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Zombie worms don’t crave brains: instead they seek bones. The 1 to 3 inch (2 to 7 centimeter) Osedax worms were first discovered living in the bones of a rotting gray whale on the...
Marine parasites may be small in size, but they can be present in very high...
During the summer of 1998, scientists at the Virginia Institute of Marine...
The blanket octopus can rip a poisonous tentacle from a Portuguese man-o-war...

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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 small comb jelly snares prey with...
Sponges are animals that eat tiny food particles as they pump water through...
Polarized sunglasses have become the norm for humans when they want to...

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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

Two bright orange anemonefish ( Amphiprion ocellaris ) poke their heads between anemone tentacles. Anemonefish are able to swim amongst the stinging tentacles without getting stung — but no one knows...
A cameraman navigates a smack of sea nettles ( Chrysaora fuscescens ) in Monterey Bay. A group of jellies is known as a "smack."
This swimming crab ( Liocarcinus holsatus ) has a parasitic barnacle rooted in its reproductive system. This invasion cuts off all reproduction for an infected crab and can even cause a male crab to...
Nine years ago I was invited by a colleague to join a research team investigating deep-sea coral habitats . I was asked to examine the invertebrates associated with these ecosystems. After my first...
A rockfish finds refuge in a deep-sea coral—a red tree coral of the Primnoidae family in the Olympic Coast National Marine Sanctuary. Learn more about deep-sea coral reef ecosystems in our Deep-sea...
Polarized sunglasses have become the norm for humans when they want to filter out the strong glare from the sunlight bouncing off of water in a horizontal direction. But how do animals do that live...
An octopus shoots ink in defense as it swims away from a scuba diver.
This jelly’s red color provides camouflage in the deep ocean. Red light rarely reaches those depths, and most deep-sea animals have lost the ability to see red. The long, complex tentacles of this...
In this photo of a shallow coral reef in the Pacific there are three species of forams . On the left, Peneroplis planatus . In the center, Amphistegina lessonii . And on the right, Laevipeneroplis sp...
Sample the surprising diversity of deep-sea corals. See some of the ways they differ in color, shape, and size. Explore more in the multimedia feature " Coral Gardens of the Deep Sea ."
Seahorses range in size—from as small as a pine nut to as large as a banana. The largest seahorse species (pictured here) is Hippocampus abdominalis , or the big-bellied seahorse, which can reach...
All over the world, people have been witnessing gigantic blooms of tens of thousands of jellyfish where once there were only a few. Fishers find them clogging their nets and costing them dearly. In...
Inside the giant squid's sharp beak is a tongue-like organ called the radula (shown in yellow). Covered with rows of tiny teeth, it rams bite size pieces of food down the squid's throat. The pieces...
A chambered nautilus shell.
Smithsonian Marine Science Network Postdoctoral Fellow, Seabird McKeon, returns from the Smithsonian field site in Belize. Together with Dan Barshis of Stanford University, Seabird reports on the...
A giant squid left this tentacle behind after getting entangled on a hook below a Japanese research vessel, and eventually escaping. An underwater camera took footage of the event—the first time a...
Sponges are animals that eat tiny food particles as they pump water through their bodies. They are very common on Caribbean coral reefs, and come in all shapes, sizes and colors. There is great...
Claws, spines, spikes, tentacles, and fangs. Aliens, monsters, and ghostly apparitions glowing in the night. Marine life forms have some of the best looks for Halloween—no costumes needed. From...
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