An interactive scroll-driven journey by Woods Hole Oceanographic Institution (WHOI). Visitors descend from sea level to the Challenger Deep at roughly 11,000 meters, encountering 177 marine organisms and ocean features and 16 depth milestones along the way. Real-time readouts track depth (ft/m), pressure (ATM/PSI), temperature (°F/°C), and the visible-light spectrum that survives at each depth.
The Sunlit Zone (epipelagic) extends from the surface to 200 meters. Sunlight penetrates this zone, supporting photosynthesis and the vast majority of marine life — from plankton to whales. Temperatures are warm and variable, and most familiar ocean creatures live here.
Depth: 0m · Type: Ocean zone callout
The surface is home to a massive number of organisms large and small. In this layer, phytoplankton produce about half the oxygen on Earth.
Source: https://ocean.si.edu/ocean-life/plankton/every-breath-you-take-thank-ocean
Depth: 1m · Depth range: 0–1.5m · Average length: 60 cm · Tags: Organism, Fish, Predator
Slender fish with elongated jaws, often found near the surface.
Source: iNaturalist
Depth: 3m · Average length: 0.25 m · Tags: Organism, Filter feeder
Barrel-shaped, transparent free-floating tunicates that pump seawater through their bodies to filter out phytoplankton. Salps reproduce rapidly into long chains and play an outsized role in the ocean's carbon cycle—their dense fecal pellets sink quickly, transporting carbon from surface waters to the deep sea.
Depth: 7m · Depth range: 0–100m · Average length: 2 cm · Tags: Organism, Crustacean, Filter feeder, Migratory
Small shrimp-like crustaceans that form some of the largest swarms of any animal on Earth. They are a foundational food source for whales, seals, seabirds, and fish, and participate nightly in diel vertical migration — rising toward the surface to feed and retreating to depth during the day.
Depth: 7m · Depth range: 0–20m · Average length: 36.6 m · Tags: Organism, Cnidarian, Predator
Large jellyfish with flowing tentacles resembling a lion's mane. It's bell, or main body, can exceed 1 meter (~3 feet) in diameter and tentacles can be up to 30 meters (~98 feet) long.
Depth: 7m · Depth range: 0–1m · Average length: 2.1 m · Tags: Organism, Fish, Predator
The name "Mahi-mahi" is Hawaiian for "very strong."
Source: MBARI "Animals A to Z"
Depth: 10m · Depth range: 0–10m · Average length: 4 cm · Tags: Organism, Crustacean
Small crustacean that creates a 210 decible snapping sound with its claw to stun prey.
Depth: 10m · Depth range: 0–20m · Average length: 10 cm · Tags: Organism, Mollusk, Predator
Small but highly venomous octopus with distinctive blue rings.
Source: https://inaturalist.ca/taxa/199917-Hapalochlaena-lunulata
Depth: 16m · Depth range: 0–170m · Average length: 14.5 m · Tags: Organism, Cetacean, Filter feeder, Endangered
One of the world's most endangered large whale species, with fewer than 370 individuals remaining. They feed by skimming dense patches of copepods near the surface and are critically threatened by vessel strikes and entanglement in fishing gear.
Source: https://www.fisheries.noaa.gov/species/north-atlantic-right-whale
Depth: 16m · Depth range: 3–25m · Average length: 45 cm · Tags: Organism, Fish
Colorful reef fish that feeds on algae and coral.
Depth: 20m · Depth range: 0–140m · Average length: 1.5 m · Tags: Organism, Reptile, Endangered
The only sea turtle that is strictly herbivorous as an adult, grazing on seagrasses and algae which give its body fat the greenish tint that earned the species its name. Green turtles undertake long migrations between feeding grounds and natal nesting beaches.
Depth: 20m · Depth range: 0–250m · Average length: 2.75 m · Tags: Organism, Pinniped
The largest of the eared seals, with males reaching over 1,000 kg. They forage on fish, squid, and octopus in the North Pacific and can dive to nearly 300 meters. Listed as a species of concern after major population declines in the western range.
Source: https://www.fisheries.noaa.gov/species/steller-sea-lion
Depth: 21m · Depth range: 0–60m · Average length: 2.26 m · Tags: Organism, Cetacean
These communal dolphins live in groups of up to 50. Google is training an AI model to decipher their language.
Source: https://inaturalist.ca/taxa/41503-Stenella-frontalis
Depth: 23m · Depth range: 0–40m · Average length: 70 cm · Tags: Organism, Fish
Popular game fish with distinctive horizontal stripes.
Source: iNaturalist: https://www.inaturalist.org/taxa/51392-Morone-saxatilis
Depth: 23m · Depth range: 0–35m · Average length: 23 cm · Tags: Organism, Crustacean
Important commercial crustacean with distinctive blue claws.
Source: https://www.inaturalist.org/taxa/49504-Callinectes-sapidus
Depth: 24m
Depth: 25m · Tags: Vehicle, Autonomous, Active
A WHOI reef-exploration AUV compact enough to be flown as checked airline luggage and deployed by a single operator. CUREE "hops" through a reef — moving in short bursts, then setting down to listen and observe — so it can stalk fish, record snapping-shrimp soundscapes, and study coral ecosystems without disturbing them.
Source: https://warp.whoi.edu/curee/
Depth: 26m · Depth range: 0–70m · Average length: 25 cm · Tags: Organism, Fish
Compressed fish with rough, file-like skin texture.
Source: https://www.inaturalist.org/taxa/130765-Cantherhines-dumerilii
Depth: 27m · Depth range: 0–30m · Average length: 2.9 m · Tags: Organism, Pinniped
Large Arctic marine mammal with distinctive "tusks" that are actually teeth.
Source: https://www.fisheries.noaa.gov/species/pacific-walrus
Depth: 30m · Depth range: 0–30m · Average length: 60 cm · Tags: Organism, Ancient
A living fossil more closely related to spiders than to crabs, essentially unchanged for over 400 million years. Their distinctive blue, copper-based blood is uniquely sensitive to bacterial contamination and is harvested by the biomedical industry to test the safety of vaccines and medical devices.
Source: https://inaturalist.ca/taxa/48302-Limulus-polyphemus
Depth: 30m · Type: Depth milestone
Depth: 33m · Depth range: 0–500m · Average length: 1.85 m · Tags: Organism, Pinniped
Coastal seal species that can dive to impressive depths.
