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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...
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I have been at the Smithsonian’s National Museum of Natural History since 1966...

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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 around 2 centimeters per...
Smaller than the head of a pin, this arrow squid (Doryteuthis plei ) embryo...
Anemones are known for serving as homes for Nemo and countless other small...

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Jellyfish and comb jellies are gelatinous animals that drift through the ocean's water column around the world. They are...
Several species of amphipod like this one, Gammarus wilkitzkii , live permanently within Arctic sea ice . These animals are endemic, meaning they only live here. They acclimate to a wide range of...
Despite the cold and dark environment, soft-bodied animals like anemones abound under the ice. Using their sticky arms, they grab zooplankton, which can be hard to come by during the long winter with...
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,...
Like it or not, giant squids are related to snails, clams, and even slugs. They are all mollusks and have soft, fleshy bodies. More can be found in the Giant Squid section .
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...
Dr. Clyde Roper, Smithsonian zoologist and squid expert, tries to measure up to a giant squid specimen (Architeuthis) from New Zealand. The squid wins. More about the giant squid can be found in our...
A sea star , Hymenaster pellucidus , brought up from a benthic ROV dive. View the “Under Arctic Ice” photo essay to learn more.
The shrimp shown in this picture is a lot smaller then it looks- most adult anemone shrimp will only grow to about ½-1 inches long. Anemone shrimp ( Periclimenes inornatus ), reside as the name...
From parrotfish that cover themselves in a blanket of their own mucus to tiny pygmy sea horses, there are some bizarre sea creatures that live in coral reefs . In this slideshow you can explore some...
Marine biologists from MBARI nicknamed this startlingly large jellyfish—which grows over one meter (three feet) in diameter—"big red." It would be hard to miss, except that it lives at depths of 650...
Scypholanceola aestiva looks like an armored alien of the deep. It doesn’t have compound eyes like other hyperiids, but instead sees variations in light using reflective cups embedded in the...
A chambered nautilus shell.
Like other cephalopods, the common cuttlefish ( Sepia officials ) is no dummy. But while octopuses are quick to learn manual tasks like opening jars, cuttlefish have a different skillset: the social...
Chrysaora melanaster , one of the largest jellyfish commonly found in the Arctic, swims underneath the Arctic ice . Its tentacles can stretch to more than 3 meters long and pack a mean sting for...
Collect, sort, identify, photograph, sample, record. Repeat a couple thousand times. This is what the students and researchers have been doing as the Indonesian Biodiversity Research Center (IBRC)...
Ari Daniel Shapiro is joined for this episode of One Species at a Time by serious beachcombers along the high-tide line of Sanibel Island, Florida. These “shellers” come in search of beautiful sea...
The veined octopus ( Amphioctopus marginatus ), also known as the coconut octopus, has a skill beyond other cephalopods: it hides under animal and coconut shells, dragging them along the seafloor for...
Fever. Aching muscles. Coughing. Sniffling. It’s flu season . Have you had your shot? If so, thank a horseshoe crab. In fact, if you’ve been put on an IV, had a medical device implanted, or received...
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