0–200 m
Epipelagic zone
The sunlit zone: enough sunlight penetrates to allow photosynthesis. This is where the vast majority of known marine species live.
Giant carpet anemone
Heteractis magnifica
Giant carpet anemone
Host to many clownfish that are immune to its own sting, it can live for decades in the same spot without ever moving.
🌊 0–20 m
- ⚡ Can live for decades in the same spot without ever moving
- ⚡ Maintains a symbiosis with the clownfish, which in turn protects it from certain predators
Humpback whale
Megaptera novaeangliae
Humpback whale
Famous for its spectacular breaches out of the water and its complex songs that can last for hours, it undertakes one of the longest migrations known in any mammal every year.
🌊 0–200 m
- ⚡ Songs that can last for hours and spread from one population to another
- ⚡ Hunts in groups using a coordinated bubble net, a rare technique among whales
Hermit crab
Coenobita sp.
Hermit crab
Unable to build its own shell, it spends its life squatting in abandoned ones, trading up for a bigger one as it grows — sometimes in genuine collective exchange chains.
🌊 0–10 m
- ⚡ Can organise a shell-exchange chain among several individuals of different sizes
- ⚡ Some species live almost entirely on land while still depending on the ocean to reproduce
Sperm whale
Physeter macrocephalus
Sperm whale
The unwitting hero of the novel Moby-Dick and centuries of sailors' legends of titanic battles against monsters of the deep, the sperm whale does indeed fight real duels with the giant squid, whose sucker scars it often carries on its skin.
🌊 0–2000 m
- ⚡ Often carries sucker scars on its skin left by battles with giant squid
- ⚡ Among the deepest divers of all marine mammals, beyond 2,000 m, on a single breath for over an hour
Humboldt squid
Dosidicus gigas
Humboldt squid
Nicknamed the "red devil" for its shifting colour and aggression during group hunts, it can hunt in shoals of several hundred and communicates by rapidly changing colour.
🌊 0–1200 m
- ⚡ Changes colour in a fraction of a second, probably to coordinate group hunting
- ⚡ Tolerates extremely oxygen-poor zones inaccessible to most of its predators
Coelacanth
Latimeria chalumnae
Coelacanth
Believed extinct for 65 million years, alongside the dinosaurs, until its spectacular rediscovery in 1938 off South Africa.
🌊 150–700 m
- ⚡ Believed extinct for 65 million years until its rediscovery in 1938
- ⚡ Fleshy fins that move like limbs, close to the ancestor of the first land vertebrates
Sea cucumber
Holothuria sp.
Sea cucumber
A true vacuum cleaner of the seafloor, continuously recycling sand and sediment — some species defend themselves by expelling their own internal organs at an attacker.
🌊 0–1000 m
- ⚡ Can expel its own internal organs to repel a predator, then regenerate them entirely
- ⚡ Recycles a considerable amount of marine sediment every year, an essential ecological role
Peacock mantis shrimp
Odontodactylus scyllarus
Peacock mantis shrimp
A reef crustacean able to strike with such speed and force that it can crack an aquarium's glass — one of the fastest movements in the animal kingdom.
🌊 0–40 m
- ⚡ One of the fastest, most powerful strikes in the animal kingdom (acceleration comparable to a bullet)
- ⚡ Unique vision able to perceive polarised light and ultraviolet
Leafy seadragon
Phycodurus eques
Leafy seadragon
A fish that looks exactly like a drifting piece of seaweed — the most spectacular camouflage in temperate marine wildlife.
🌊 3–50 m
- ⚡ Near-perfect camouflage mimicking the surrounding seaweed
- ⚡ The male carries and protects the eggs until they hatch
Swordfish
Xiphias gladius
Swordfish
Its sharp bill, as long as a sword, lets it strike prey at full speed, making it one of the fastest fish in the ocean.
🌊 30–180 m
- ⚡ Actively warms its eyes and brain thanks to a unique thermogenic organ
- ⚡ Among the fastest fish in the ocean thanks to its hydrodynamic body and bill
Crown-of-thorns starfish
Acanthaster planci
Crown-of-thorns starfish
Able to devour an entire coral reef within months during massive outbreaks, it is also one of the few starfish with genuinely venomous spines.
🌊 0–30 m
- ⚡ Can regenerate a whole individual from a fragment of its body
- ⚡ Can devour an entire coral reef within months during a massive outbreak
Sunflower sea star
Pycnopodia helianthoides
Sunflower sea star
One of the largest starfish in the world, able to move surprisingly fast thanks to more than 15,000 tube feet, but today decimated by over 90% by a mysterious disease.
