Prof. Jörg Wiedenmann
Prof. Jörg Wiedenmann

Scientists Find Awesome Fluorescent Corals in the Red Sea

Prof. Jörg Wiedenmann
Prof. Jörg Wiedenmann

The deep sea is more colorful than we thought. Corals living 165 feet beneath the surface of the Red Sea glow green, yellow, and red, according to a new report by an international team of scientists in PLOS ONE.

Green fluorescent corals have been routinely observed in shallow waters, but the deep water corals spotted off the coast of Eliat, Israel are unusual for their wide spectrum of color. Orange-red colors are absent from shallow reefs, but present at greater depths of 165 to 195 feet below the surface.

Fluorescent pigments act as a kind of sunblock for coral at shallow depths, protecting it from harmful UV rays. But some of the corals produce a fluorescent glow even in the absence of a light source in regions of the ocean where getting any sunlight at all can be difficult. These corals don’t need sunscreen. So why the glow?

While scientists are still figuring that out, it might be a way to get more light to the symbiotic algae that live in the reefs and produce oxygen for the corals. These zooxanthellae undergo photosynthesis, so the light produced by the corals may help them survive and thrive at greater depths in the absence of sunlight.

The pigments found in corals might also be useful in scientific laboratories. The fluorescent pigments could be used to highlight specific cells or structures in biomedical imaging.

[h/t: Nature News]

All images by Prof. Jörg Wiedenmann

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These Sparrows Have Been Singing the Same Songs for 1500 Years
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Swamp sparrows are creatures of habit—so much so that they’ve been chirping out the same few tunes for more than 1500 years, Science magazine reports.

These findings, published in the journal Nature Communications, resulted from an analysis of the songs of 615 adult male swamp sparrows found in six different areas of the northeastern U.S. Researchers learned that young swamp sparrows pick up these songs from the adults around them and are able to mimic the notes with astounding accuracy.

Here’s what one of their songs sounds like:

“We were able to show that swamp sparrows very rarely make mistakes when they learn their songs, and they don't just learn songs at random; they pick up commoner songs rather than rarer songs,” Robert Lachlan, a biologist at London’s Queen Mary University and the study’s lead author, tells National Geographic.

Put differently, the birds don’t mimic every song their elders crank out. Instead, they memorize the ones they hear most often, and scientists say this form of “conformist bias” was previously thought to be a uniquely human behavior.

Using acoustic analysis software, researchers broke down each individual note of the sparrows’ songs—160 different syllables in total—and discovered that only 2 percent of sparrows deviated from the norm. They then used a statistical method to determine how the songs would have evolved over time. With recordings from 2009 and the 1970s, they were able to estimate that the oldest swamp sparrow songs date back 1537 years on average.

The swamp sparrow’s dedication to accuracy sets the species apart from other songbirds, according to researchers. “Among songbirds, it is clear that some species of birds learn precisely, such as swamp sparrows, while others rarely learn all parts of a demonstrator’s song precisely,” they write.

According to the Audubon Guide to North American Birds, swamp sparrows are similar to other sparrows, like the Lincoln’s sparrow, song sparrow, and chipping sparrow. They’re frequently found in marshes throughout the Northeast and Midwest, as well as much of Canada. They’re known for their piercing call notes and may respond to birders who make loud squeaking sounds in their habitat.

[h/t Science magazine]

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This Plant Can Burn Your Skin With Its Sap—And It May Be Coming to Your Neighborhood
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It's huge, it's extremely dangerous, and it's spreading. The giant hogweed (Heracleum mantegazzianum) contains a corrosive sap that causes severe rashes, third-degree burns, and even permanent blindness if you get the photosensitive chemicals on your skin or in your eyes, Science Alert reports.

The noxious, invasive weed was just identified in Clarke County, Virginia, near the Massey Herbarium at Virginia Tech. That brings the number of states it's been spotted in to 11, including Washington, Oregon, Illinois, Michigan, North Carolina, Pennsylvania, New York, Connecticut, Massachusetts, and Maine. Beyond the U.S., it has taken root all over the world, from the UK to Iceland to Australia.

Similar to the common but slightly less dangerous cow parsnip, giant hogweed is native to Central Asia and was first brought to North America in the early 1990s as an ornamental plant, its unique shape making it popular among gardeners. But it soon became invasive: Once it’s established in an area, it can take up to five years to eradicate a colony.

Now the plant is considered a public health concern. Hogweed can cause a reaction known as phytophotodermatitis when it comes into contact with skin that is subsequently exposed to UV rays—but the effects of hogweed are much more severe. A painful blister can develop within hours and last for months; the exposed skin can remain sensitive to sunlight for years even after the blisters heal.

Hogweed can be difficult to distinguish from the cow parsnip, and the plant is often misidentified. First, check for height: Hogweeds are typically taller than 8 feet, while cow parsnip tends to be 5 to 8 feet tall. Hogweed stems are green with purple specks and coarse white hairs, while parsnip stems are green with fine white hairs. For more tips and photos, check out the New York Department of Environmental Conservation’s guide.

If you see a plant you think might be a giant hogweed, take a few photos and send them to your state's department of agriculture to identify—and whatever you do, don't touch it.

[h/t Science Alert]

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