9 Unexpectedly Beautiful Sea Creatures

The shrimp mantis is neither shrimp nor mantis, but its name comes from its close resemblance to a praying mantis and, well, shrimp. (Photo: Jens Petersen [CC SA 3.0]/Wikimedia Commons)

You've likely oohed and ahhed at playful dolphins and majestic blue whales, but when's the last time you gave a shout-out to the humble snail or mollusk? This summer, a lobsterman in Maine took the Internet by storm (pun intended) when he posted a 1 in 100 million catch: a "cotton candy" lobster. The purple, pink, and blue crustacean practically sparkled in its prettiness, and got us wondering: what other overlooked beauties might lurk below the sea?


Nembrotha cristata, a species of a colorful sea slug, pictured at Lekuan II dive site, Bunaken Marine National Park, North Sulawesi, Indonesia. (Photo: Chriswan Sungkono [CC SA 3.0]/Wikimedia Commons)

Nudibranchs are probably better known by their street name, sea slugs. These soft-bodied marine mollusks include more than 3,000 species and live in seas all over the world. They're anything but sluggish, though; these gastropods are hermaphroditic and carnivorous, and some are even cannibals.

Coconut octopus

The coconut octopus is notable for using tools to catch prey — namely, seashells and coconut shells. (Photo: Rickard Zerpe [CC by 2.0]/Wikimedia Commons)

Watch this video of a coconut octopus casually walking on two legs and you might never order pulpo gallego at a tapas restaurant again. This cephalopod is one of the most intelligent invertebrates around, gathering and saving coconut shells and seashells as shelters to hide in before attacking their prey.

Brittle star

A green brittle star in the UK's Chester Zoo. (Photo: Neil [CC by SA 3.0]/Wikimedia Commons)

Closely related to starfish, brittle stars move briskly along the seafloor, thanks to their long, slender arms. They're also excellent multitaskers, with a five-jawed mouth that also serves as an anus (eek!), and the ability to regenerate lost arms.

Mantis shrimp

A peacock mantis shrimp strikes a pose. (Photo: Rickard Zerpe [CC by SA 2.0]/Wikimedia Commons)

Neither a shrimp nor a mantis, this stomatopod may look cute but is considered the world's "deadliest shrimp." Only four inches long, it uses its tiny but powerful clubs to break the shells of its prey. In fact, when being studied, scientists must keep them in thick plastic tanks because their powerful punches can actually break glass.

Leafy seadragon

A leafy sea dragon near Australia's Kangaroo Island. (Photo: James Rosindell [CC SA 4.0]/Wikimedia Commons)

The king of camouflage, these "leafies" live amongst kelp and seaweed in the waters off south and east Australia. Their reproductive systems are as progressive as their seahorse cousin, with males incubating their eggs on the underside of their tail until they hatch. Divers often caught and kept them as pets until the Australian government placed protective regulations on them in the 1990s.

Flying gurnard

The flying gurnard goes for a swim in the Mediterranean off Greece. (Photo: Beckmannjan [CC by SA 3.0]/Wikimedia Commons)

Just check out the gorgeous wingspan on these underwater creatures! Gurnards usually keep their huge pectoral fins held close against their body, but they flare out spectacularly when a predator is near. And in case you're wondering, gurnard is derived from French for "grunt," which is exactly the sound their swim bladder makes as water moves through it.

Christmas tree worms

Assorted Christmas tree worms take shelter on a coral reef. (Photo: Nick Hobgood [CC SA 3.0]/Wikimedia Commons)

These spiraled beauties are scattered throughout oceans worldwide, but you'll most likely find them setting up shop on a stony coral. Their feathery "crowns" act as both a filter for food and a harness for oxygen, with each worm having two trees. They can live as long as 40 years, making them a much better investment than your typical Christmas fir tree.

Enypniastes eximia

This benthopelagic sea cucumber enjoys swimming in freezing waters. (Photo: NOAA Okeanos Explorer [public domain]/Wikimedia Commons)

These deep-sea sea cucumbers were not caught on camera until 2017, though they were discovered sometime in the 1880s. Unkindly called a "headless chicken monster" by scientists, the see-through animal has the important job of filtering sediment on the ocean floor. It doesn't have a true brain or sensory organs, but you can watch its entire digestive system at work! Because after all, beauty really is in the eye of the beholder.