🌊 0–120 m
- ⚡ Can have up to 24 arms and more than 15,000 tube feet
- ⚡ One of the fastest starfish known, over a metre per minute
Great white shark
Carcharodon carcharias
Great white shark
An iconic apex predator able to leap clean out of the water to surprise prey, and to cover thousands of kilometres on transoceanic migrations still poorly understood.
🌊 0–1200 m
- ⚡ Can leap entirely out of the water to surprise prey at the surface
- ⚡ Ultra-fine electroreception via hundreds of ampullae of Lorenzini
Bargibant's pygmy seahorse
Hippocampus bargibanti
Bargibant's pygmy seahorse
No bigger than a fingernail, this tiny seahorse lives exclusively on a single species of soft coral, whose colour and bumps it mimics perfectly.
🌊 10–40 m
- ⚡ Camouflage so perfect it was discovered by accident, in a lab, on coral already collected for study
- ⚡ The male carries and hatches the eggs, one of the rare parental-role reversals in the animal kingdom
Caribbean manatee
Trichechus manatus
Caribbean manatee
Nicknamed the "sea cow", its peaceful demeanour and habit of grazing on seagrass may have inspired mermaid tales among sailors of old.
🌊 0–10 m
- ⚡ Can eat up to 50 kg of aquatic vegetation a day
- ⚡ Its peaceful habits may have inspired mermaid tales among sailors
Box jellyfish
Chironex fleckeri
Box jellyfish
Considered one of the most venomous creatures in the sea, its tentacles carry a venom able to trigger cardiac arrest in humans within minutes.
🌊 0–20 m
- ⚡ Has up to 24 eyes, some able to form a true image
- ⚡ One of the fastest, most potent venoms in the animal kingdom
Walrus
Odobenus rosmarus
Walrus
Recognisable by its long tusks, used to haul itself out of the water and assert its social rank, it locates prey buried in the sediment using extremely fine sensory whiskers.
🌊 0–80 m
- ⚡ Locates buried prey using hundreds of sensory whiskers
- ⚡ Uses its tusks like ice axes to haul itself out of the water onto the pack ice
Giant moray
Gymnothorax javanicus
Giant moray
Often perceived as menacing because of its half-open mouth, it simply breathes that way — and hides a second, retractable jaw worthy of a science-fiction film.
🌊 0–50 m
- ⚡ Has a second, retractable jaw that shoots into its throat to seize prey
- ⚡ Sometimes hunts as a team with groupers, a rare inter-species cooperation among fish
Narwhal
Monodon monoceros
Narwhal
Nicknamed "the unicorn of the sea", this Arctic whale carries a long spiralled tusk that long fuelled the unicorn myth in Europe.
🌊 0–800 m
- ⚡ Its spiralled tusk, actually a tooth, can exceed 2.5 metres in length
- ⚡ Dives up to 800 m on a single breath to hunt, one of the deepest dives known in a marine mammal
Chambered nautilus
Nautilus pompilius
Chambered nautilus
A true living fossil whose shape has barely changed in over 500 million years, it navigates using a chambered shell that works like a natural submarine.
🌊 0–700 m
- ⚡ A shape virtually unchanged for over 500 million years
- ⚡ Regulates its depth like a submarine, using a shell with gas-filled chambers
Orca
Orcinus orca
Orca
The largest dolphin in the world and such a sophisticated apex predator that some populations develop hunting techniques passed down culturally from generation to generation.
🌊 0–500 m
- ⚡ Develops hunting techniques unique to each population, passed down culturally
- ⚡ A distinct vocal repertoire per family group, a form of dialect
Northern fur seal
Callorhinus ursinus
Northern fur seal
Able to sleep at sea by folding its flippers out of the water like sails, it spends nearly ten months a year at sea, far from any coast.
🌊 0–200 m
- ⚡ Can sleep at sea by folding its flippers out of the water like sails
- ⚡ The densest fur in the animal kingdom, up to 300,000 hairs per square centimetre
Polar bear
Ursus maritimus
Polar bear
Revered and feared as Nanuq in Inuit mythology, where it is sometimes described as an almost-human spiritual ancestor for its intelligence, it is also classified as a marine mammal, given how much its life depends on sea ice and its swimming ability.
🌊 0–5 m
- ⚡ Can smell a seal through more than a metre of compacted snow and ice
- ⚡ Classified as a marine mammal: able to swim continuously for over 100 km in open sea
Diadem sea urchin
Diadema setosum
Diadem sea urchin
Its long, thin black spines, able to break off and remain lodged in the skin, make it one of the sea urchins divers fear most, despite its essential ecological role.
