Linda Pitkin / 2020VISION / Pink sea fan / Warty coral (Eunicella verrucosa) with attached eggs of a Common squid (Loligo vulgaris), eggcase of a Lesser-spotted dogfish (Scyliorhinus canicula), and Spiny starfish (Marthasterias...

Philippe Clement / Barrel jellyfish (Rhizostoma octopus) washed up on beach along the North Sea coast, Nord-Pas-de-Calais, France, August

Alex Mustard / A Caribbean reef octopus (Octopus briareus) swimming through spawning Sea rods (Pseudoplexaura) at night, East End, Grand Cayman, Cayman Islands, British West Indies, Caribbean Sea.

Jeff Rotman / Common reef octopus (Octopus cyanea) with diver observing, Eilat, Israel, Red Sea. Model released. January 2011 Model released.

Jeff Rotman / Common reef octopus (Octopus cyanea) camouflaged on coral reef, Eilat, Israel, Red Sea

Solvin Zankl / The Tail-Light Squid Shell (Spirula spirula) has a chambered, delicate shell, with diameter of about 1 cm from Raja Ampat, Indonesia. Digital focus stacking image

Solvin Zankl / GEOMAR / Bobtail squid (Rossia glaucopis) from Trondheimfjord, North Atlantic Ocean, Norway. Photo taken in cooperation with GEOMAR coldwater coral research project

Alex Mustard / Common reef / day octopuses (Octopus cyanea) courting. The male, on the right, is rearing up and showing his mouth and tentacles, while still maintaining contact with the female. This is a rarely seen...

Alex Mustard / Common reef / day octopuses (Octopus cyanea) mating. The male, on the right, it passing his sperm to the female, on the left, by placing it under her mantle. His arm is visible on her body next to her...

Alex Mustard / Tropical blue ring octopus (Hapalochlaena lunulata) is small but has one of the most venomous creatures in the ocean, its bite injects a neurotoxin that paralyses its victim. It flashes its blue rings...

Alex Mustard / A blue ring octopus (Hapalochlaena lunulata) flashes its blue rings as it crawls over a coral reef. Kapalai Island, Sulu Sea, Sabah, Borneo, Malaysia..

Alex Mustard / Striped pyjama squid (Sepioloidea lineolata) hovers above the seabed. Gulf St Vincent Edithburgh, Yorke Peninsular, South Australia, Australia

Alex Mustard / Common Sydney octopus (Octopus tetricus) peers out from its den. Sydney Harbour, New South Wales, Australia.

Alex Mustard / Two spotted octopus (Octopus bimaculatus) moves across rocks. Revillagigedos Islands, Mexico.

Alex Mustard / A pair of mimic octopus (Thaumoctopus mimicus) mating. The male, behind, has grabbed the female and grasps her as he tries to place his sperm sac inside her mantle with his arm. Lembeh Strait, Molucca...

Alex Mustard / A pair of mimic octopus (Thaumoctopus mimicus) mating/courtship. The smaller male, right, is riding on top of the female as he tries to place his sperm sac inside her mantle with his arm. Lembeh Strai...

Alex Mustard / Pfeffer's flamboyant cuttlefish (Metasepia pfefferi) hovers just above the seabed. The largest individuals of this species, such as this one, are not as brightly coloured as the younger ones. Lembeh S...

Alex Mustard / A veined octopus (Amphioctopus marginatus) peers out from a discarded plastic bottle. Lacking a skeleton, octopuses can squeese their bodies into the smallest spaces and through the tiniest holes. Lem...

Alex Mustard / Tropical blue ringed octopus (Hapalochlaena lunulata) free swims just above the seabed. Lembeh Strait, Molucca Sea Sulawesi, Indonesia

Alex Mustard / A young veined octopus (coconut octopus: Amphioctopus marginatus) shelters in an empty bivalve shell by pulling the two halves together with its arms. Lembeh Strait, Molucca Sea, Sulawesi, Indonesia.

Alex Mustard / Pfeffer's flamboyant cuttlefish (Metasepia pfefferi) walks across the seabed using special flaps on the underside of its body, and its outermost arms as four legs. This species rarely swims. Lembeh St...

