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The ocean is home to a phenomenal diversity of marine organisms. They have evolved to inhabit warm waters near the equator and the icy waters of the Earth’s poles. Marine life takes advantage of...
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This summer, many of you have likely enjoyed feasting on crabs, be they blue,...
Zombie worms don’t crave brains: instead they seek bones. The 1 to 3 inch (2 to...
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Today’s discoveries about our planet’s biological diversity build upon the...

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The whitish spots on this fish are individual parasitic trematode worms. Trematodes have complicated life cycles that usually involve multiple hosts -- often starting in a snail and then moving on to other hosts, such as fish,...
Talk about an investment! This octopus mom protected her brood of about 160...
This deep-sea black coral from Hawaii ( Leiopathes sp. ) is more than 4,200...

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Nudibranchs are a kind of sea slug, and their 3000 species are found from the poles to the tropics in both shallow and deep...
Dr. Clyde Roper, squid expert, explains how he developed a passionate interest in the giant squid ( Architeuthis dux) in this excerpt of "Eyeball to Eyeball," an episode of Errol Morris' First Person...
A chambered nautilus shell.
Smithsonian squid expert Dr. Clyde Roper collaborated with National Geographic to attach this Crittercam to the head of a sperm whale, hoping to get footage of the whale’s favorite prey—giant squid...
Nudibranchs are mollusks that have evolved from shelled ancestors. Like the reddish-orange Coryphella verrucosa shown here, they're often noted for their vibrant colors and striking forms. View other...
Most wild seahorses (here the thorny seahorse Hippocampus histrix ) are monogamous and some species mate for life. Searching for mates can be difficult and risky since seahorses are poor swimmers,...
Weighing 600 pounds (around 272kg) and having a 30 foot (around 9 meters) arm span, the largest recorded giant pacific octopus was truly enormous. Giant pacific octopuses are powerful predators that...
Anemones are known for serving as homes for Nemo and countless other small fish and invertebrates. But these Cnidarians (in the same phylum as jellyfish and same class as corals ) have a long journey...
An orange brisingid starfish sits on a large reef of Lophelia pertusa, cold-water corals in the Gulf of Mexico, at 450 m depth as a school of fish swims above. They have many arms—up to 20!—covered...
Staghorn (seen here) and elkhorn corals are listed as Threatened under the U.S. Endangered Specis Act, as their numbers have fallen catastrophically due to disease. Listed in 2006, they were the only...
Recently, Smithsonian National Museum of Natural History researcher Chris Mah and collaborators with the British Antarctic Survey and the Monterey Bay Aquarium Research Institute used molecular tools...
Sample the surprising diversity of deep-sea corals. See some of the ways they differ in color, shape, and size. Explore more in the multimedia feature " Coral Gardens of the Deep Sea ."
Talk about an investment! This octopus mom protected her brood of about 160 eggs for 4.5 years for the longest ever recorded brooding time of any animal. She was first observed by scientists from the...
Squids come in a wide range of sizes but despite differences in size and shape, all work basically the same way inside. More about the giant squid can be found in the Giant Squid section .
It’s an honor to have something or someone named after you. Dr. David Pawson , Senior Research Scientist and Curator of Echinoderms at NMNH, has several genera and species, living and fossil, named...
A mass of white muscle the size of a softball surrounds the dark brown beak of a giant squid. Learn more about this animal's oversized anatomy in our Giant Squid section .
All over the world, people have been witnessing gigantic blooms of tens of thousands of jellyfish where once there were only a few. Fishers find them clogging their nets and costing them dearly. In...
Each month, the Naked Oceans podcast invites a leading marine researcher to pick the "critter of the month" by asking: if you were a marine organism, which one would you be? This month, Dr. Nancy...
A blue cod and sea pens , a unique type of cnidarian , speckle the seafloor in New Zealand's Fiordland region.You can see more beautiful underwater photos from Brian Skerry in his image gallery .
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