🌊 0–40 m
- ⚡ Its entire body is light-sensitive, acting like one giant, distributed eye
- ⚡ Plays an essential role in controlling algae populations on coral reefs
Leopard seal
Hydrurga leptonyx
Leopard seal
Antarctica's top predator after the orca, recognisable by its reptilian head and immense jaw, able to hunt both penguins and other seals.
🌊 0–300 m
- ⚡ Can both filter krill and hunt large prey such as a penguin or a young seal
- ⚡ One of the few seals known to actively prey on other seals
Blue-ringed octopus
Hapalochlaena lunulata
Blue-ringed octopus
Tiny and unassuming, it is one of the most venomous animals in the sea: its fluorescent blue rings are a warning to be taken very seriously.
🌊 0–20 m
- ⚡ Venom (tetrodotoxin) among the most powerful in the animal kingdom, with no known antidote
- ⚡ Bioluminescent-style rings that can flash in a fraction of a second
Clownfish
Amphiprion ocellaris
Clownfish
Immune to the venom of the anemone that hosts it, it spends its entire life in one spot, and can literally change sex if the group's female disappears.
🌊 1–15 m
- ⚡ Immune to the anemone's stinging tentacles thanks to a protective mucus
- ⚡ Sequential hermaphroditism: born male, can become the dominant female
Oyster toadfish
Opsanus tau
Oyster toadfish
Able to produce a low, sustained call to attract females, it is also one of the toughest fish on the coast, able to survive several hours out of water.
🌊 0–40 m
- ⚡ Can produce a call audible out of water thanks to muscles vibrating up to 200 times per second
- ⚡ Can survive several hours out of water thanks to skin that limits dehydration
Crocodilefish
Papilloculiceps longiceps
Crocodilefish
Elongated and flattened like a submerged log, it spends most of its time motionless on the sand, its bulging eyes the only clue to attentive divers of its presence.
🌊 1–100 m
- ⚡ Camouflage so perfect it is often mistaken for a piece of debris or a submerged log
- ⚡ Eyes able to move independently to scan its surroundings without moving
Pufferfish (fugu)
Takifugu rubripes
Pufferfish (fugu)
As famous as a Japanese delicacy as it is feared as a poison, its preparation in the kitchen is reserved for specially certified chefs, since its toxin can be fatal if a mistake is made.
🌊 0–50 m
- ⚡ Can double in size within seconds by swallowing water
- ⚡ A toxin so powerful that its culinary preparation requires specific certification in Japan
Lanternfish
Myctophum punctatum
Lanternfish
One of the most abundant fish in the ocean: every night it rises from the depths to feed near the surface, then dives back at dawn — a planet-wide daily migration.
🌊 10–700 m
- ⚡ Counter-illumination: its photophores mimic daylight to make it invisible from below
- ⚡ Undertakes one of the planet's largest animal migrations by biomass, every single day
Lionfish
Pterois volitans
Lionfish
As spectacular as it is fearsome, its long venomous fan-like fins conceal a species that has become one of the greatest invasive threats to Caribbean reefs.
🌊 0–50 m
- ⚡ Venomous fins fanned out to intimidate and defend itself
- ⚡ A voracious appetite that fuelled a record invasion of the Atlantic and the Caribbean
Stonefish
Synanceia verrucosa
Stonefish
Considered the most venomous fish in the world, it blends perfectly with rocks and dead coral, making it nearly impossible to spot until it's too late.
🌊 0–30 m
- ⚡ Near-perfect camouflage, blending in with an algae-covered rock
- ⚡ One of the most powerful venoms known in any fish
Sawfish
Pristis pristis
Sawfish
A sacred figure of the Dreamtime in several Aboriginal cultures of northern Australia, where its saw-shaped rostrum is said to have carved the course of certain rivers, it is today one of the most endangered fish families in the world.
🌊 0–40 m
- ⚡ Its rostrum acts as both a slashing weapon and an ultra-sensitive electrical radar
- ⚡ Can tolerate both salt and fresh water, sometimes travelling very far up rivers
Giant Pacific octopus
Enteroctopus dofleini
Giant Pacific octopus
Long feared as the "devilfish" in the legends of Indigenous peoples of the North American Pacific coast, this largest known octopus in the world turns out to be remarkably intelligent, able to open jars and recognise individual humans.
🌊 0–1500 m
- ⚡ Has nine brains, one central and one in each of its eight arms, able to act almost independently
- ⚡ Intelligence documented in the lab: able to open jars and recognise certain individual humans
Mimic octopus
Thaumoctopus mimicus
Mimic octopus
Able to imitate the appearance and behaviour of some fifteen different species, including venomous fish and sea snakes, to fool its predators.