Depth: 39m · Depth range: 0–100m · Average length: 22.5 m · Tags: Organism, Cetacean, Filter feeder, Endangered
Largest animal ever known, reaching over 100 feet in length.
Depth: 44m
Pressure here matches the air in a bike tire (65 psi)
Depth: 45m · Depth range: 0–310m · Average length: 23 cm · Tags: Organism, Fish, Filter feeder, Migratory
Small schooling fish vital to the marine food chain.
Source: https://www.montereybayaquarium.org/animals/animals-a-to-z/northern-anchovy
Depth: 48m · Depth range: 0–200m · Average length: 2.2 m · Tags: Organism, Cetacean
Highly intelligent marine mammal with distinctive hourglass pattern.
Depth: 50m · Depth range: 0–80m · Average length: 4.6 m · Tags: Organism, Shark, Predator, Endangered
Large shark species with distinctive hammer-shaped head.
Source: https://www.inaturalist.org/taxa/56766-Sphyrna-mokarran
Depth: 54m · Depth range: 3–825m · Average length: 85 cm · Tags: Organism, Fish, Predator
Fast-swimming fish popular in both sport fishing and cuisine.
Source: https://inaturalist.ca/taxa/1316790-Seriola-dorsalis
Depth: 60m · Depth range: 0–80m · Average length: 15.5 m · Tags: Organism, Cetacean, Filter feeder, Migratory
Massive whale known for complex songs, acrobatic breaching, and distinctive white pectoral fins.
Source: https://www.inaturalist.org/taxa/41566-Megaptera-novaeangliae
Depth: 64m · Depth range: 0–150m · Average length: 4 m · Tags: Organism, Shark, Predator, Endangered
The fastest known shark, reaching speeds of up to 46mph.
Depth: 65m · Depth range: 50–149m · Average length: 72 cm · Tags: Organism, Shark
Small shark species commonly found in temperate waters.
Source: https://www.inaturalist.org/taxa/52306-Squalus-acanthias
Depth: 70m · Type: Depth milestone
Source: https://www.usgs.gov/centers/eros/news/usgs-finds-new-way-measure-ocean-depth-landsat
Depth: 75m · Depth range: 20–100m · Average length: 30 cm · Tags: Organism, Cnidarian, Filter feeder
Large anemone with numerous fine tentacles that capture small praey with stinging cells. Can form colonies
Source: https://www.inaturalist.org/taxa/49071-Metridium-senile
Depth: 78m · Depth range: 0–200m · Average length: 30 cm · Tags: Organism, Fish, Migratory
Fast-swimming schooling fish with tiger-like stripes.
Source: iNaturalist
Depth: 78m · Depth range: 0–200m · Average length: 2.5 m · Tags: Organism, Fish
The heaviest bony fish in the world, feeds mostly on jellyfish.
Depth: 82m · Depth range: 20–200m · Average length: 3 m · Tags: Organism, Cetacean
Most well-known dolphin species, highly social and intelligent. Noted to use higher-pitched whistles around their calves, similar to the way humans baby-talk to their infants.
Source: iNaturalist
Depth: 83m · Depth range: 20–300m · Average length: 7 m · Tags: Organism, Cetacean, Predator
Apex predator also known as killer whale, highly intelligent.
Depth: 87m · Depth range: 0–88m · Average length: 1.7 m · Tags: Organism, Fish, Predator, Migratory
Fast-swimming tuna with distinctive yellow fins.
Depth: 92m · Depth range: 0–500m · Average length: 14.5 m · Tags: Organism, Shark, Filter feeder, Endangered
World's largest fish, a gentle giant filter feeder.
Depth: 100m · Type: Depth milestone
The deepest recorded technical scuba dive reached 332 meters.
Depth: 110m · Depth range: 0–150m · Average length: 16 m · Tags: Organism, Cetacean, Filter feeder
Arctic whale that can live more than 200 years, which gives it the longest known lifespan among mammals. It also has the largest mouth of the animal kingdom.
Source: iNaturalist
Depth: 115m · Depth range: 0–300m · Average length: 1.2 m · Tags: Organism, Fish, Endangered
Important commercial fish species of the North Atlantic. One of the most heavily fished species. Collapse of the several stocks in the 90's was devastating
Depth: 122m · Depth range: 0–1200m · Average length: 4.45 m · Tags: Organism, Shark, Predator
Legendary apex predator and largest predatory fish.
Source: https://inaturalist.ca/taxa/50873-Carcharodon-carcharias
Depth: 140m · Depth range: 70–140m · Average length: 1.98 m · Tags: Organism, Fish, Ancient, Endangered
The species was believed to have gone extinct over 65 million years ago but was rediscovered off the coast of South Africa in 1938.
Source: NOAA Fisheries Species Directory
Depth: 160m · Depth range: 10–160m · Average length: 44 cm · Tags: Organism, Fish
Flatfish that lies on the ocean floor with both eyes on one side.
Source: https://inaturalist.ca/taxa/53744-Paralichthys-dentatus
Depth: 178m
Depth: 186m · Depth range: 9–189m · Average length: 1.016 m · Tags: Organism, Fish
Prized food fish with distinctive reddish coloration.
Depth: 197m · Depth range: 0–200m · Average length: 45 cm · Tags: Organism, Bird
An Arctic bird that can dive 150 meters (~495 feet) deep
Source: https://www.allaboutbirds.org/guide/Thick-billed_Murre/id
The Twilight Zone (mesopelagic) spans 200 to 1,000 meters. Light fades to a dim glow that cannot support photosynthesis. The thermocline causes a rapid temperature drop. Bioluminescence becomes common, and the zone is the staging ground for diel vertical migration — the largest daily migration of life on Earth.
Depth: 200m · Type: Ocean zone callout
This depth range resembles those eerie moments when day and night overlap. It teems with life and flashes of bioluminescent light. It may contain more biomass than the rest of the ocean combined.
Depth: 214m · Type: Depth milestone
Depth: 250m · Depth range: 0–500m · Average length: 1.85 m · Tags: Organism, Fish, Predator, Migratory, Endangered
One of the largest, fastest, and most thermally adapted bony fish in the ocean, capable of warming its body well above the surrounding water. Bluefin can sprint over 65 km/h, cross entire ocean basins, and live more than 30 years — but populations have been heavily depleted by commercial fishing.
