Invertebrates

FEATURES

Article
Since summer 2013, starfish along both coasts of the United States have been dying in large numbers—and not gracefully. As their tissues collapse, the starfish (also called sea stars) start to look stretched and...
Slideshow MORE STORIES Slideshow MORE AUDIO / VIDEO
Tiny plant-like organisms called zooxanthellae live in the tissues of many...
I have been at the Smithsonian’s National Museum of Natural History since 1966...
Collect, sort, identify, photograph, sample, record. Repeat a couple thousand...

LATEST POSTS

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...

LEARN MORE

Giant squid live up to their name: the largest giant squid ever recorded by scientists was almost 43 feet (13 meters) long,...

The Ocean Blog

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...
A giant squid engages in a struggle for survival with a sperm whale. Giant squid beaks and other undigested pieces of giant squid have been found in the stomachs of sperm whales . More about the...
Can you spot the amphipod ( Phronima atlantica ) in the below photo? She's the transparent lobster-looking animal in the middle, surrounded by her own eggs -- inside a sac that once was the "barrel"...
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...
This forest of Christmas tree worms is a group of polychaete worms that live on tropical coral reefs. See more celebratory ocean creatures in our slideshow!
A cameraman navigates a smack of sea nettles ( Chrysaora fuscescens ) in Monterey Bay. A group of jellies is known as a "smack."
The sargassum is coated with encrusting organisms, such as bryozoans and hydroids, that use it as a perch to filter feed in the oceanic waters, as well as crustaceans such as thos swimming crab...
Deep-sea coral beds are true biodiversity hotspots. It’s urgent that we study these extreme environments because we know so little about them, because they are important communities for so many deep-...
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...
This red octopod ( Stauroteuthis syrtensis ) shines in a novel way. Suckers stretching in a single row down each arm flash on and off. The glowing-sucker octopod drifts through deep waters off the...
This sea potato ( Echinocardium cordatum ) looks similar to its root vegetable namesake, but it's a sea urchin! The spines on this urchin are more hair-like than the spikes seen on some more commonly...
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...
Ochre seastars ( Pisaster ochraceus ) feed on invertebrates, such as coral and shellfish, like the mussels pictured here. The starfish forces open the shell with suction disks on the underside of its...
Dr. Martha Nizinski holds a specimen of a fan sponge ( Phakellia sp. ) collected at a deep-sea coral study site off the coast of South Carolina. Deep-sea corals and sponges provide structure for a...
In the spring of 2011, a research crew from Oceana spent two months in the brackish Baltic Sea . The Baltic faces challenges from pollution, algae blooms, over fishing, and invasive species. Oceana...
Like this ctenophore ( Aulococtena acuminata ), many animals that live in the midwater zone are red—making them almost invisible in the dim blue light that filters down from the sea surface. This...
Like octopods and cuttlefishes, giant squid have eight arms. But they use their two much longer feeding tentacles to seize prey. The tentacles have powerful suckers at the ends. More about the giant...
A beroid ctenophore lunges toward prey with its mouth wide open. Beroid comb jellies don't have tentacles to catch prey: instead, they can open their mouths and snap them shut tight to trap prey...
Subscribe to Invertebrates