Marie Read / Abstract patterns of reflected sky and clouds on the ocean with a silhouetted Red-faced cormorant (Phalarocorax urile) in flight, St. Paul Island, Pribilof Islands, Alaska, USA, July.

Jurgen Freund / Timelapse of a Scolymia coral (Mussidae) feeding, lit with a UV light, Cairns, North Queensland, Australia.

Bernard Castelein / Waterviolet / featherfoil (Hottonia palustris) at sunset, Groot Schietveld, Wuustwezel, Belgium

Sue Daly,Sue Daly / Blue Maomao (Scorpis violaceus) shoal, Poor Knights Islands, New Zealand, February

Sven Zacek / Common Dog Violet (Viola riviniana) with dew. Estonia, Europe, May.

Rolf Nussbaumer / Violet-tailed Sylph (Aglaiocercus coelestis), male feeding on ginger flower in rain, Mindo, Ecuador, Andes, South America, January

Bernard Castelein / Featherfoil (Hottonia palustris). Peerdsbos, Brasschaat, Belgium. May.

Bernard Castelein / Featherfoil (Hottonia palustris). Peerdsbos, Brasschaat, Belgium. May.

Bernard Castelein / Featherfoil (Hottonia palustris). Peerdsbos, Brasschaat, Belgium. May.

Bernard Castelein / Featherfoil (Hottonia palustris). Peerdsbos, Brasschaat, Belgium. May.

Simon Littlejohn / Violet dropwing dragonfly (Trithemis annulata) taking off and landing on a stick, Sierra de Andujar Natural Park, Andalusia, Spain, August.

Doug Perrine / Cauliflower coral (Pocillopora meandrina) colony bleached during a marine heat wave, coral fluorescing violet believed to be a protective response to reduce cell damage from sunlight. Surrounding reef...

Doug Perrine / Antler coral (Pocillopora grandis), partially bleached. Healthy coral is brown due to presence of symbiotic zooxanthellae. Damaged coral is bleached white due to loss of the symbiotic algae, fluoresci...

Magnus Lundgren / Violet blanket octopus (Tremoctopus violaceus) juvenile. Balayan Bay, Luzon Island, Philippines, May. Minimum fees apply.

Magnus Lundgren / Violet blanket octopus (Tremoctopus violaceus) juvenile, Balayan Bay, Luzon Island, Philippines Minimum fees apply.

Magnus Lundgren / Violet blanket octopus (Tremoctopus violaceus) juvenile, Balayan Bay, Luzon Island, Philippines Minimum fees apply.

Magnus Lundgren / Violet blanket octopus (Tremoctopus violaceus) Balayan Bay, Luzon Island, Philippines Minimum fees apply.

Will Watson / Water Violets (Hottonia palustris), natural woodland pond, Shatsky National Natural Park, Volyn Oblast, Ukraine, May.

Will Watson / Scavenger water beetle (Hydrophilius aterrimus)m among Water Violet (Hottonia palustris), Shatsky National Natural Park, Ukraine, controlled conditons, May.

Will Watson / Water Violets (Hottonia palustris), natural woodland pond, Shatsky National Natural Park, Volyn Oblast, Ukraine, May.

Bernard Castelein / Water violet (Hottonia palustris) flowering in ditch through woodland. Groot schietveld, Wuustwezel, Belgium. May 2015.

Alex Mustard / Bluestreak cleaner wrasse (Labroides dimidiatus) cleans among the sharp teeth of a predatory roving coral grouper (Plectropomus pessuliferus) beneath an overhang on a coral reef. Ras Mohammed National...

Shane Gross / Marine biologist Dr. Heather Masonjones tags a seahorse (Hippocampus erectus) to study a land locked alakaline lagoon's population. Through this method of injecting a non-toxic dye that can only b...

Shane Gross / Marine biologist Dr. Heather Masonjones tags a seahorse (Hippocampus erectus) to study a land locked alakaline lagoon's population. Through this method of injecting a non-toxic dye, that can only...

Jurgen Freund / Timelapse of a Scolymia coral (Mussidae) feeding, lit with a UV light, Cairns, North Queensland, Australia.

Bernard Castelein / Waterviolet / featherfoil (Hottonia palustris), Groot Schietveld, Wuustwezel, Belgium

Tony Wu / Violet snail (Janthina janthina) washeld up on shore, South Africa. Atlantic ocean.

Ashley Cooper / Thermometer taking the air temperature as part of a study to measure the speed of the Russell Glacier near Kangerlussuaq, Greenland.

Alex Mustard / RF - Roving coralgrouper (Plectropomus pessuliferus) is cleaned by Bluestreak cleaner wrasse (Labroides dimidiatus). Ras Mohammed Marine Park; Sinai, Egypt. Red Sea (This image may be licensed either...

Floris van Breugel / Carbonate minerals in ancient volcano north of Lake Mono, seen here at night under ultraviolet illumination. Mono Lake, California, USA. June 2017.

Paul Harcourt Davies / Eugenia's pansy (Viola eugeniae) an Apennine endemic photographed on the Campo Imperatore, Abruzzo, Italy, April.

Solvin Zankl / Fluorescent coral photographed with ultraviolet / UV light, Bonaire, Leeward Antilles, Caribbean region, Netherlands Antilles

MYN / Dirk Funhoff / Water violet (Hottonia palustris) flowers, Büchelberg, Pfalz, Germany. May. Meetyourneighbours.net project

Gabriel Rojo / Eared dove (Zenaida auriculata) by water, Calden forest, La Pampa, Argentina

Alex Mustard / Coral demoiselle (Neopomacentrus violascens) shoal throng around a colourful seafan (Melithaea sp.) on a coral reef. Two Tree Rock, Balbulol, Misool, Raja Ampat, West Papua, Indonesia. Ceram Sea.

Pal Hermansen / Flowers including wild Violas (Viola sp) on the coast of Stott Melloy, Nordland, Norway, July 2015.

Bernard Castelein / Green-veined white (Pieris napi) on Water violet (Hottonia palustris), Groot Schietveld, Wuustwezel, Belgium, May.

Willem Kolvoort / Water violet (Hottonia palustris) and Yellow waterlily (Nuphar lutea) in a bog lake, De Weerribben-Wieden National Park, Holland. June.

Willem Kolvoort / Water violet (Hottonia palustris) De Weerribben-Wieden National Park National Park, Holland. June.

Willem Kolvoort / Water violet (Hottonia palustris) in drainage ditch, Holland. May.

Willem Kolvoort / Water violet (Hottonia palustris) in drainage ditch, Holland. May.

Willem Kolvoort / Water violet (Hottonia palustris) in drainage ditch, central Holland. May.

Willem Kolvoort / Water violet (Hottonia palustris) in drainage ditch, central Holland. May.

Willem Kolvoort / Water violet (Hottonia palustris) in drainage ditch, central Holland. May.

Angelo Gandolfi / Violet-capped woodnymph (Thalurania glaucopis), male, Parana State, Iguazu, Brazil, September.

Solvin Zankl / Blue maomao (Scorpis violacea) shoal close to the shore, Poor Knights Islands, Marine Reserve, New Zealand, South Pacific Ocean, July.

Solvin Zankl / Blue maomao (Scorpis violacea) shoal, Poor Knights Islands, Marine Reserve, New Zealand, South Pacific Ocean, July.

MYN / Dimitris Poursanidis / Ventral view of Mediterranean Violet Aeolid (Flabellina affinis) Crete, Greece, November. Meetyourneighbours.net project