Source: https://www.fisheries.noaa.gov/species/western-atlantic-bluefin-tuna
Depth: 280m · Depth range: 0–350m · Average length: 3.8 m · Tags: Organism, Shark, Predator, Migratory
Sleek, oceanic sharks known for the longest migrations of any shark — some crossing entire ocean basins. They feed on squid and small fish and are one of the most heavily caught sharks worldwide, mainly as fisheries bycatch.
Source: MBARI "10 minutes of fascinating deep sea animals"
Depth: 300m
Temperature drops fast here while pressure and density increase.
Source: https://oceanservice.noaa.gov/facts/thermocline.html
Depth: 332.35m · Type: Depth milestone
Depth: 345m · Depth range: 70–700m · Average length: 19 cm · Tags: Organism, Mollusk, Ancient
An ancient cephalopod whose ancestors swam Earth's seas more than 500 million years ago. It controls buoyancy by adjusting gas and fluid in the sealed chambers of its spiral shell, drifting up and down the reef walls at night to scavenge for food.
Source: MBARI "Animals A to Z"
Depth: 405m · Depth range: 0–500m · Average length: 2 cm · Tags: Organism, Crustacean, Filter feeder, Migratory
Daytime resting depth for many krill, which migrate hundreds of meters between deep waters and the surface every 24 hours. This nightly journey is part of the largest animal migration on Earth — the diel vertical migration of the deep scattering layer.
Depth: 420m
Animals may have large eyes to see what little light penetrates here. They may even be able to make their own light through bioluminescence. In some cases, the animals are home to bacteria which actually produce light.
Depth: 438m · Depth range: 100–900m · Average length: 9 cm · Tags: Organism, Fish, Bioluminescent
A small, mirrored mesopelagic fish named for its hatchet-shaped body. Light-producing organs along its belly precisely match the faint sunlight filtering down from above, a strategy called counter-illumination that erases its silhouette from predators looking up.
Source: https://inaturalist.ca/taxa/459329-Argyropelecus-olfersii
Depth: 465m · Depth range: 0–1000m · Average length: 1 m · Tags: Vehicle, Autonomous, Active
A hybrid midwater robot, whose development was led by Dana Yoerger at WHOI and in collaboration with colleagues from WHOI, MBARI, Stanford, and Univeristy of Texas Rio Grande Valley. Mesobot follows midwater animals through the ocean twilight zone without spooking them. Powered for more than 24 hours on lithium-ion batteries, it uses slow, large propellers and red lights—invisible to most deep-sea species—to observe and sample without disturbance. Mesobot can also carry eDNA samplers, to autonomously collect genetic traces of midwater animals.
Source: https://www.whoi.edu/what-we-do/explore/underwater-vehicles/auvs/mesobot/
Depth: 475m · Depth range: 200–1500m · Average length: 15 cm · Tags: Organism, Fish, Bioluminescent, Migratory
Bioluminescent fish that migrates to surface at night. There are 246 species in the family Myctophidae.
Source: https://twilightzone.whoi.edu/explore-the-otz/creature-features/lanternfish/
Depth: 493m · Depth range: 283–439m · Average length: 14 cm · Tags: Organism, Shark, Bioluminescent
Record smallest shark of 2017. The specimen pictured here was discovered in the Caribbean Sea off the coast of Colombia in 1985 at a depth of 290 m (950 ft).
Source: Smithsonian Ocean
Depth: 500m · Depth range: 0–500m · Average length: 17 cm · Tags: Organism, Fish, Predator
Despite its menacing appearance and proportionally largest teeth of any ocean fish, the fangtooth is only about the length of a human hand. It lives in deep, dark waters and migrates upward at night to hunt small fish and crustaceans.
Source: https://ocean.si.edu/ocean-life/fish/common-fangtooth
Depth: 510m · Depth range: 0–1000m · Average length: 4.87 m · Tags: Vehicle, Tethered, Active
A WHOI-built towed sensor platform that surveys the ocean twilight zone, packed across three modular sections with sonars, cameras, an environmental-DNA sampler, and a CTD. Towed at roughly 1 m/s on an electro-optical cable to 1,000 meters, it streams data and imagery to the ship in real time across ~23-hour deployments.
Source: https://www.whoi.edu/what-we-do/explore/underwater-vehicles/towed-vehicles/deep-see/
Depth: 520m · Depth range: 0–1000m · Average length: 20 cm · Tags: Organism, Mollusk, Bioluminescent
A mesopelagic squid named for the red, strawberry-like spots covering its body. It has two strikingly mismatched eyes: a large yellow upward-facing eye that searches for silhouettes in the dim light above, and a smaller blue eye that scans below for bioluminescent flashes.
Source: https://www.mbari.org/news/strawberry-squid-mismatched-eyes/
Depth: 540m · Depth range: 0–565m · Average length: 1.2 m · Tags: Organism, Bird
Largest penguin species, can dive to over 500 meters(~1640 feet), making it the deepest-diving bird.
Source: https://www.inaturalist.org/taxa/3820-Aptenodytes-forsteri
Depth: 550m
As the sun sets many animals living in the ocean twilight zone rise up to the surface to feed on plankton and other microorganisms. When the sun reappears at dawn, they descend back to the depths. This is the largest migration of animal life on earth.
Depth: 580m · Depth range: 50–600m · Average length: 3.8 m · Tags: Organism, Crustacean
The world's largest living crab.
Source: MBARI "Animals A to Z"
Depth: 600m · Depth range: 0–600m · Average length: 6 cm · Tags: Organism, Mollusk
A large sea slug without a shell that lives in cold water and preys on shelled pteropods.
Source: iNaturalist
Depth: 600m · Depth range: 100 - ~5000m · Average length: 3 cm · Tags: Organism, Fish, Bioluminescent
These fish are the most abundant vetabrete on earth, with estimates in the trillions or quadrillions!
