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Depending on whom you talk to, jellyfish are either fascinating, a nuisance, a toxic menace, or some combination of the above. Jellyfish plop into the media spotlight when their presence causes beach closures, or...
The ocean is home to a phenomenal diversity of marine organisms. They have...
What reef animal comes in a rainbow of crazy colors, can throw out its stomach...
This summer, many of you have likely enjoyed feasting on crabs, be they blue,...

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This pair of sea butterflies ( Limacina helicina ) flutter not far from the ocean's surface in the Arctic. Sea butterflies are a type of sea snail, but instead of dragging themselves around the seafloor with a muscular foot, they...
The sea hare gets its common name from its equivalent of nose and tongue—...
“Upon returning from the reef after a night dive, I swam toward a bright...

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Giant squid live up to their name: the largest giant squid ever recorded by scientists was almost 43 feet (13 meters) long,...

The Ocean Blog

This pair of sea butterflies ( Limacina helicina ) flutter not far from the ocean's surface in the Arctic. Sea butterflies are a type of sea snail, but instead of dragging themselves around the...
This male giant squid is on display in the Sant Ocean Hall at the Smithsonian’s National Museum of Natural History . It measures about 2.7 meters (9 feet) long and weighs a little more than 45.5...
A smasher mantis shrimp came out from its burrow on a fringing reef adjacent to the USS Liberty ship wreck in Tulamben, Bali, Indonesia at a depth of 6 meters. The smashers use their raptorial claw...
Amidst the bright blue tufts and the dark blue fringes of the beautiful Risbecia tryoni , you might not even notice the red emperor shrimp. The two animals are native to the Indo-Pacific region, and...
Octopuses are colorblind, but manage to blend into the background seamlessly—or stand out in bright color to startle their enemies. So how do they do it? That's the question Roger Hanlon of the...
Named for the radiant blue color on its back and sides, the blue shark ( Prionace glauca ) traverses the world’s temperate and tropical seas. Known for traveling great distances and being a swift...
This ctenophore (a stingless jellyfish-like animal) is native to the east coast of North and South America. In 1982, it was discovered in the Black Sea, where it was transported by ballast water . It...
Ochre seastars ( Pisaster ochraceus ) feed on invertebrates, such as coral and shellfish, like the mussels pictured here. The starfish forces open the shell with suction disks on the underside of its...
In 1874 Reverend Moses Harvey of Newfoundland displayed the giant squid he bought on the side of his barn, much to the dismay of Mrs. Harvey. More about the giant squid can be found in our Giant...
Bottom trawl treasures from the shallow Chukchi Seafloor near the Canada Basin: sea stars , brittle stars , clams, some snails and crabs. View the “Under Arctic Ice ” photo essay to learn more.
These deep-sea photographs show a variety of broad-collared enteropneusts or acorn worms . These wormlike animals make spiral tracks on the sea floor. All the species shown here are new to science,...
The toothy goby or common ghost goby ( Pleurosicya mossambica ) lives among soft corals and sponges in the Indo-Pacific ocean. The relationship it has with its host is commensal , which means the...
These cancer cells have been treated with discodermolide, a chemical obtained from a sponge that grows on deep-sea coral reefs. It prevents the cells from dividing and spreading. Learn more about...
A specimen from the Smithsonian’s squid collection and videos of a mystery squid helped scientists identify a new family of deep sea squid—the Magnapinnidae, known as the bigfin squids. More about...
This forest of Christmas tree worms is a group of polychaete worms that live on tropical coral reefs. See more celebratory ocean creatures in our slideshow!
The yellow bioluminescent ring on this female octopus ( Bolitaena pygmaea ) may attract mates. Bioluminescence is an important adaptation that helps many deep sea animals survive in their dark world...
This nudibranch has a few tricks up its sleeve: it steals jellyfish tentacles to use as weapons again its own enemies. How does it do this? Many fleshy, tentacle-like growths, called cerata (singular...
For a long time, scientists thought that some small tentacled fossils were early ancestors of jellyfish. But a new study has found that these ancient animals are actually related to an entirely...
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