The Great Barrier Reef site in Australia was inscribed on the World Heritage List in 1981. The site is the world’s most extensive stretch of coral reef with probably the richest animal diversity...
About 100 million years ago, during the heyday of the dinosaurs , reefs were built by mollusks called rudist clams . They looked very different from today's coral reefs . Discover more about the...
These "elevator" rudists, an ancient bivalve, used one long heavy valve to anchor themselves in the sediment. They used their tentacles (shown here in pink) to filter food from the sea water. And...
A colony of 100 million flame shells ( Limaria hians ) was discovered in Scotland in 2012 , and is thought to be the biggest in the world. Flame shells are bivalve mollusks that are shaped a bit like...
Portrait of a scallop with black and white striped lips, whose shell is encrusted with a red sponge.
Invasive species can have a range of environmental and economic impacts. In this photo sea squirts foul an oyster cage. Scientists at the Smithsonian Environmental Research Center's Marine Invasions...
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...
Shellfish from the Chesapeake Bay are prized by seafood lovers. But the Bay's ecosystem and fisheries are threatened by human disturbances, including the introduction of non-native species. Non-...
The jingle shell ( Anomia simplex ) is a common bivalve found on the Atlantic coast of North America, amongst the more commonly known clams and oysters. As with oysters, the lower shell is glued to a...
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 Smithsonian's Department of Invertebrate Zoology has a collection of over 57,000 specimens from over 5,700 sites in the Gulf of Mexico, which are now catalogued on Google Earth . Below is a tiny...
This illustration shows the edge of a warm inland sea during the Cretaceous Period, heyday of the dinosaurs. Constantly shifting sediment supported new groups of organisms, including rudist clams—...
Ocean acidification is sometimes called “climate change’s equally evil twin,” and for good reason: it's a significant and harmful consequence of excess carbon dioxide in the atmosphere that we don't...
This beautiful spider conch ( Lambis chiragra ) was collected by Census of Marine Life scientists conducting research near China.
Melissa Frey, Encyclopedia of Life (EOL) Rubenstein Fellow, examines a Pacific oyster ( Crassostrea gigas ) on a chilly day in Sidney, British Columbia. In addition to holding an EOL Fellowship ,...
This pair of sea butterflies ( Limacina helicina ) flutter not far from the ocean's surface in the Arctic. Sea butterflies are a type of sea snail, but instead of dragging themselves around the...
White abalones are slow-moving, algae-eating mollusks. Rapid overharvesting since the 1970s has resulted in white abalones becoming the first marine invertebrate listed as endangered on the...
The feathery strands at the back of this nudibranch’s ( Chromodoris willani ) body are no mere adornment: they’re its gills! Nudibranchs, shell-less snails or sea slugs, are named for these tufted...