Source: https://www.fishbase.se/summary/Gonostoma-elongatum.html
Depth: 640m · Depth range: 0–1000m · Average length: 4.5 m · Tags: Organism, Ray, Filter feeder
The largest ray in the ocean, with a wingspan that can exceed 7 meters. Highly intelligent and one of the few fish that can recognize themselves in a mirror, oceanic mantas filter-feed on zooplankton and routinely dive past 1,000m, likely to forage in the deep scattering layer.
Source: https://www.inaturalist.org/taxa/623966-Mobula-birostris
Depth: 675m · Depth range: 600–800m · Average length: 15 cm · Tags: Organism, Fish
Has eyes pointing upward within a transparent dome that it can rotate to look forward.
Source: MBARI "Animals of the Deep"
Depth: 695m · Depth range: 200–700m · Average length: 2.5 m · Tags: Organism, Mollusk, Predator
Unlike most cephalopods, who have a reputation for being solitary, humboldt squids are pack hunters that communicate via bioluminesce to coordinate attacks. You may recognize them from the Nat Geo Wild documentary "Man Eating Super Squid: A Monster Invasion" & BBC's Blue Planet II.
Source: iNaturalist
Depth: 701m · Type: Depth milestone
Saturation divers will spend as long as a month working at depths between 20m to 300m, after which their bodies are completely saturated with dissolved nitrogen. To reascend without injury, divers are first brought to the surface by a pressurized diving bell, then to specialized chambers for decompression. They are often needed for underwater construction, salvage operations, and maintenance of oil and gas rigs or pipelines.
Depth: 720m · Depth range: 0–1830m · Average length: 2.15 m · Tags: Organism, Fish, Predator
Also known as "cannibal fish," they are an important middleman in deep water food webs. They migrate daily between the sunlit and midnight zones in search of prey, and are a food source for yellowfin tuna, opah, fur seals, Pacific cod, and salmon sharks.
Source: https://www.inaturalist.org/taxa/93644-Alepisaurus-ferox
Depth: 750m · Depth range: 0–2878m · Average length: 3 m · Tags: Organism, Fish, Predator, Migratory
Atlantic swordfish are one of the fastest predators in the ocean. Their streamlined body allows them to swim at high speeds, up to 50 mph. In 2000, their population had dropped to 65% of the target level, but was fully rebuilt by 2009 through implementing more sustainable fishing practices
Source: Fishbase USA
Depth: 750m · Depth range: 200–1500m · Average length: 30 cm · Tags: Organism, Fish, Predator, Bioluminescent
A small but ferocious mesopelagic predator with fangs so long they don't fit inside its mouth. A glowing photophore at the tip of its dorsal spine allows for signaling, attracting mates, and luring curious prey within striking range.
Source: MBARI "Animals of the Deep"
Depth: 900m · Depth range: 600–900m · Average length: 30 cm · Tags: Organism, Mollusk
Despite its name ("vampire squid from hell"), this small cephalopod is gentle and eats marine snow — drifting flakes of organic detritus. It lives in oxygen-minimum zones where few other animals can survive and produces clouds of glowing mucus instead of ink when threatened.
Source: MBARI "Animals of the Deep"
Depth: 900m · Depth range: 0–1000m · Average length: 14 m · Tags: Organism, Cetacean, Predator
AI has revealed that sperm whale songs utilize a phonetic alphabet similar to those found in human languages.
Source: NOAA Fisheries Species Directory
Depth: 950m · Depth range: 0–3700m · Average length: 60 cm · Tags: Organism, Worm
This worm can produce unique yellow bioluminescence to distract predators. It hunts for zooplankton and swims so quickly and efficiently that engineers are using it as a model for underwater robots.
Source: MBARI "Animals of the Deep"
Depth: 985m · Depth range: 200–1000m · Tags: Organism, Biology
Nicknamed the "pram bug," this transparent twilight-zone amphipod hollows out the body of a salp or siphonophore to make a barrel-shaped home — then pushes the barrel through the water like a baby carriage while brooding her young inside. Reportedly inspired the design of the creature in the film Alien.
Source: https://www.sciencedirect.com/science/article/pii/S001282521830429X
Depth: 990m · Depth range: 200-1500m · Average length: 3.5 m · Tags: Organism, Mollusk
A transparent, gelatinous deep-sea squid whose body is mostly water-filled tissue. Tucked-up arms held over its head give it a crest-like silhouette resembling a cockatoo, and its mantle is dotted with tiny photophores used to hide its outline from below.
Source: https://www.inaturalist.org/taxa/432421-Galiteuthis-phyllura
The Midnight Zone (bathypelagic) reaches from 1,000 to 4,000 meters. No sunlight penetrates. Water hovers near 4°C and pressure is crushing. Life is sparse but specialized: anglerfish, vampire squid, gulper eels, and the ecosystems around hydrothermal vents and whale falls.
Depth: 1000m · Type: Ocean zone callout
This is largest habitat on the planet. All light in the ocean has vanished—except bioluminescence—and temperatures are near freezing. Many animals do not have eyes or have specialized sensors to see. They find mates, communicate, and find food using bioluminescence, sound, vibration, and scents.
Depth: 1025m · Depth range: 0–700m · Average length: 5.49 m · Tags: Organism, Cetacean
Highly social toothed whales that travel in tight-knit family pods. They hunt squid with explosive sprint dives — sometimes called "cheetahs of the deep" — descending more than 600 meters in pursuit of prey before returning to the surface.
Source: https://www.fisheries.noaa.gov/species/short-finned-pilot-whale
Depth: 1025m · Depth range: 0–100m · Average length: 20 m · Tags: Organism, Cnidarian, Predator
Siphonophores are predators that use stinging cells and tentacles to catch prey, ranging from tiny crustaceans to fish. There are hundreds of species living in surface to deep waters, from a few centimeters to many meters in size. Apolemia is the only genus known to reach tens of meters in length.
Depth: 1040m
Depth: 1100m · Depth range: 300–1000m · Average length: 9.5 m · Tags: Organism, Mollusk, Predator
The first ever live recording of a giant squid in its natural habitat was taken in 2012, at a depth of 900 meters. The largest recorded giant squid was 13 meters (~43 feet) long.
Source: iNaturalist
Depth: 1150m
Temperatures here are relatively consistent between 0-3°C. If you're diving in Alvin, it's time to put on another layer. Even with the heat from three people and electronics, the inside of the vehicle can drop as low as 4°F.
