Invertebrates

FEATURES

Blog entry
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...
Blog entry MORE STORIES Blog entry MORE AUDIO / VIDEO
The ocean is home to a phenomenal diversity of marine organisms. They have...
Blog entry MORE STORIES Blog entry MORE AUDIO / VIDEO
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...

LATEST POSTS

What are corals? Corals themselves are animals. But tropical reef-building corals have tiny plant-like organisms living in their tissue. The corals couldn’t survive without these microscopic algae–called zooxanthellae (zo-zan-...
In recent years, blooms of jellyfish, such as these moon jellies ( Aurita...
An orange brisingid starfish sits on a large reef of Lophelia pertusa, cold-...

LEARN MORE

Coral reefs are the most diverse of all marine ecosystems. They teem with life, with perhaps one quarter of all ocean...
This beautiful spider conch ( Lambis chiragra ) was collected by Census of Marine Life scientists conducting research near China.
A coral hermit crab, Paguritta harmsi , about the size of two grains of rice, living in coral in the waters of Japan's Ogasawara Islands.
This close-up view of salps, which have aggregated together into a long chain, have brilliant red guts from eating red plankton. They were observed by researchers with the Census of Marine...
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 .
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...
These Pacific cephalopods illustrate the wide diversity among this group of mollusks. You can learn about a relative, the giant squid ( Architeuthis dux ), in our Giant Squid section.
This bright purple sea star is a new species found by the Census of Coral Reef Ecosystems , a project of the Census of Marine Life. This particular specimen was seen on the reefs of the French...
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...
Throughout their lifecycle, jellyfish take on two different body forms: medusa and polyps. Polyps can reproduce asexually by budding, while medusae spawn eggs and sperm to reproduce sexually. Learn...
With 1,400 named species of ribbon worms inhabiting every ecosystem on earth, seeking one out should be an easy proposition. But I quickly learned that it can be quite daunting when you’re looking...
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...
Smithsonian Zoologist Dr. Clyde Roper (rear) and museum specialist Mike Sweeney examine the mantle of a dead giant squid. Everything we know about giant squid comes from studying specimens found...
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,...
Swimming by a black sea nettle may be a bit of a shock. These large jellyfish can grow to be over three feet in diameter, and their tentacles can be over 25 feet long. Despite their large size, much...
In 1874 Reverend Moses Harvey of Newfoundland displayed the giant squid he bought on the side of his barn, much to the dismay of Mrs. Harvey. More about the giant squid can be found in our Giant...
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...
The festive Christmas tree worm ( Spirobranchus giganteus ) lives on tropical coral reefs and resembles a fluffy fir tree adorned with ornaments. The multi-functional branch-like appendages are used...
Atolla tenella , a midwater scyphomedusa , as seen under a microscope. View the “Under Arctic Ice” photo essay to learn more.
Subscribe to Invertebrates