The ocean is full of uncharted territory—and of breathtaking natural wonders that look as tough they might hail from another planet. From sea anemone to sun coral, these 6 stunning underwater organisms offer an ethereal beauty hard to reproduce on land.
Green Sea Anemone
This vibrant green sea anemone bears a strong resemblance to the land-based Anastasia flower, a type of spider chrysanthemum. Most of the anemone’s color occurs because of the symbiotic relationship it has with the photosynthetic organisms that live in its tissues. Like other anemones, these attach themselves to hard surfaces—like rocks and coral reefs—to wait for fish that inadvertently swim into their stinging tentacles.
Kelp is especially stunning when seen from below because it can look just like lush, leafy woodland. Nutrient-rich kelp may show up on the beach as torn piles of seaweed, but underwater it has a whole different life. A type of brown algae, this plant can grow up to 18 inches per day and can reach depths of up to 131 feet—hence why their habitats are called kelp forests.
When scientists stumbled upon a kelp forest in the Pacific Ocean in 2007, the discovery highlighted how much we still have to learn about the world's waters. Prior to this discovery, biologists thought kelp could not grow in warm tropical waters.
Open Brain Coral
It's clear how open brain coral got its name: The invertebrate—known scientifically as Trachyphyllia—exhibits a flabello-meandroid growth pattern in which curling valleys and fleshy walls are visible on its exterior. A type of stony coral, open brain coral are near threatened due to the reduction of coral reef habitat and harvesting for aquariums. This species of coral is small, less than eight inches, and is both solitary and colonial. It may be found among other types of free-living coral. It is found in the warm, shallow waters of the Indo-Pacific.
Despite the name, sun coral are a species of coral that don't require much sunlight. They are deep-sea dwellers that make their homes in caves and other dark spaces. They get the energy they need (and their yellow to bright-orange color) by feeding on zooplankton. They're also the only stony coral that set up permanent digs in the Caribbean after invading the ocean in the ballasts of ships coming from the Indo-Pacific, this coral's native ocean.
Feathery soft corals make up this bouquet of brightly-colored sea life. Soft coral are members of the Octocorallia subclass, named for their "eightfold radial symmetry," which means they have eight smaller pieces that branch off of each main tube to give the downy appearance. Soft coral, which have significant variation in shape and size, can thrive in deep water or shallow tropical water.
The vibrant hue of this lilac-looking purple coral isn't the only striking thing about it: Though the color is rare, acropora coral is one of the most plentiful types of coral. It's immensely beneficial, too, as it provides a habitat for fish and other sea life. These corals are also a reef-building species, which means they're often the first on the scene of a new reef, and they spread to provide homes for other corals.