Depth: 1200m · Depth range: 0–1200m · Average length: 2.7 m · Tags: Organism, Reptile, Migratory, Endangered
The largest sea turtle and the deepest-diving reptile in the ocean, regularly diving past 1,000m in pursuit of jellyfish. Its leathery, oil-saturated shell and unique counter-current heat exchange allow it to forage from tropical seas to subpolar waters.
Source: https://www.fisheries.noaa.gov/species/leatherback-turtle
Depth: 1200m
Water pressure here equals that of Mike Tyson's punch(1800 psi)
Depth: 1275m
In most parts of the mesopelagic, marine snow is the most conspicous thing you see. Each tiny flake is a clump of marine detritus: dead microscopic animals called plankton, poop, bacteria, and other carbon-rich particles that together provide a rich source of food for deep-sea fish, jellies, and crustaceans.
Depth: 1325m
Depth: 1375m
Depth: 1410m
Depth: 1450m · Depth range: 50–1520m · Average length: 1.8 m · Tags: Organism, Shark, Ancient
Sometimes called a "living fossil," this deep-sea shark has changed little in 80 million years. Its eel-like body and 300 backward-curved teeth in 25 rows let it strike like a snake to seize squid and small fish in the perpetual dark.
Source: https://inaturalist.ca/taxa/47302-Chlamydoselachus-anguineus
Depth: 1450m · Depth range: 0–2200m · Average length: 4.5 m · Tags: Organism, Shark
At 392 +/- 120 years, it has the longest lifespan of all vertebrate species. Its diet includes fish, seals, and polar bears!
Source: https://inaturalist.ca/taxa/112841-Somniosus-microcephalus
Depth: 1485m
Depth: 1500m · Depth range: 0–1500m · Average length: 15 cm · Tags: Organism, Crustacean
The largest hyperiid amphipod, up to 10 centimeters long. The body is completely transparent except for the pigment of its large, reflective eyes, which make up a third of its body length. Found in all the world's oceans.
Source: MBARI "Animals of the Deep"
Depth: 1500m · Depth range: 250–1500m · Average length: 16 cm · Tags: Organism, Ctenophore
Native to the North Pacific. Discovered and described by WHOI scientist Richard Harbison. Its red coloration allows it to live invisibly in the Twilight Zone, where red wavelengths have been long since filtered out.
Source: MBARI "Animals of the Deep"
Depth: 1520m · Depth range: 0–2800m · Average length: 7 cm · Tags: Organism, Ctenophore, Bioluminescent
Its red gut prevents it from being lit up from the inside by its bioluminescent prey. Lives in the Arctic Ocean and Northern Pacific.
Source: MBARI "Animals of the Deep"
Depth: 1540m
Depth: 1555m · Depth range: 0–1550m · Average length: 23 cm · Tags: Organism, Fish, Bioluminescent, Predator
One of the most commonly sighted dragonfish species of the Pacific, it possess the rare ability to perceive red light at depth, allowing it to pursue a wider variety of prey.
Depth: 1565m
Depth: 1609m · Type: Depth milestone
Depth: 1760m
Depth: 1800m · Depth range: 100–1800m · Average length: 75 cm · Tags: Organism, Echinoderm, Filter feeder
The basket star's sprawling mass of branching arms allow it a much larger range of movement than most others in the brittlestar family (Ophiuroidea). The microscopic hooks on its arms allow it to snag prey, which it brings to its mouth located beneath its central disk.
Source: MBARI "Animals of the Deep"
Depth: 1830m · Depth range: 50–1800m · Average length: 3 m · Tags: Organism, Cnidarian
The largest bubblegum corals are thousands of years old, creating dense forests along seamounts and submarine canyons – places with a good amount of current so they can filter feed. These "rainforests of the deep" shelter an enormous diversity of fish and invertebrates.
Source: MBARI "Animals of the Deep"
Depth: 1875m
Depth: 2000m · Type: Depth milestone
Vents are the subsea part of Earth's plumbing system along with geysers and fumaroles on land.
Depth: 2025m · Depth range: 1000–3048m · Average length: 14 cm · Tags: Organism, Shark, Bioluminescent
Not many have been found, but the first specimen was collected off Chile and the second from the Gulf of Mexico, which indicates a very large range.
Source: NOAA fisheries
Depth: 2075m · Depth range: 170–2100m · Average length: 40 cm · Tags: Organism, Crustacean, Scavenger
The largest isopod species, it is commonly found gorging itself at whale falls. Organs called fat bodies store vast amounts of energy from a single meal, allowing them to go years without food.
Source: MBARI "Animals A to Z"
Depth: 2110m · Depth range: 700–2745m · Average length: 1.075 m · Tags: Organism, Fish, Predator
Its flexible stomach allows it to swallow prey up to 3 times its size – an adaptation to its food scarce environment.
Depth: 2160m · Depth range: 1000–3300m · Average length: 3 cm · Tags: Organism, Cnidarian, Bioluminescent
Called 'psychedelic' for it's red pigmentation and bright bioluminescence. Females brood their young, nourishing them with food from their bell until the babies are ready to swim off on their own.
Source: MBARI "Animals of the Deep"
Depth: 2200m · Depth range: 0–2500m · Average length: 18 cm · Tags: Organism, Fish, Bioluminescent, Predator
Famous for the glowing lure dangling from her forehead, the female anglerfish uses bioluminescent bacteria housed in the bulb to attract curious prey. In some species the dwarf male permanently fuses to the female's body, becoming a parasitic mate for life.
Depth: 2225m · Average length: 15 cm · Tags: Organism, Crustacean, Vent dweller
Its fuzzy arms house chemosynthetic bacteria, which produce the crab's main food source.
Depth: 2240m
Mid-ocean ridges form the longest mountain range in the world—65,000 kilometers (about 40,000 miles)—nearly all of which lies beneath the sea. They form along the seams between tectonic plates and most of Earth's volcanic activity occurs here.
Depth: 2275m · Depth range: 2000–3000m · Average length: 1 m · Tags: Organism, Fish, Predator
Almost all mouth and stomach, this bizarre eel can unhinge its loose jaws to swallow prey larger than itself — an essential adaptation where meals are rare. A long whip-like tail tipped with a small bioluminescent organ may lure curious prey within reach.