Alex Mustard / Pfeffers's flamboyant cuttlefish (Metasepia pfefferi) displays on the seabed. Lembeh Strait, Molucca Sea, North Sulawesi, Indonesia, South East Asia

Alex Mustard / A common reef octopus (Octopus cyanea) foraging attracts several large reef fish, hoping to get an easy meal. Octopuses may try to hit fish with their arms to scare them off. Cannibal Rock, Sawu Sea,...

Alex Mustard / A common cuttlefish (Sepia officinalis) above seagrass meadow (Posidonia oceanica). Xlendi Bay, Gozo Island, Malta, Mediterranean Sea.

Alex Mustard / A diver encounters a common cuttlefish (Sepia officinalis) above seaweeds, Xlendi Bay, Gozo Island, Malta, Mediterranean Sea. June 2012, Model released

Alex Mustard / A common cuttlefish (Sepia officinalis) below the surface in shallow water, Xlendi Bay, Gozo Island, Malta, Mediterranean Sea.

Alex Mustard / A common octopus (Octopus vulgaris) scavenges a dead fish, dragging it to its burrow. West Palm Beach, Florida, USA

Alex Mustard / An Atlantic long arm octopus (Octopus defilippi) swims across the seabed. This is a typical swimming posture for long arm octopus, but it has been suggested as mimicking a poisonous sole in the mimic...

Alex Mustard / A pair of mating Atlantic longarm octopus (Octopus defilippi), with the male, on the right, gripping the female, West Palm Beach, Florida, USA

Alex Mustard / A male common cuttlefish (Sepia officinalis) displays to another cuttlefish buried in the sand, while a diver photographs them, Gran Canaria, Canary Islands, Spain, May 2008, Model released

Alex Mustard / A common cuttlefish (Sepia officinalis) is photographed by a diver, Sardina, Gran Canaria, Canary Islands, Spain, May 2008, Model released.

Alex Mustard / A common octopus (Octopus vulgaris) shelters between rocks. Gran Canaria, Canary Islands, Spain

Alex Mustard / A pair of male common cuttlefish (Sepia officinalis) displaying to each other, the male behind is flaring his eye and angling his arms towards the male in front to look as large as possible. Gran Cana...

Alex Mustard / A school of Caribbean reef squid (Sepioteuthis sepioidea) in mid water over a coral reef. East End, Grand Cayman, Cayman Islands,West Indies. Caribbean Sea.

Alex Mustard / A long arm octopus (Octopus sp) looks out from its burrow in a rubble slope. Java Sea, Seraya, Tulamben, Bali, Indonesia, South East Asia

Alex Mustard / A pair of golden cuttlefish (Sepia esculenta) mating. The male (on the right) transfering sperm to the female (left), which is done when he wraps his arms around her face and deposits a sac of his spe...

Alex Mustard / A mimic octopus (Thaumoctopus mimicus) makes a 'poisonous sole' impression, Java Sea, Puri Jati, Bali, Indonesia. South East Asia, Java Sea

Alex Mustard / Mimic octopus (Thaumoctopus mimicus) hiding, half buried in the sand. Java Sea, Jati, Bali, Indonesia, South East Asia

Alex Mustard / A young veined octopus / coconut octopus (Amphioctopus marginatus) shelters in an old snail shell, while exposed on the open sand. Java Sea, Puri Jati, Bali, Indonesia, South East Asia.

Alex Mustard / An undescribed species of blue ring octopus (Hapalochlaena sp.) swimming at night. Java Sea, Puri Jati, Bali, Indonesia. South East Asia.

Alex Mustard / A pair of needle cuttlefish (Sepia aculeata) hover over the sand, while the male, on the left, gives a warning display with his arms raised, Seraya, Tulamben, Bali, Indonesia, South East Asia.

Alex Mustard / Veined octopus /coconut octopus (Amphioctopus marginatus) young, shelters in an old bivalve shell, while exposed on the open sand. Puri Jati, Bali, Indonesia, South East Asia.

Alex Mustard / Southern / pacific blue-ringed octopus (Hapalochlaena maculosa) swims across the seabed. Port Philip Bay, Blairgowrie, Melbourne, Victoria, Australia.

