Meet siphonophores, breathtaking jellyfish-like organisms

The 10 most amazing deep sea creatures

In this video, researchers from the world-renowned Monterey Bay Aquarium discuss the most fascinating deep sea creatures, and how they developed some of their strangest features.

View a gallery of animals found on abyssal plains, hydrothermal vents, seamounts, and other deep-sea habitats.

View a gallery of bioluminescent organisms, including jellyfish and mushrooms

Some species produce a quick flash of light, while others glow steadily with an eerie glow, often to seek attention or in response to being disturbed. Snails, worms, fungi, and other organisms highlight that this ability evolved independently, rather than from one common ancestor.

Underwater nighttime photos capture the ocean's diversity

Self-taught photographer Steven Kovacs explores Palm Beach's ocean after sunset, capturing tiny sea creatures in deep waters. Over eight years, he's dived into Florida's eastern coast, drifting from 0 to 100 feet, photographing rarely seen larval fish. Lacking formal marine biology training, Kovacs collaborates globally to identify species like cusk eels and the female blanket octopus, known for its revealing membrane. Check out his photos here.

Meet Cystisoma, the 7-inch crustacean with eyes for a head

In deep midwater, roughly 1,000 feet below the water's surface, completely transparent Cystisoma hide in plain sight from predators. Their retinas are splayed out thin across their disproportionately large eyes to avoid detection, and their entire bodies are transparent, difficult to see even as they are held in the palm of your hand. Learn more about the creatures here.

Massive blooms of microscopic algae called dinoflagellates produce the neon blue light seen in glowing tides.

Take an interactive dive and see the animals that populate the oceans, from coral near the surface to shrimp-like organisms near the seafloor.

The world's weirdest flowers

We mostly marvel at the beauty of flowers, but some kinds of flowers are incredibly weird. This video highlights 15 of the world's strangest flowers, from the massive Titan Arum to the rare Lady Slipper Orchid.

Coral reefs are built by thousands of coral polyps—tiny animals whose mouths both consume food and expel waste.

Divers capture a blanket octopus unveiling her billowing membrane

In a short clip captured during a blackwater night dive in the Lembeh Strait, a blanket octopus unfolds and displays a colorful web multiple times its original size. The aquatic animal’s iridescent body and tentacles glow against the nighttime...

An interactive of the deep sea

View a gallery of diatoms—algae surrounded by glass-like shells—captured via microscope.

What we know about the mysterious colossal squid

The colossal squid, the world's largest invertebrate, remained hidden from human discovery until nearly a century ago. Explore the world of the enormous and mysterious creature, including its features, habitat, and scientific significance. You can even plan a visit to the Museum of New Zealand Te Papa Tongarewa and marvel at a real-life display.

The love lives of pygmy seahorses

Inch-long pygmy seahorses live fascinating lives in the Coral Triangle of Southeast Asia, where the tiny sea creatures thrive. They are one of the few species in the world where the male carries its progeny to term, in this case, after receiving an egg from the female, who keeps busy checking in on her two male mates, one of whom is always pregnant. Dive into the marine romance in this fascinating essay.

The deep-sea fangtooth has the largest teeth of any marine species relative to body size

From transparent fish to the heaviest worms on the planet, these seven creepy creatures lurk in the deep sea. Learn all about them and the unique traits that help them survive and hunt.

Some organisms are composed of a single cell visible to the naked eye

By incorporating tough, cellulose-rich cell walls, rapid movement of molecules via cytoplasmic streaming, and other biological techniques, some unicellular organisms can bypass the physical limitations that restrict the size of cells. Organisms such as the Stentor coeruleus and Acetabularia can be seen without microscopes.

Watch this octopus win every single Escape Room challenge

Octopuses are famously intelligent, solitary creatures covered in hundreds of chemical-sensing suckers. They're also pretty fascinating pets, and even enjoy playing. The crew at OctoLab put one of its more playful mollusks into four different Escape Room-like cages to see how long it would take for it to escape. Watch this video to see the brilliant, if a bit unsettling, methods the animal uses.

The Turritopsis dohrnii jellyfish can reverse its life cycle

Discovered in the 1980s, this creature has been dubbed the "immortal jellyfish" for its ability to revert from medusa to polyp form and back, preventing it from dying of old age. However, the jellyfish remains prey to fish and turtles and is defenseless to sea slugs as a polyp.

Acetabularia jalakanyakae is one of the largest known single-celled organisms and is nicknamed the 'mermaid's wineglass' for its umbrella-shaped cap.

Research has found that when their symbiotic algae are not producing oxygen via photosynthesis, corals twirl hairlike structures to circulate water and draw oxygen into their outer tissues.

The fish can climb walls

Scientists in Brazil captured rare footage of bumblebee catfish climbing waterfalls. How they do it is clear, but why remains a mystery.

A look at how fish less than two inches long climb up 50-foot waterfalls

Shellears use tiny hooks on their front pectoral fins to grip rock like Velcro and take many pauses to recover energy between bursts of movement. Their pectoral girdle—an arch of bone—supports the muscle system needed for the roughly ten-hour climb.

What a tiny marine worm can tell us about our brains

Meet the amphioxus, a small eel-like animal that has a lot to teach us about brain evolution. The genetic roots of our brains can be seen in these unusual creatures. This three-minute educational video focuses on the evolutionary history of the human brain through these odd little critters with a 500-million-year-old history.

Deep water corals—located throughout the world's ocean basins at depths beyond 200 meters (660 feet)—slowly build small coral gardens in the dark with the help of underwater worms.