Source: MBARI "Animals of the Deep" – says 300 – 2000m (typo?): https://www.mbari.org/animal/whiptail-gulper-eel/
Depth: 2305m · Depth range: 600–2300m · Average length: 3 cm · Tags: Organism, Crustacean
Gigantocypris is the largest of the seed shrimp, measuring up to 3.2 cm in diameter. Their mirror-like eyes are capable of perceiving more light than any other animal. They also have enormous hearts for their body size, which allows them to vigorously hunt copepods, arrow worms, and other ostracods.
Source: WHOI Ocean Twilight Zone "Creature Feature"
Depth: 2375m · Average length: 6.4 m · Tags: Organism, Mollusk
The deepest-known squid! It is yet unknown how they hunt, but the presence of microscopic suckers suggest it can trap prey that unwittingly swim through their long, spindly arms.
Source: NOAA Ocean Explorer
Depth: 2475m
Depth: 2595m
The vents act as Earth's plumbing systems, transporting heat and nutrients out of the crust.
Depth: 2700m
Depth: 2745m · Depth range: 800–2800m · Average length: 70 cm · Tags: Organism, Fish
Best known as the "World's Ugliest Fish" for its unflattering appearance after being brought to the surface without compression. At depth, their gelatinous bodies offer resilience against the immense pressure. Blobfish are devoted parents that will guard their eggs until they hatch, fanning them to keep them clean and oxygenated.
Source: MBARI "10 minutes of fascinating deep sea animals"
Depth: 2760m
Depth: 2830m · Average length: 9 cm · Tags: Organism, Worm
Collected off Tawi-Tawi, Phillipines by WHOI researcher WHOI researcher (Laurence Madin) and his colleagues, the squidworm was chosen by the World Register of Marine Species (WoRMS) as one of the 10 most astounding marine species of the last decade.
Depth: 2950m · Depth range: 300-2992m · Average length: 6.4 m · Tags: Organism, Cetacean
The deepest-diving whale! Its concave skull houses the melon, the organ whales & dolphins use for echolocation.
Source: https://inaturalist.ca/taxa/41428-Ziphius-cavirostris
Depth: 2955m · Depth range: 1000–4000m · Average length: 2.0193 m · Tags: Organism, Cnidarian, Bioluminescent
When attacked, this deep-sea jelly fires off a pinwheel of bright blue light known as a "burglar alarm" — a flashing distress beacon meant to attract an even larger predator that will eat its attacker, letting the jelly escape in the chaos.
Source: https://twilightzone.whoi.edu/explore-the-otz/creature-features/atolla-jellyfish/
Depth: 3000m · Depth range: 0–3000m · Average length: 3.7 m · Tags: Vehicle, Autonomous, Active
A 3,000-meter-rated AUV operated by WHOI's Oceanographic Systems Lab, built around a titanium hull to handle the pressure at depth. Over missions up to 49 hours long at 3 knots, dual-frequency Edgetech sidescan sonars and digital cameras map and image the seafloor for survey, search, and scientific imaging work.
Depth: 3048m · Type: Depth milestone
Not all corals are tropical, shallow-water reef-builders! Many cold water corals are found in deep waters, where they provide habitat for other invertebrate species. Deep water corals are exceptionally slow growing.
Depth: 3292m · Depth range: 300–3292m · Average length: 10 cm · Tags: Organism, Crustacean
A deep-sea shrimp that defends itself by ejecting a cloud of glowing bioluminescent fluid from its mouth, blinding predators while it escapes into the darkness — a marine analogue of a squid's ink cloud.
Source: WHOI HADES
Depth: 3350m · Depth range: 2000–4700m · Average length: 30 cm · Tags: Organism, Fish, Scavenger
One of the most abundant fish on the deep seafloor, the abyssal grenadier locates food by detecting faint chemical trails — homing in on dead carcasses that drift down from above. Its long, tapering tail and large head are typical of the rat-tail family.
Source: https://inaturalist.ca/taxa/194844-Coryphaenoides-armatus
Depth: 3375m
Depth: 3510m · Depth range: 2700–3600m · Average length: 3 cm · Tags: Organism, Worm, Bioluminescent
A small swimming worm that defends itself by detaching glowing green "bombs" from its body — sacrificial sacs of bioluminescent fluid that flash brightly to distract predators while the worm slips away in the darkness.
Source: MBARI "Animals of the Deep"
Depth: 3900m · Depth range: 1200–3900m · Average length: 14 cm · Tags: Organism, Mollusk, Vent dweller
Gather at deep sea thermal springs, where the warm water is ideal for brooding their developing eggs. The largest of these is the Octopus Garden near the Davidson Seamount, the largest known aggregation of octopus on Earth.
Source: MBARI "Animals of the Deep"
The Abyssal Zone (abyssopelagic) covers 4,000 to 6,000 meters and includes most of the abyssal plains — the largest habitat on Earth. Pressure exceeds 400 atmospheres. Life is sparse, slow, and pressure-adapted: sea cucumbers, brittle stars, and microbial mats.
Depth: 4000m · Type: Ocean zone callout
The abyss is defined by wide plains broken by trenches, seamounts, and oceanic ridges. It contains cold- and pressure-tolerant animals found nowhere else on earth.
Depth: 4010m · Depth range: 2200–4000m · Average length: 51 cm · Tags: Organism
Found in all the world's oceans, it is the largest species of sea spider, growing larger than a dinner plate. It uses its sharp, tube-like proboscis to suck the guts out of soft bodied animals like anemones and sponges.
Source: MBARI "Animals of the Deep"
Depth: 4025m · Depth range: 300–4000m · Average length: 1.5 m · Tags: Organism, Fish
They can get up to five feet long!
Source: MBARI "Animals A to Z"
Depth: 4155m
Depth: 4360m · Depth range: 2500–4360m · Average length: 2 mm · Tags: Organism, Crustacean
A member of family Parapaguridae, which live at depths beyond 3600m. Instead of inhabiting empty snail shells like most hermit crabs, these will often carry around anemones, zoanthid corals, or even clam shells.
