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Steven G. Johnson via Wikimedia Commons // CC BY-SA 3.0

Invasive Comb Jellies Crowd the Adriatic Sea

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Steven G. Johnson via Wikimedia Commons // CC BY-SA 3.0

In 1982, an unwelcome visitor arrived in the Black Sea. An oil tanker traveling from the American Atlantic dumped its ballast water into the sea, releasing a flood of warty comb jelly stowaways along with it. The alien invaders have since ravaged the area’s native fish populations, and now New Scientist reports that they’ve become a threat along the northern Adriatic coast.

Warty comb jellies (Mnemiopsis leidyi) have been seen in the Adriatic sea since 2005, but this summer marked the first time they’ve been present in such great numbers. Davor Lučić of the Institute for Marine and Coastal Research in Dubrovnik, Croatia told New Scientist that the clusters get as dense as 500 jellies per square meter in some spots. That estimate is based on fully-matured specimens—the number of juveniles is likely even higher.

The swarms have been documented along the Adriatic coast from Slovenia to Pesaro, Italy. Lagoons in northern Italy have been clogged with the creatures since July. The animals pose no direct threat to people, but their appetite has already proven disastrous to whatever ecosystem they invade.

A few of the warty comb jelly's meals of choice include fish eggs, fish larvae, and zooplankton. Zooplankton also happens to be the main food source for many commercial fish in the area. Less than a decade after the introduction of the comb jelly into the Black Sea, local anchovy and sardine fisheries were devastated. The seafood industry had lost billions by the mid-'90s.

Now, there’s threat of a repeat catastrophe in the Adriatic Sea. The mass emergence of the species coincides with anchovy spawning season, a crucial time for one of the sea’s most commercially significant fish. Some scientists are looking on the bright side: the Adriatic is more open and less polluted than the Black Sea, and its local fauna is more diverse. This makes the native populations better equipped to survive the invasion. Additionally, Mnemiopsis leidyi isn’t the sea’s only uninvited guest. Another comb jelly, Beroe ctenophore, has also invaded the waters, and scientists hope the aliens might contribute to one another’s demise.

Mnemiopsis likely entered the Adriatic through a ship’s ballast, the same Trojan horse it rode into the Black Sea. This problem isn’t limited to invasive jellies: A list of destructive species from ants to mussels have been introduced to new environments this way. A global treaty that aims to put an end to the issue will go into effect next year.

[h/t New Scientist]

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Focus Features
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Animals
25 Shelter Dogs Who Made It Big
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Focus Features

If you’ve been thinking of adding a four-legged friend to your brood and are deciding whether a shelter dog is right for you, consider this: Some of history’s most amazing pooches—from four-legged movie stars to heroic rescue dogs—were found in animal shelters. In honor of Adopt-a-Shelter-Dog Month, here are 25 shelter dogs who made it big.

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This High-Tech Material Can Change Shape Like an Octopus
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iStock

Octopuses can do some pretty amazing things with their skin, like “see” light, resist the pull of their own sticky suction cups, and blend in seamlessly with their surroundings. That last part now has the U.S. Army interested, as Co.Design reports. The military branch’s research office has funded the development a new type of morphing material that works like an octopus’s dynamic skin.

The skin of an octopus is covered in small, muscular bumps called papillae that allow them to change textures in a fraction of a second. Using this mechanism, octopuses can mimic coral, rocks, and even other animals. The new government-funded research—conducted by scientists at Cornell University—produced a device that works using a similar principle.

“Technologies that use stretchable materials are increasingly important, yet we are unable to control how they stretch with much more sophistication than inflating balloons,” the scientists write in their study, recently published in the journal Science. “Nature, however, demonstrates remarkable control of stretchable surfaces.”

The membrane of the stretchy, silicone material lays flat most of the time, but when it’s inflated with air, it can morph to form almost any 3D shape. So far, the technology has been used to imitate rocks and plants.

You can see the synthetic skin transform from a two-dimensional pad to 3D models of objects in the video below:

It’s easy to see how this feature could be used in military gear. A soldier’s suit made from material like this could theoretically provide custom camouflage for any environment in an instant. Like a lot of military technology, it could also be useful in civilian life down the road. Co.Design writer Jesus Diaz brings up examples like buttons that appear on a car's dashboard only when you need them, or a mixing bowl that rises from the surface of the kitchen counter while you're cooking.

Even if we can mimic the camouflage capabilities of cephalopods, though, other impressive superpowers, like controlling thousands of powerful suction cups or squeezing through spaces the size of a cherry tomato, are still the sole domain of the octopus. For now.

[h/t Co.Design]

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