Alex Mustard / A Southern sand octopus (Octopus kaurna) digs into the sediment with its long arms at night. While many octopus dig holes, this is the only known species that forms a mucous-lined burrow complete with...

Alex Mustard / Southern sand octopus (Octopus kaurna), photographed at night. This species spends the day burried, with a thin chimney to the surface. Port Philip Bay, Blairgowrie, Melbourne, Victoria, Australia

Alex Mustard / Southern keeled octopus (Octopus berrima) moves across the sand at night. Port Philip Bay, Blairgowrie, Melbourne, Victoria, Australia.

Alex Mustard / Giant cuttlefish (Sepia apama) blows water out through its syphon to jet backwards through sea grass meadow. Manly, Sydney, New South Wales, Australia, digitially manipulated image

Alex Mustard / Striking / mourning cuttlefish (Sepia plangon) displays. Sydney Harbour, New South Wales, Australia.

Alex Mustard / Striking / Mourning cuttlefish (Sepia plangon) in algae. Mosman, Sydney Harbour, Sydney, New South Wales, Australia

Sue Daly / Common cuttlefish (Sepia officinalis) Channel Islands, UK August

Sue Daly / Common cuttlefish (Sepia officinalis) portrait, Channel Islands, UK July

Sue Daly / Common cuttlefish (Sepia officinalis) close up of face, Channel Islands, UK July

Sue Daly / Common cuttlefish (Sepia officinalis) swimming profile, Channel Islands, UK July

Nick Upton / Common European squid egg sacs (Alloteuthis / Loligo subulata), with developing embryos visible, in rockpool after being washed ashore, St.Bees, Cumbria, UK, July.

Nick Upton / Common European squid egg sacs (Alloteuthis / Loligo subulata), with developing embryos visible, in rockpool after being washed ashore, St.Bees, Cumbria, UK, July.

Juan Carlos Munoz / Close up of coil of spiral shell of an Ammonite fossil, Asturias, Spain

Juan Carlos Munoz / Fossil of Ammonite shells, from Phokara valley, Nepal

Alex Mustard / 2020VISION / Common cuttlefish (Sepia officinalis) male closely guarding his female mate, caressing her with his tentacles as he displays to a rival male in the background, Babbacombe Bay, Devon, UK, English Chann...

Alex Mustard / 2020VISION / Common cuttlefish (Sepia officinalis) male closely guarding his female mate caressing her with his tentacles as he displays to a rival male in the background and extending one of his tentacles. Babba...

Alex Mustard / 2020VISION / Common cuttlefish (Sepia officinalis) mating pair, male (on the left) transfering sperm to female (right) by wrapping his arms around her face and depositing a sac of his sperm into her spermatheca, a...

Alex Mustard / 2020VISION / Two pairs of mating Common cuttlefish (Sepia officinalis) the two large males show off their stripy colouration as they protect their females during the mating season, Babbacombe, Devon, UK, English C...

Todd Mintz / Giant Pacific octopus (Enteroctopus dofleini) Port Hardy, British Columbia, Canada.

Todd Mintz / Giant Pacific octopus (Enteroctopus dofleini) Port Hardy, British Columbia, Canada.

Todd Mintz / Giant Pacific octopus (Enteroctopus dofleini) Port Hardy, British Columbia, Canada.

Todd Mintz / Giant Pacific octopus (Enteroctopus dofleini) Port Hardy, British Columbia, Canada.

Solvin Zankl / Octopus (Octopus vulgaris) close up of eyes, San Pietro Island, Sardinia, Italy, Mediterranean, July

Solvin Zankl / Octopus (Octopus vulgaris) camouflaged, resting, San Pietro Island, Sardinia, Italy, Mediterranean, July

Solvin Zankl / Octopus (Octopus vulgaris) camouflaged, San Pietro Island, Sardinia, Italy, Mediterranean, July

Pedro Narra / Juvenile Bottlenose dolphin (Tursiops truncatus) catching a Common octopus (Octopus vulgaris) Sado Estuary, Portugal, November

Michele Westmorland / Portrait of Caribbean reef squid (Sepioteuthis sepioidea), St Vincent, West-Indies, Caribbean, May.

