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Tiny plant-like organisms called zooxanthellae live in the tissues of many animals, including some corals , anemones, and jellyfish , sponges, flatworms, mollusks and foraminifera . These microscopic algae capture sunlight and convert it...
I have been at the Smithsonian’s National Museum of Natural History since 1966...
Collect, sort, identify, photograph, sample, record. Repeat a couple thousand...
Boring sponges get a bad rap. Their own name betrays them, announcing to the...

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How does a coral spend its day? Most of us would say: not doing much. To the human eye, a coral looks relatively still, waiting in the current and hoping some food will run into its tentacles. But this video "Slow Life" by marine...
The blue crab ( Callinectes sapidus ) is one of the most important...
Like this ctenophore ( Aulococtena acuminata ), many animals that live in...

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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...

The Ocean Blog

Massachusetts ceramics artist Joan Lederman glazes her work —including this bowl—with deep sea sediments. Some contain tiny single-celled organisms called foraminifera. Lederman has noticed that...
A thicket of white stony coral ( Lophelia pertusa ) shelters a squat lobster (Eumunida picta). This is the typical shape of this widespread species of deep-sea coral. See more pictures of coral in...
Hermit crabs, like this one collected in Moorea, usually protect their soft, vulnerable abdomens from predators by reusing empty snail shells. They are picky home owners and they will trade shells...
A huge colony of brittlestars (likely Ophiacantha rosea ) covers the peak of a seamount in the deep ocean. What’s the attraction? Food! Their arms reach out for tiny food particles carried by the...
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...
This 200-year-old bamboo coral colony is growing on the Davidson Seamount off the coast of California. The skeleton of this deep-sea coral has bamboo-like segments. See more pictures of coral in our...
Tectitethya crypta (formerly known as Cryptotheca crypta ) is a large, shallow-water sponge found in the Caribbean. It was first studied for medical purposes in the 1950s when few scientists or...
You may not think of the ocean as a pharmacy but scientists are developing exciting new medicines from the sponges, corals, and other marine organisms found in the sea. Explore other videos that...
The Arctic comb jelly or sea nut ( Mertensia ovum ) is commonly found in the surface (top 50 meters) in cold, northern waters. Like other cydippid ctenophores, it has two tentacles fringed with...
This bearded fireworm ( Hermodice carunculata ) must have a strong stomach -- it’s sucking on fire coral ( Millepora sp. ), which would give the unlucky snorkeler a nasty sting. Encountered in St...
Last week, Smithsonian research zoologists Dr. Jerry Harasewych and Dr. Martha Nizinski were in Curaçao looking for deep-sea marine gastropods and decapod crustaceans , respectively. I learned they...
Comb jellies (such as this Bolinopsis species) are named for their combs: the rows of cilia lining their bodies that propel them through the ocean. Read more about jellyfish and comb jellies .
This new species of deep-water sea cucumber ( Elpidia belyaevi ) was discovered by Census of Marine Life researchers in the frigid waters of the Arctic . Since the 1800s, researchers observed sea...
About 100 million years ago , during the heyday of the dinosaurs, reefs were built by mollusks called rudist clams. Like modern clams, rudists were bivalves , with two shells (or valves) joined at a...
In this close-up photo, you can actually see the photosynthetic algae, or zooxanthellae, living inside a tiny coral polyp. Look for the brownish-green specks in the colorless polyp. Corals depend on...
The larger of two giant squids on display in the Smithsonian's Sant Ocean Hall , this female was caught in a fisherman's net off the coast of Spain in 2005. It was probably 2-3 years old and, when...
A male mudflat fiddler crab ( Uca rapax ) waves its huge claw to impress females and threaten male competitors. More about the animals and plants living in mangrove ecosystems can be found in the...
Giant anemone. More about mangrove ecosystems can be found in the Mangroves section .
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