View a collection of glass sculptures of corals threatened by fishing and deep-sea mining.

The science of symmetry | The Royal Society

Nature is full of symmetries, from spiral galaxies to florets of broccoli. So why do complex creatures break the pattern?This short video discusses why symmetry came to dominate life on Earth, and how many complex life forms, such as humans, transitioned from radial to lateral symmetry.

One jellyfish species is biologically immortal

Turritopsis dohrnii is a type of jellyfish that can revert back to a juvenile stage after reaching sexual maturity, theoretically allowing it to stay alive for good. But that's a tough sell in a world full of predators. See this list of some of the longest-living species on Earth.

Watch David Attenborough's documentary on bioluminescent creatures, which have been observed using light for hunting, mating, communication, and self-defense, and number in the thousands of species.

Visualizing the 75 largest underwater animals

With so many fish in the sea, which are the largest? This infographic shows fantastic illustrations of the 75 largest sea animals, ranked by average size. The detailed visual is organized in descending order of size, starting with the blue whale,...

Take a 3D underwater trip near the Great Barrier Reef

The Great Barrier Reef is the world's largest coral reef system, comprising more than 900 islands and almost 3,000 individual reefs. This video lets you tag along with divers as they explore the reef off the southern coast of Lady Elliot Island in full 3D (use the direction buttons in the upper left of the video, or your keypad).

Biofluorescent animals—those that absorb light, such as ultraviolet rays, and re-emit other types of light, such as neon green—include some flying squirrels, scorpions, sea turtles, and platypuses.

See an anamorphic illusion of a massive crashing wave in South Korea

An enormous aquarium with perpetually crashing waves has popped up amidst an urban landscape in South Korea, but don’t expect to hear the water sloshing around if you walk by. Designed by District, the elevated tank is actually a massive anamorphic illusion. The digital media company created the pub

River dolphins manhandle an unlucky anaconda

The natural world around us is endlessly inspiring, and fascinating, and often very odd too: like when researchers snapped a photo of Bolivian river dolphins swimming around with a Beni anaconda snake in their mouths, for example.

View illustrations of bioluminescent functions in marine organisms

Bioluminescence can startle predators, camouflage, lure prey, confuse rivals, or facilitate mate recognition. One tactic—the burglar alarm—involves an organism releasing light to attract a larger predator to its attacker as a means of defense.

Watch insects and animal pollinators in slow motion

Louie Schwartzberg's "Moving Art" series showcases slow-motion footage of oceans, forests, deserts, flowers, and more. In this excerpt, organisms such as bats, monarch butterflies, bees, and hummingbirds are shown interacting with one another and with flowering plants.

Despite being multicellular and photosynthetic, organisms such as kelp and sea moss are macroalgae, not plants, because they lack specialized roots and stems to pump water.

Over 1 million fish, marine mammals, and invertebrate species depend on coral reefs for habitats, camouflage, and food.

The world's largest species of marine algae is giant kelp, which can grow as much as two feet per day from depths of about 100 feet up to the ocean surface.

Solutions of bioluminescent bacteria can create FOMO-inducing living art

A 2002 exhibition at Montana State University-Bozeman placed the bacteria onto petri dishes that served as macroscopic pixels to create images. Once the bacteria finished eating all the food in the sealed dishes, the light slowly faded away, ending the exhibit.

Watch underwater photosynthesis make water look like champagne

In shallow waters where sunlight can reach, photosynthetic reactions absorb water and dissolved carbon dioxide, producing bubbles of oxygen at the surface of plants. As these bubbles rise to the water's surface, a fizzy appearance is created.

As of 2026, the Great Atlantic Sargassum Belt is the world's largest macroalgal bloom, with seaweed stretching from the Caribbean to West Africa.

The Southern Ocean features the Antarctic Circumpolar Current—the largest ocean current on Earth—which encircles Antarctica and creates a unique biogeographical zone.

Listen to recordings of different fish species

Scientists have captured and curated this collection of species-specific recordings, helping us gain a deeper understanding of underwater ecosystems. Uncover their sounds, which include a lot of thumps, burps, and grunts.

Explore the deepest parts of the ocean

The deeps of the Earth's oceans are some of the most extreme environments on the planet. Take a trip 36,000 feet to the deepest parts of the sea in this informative, 10-minute animated video.

Watch how deep-sea mining equipment collects and processes polymetallic nodules—metal-rich, potato-shaped rocks—from the ocean floor and creates environmentally damaging plumes of sediments.

Fish populations in the Great Barrier Reef have increased after installing waterproof speakers on the ocean floor that played recordings of sounds from healthy coral reefs.

Watch a diving expedition through the world's longest coral colony, which spans more than a football field and whose exact location is kept secret for its protection.

The first appearance of bioluminescence was at least 540 million years ago

After analyzing fossils, genetic data, and statistical methods, scientists believe octocorals were the first organisms to evolve light-producing abilities. As a result of independent evolution across at least 94 species, this phenomenon is connected to a diverse range of behaviors.

Korea's "real-life mermaids"

Explore the incredible world of Haenyeo, Korea's female freedivers who dive to depths of up to 60 feet without oxygen tanks. These amazing women have been practicing this ancient tradition for centuries, and yet, their story remains largely unknown.

Take an interactive tour through Australia's Great Barrier Reef, featuring spherical panoramas of marine wildlife, including manta rays, loggerhead turtles, and bottlenose dolphins.