Source: Resultats des Campagnes Musorstom Vol. 20, French National Museum of Natural History
Depth: 4500m · Depth range: 3–4500m · Average length: 45 cm · Tags: Organism, Fish
A long-lived North Pacific flatfish that can live more than 50 years. Both eyes migrate to the right side of its head as it grows, and the adult settles on the seafloor on its blind side. Fishermen nickname it the "slime sole" for the copious mucus it produces, and its larvae spend up to two years drifting in open water before settling to the bottom — the longest pelagic larval stage of any flatfish.
Depth: 4660m
Depth: 4695m · Depth range: 4000–4700m · Average length: 30 cm · Tags: Organism, Fish
Stands on three stilt-like fin rays that act as a tripod, propping it stationary on the soft seafloor. Facing into the current, it holds out two long pectoral fins to detect and snare tiny crustaceans drifting past — fishing with its body instead of swimming.
Source: https://www.marinespecies.org/aphia.php?p=taxdetails&id=126343
Depth: 4879m · Depth range: 0–4879m · Average length: 5 cm · Tags: Organism, Cnidarian
Despite the common name, these abyssal cnidarians are corallimorpharians — close relatives of stony corals that lack a hard skeleton. Anchored to the deep seafloor, they capture drifting marine snow and small prey with their tentacles in one of Earth's most food-scarce habitats.
Source: https://oceanexplorer.noaa.gov/edu/learning/9_benthos/activities/benthic_animals.html
Depth: 4970m · Depth range: 0–5000m · Tags: Vehicle, Tethered, Hadal-rated
A WHOI-built hybrid ROV designed to explore beneath ice shelves and floating sea ice, relaying video and data through a hair-thin 20 km fiber-optic microtether that it can release to continue the mission autonomously. Rated to 5,000 meters, NUI has operated from the Fram Strait pack ice to the calving front of Greenland's Kangerlussuup Sermia glacier.
Source: https://www.whoi.edu/what-we-do/explore/underwater-vehicles/hybrid-vehicles/nereid-under-ice/
Depth: 5045m · Depth range: 0–6000m · Average length: 3.84 m · Tags: Vehicle, Autonomous, Active
The largest member of the REMUS AUV family, developed jointly by WHOI, the Office of Naval Research, and the Naval Oceanographic Office. Rated to 6,000 meters with mission endurance up to 22 hours, REMUS 6000 carries out hydrographic surveys, debris-field mapping, and deep-ocean search and salvage missions where almost no other vehicle can reach.
Depth: 5180m · Depth range: 282-5180m · Average length: 50 cm · Tags: Organism, Fish, Scavenger
A Pacific-exclusive grenadier and the only member of its family known to enter the hadal zone — recorded at over 7,000 meters in the Mariana Trench. The rough abyssal grenadier is an active benthic forager, hunting squid, crustaceans, and polychaete worms on the deep seafloor while also scavenging whatever organic matter drifts down from above.
Source: https://en.wikipedia.org/wiki/Coryphaenoides_yaquinae
Depth: 5460m · Average length: 3 cm · Tags: Organism, Crustacean
Found via baited video lander deployed in the Kermadec Trench, Tonga Trench and the Japan Trench and in the Marianas region (NW Pacific).
Source: WHOI HADES
Depth: 5669m · Type: Depth milestone
Deepest point in the Arctic Ocean
Source: https://www.sciencedirect.com/science/article/pii/S001282521830429X
Depth: 5700m
Depth: 5772m · Average length: 2 m · Tags: Organism, Cnidarian
A photograph of this soft coral was taken March 24, 2017 by NOAA Okeanos Explorer at Hadal Trough "Kinono," Phoenix Islands Protected Area (South Pacific).
Source: NOAA Benthic Deepwater Animal Identification Guide
Depth: 5990m · Depth range: 5100–6000m · Average length: 3 cm · Tags: Organism, Mollusk, Vent dweller
Often found at cold seeps, this clam obtains its food from methane-producing bacteria that live inside it. Discovered 1985 by the Nautile's series of dives in the Japan & Kurile Trenches.
Source: WHOI HADES
The Hadal Zone (hadopelagic) is the realm of the ocean trenches, from 6,000 meters to nearly 11,000 meters. Named after Hades, it is the least-explored habitat on Earth. The Challenger Deep in the Mariana Trench, at roughly 10,935 meters, is the deepest known point in the world ocean.
Depth: 6000m · Type: Ocean zone callout
Deep ocean trenches make up the entirety of the hadal zone, which is named for Hades, the Greek god of the underworld. This zone is characterized by extreme depth, pressure, and temperatures that hover just above freezing.
Depth: 6020m · Depth range: 0–6000m · Average length: 2.9 m · Tags: Vehicle, Autonomous, Hadal-rated
A WHOI-built autonomous mapping AUV rated to 6,000 meters and engineered to fly through extreme deep-sea terrain — including volcano calderas, mid-ocean ridges, and hydrothermal vent fields. Sentry produces high-resolution bathymetric, sidescan, sub-bottom, and magnetic maps of the seafloor and can be re-tasked acoustically from the surface mid-mission.
Source: https://ndsf.whoi.edu/sentry/
Depth: 6350m · Depth range: 0–6500m · Average length: 3.4 m · Tags: Vehicle, Tethered, Active
A workhorse remotely operated vehicle built by WHOI's Deep Submergence Laboratory, flown from the ship through a 10-kilometer reinforced fiber-optic cable that delivers power, commands, and live video in real time. Now in its third generation, Jason has made hundreds of dives to hydrothermal vents in the Pacific, Atlantic, and Indian Oceans.
Source: https://ndsf.whoi.edu/jason/
Depth: 6500m · Depth range: 0–6500m · Average length: 7 m · Tags: Vehicle, Manned, Historic, Active
The most storied research submersible in the world, carrying a pilot and two scientists inside its titanium personnel sphere for dives of up to 12 hours. Following a major 2020–2022 overhaul, Alvin can now reach 6,500 meters — putting roughly 99% of the global seafloor within reach of in-person scientific study.
Source: https://ndsf.whoi.edu/alvin/
Depth: 6525m
Depth: 6600m · Depth range: 250–6600m · Average length: 17 cm · Tags: Organism, Fish
It gets its name from its huge eyes that are adapted to capture as much light as possible.
