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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...
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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The blue crab ( Callinectes sapidus ) is one of the most important commercial species in the United States, especially in the Chesapeake Bay region on the Mid-Atlantic coast. Its populations are affected by local water quality,...
Like this ctenophore ( Aulococtena acuminata ), many animals that live in...
Sponges are animals that eat tiny food particles as they pump water through...

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Coral reefs are the most diverse of all marine ecosystems. They teem with life, with perhaps one quarter of all ocean...

The Ocean Blog

This 1874 photo of a squid draped over a bathtub was the first ever taken of a giant squid. It belonged to the Reverend Moses Harvey of Newfoundland. More about the giant squid can be found in the...
Many expeditions in the Arctic reveal new species, such as this jellyfi sh Bathykorus bouilloni , which, strangely, has only four tentacles! Dr. Kevin Raskoff from California State University,...
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...
Bright colors seem to jump off of this comb jelly, or ctenophore. The rainbow effect appears when light emanates from comb jellies' namesake combs, which are rows of cilia that run up and down their...
Polarized sunglasses have become the norm for humans when they want to filter out the strong glare from the sunlight bouncing off of water in a horizontal direction. But how do animals do that live...
Dr. Karen Bice studies the foraminifera in ocean sediment to better understand climate change. More about scientists studying world climate change can be found in our Climate Change featured story .
This jelly’s red color provides camouflage in the deep ocean. Red light rarely reaches those depths, and most deep-sea animals have lost the ability to see red. The long, complex tentacles of this...
The blanket octopus can rip a poisonous tentacle from a Portuguese man-o-war and wield it like a sword to ward off enemies as it soars through the ocean trailing its webbed cloak behind it...
A humboldt squid ( Dosidicus gigas )—also known as the jumbo squid—releases a cloud of ink at night in Mexico's Sea of Cortez. These large, carnivorous squids can reach more than 5 feet in length and...
Squids come in a wide range of sizes, from smaller-than-your-thumb to the enormous giant squid. Giant squid grow up to 16 meters (50 feet). Learn more the life, range, and ecology of the giant squid...
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 .
The mauve stinger’s ( Pelagia noctiluca ) name in German means “night light,” referring to the jelly’s reddish coloring and its bioluminescence, the display of light by a living creature. Unlike a...
“Upon returning from the reef after a night dive, I swam toward a bright reflection and came eye-to-eye with this beautiful, curious squid," said Charles Viggers, a Nature's Best photographer. Squids...
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 .
A small horseshoe crab ( Limulus polyphemus ) rests on seaweed in Stage Harbor, Massachusetts. Atlantic horseshoe crabs can be found along the coast of North America from the Yucatán Peninsula to...
Light refracts off the comb-rows of the Mertensia ovum , a ctenophore , producing stripes of rainbow colors . The jelly eats copepods and small crustaceans that become stuck to its sticky tentacles...
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...
Sea cucumbers might have a cucumber shape, but are definitely animal, not vegetable… or fruit. They belong to the Phylum Echinodermata , which also includes sea urchins, sand dollars, sea stars and...
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