Our oceans and seas are a hotbed of strange nature, dwelling to a few of the most exceptional species recognized to science. In these excessive ecosystems, weird creatures thrive and carry out feats that scientists as soon as thought have been unattainable.
On this record, we plunge beneath the waves to discover a few of the most shocking life types that the marine world has to supply. We’ll soak up worms that eat skeletons, catfish that may climb waterfalls, and steamy leopard shark trysts. From tiny dolphins to poisonous blue dragons, listed below are ten of the strangest aquatic species from throughout the globe.
Associated: 10 Extremely Unsettling Issues We Nonetheless Don’t Know concerning the Ocean
10 World’s Smallest Dolphin
The smallest marine dolphins recognized to science are Hector’s dolphins—tiny divers with a knack for dazzling acrobatics. They develop to round 4.5 ft (1.4 meters) lengthy and might be discovered racing by means of the waters off New Zealand. These close to the North Island fall below the critically endangered Māui subspecies, whereas their cousins are referred to as South Island Hector’s dolphins.
Hector’s dolphins can dive to spectacular depths for his or her small measurement. The petite swimmers plunge to round 400 ft (120 meters), flipping and rolling like acrobats as they descend. In a 2025 research, College of Auckland researchers fitted 11 South Island Hector’s dolphins with monitoring tags and have been surprised by their vary. One swam 9.3 miles (15 kilometers) alongside the coast.
At shallower depths, the dolphins drift slowly to grab cod and flatfish. Halfway up, they plow by means of the water, snapping at colleges of smaller fish as they go.[1]
9 Leopard Shark Tryst
In 2024, marine biologists found simply how steamy shark courtship can get. In a world first, Australian scientist Hugo Lassauce filmed three leopard sharks mating collectively on the seabed.
Researchers know little or no about how these freckled fish reproduce within the wild, as most research have targeted on captive specimens. The brand new footage, captured close to New Caledonia within the South Pacific, was the primary time leopard sharks had been caught on digicam mating of their pure habitat. Lassauce got here throughout two males participating with a feminine throughout a dive and filmed the trio for 90 minutes.
The encounter wasn’t precisely romantic for the feminine—each males bit her pectoral fins and held on whereas she struggled to interrupt free. When it was over, the males lay exhausted on the seabed whereas the feminine swam off.
Leopard sharks (Stegostoma tigrinum) are endangered, and scientists hope that new insights into their reproductive conduct might assist conservation efforts. Lassauce plans to proceed learning how the species breeds and raises its younger within the wild.[2]
8 Elusive Blue Dragons
The oceans are dwelling to a few of nature’s most surreal creatures, together with the beautiful blue dragon—Glaucus atlanticus. These dazzling sea slugs drift on their backs by means of tropical and temperate waters, floating wherever the currents take them.
Their iridescent coloring isn’t only for present. The blue and silver hues camouflage them in opposition to the waves, hiding them from predators each above and under. Blue dragons feed on different surface-dwelling marine creatures, resembling by-the-wind sailors and violet snails, however their favourite prey is the Portuguese man o’ battle. They devour the person o’ battle’s tentacles and retailer its stinging cells inside their very own tissues, able to unleash them if threatened.
Blue dragons are weak swimmers and sometimes wash ashore when winds and tides shift. In 2024, a number of washed up on Texas seashores. Regardless of their magnificence, specialists warn beachgoers to not contact them—their borrowed toxins may cause painful stings or much more extreme reactions.[3]
7 Gravity-Defying Catfish
In 2024, officers in Rochedo, Brazil, made a exceptional discovery. They witnessed hundreds of bumblebee catfish scaling the slippery rock face of a waterfall within the Aquidauana River. Usually, these orange-and-black striped fish dwell on the backside of fast-moving streams—however come dusk, they start climbing.
Scientists have been baffled. How might fish ascend a vertical waterfall? By analyzing their actions, researchers discovered that the catfish use specialised fin placements and suction-like strain bubbles to cling to the rocks. They imagine the tiny climbers make the ascent to achieve slender upstream channels the place they breed.
No matter their motive, these miniature mountaineers proved that nature at all times finds a manner.[4]
6 Historical Bone-Munching Worms
On the ocean flooring, some worms reside as much as a grim popularity. For greater than 100 million years, bone-eating worms have feasted on the stays of fallen sea creatures.