🌊 0–25 m
- ⚡ Able to imitate the appearance of about fifteen different species, including venomous fish
- ⚡ Chooses which species to mimic based on the predator detected nearby
Giant manta ray
Mobula birostris
Giant manta ray
The largest ray in the world, a peaceful filter feeder with a brain proportionally among the largest of all fish, able to recognise itself in a mirror in the laboratory.
🌊 0–1000 m
- ⚡ One of the few fish to pass a mirror self-recognition test in the laboratory
- ⚡ A brain proportionally among the largest of all fish
Giant oarfish
Regalecus glesne
Giant oarfish
In Japan it is nicknamed the "messenger from the palace of the dragon god", and its appearance near the coast is sometimes seen as an omen of an imminent earthquake — a legend science has never confirmed but which likely explains the origin of many sea-serpent tales.
🌊 20–1000 m
- ⚡ Can swim in a perfectly vertical, motionless position, rippling only its dorsal fin
- ⚡ Its rare, spectacular strandings have fuelled the sea-serpent legend for centuries
Frilled shark
Chlamydoselachus anguineus
Frilled shark
Nicknamed the "snake shark" or a living fossil, it has changed very little in 80 million years and resembles a giant eel with 300 needle-like teeth.
🌊 50–1500 m
- ⚡ Considered a living fossil, virtually unchanged for 80 million years
- ⚡ The longest known gestation period of any vertebrate: about 3.5 years
Whale shark
Rhincodon typus
Whale shark
The largest fish in the world, a peaceful filter feeder that can reach the size of a school bus while feeding almost exclusively on plankton.
🌊 0–1900 m
- ⚡ The largest fish in the world, able to exceed 18 metres in length
- ⚡ A spot pattern unique to each individual, like a fingerprint
Bull shark
Carcharhinus leucas
Bull shark
The only large shark able to survive in fresh water for long periods, it has been found more than 4,000 km up the Amazon.
🌊 0–150 m
- ⚡ The only large shark able to survive long-term in fresh water, found far up major rivers
- ⚡ A hunting technique of ramming before biting
Megamouth shark
Megachasma pelagios
Megamouth shark
So rare it was only discovered in 1976, with fewer than 100 individuals observed since, despite reaching over 5 metres in length.
🌊 12–250 m
- ⚡ A species discovered only in 1976, one of the major zoological discoveries of the 20th century
- ⚡ A mouth that can open over a metre wide to filter plankton
Goblin shark
Mitsukurina owstoni
Goblin shark
Nicknamed the "alien shark", it projects its jaws out of its head at blinding speed to catch prey — one of the strangest attacks in the animal kingdom.
🌊 100–1300 m
- ⚡ Can project its jaws out of its head in a fraction of a second to catch prey
- ⚡ Detects prey via electrical sensors spread across its long snout
Scalloped hammerhead shark
Sphyrna lewini
Scalloped hammerhead shark
Its hammer-shaped head, the cephalofoil, is an extraordinary biological radar, studded with electrical sensors able to detect prey buried in the sand.
🌊 0–80 m
- ⚡ Ultra-sensitive electroreception via ampullae of Lorenzini spread across its cephalofoil
- ⚡ Near-360° panoramic vision
Tiger shark
Galeocerdo cuvier
Tiger shark
Nicknamed "the wastebasket of the sea" for its extraordinarily opportunistic diet, it has been known to swallow objects as improbable as licence plates or tyres.
🌊 0–350 m
- ⚡ The most varied diet known in any shark, including non-food objects
- ⚡ Teeth able to slice through the shell of an adult sea turtle
Atlantic bluefin tuna
Thunnus thynnus
Atlantic bluefin tuna
One of the fastest fish in the ocean, able to keep its muscles warmer than the surrounding water to cross the Atlantic during its migrations.
🌊 0–250 m
- ⚡ Can keep its muscle temperature above that of the surrounding water (regional endothermy)
- ⚡ Top speed among the highest of all bony fish
Leatherback turtle
Dermochelys coriacea
Leatherback turtle
The largest sea turtle and the deepest-diving reptile known, able to keep its body warmer than the icy deep water thanks to a unique soft, cartilaginous shell.
🌊 0–1280 m
- ⚡ The deepest-diving reptile known, beyond 1,000 m
- ⚡ Can keep its body warmer than the icy water thanks to a unique vascular system
Giant triton
Charonia tritonis
Giant triton
Named after Triton, the sea's messenger god in Greek mythology who blew a conch shell to calm or unleash the waves, this huge sea snail is also one of the few natural predators able to keep crown-of-thorns starfish outbreaks in check on coral reefs.
🌊 0–30 m
- ⚡ One of the only natural predators able to keep devastating crown-of-thorns starfish outbreaks in check
- ⚡ Its shell has served for millennia as a ceremonial wind instrument in many Pacific cultures