UK, August.

Sue Daly / Norwegian topknot (Phrynorhombus norvegicus) St Abbs Voluntary Marine Reserve, Scotland (North Sea).

Gavin Hellier / Ahu Tongariki, the largest ahu on the Island, one of the Tongariki row of 15 giant Moai statues, only this one still has a topknot in place, Isla de Pascua / Easter Island, Rapa Nui, Chile, 2008

Sue Daly / Topknot (Zeugopterus punctatus) camouflaged against rock. Gouliot Caves, Sark, British Channel Islands, July.

Sue Daly / Topknot (Zeugopterus punctatus) a type of flatfish. Gouliot Caves, Sark, British Channel Islands, August.

Christophe Courteau / Topknot camouflaged on seabed {Zeugopterus punctatus} Brittany France

Sue Daly / Topknot (Zeugopterus punctatus) close up of face, Channel Islands, UK July

Sue Daly / Topknot (Zeugopterus punctatus) close up of face, Channel Islands, UK July

Alex Mustard / 2020VISION / Norwegian topknot (Phrynorhombus norvegicus) flatfish showing bright colours as it attempts to remain camouflaged on the rusting shipwreck of the MV Pionersk (a Russian fish factory ship). Ness of Tre...

Alex Mustard / 2020VISION / Topknot (Zeugopterus punctatus) flatfish camouflaged on seabed, Loch Fyne, Argyll, Scotland, UK, June

Alex Mustard / 2020VISION / Eye detail of Topknot (Zeugopterus punctatus) flatfish, Loch Fyne, Argyll, Scotland, UK, July

Alex Mustard / 2020VISION / Topknot (Zeugopterus punctatus) camouflaged, resting on bed of seaweeds, Babbacombe Bay, Devon, England, UK, April

Sue Daly / Topknot (Zeugopterus punctatus) camouflaged against habitat. Channel Islands, UK, June.

Jane Burton / Topknot {Zeugopterus punctatus} camouflaged on rocks covered in algae, showing left side with eyes on it, captive, from northern Europe

Jane Burton / Topknot {Zeugopterus punctatus} swimming, showing right side which is blind, captive, from northern Europe

Florian Graner / Topknot flatfish (Zeugopterus punctatus) camouflaged against seabed, Norway

Phil Chapman / Moai with stone topknot on the clifftop at Hangaroa, Easter Island, with setting sun

Steve Knell / Topknot pigeon {Lopholaimus antarcticus} Australia

Joel Sartore / Photo Ark / Common topknot (Zeugopterus punctatus) moving its fins, Aquazoo Loebbecke Museum, Dusseldorf. Captive.

Joel Sartore / Photo Ark / Close up of a Common topknot (Zeugopterus punctatus) head. The animal is looking at the camera. Aquazoo Loebbecke Museum, Dusseldorf. Captive.

Roland Seitre / Top-knot pigeon (Lopholaimus antarcticus) head portrait, Australia. Captive.

Roland Seitre / Top-knot pigeon (Lopholaimus antarcticus) portrait, Australia. Captive.

Roland Seitre / Top-knot pigeon (Lopholaimus antarcticus) portrait, Australia. Captive.

Roland Seitre / Top-knot pigeon (Lopholaimus antarcticus) head portrait, Adelaide, South Australia. Captive.

Roland Seitre / Topknot Pigeon (Lopholaimus antarcticus), native to Australia

Alex Mustard / Topknot (Zeugopterus punctatus) rests on the seabed, covered in tiny copepod parasites. Swanage, Dorset, England, United Kingdom. English Channel. North East Atlantic

Alex Mustard / Portrait of Topknot (Zeugopterus punctatus). Swanage, Dorset, England, United Kingdom. English Channel. North East Atlantic