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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...
Nudibranchs are a kind of sea slug, and their 3000 species are found from the poles to the tropics in both shallow and deep water. Though they often only reach two centimeters in length, they are...
This summer, many of you have likely enjoyed feasting on crabs, be they blue, stone, or Dungeness, and a special treat will have been the big, easy morsels of claw meat. The size of this muscle is...
When most people think of catfish, they think of a freshwater fish. But the striped eel catfish ( Plotosus lineatus ) is found in marine systems including coral reefs, estuaries, tide pools and other...
This bait ball shows how small fish can react when larger predators are near by gathering tightly together in a ball-like formation that exposes the least number of fish. Fish species found in the...
The ROV Hyper Dolphin caught this deep-sea jelly (Atolla wyvillei) on film east of Izu-Oshina Island, Japan. When attacked, it uses bioluminescence to "scream" for help—an amazing light show known as...
The lion’s mane jellyfish ( Cyanea capillata ) is the largest among the jelly species, with the largest known specimen stretching across 120 feet (36.5 meters) from its top to the bottom of its...
One of the first signs of a sick coral reef is seaweed creeping across the corals, stealing their precious sunny real estate. Healthy corals, however, aren't completely hopeless: in some reefs, small...
A humboldt squid ( Dosidicus gigas )—also known as the jumbo squid—releases a cloud of ink at night in Mexico's Sea of Cortez. These large, carnivorous squids can reach more than 5 feet in length and...
An octopus shoots ink in defense as it swims away from a scuba diver.
Not all slugs (snails without shells) are slimy brown pests found in your backyard garden. In the ocean they come in a huge variety of colors — some match the background and are hard to spot, but...
This nudibranch has a few tricks up its sleeve: it steals jellyfish tentacles to use as weapons again its own enemies. How does it do this? Many fleshy, tentacle-like growths, called cerata (singular...
Is that fruit swimming in the ocean? Well it may look like fruit, but it's actually a pineapplefish ( Cleidopus gloriamaris ). Like the hard outer part of a pineapple, this fish also has an outer...
This crab ( Neolithodes sp. ) was collected on a NOAA/MAR-ECO cruise to the Mid-Atlantic Ridge in the summer of 2009. Its red color provides camouflage and protection from predators. Red wavelengths...
Beluga whales are naturally vocal animals. They are often called “ canaries of the sea ” thanks to their wide repertoire of sounds such as whistles, squeals, moos, chirps, and clicks. Some...
You may have seen the sparkle of fireflies on a summer’s night. The fireflies produce light through a chemical reaction in their glowing abdomens, a process known as bioluminescence. But did you know...
These beautiful mandarinfish ( Synchiropus splendidus ) are covered in bright blue, red, yellow and orange waves. What they lack, however, are traditional fish scales. They live in western Pacific...
It's a pygmy seahorse ( Hippocampus bargibanti ), found in Indonesia's biodiverse Coral Triangle and one of the smallest seahorse species in the world! They can change colors like a chameleon to...
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