Alex Mustard / 2020VISION / Male Common cuttlefish (Sepia officinalis) caressing a female with his tentacles during courtship, Babbacombe Bay, Devon, UK, April

Alex Mustard / 2020VISION / Male Common cuttlefish (Sepia officinalis) in striped breeding colouration, guarding a female as she lays eggs within the seaweeds. Babbacombe Bay, Torbay, Devon, UK, May spawning period. Did you know...

Alex Mustard / 2020VISION / Pair of Common cuttlefish (Sepia officinalis), male above, during spring spawning season, This pair have already mated and the male is guarding the female (from other males) as she lays her eggs with...

Alex Mustard / 2020VISION / Female Common cuttlefish (Sepia officinalis) laying black eggs amongst seaweed, while male stands guard, Babbacombe, Torbay, Devon, UK, May

Alex Mustard / 2020VISION / Diver observing a Common cuttlefish (Sepia officinalis) Babbacombe Bay, Devon, UK, April.

Alex Mustard / 2020VISION / Common cuttlefish (Sepia officinalis) mating pair, male (on right) transfering sperm to female by wrapping his arms around her face and depositing a sac of sperm into her spermatheca, a pouch beneath...

Alex Mustard / 2020VISION / Male Common cuttlefish (Sepia officinalis) caressing a female during courtship, Babbacombe Bay, Torbay, Devon, UK, May

Alex Mustard / 2020VISION / Pair of Common cuttlefish (Sepia officinalis), male behind caressing female during spring spawning season, This pair have already mated and the male is guarding the female (from other males) as she la...

Alex Mustard / 2020VISION / Cuttlefish eggs (Sepia officinalis) recently laid in clutch attached to seaweed. The black colour of the eggs comes from the cuttlefish's ink, which the female injects into her eggs as she lays them....

Jeff Rotman / Benthic Octopus (Octopus rubescens) camouflaged on coral, Channel Islands, California, USA, Pacific Ocean

Jeff Rotman / Southern pygmy squids (Idiosepius notoides) schooling at night, Sydney, Australia, Pacific

Jeff Rotman / Scientist holding a poisonous Pacific blue-ringed octopus (Hapalochlaena maculosa) in his hand. The octopus can emmit a fatal neurotoxin through it's saliva when provoked, and there is no known anti-v...

Jeff Rotman / Pelagic Octopus (Tremoctopus violaceus) in open ocean at night, Red Sea, Egypt

Jeff Rotman / Giant pacific octopus (Enteroctopus dofleini) feeding on a Cabazon fish (Scorpaenichthys marmoratus). British Columbia, Canada, North Pacific Ocean.

Jeff Rotman / Giant Pacific Octopus (Enteroctopus dofleini) weighing over 20 Kilos interacting with a diver. Victoria Island, British Columbia, Canada, Pacific Ocean. Model released.

Jeff Rotman / Giant Pacific Octopus (Enteroctopus dofleini) swimming, squirting ink at a diver, British Columbia, Canada, Pacific Ocean. Model released.

Jeff Rotman / Close up of suckers on the tentacles of Giant Pacific Octopus (Enteroctopus dofleini) British Columbia, Canada, Pacific Ocean.

Jeff Rotman / Close up of Giant pacific octopus (Octopus dofleini) crawling along the seabed, British Columbia, Canada, Pacific

Jeff Rotman / Giant pacific octopus (Octopus dofleini) crawling along the seabed, British Columbia, Canada, Pacific

Georgette Douwma / Juvenile Broadclub Cuttlefish (Sepia latimanus) at rest over a sea pen. Indonesia.

Sue Daly / Common Cuttlefish (Sepia officinalis) head with unusual eye morphology. Channel Islands, UK, August.

Sue Daly / Common Cuttlefish (Sepia officinalis). Channel Islands, UK, August.

Sue Daly / Eggs of European Squid (Loligo vulgaris). Channel Islands, UK, July.

Georgette Douwma / Day / Common Reef Octopus (Octopus cyanea), mating pair on wreck. Egypt, Red Sea.

Georgette Douwma / Broadclub Cuttlefish (Sepia Latimanus). Komodo National Park, Indonesia.

Nature Production / Swordtip Squid (Loligo edulis) larvae, Japan