Invertebrates

Animals without backbones make up a huge percentage of the ocean’s biodiversity. They aren’t just small (like pteropods) or squishy (like jellyfish); the giant squid and corals that build huge reefs are also invertebrates.

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Seaside Lichens

Horizontal bands of color represent different species of lichen that have...

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Diversity of Deep-Sea Corals

Sample the surprising diversity of deep-sea corals. See some of the ways they differ in color, shape, and size. Explore more...
A bloom of moon jellies.

A Bloom of Moon Jellies

In recent years, blooms of jellyfish, such as these moon jellies ( Aurita aurita ) in the Chesapeake Bay, have become more common around the world for a number of different reasons . One...

The Amazing Horseshoe Crab

There’s a lot more to a horseshoe crab than meets the eye. They are not even crabs and are actually more closely related to spiders and scorpions. They don’t have teeth or jaws, and...
Sea otters floating on the surface of the ocean.

Not Just Another Fuzzy Face

A raft of sea otters grooming and resting after foraging. Credit: © Elise Newman Montanino Who hasn’t grinned at the sight of a sea otter floating on its back while grooming itself? No doubt...

Anemone Feeding Time

Anemones are known for serving as homes for Nemo and countless other small fish and invertebrates. But these Cnidarians (in the same phylum as jellyfish and same class as corals ) have a long...
Two nautiluses in the open ocean off the coast of Palau.

A Couple of Nautiluses

These two nautiluses ( Nautilus belauensis ) are pictured off the coast of Palau in the Pacific Ocean. There are six living species of nautilus who live in chambered shells. As they get bigger,...
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It’s All in the (Jellyfish) Family

They may not all look the same, but cnidarians all have cells that are specially designed for stinging. Credit: Allen Collins, Smithsonian By Kalila Morsink With their huge number of venomous stinging cells, jellyfish...
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A Microscopic Identity Crisis

Using DNA to identify larval species in the Gulf Stream When swimming in the water, the planktonic sea snail, Diacria trispinosa , flutters two wings much like a butterfly. When they retract their bodies...

Why the Octopus Brain is so Extraordinary

An octopus is a lot brainier than you might imagine considering one of its closest living relatives is a sea slug. In fact, some scientists argue it could be the first intelligent being on...

Jellyfish predate dinosaurs. How have they survived so long?

Gelatinous drifters that move in a mesmerizing way, jellyfish are beautiful creatures. But take a closer look and you'll see there's more to these creatures than a pretty picture. Some shoot a deadly venom,...

Farming Oysters Despite Acidic Seas

Bill Taylor, Paul Taylor, Diani Taylor and Brittany Taylor have more in common than just a last name; they also share a business. The Taylors have been in the family oyster-farming business in Washington...
Venomous Box Jelly from South Carolina

Pinning Down the Jellyfish

Credit: Bastian Bentlage 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...
Coral Spawning by Moonlight

A Tale of Sex and Stress in the Ocean

A coral has just spawned. Each of the hundreds of polyps releases a small pink bundle of sperm and eggs. Credit: Raphael Williams Welcome to Citizens of the Sea , a new blog series...
Horseshoe Crab in Stage Harbor, Massachusetts

This Flu Season, Thank a Horseshoe Crab

A small horseshoe crab rests on seaweed in Stage Harbor, Massachusetts. Credit: © Luke Robinson (Creative Commons via Flickr) Fever. Aching muscles. Coughing. Sniffling. It’s flu season . Have you had your shot? If...

Hydrothermal Vent Creatures

Travel to a world of perpetual night--the deep ocean hydrothermal vents near the Galapagos Rift where life thrives around superheated water spewing from deep inside the Earth. Discovered only in 1977, hydrothermal vents are...
An underwater photo of coral recovering from a bleaching event.

A Pleasant Surprise: The Recovery of Bleached Panamanian Corals

These corals are still in recovery after a mass bleaching in Panama, in the summer of 2010. You can see some bleaching on the tops, but the sides are looking good. Credit: Amanda Feuerstein...
Common cuttlefish

So You Think You're Smarter Than a Cephalopod?

Like other cephalopods, the common cuttlefish ( Sepia officials Linnaeus, 1758) possesses serious brain power. Credit: Hans Hillewaert, WoRMS for SMEBD The blanket octopus can rip a poisonous tentacle from a Portuguese man-o-war and...
A zoomed-in image of the crown-of-thorns sea star.

A Plague of Sea Stars

Scientists have been studying why populations of crown-of-thorns sea stars ( Acanthaster planci ) have mushroomed in recent decades. Coral reefs can suffer when the sea star's numbers explode; the echinoderm has a healthy...

The Dumbo Octopus: An Underwater Dance

This short video takes you two hundred miles off the coast of Oregon and some 6,600 feet below the water's surface to observe the Dumbo octopus ( Grimpoteuthis bathynectes ). Little is known about...

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