Source: iNaturalist
Depth: 6800m
Depth: 6920m · Depth range: 1000–6957m · Average length: 20 cm · Tags: Organism, Mollusk
This deepest-known group of octopuses are named for the large ear-like fins that they swim with.
Depth: 7030m · Depth range: 500–7000m · Average length: 25 cm · Tags: Organism, Echinoderm
Due to its odd appearance, this genus of swimming sea cucumbers has been called many different names:. "the headless chicken monster," "the spanish dancer," "the pink see-through fantasia," and others. They mainly eat detritus off the sea floor, but will swim as much as 1000m up into the water column to search for new feeding grounds.
Source: SeaLifeBase (https://www.sealifebase.se/search.php)
Depth: 7187m · Type: Depth milestone
Deepest point in the Indian Ocean
Source: https://www.sciencedirect.com/science/article/pii/S001282521830429X
Depth: 7230m · Depth range: 4000m+ · Average length: 34 cm · Tags: Organism, Crustacean, Scavenger
A staggering example of "abyssal gigantism" — this scavenging amphipod reaches more than 30 cm long, far larger than its centimeter-scale shallow-water relatives. It descends on baited traps in the deep ocean to feed on whale falls and other carrion.
Source: https://inaturalist.ca/taxa/425121-Alicella-gigantea
Depth: 7432m · Type: Depth milestone
Deepest point in the Southern Ocean
Source: https://www.sciencedirect.com/science/article/pii/S001282521830429X
Depth: 7800m · Depth range: 550–7800m · Average length: 15 cm · Tags: Organism, Crustacean, Scavenger
Collected by Dr. Alan Jamieson from the Peru-Chile Trench. A fast swimmer with an incredible ability to sniff out food at distance, this species is one of the fastest to arrive at bait traps.
Source: WHOI HADES
Depth: 7840m
Depth: 7910m · Average length: 4 cm · Tags: Organism, Crustacean, Hadal, Predator
A fast-swimming predator originating from Atacama Trench off the coast of Peru and Chile. Its genus name, "Dulcinea," is a character from Miguel de Cervantes's novel Don Quixote, and its species name "camanchaca" means "darkness" or "mist" in Quechua, a language indigenous to the Andes region.
Source: OCEANUS: "Deep-sea amphipod name inspired by literary masterpiece"
Depth: 8100m
Depth: 8150m
Depth: 8200m
Depth: 8336m · Depth range: 6198–8336m · Average length: 29 cm · Tags: Organism, Fish, Hadal
Holds the record for the deepest-living fish ever filmed, observed past 8,000 meters. Its gelatinous, scale-less body and partially open skull are evolutionary solutions to surviving pressures over 800 times that at sea level.
Source: https://oceanexplorer.noaa.gov/ocean-fact/what-is-the-deepest-living-fish/
Depth: 8375m
1977 record deepest fish 8370m
Depth: 8500m
Depth: 8570m
Depth: 8605m · Type: Depth milestone
Deepest point in the Atlantic Ocean
Source: https://www.sciencedirect.com/science/article/pii/S001282521830429X
Depth: 8848.9m · Type: Depth milestone
Depth: 9330m · Depth range: 7703–9316m · Average length: 6 cm · Tags: Organism, Crustacean, Hadal
Filmed and caught by Dr. Alan Jamieson on HADEEP research cruise at Japan Trench in 2008, then at Izu-Bonin Trench in 2009. The genus Princaxelia was named for Prince Axel of Denmark in 1959 when Danish Galathea expeditions discovered this kind of shrimp.
Source: WHOI HADES
Depth: 9480m
Depth: 9530m
Depth: 9807m · Average length: 0.5 mm · Tags: Organism, Microbe
Found in a grab sample on the floor of the Philippine Trench by R. R. Hessler (Scripps) during research cruise on the research vessel Washington. Also common in benthic sediments everywhere; some are also planktonic.
Source: WHOI HADES
Depth: 9860m · Depth range: 1000–9997m · Average length: 2 cm · Tags: Organism, Echinoderm, Scavenger
One of the deepest-living sea cucumbers, it uses the ring of tentacles around its mouth to snuffle around in the mud for food. Sometimes, juvenile king crabs will hitch a ride on their bellies.
Source: https://inaturalist.ca/taxa/568142-Scotoplanes-globosa
Depth: 9870m
Depth: 9890m
Depth: 9940m
Depth: 10120m
Depth: 10525m · Depth range: 0–10937m · Average length: 23.8 m · Tags: Vehicle, Manned, Historic, Retired
On January 23, 1960, the Bathyscaphe was first crewed vessel to ever reach the Challenger Deep. It was designed by Swiss scientist Auguste Piccard, whose son, Jaques Piccard, piloted its historical descent alongside American oceanographer Don Walsh. In 1984, it was deactivated and is now on display at the National Museum of the US Navy in Washington D.C.
Depth: 10580m
Depth: 10825m · Type: Depth milestone
2nd deepest point on Earth
Depth: 10860m · Depth range: 10898m · Tags: Organism, Biology
Obligately barophilic, meaning it can only survive under extreme pressure. Discovered by ROV Kaiko in the Mariana Trench, Challenger Deep.
Depth: 10870m · Depth range: 0–11000m · Average length: 1.7 m · Tags: Vehicle, Autonomous, Full-ocean depth
A WHOI-built hadal AUV designed as part of a networked fleet of small, modular trench explorers — even repurposing leftover syntactic foam from James Cameron's Deepsea Challenger submersible. Rated to 11,000 meters, Deep Venture uses visual terrain-relative navigation to land softly on the seafloor and sample without disturbing the environment.
Source: https://www.whoi.edu/what-we-do/explore/underwater-vehicles/auvs/orpheus/
Depth: 10885m
Depth: 10900m · Type: Depth milestone
The deepest point of the ocean, named after the HMS Challenger Earth's first oceanographic research mission
Depth: 10915m
Depth: 10932m · Depth range: 0–11000m · Average length: 3 cm · Tags: Organism, Crustacean, Hadal
A scavenging amphipod discovered in the Mariana Trench in 2020, named after the microplastic fragments found in its gut at the time of its description. Its scientific name was deliberately chosen to highlight that human plastic pollution has now reached even the deepest places on Earth.
Source: https://inaturalist.ca/taxa/1044372-Eurythenes-plasticus
Depth: 10960m
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