Invertebrates

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From the giant squid to microscopic squid babies, squids are beautiful and fascinating. As cephalopods, the same family as octopuses and cuttlefish, they have no bones, and swim head-first through the water with their...
Since summer 2013, starfish along both coasts of the United States have been...
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Tiny plant-like organisms called zooxanthellae live in the tissues of many...
I have been at the Smithsonian’s National Museum of Natural History since 1966...

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Discovering new species is an exciting quest, right? Well, some parts are—but after you find a cool-looking organism that you think is a new species, there's a lot more to be done. You have to confirm that it's new, write a...
How does a coral spend its day? Most of us would say: not doing much. To the...
The blue crab ( Callinectes sapidus ) is one of the most important...

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Jellyfish and comb jellies are gelatinous animals that drift through the ocean's water column around the world. They are...

The Ocean Blog

This nudibranch, or shell-less marine snail, is making a comeback to a location it hasn't been to in years along the California coast. First discovered off the coast of Southern California in 1902,...
This tiny, shrimplike creature is no more than 2.5 centimeters (1 inch) long, but it’s as ferocious as a shark. Its giant eyes spot prey. Huge claws grab the prey, and a tiny mouth rips it to shreds...
A morning sun star ( Solaster dawsoni ) loses its grip on a rock surface as its body slowly decomposes from starfish wasting syndrome off the coast of Vancouver in September 2013. These photos are...
Adaptation is the key word if you are looking to survive in a tide pool, a space that some scientists describe as the most competitive real estate in the ocean. Tide pools are exposed to the water's...
Nudibranchs are a kind of sea slug, and their 3000 species are found from the poles to the tropics in both shallow and deep water. Though they often only reach two centimeters in length, they are...
Dr. Clyde Roper discusses the fascinating anatomy of the giant squid ( Architeuthis dux) in this excerpt of "Eyeball to Eyeball," an episode of Errol Morris' First Person television series. Watch...
Discovering new species is an exciting quest, right? Well, some parts are—but after you find a cool-looking organism that you think is a new species, there's a lot more to be done. You have to...
Atolla tenella , a midwater scyphomedusa , as seen under a microscope. View the “Under Arctic Ice” photo essay to learn more.
This purple urchin Paleopneustes cristatus is seldom seen by itself, and can be found in groups of hundreds. Dr. Dave Pawson , a senior scientist at NMNH who studies deep-sea echinoderms, is testing...
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,...
This summer, many of you have likely enjoyed feasting on crabs, be they blue, stone, or Dungeness, and a special treat will have been the big, easy morsels of claw meat. The size of this muscle is...
Census of Marine Life researchers discovered this unusual transparent sea cucumber ( Enypniastes sp.) in the Gulf of Mexico at 2,750 meters depth. It creeps forward on its tentacles pretty slowly, at...
A coral hermit crab, Paguritta harmsi , about the size of two grains of rice, living in coral in the waters of Japan's Ogasawara Islands.
A pile of sea stars decomposing from starfish wasting syndrome on the coast of Vancouver in September 2013.
Riftia tubeworm ( Riftia pachyptila ) colonies grow where hot, mineral-laden water flows out of the seafloor in undersea hot springs—such as the Guymas Basin of the Gulf of California at 2,000 meters...
This deep-sea black coral from Hawaii ( Leiopathes sp. ) is more than 4,200 years old. Black corals are named for the color of their skeletons, but the external tissues of black corals come in many...
With 1,400 named species of ribbon worms inhabiting every ecosystem on earth, seeking one out should be an easy proposition. But I quickly learned that it can be quite daunting when you’re looking...
This close-up photo shows the tough, serrated ring around the opening of a giant squid sucker. The ring is made of chitin—the same material that’s in your fingernails. Using suction, the sucker...
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