When massive animals die and sink, scavengers strip away the flesh, leaving the skeletons to turn out to be meals for huge colonies of bone-eating worms. These deep-sea dwellers, referred to as Osedax, burrow into bones and soak up fat and proteins with the assistance of symbiotic micro organism.
Fashionable Osedax worms are discovered on the carcasses of whales and different massive animals. Fossil proof reveals that their ancestors as soon as consumed the bones of huge marine reptiles resembling plesiosaurs and ichthyosaurs. They don’t have any mouth or digestive tract, making their distinctive methodology of feeding certainly one of evolution’s most weird variations.[5]
5 Squishy-Headed Barreleye Fish
Deep within the northern Pacific Ocean swims certainly one of nature’s strangest-looking fish. With inexperienced, tubular eyes and a clear head, the barreleye appears to be like like one thing out of a science-fiction film.
Scientists hardly ever see these shy, slow-moving fish. Their dome-shaped heads are crammed with a transparent fluid that cushions and protects their upward-facing eyes. Barreleyes sometimes hover in near-darkness, gazing upward to identify silhouettes of potential prey. As soon as they find meals—tiny crustaceans or zooplankton—they will rotate their eyes ahead to trace and intercept it.
Researchers imagine Macropinna microstoma typically steals its meals from siphonophores and different gelatinous creatures drifting within the deep.[6]
4 Big Marine Viruses
When individuals think about underwater threats, sharks and octopuses often come to thoughts. However lurking within the Pacific are different monsters—large viruses that dwarf most recognized pathogens. Some carry hundreds of genes and boast advanced tails extra paying homage to alien equipment than biology.
One standout is PelV-1, found in 2024. Most viruses with tails are tiny, however PelV-1 has a most important shell about 200 nanometers huge and a unprecedented tail stretching 2.3 micrometers—the longest recognized within the viral world. For comparability, that’s roughly 19 instances longer than a complete coronavirus particle.
Scientists assume PelV-1’s tail helps it penetrate host cells and infect plankton. As soon as inside, the tail disintegrates, forsaking a viral manufacturing unit prepared to duplicate. Even on the microscopic scale, the ocean has its share of monsters.[7]
3 Supergiant Amphipods
On the backside of the ocean lives a shrimp-like large roughly the scale of a loaf of bread. These ghostly crustaceans, known as supergiant amphipods, are among the many largest members of their type.
Alicella gigantea belongs to a household of over 10,000 amphipod species, however none come near its measurement. Measuring as much as 13 inches (34 centimeters) lengthy, it was first recorded within the Nineteen Seventies within the North Pacific Ocean. For many years, scientists assumed it was uncommon, however a 2025 research proved in any other case.
By analyzing DNA information and a long time of data, researchers discovered that these pale behemoths may inhabit as much as 59% of the world’s oceans—together with all six main ocean basins. Removed from being elusive, A. gigantea could also be one of many deep sea’s quiet success tales.[8]
2 Portuguese Man o’ Battle
The Portuguese man o’ battle is likely one of the ocean’s strangest organisms—and it’s not even a single creature. What seems to be one jellyfish-like physique is definitely a colony of specialised clones known as zooids, all working collectively as one.
This association is named a siphonophore. Every zooid performs a particular activity: one retains the colony afloat, whereas others deal with searching, digestion, and copy.
The Portuguese man o’ battle (Physalia physalis) will get its title from its resemblance to an 18th-century warship. Its blue, violet, or pink float drifts on the floor whereas tentacles path under, typically stretching 30 ft (10 meters). These tentacles are lined with venomous stinging cells highly effective sufficient to paralyze small fish and different prey—and painful sufficient to depart people in agony.[9]
1 Beautiful Glass Octopus
Few marine species are as mesmerizing because the glass octopus. This practically clear cephalopod reveals its interior workings—eyes, optic nerves, and even its digestive tract—by means of a ghostly clear physique.
Solely a handful of individuals have ever seen Vitreledonella richardi within the wild. These ten-tacled wonders glide by means of tropical waters roughly 3,000 ft (900 meters) under the floor and develop to about 1.5 ft (0.5 meters) lengthy.
A lot of what we find out about glass octopuses comes from specimens discovered inside predators’ stomachs. However in 2017, scientists from the Schmidt Ocean Institute captured uncommon video footage of two dwelling people throughout a deep-sea expedition within the Pacific—providing a fascinating glimpse into certainly one of nature’s most mysterious creatures.[10]
