It’s Easy Being Green: Most Amphibians Are Biofluorescent, Study Finds

An alpine newt glows green after being exposed to blue light.
An alpine newt glows green after being exposed to blue light.
Jennifer Y. Lamb and Matthew P. Davis

If you walk through a forest at night, you see only darkness and shadows, and perhaps the smudgy outline of trees against the sky. But if you were a salamander snuggled in the leaf litter, under the right light conditions, you might see something completely different: foliage glimmering in shades of red, and your fellow amphibians glowing in brilliant greens.

Biofluorescence—in which animals emit a fluorescent glow after absorbing high-energy wavelengths of light—is likely widespread among most, if not all, amphibians, according to a new study published in the journal Scientific Reports. Previously, only one species of salamander and three frog species were known to biofluoresce.

The same view of an alpine newt under white lightJennifer Y. Lamb and Matthew P. Davis

“I do field work, so I’m out there capturing species of amphibians, and I think, ‘huh, I wonder if this fluoresces,’” says Jennifer Y. Lamb, an assistant professor of biology at St. Cloud State University in Minnesota. She and co-author Matthew P. Davis, an assistant professor at the university, collected representatives from eight of the 10 salamander families, five families of frogs, and one family of caecelians, a type of limbless amphibian. They exposed each critter to high-energy blue light and then viewed them through a yellow filter to see if and how they glowed.

“One of the first salamanders we tested was the Eastern tiger salamander. We saw that it fluoresced really brightly, and that kind of got us hooked,” Lamb tells Mental Floss. “We started [to look] across salamander diversity, [and asked ourselves], ‘OK, how many species do we see within salamanders that biofluoresce?’ When we started to notice, ‘hey, it’s actually a lot of them!’, the question became, ‘can frogs do it?’ Then we looked at a relative of frogs, the caecelians—‘do they do it?’ And it seemed like biofluorescence in some form or fashion is present in all of these lineages.”

A biofluorescent Eastern tiger salamanderJennifer Y. Lamb and Matthew P. Davis

The various amphibians fluoresced in unique patterns depending on their skin’s coloration and markings as seen under normal white light. Some gleamed in blotches, others in stripes. A few animals' bones glowed. Lamb was surprised to see that salamanders’ bellies, which were usually red or orange under white light, glowed brighter than their backs after exposure to blue light.

“A lot of these newts have evolved what we call aposematic coloration, or warning colors. When they’re threatened by a predator, they’ll basically contort their bodies to show off their bellies as a warning,” Lamb says. “So it begs the question, if these bellies are also biofluorescent, then maybe some of their predators can visualize biofluorescence.”

The researchers intend their study to be a roadmap for further study into the fascinating ability. “Now that we know that this phenomenon exists across amphibians, there’s all kinds of interesting applications that future researchers may head towards,” Davis tells Mental Floss. For example, no one yet knows what kind of mechanisms allow amphibians to biofluoresce: In some groups it might be a color-based molecule or compound; in others, maybe something in their mucus.

A Cranwell's frog glows under blue light.Jennifer Y. Lamb and Matthew P. Davis

Scientists also don’t know exactly how different amphibians might visualize their own biofluorescence. Salamanders, frogs, and caecelians have rod cells in their eyes that are sensitive to green light, suggesting that they may have evolved green biofluorescence and the ability to see it at the same time, though further research is needed on that front.

“We have to be careful about not falling into the trap of only perceiving the world through our own eyes,” Lamb says. “Human vision is set to a particular set of wavelengths, and that’s not the case across all animal diversity. And that may not be the case in terms of these amphibians.”

A biofluorescent three-lined salamanderJennifer Y. Lamb and Matthew P. Davis

Finally, researchers are debating what purpose biofluorescence serves. In other animals, scientists have suggested it could play a role in communication, camouflage, or choosing a mate. Amphibians might use biofluorescence to locate each other in dense leaf litter.

“We’re hoping this study stimulates researchers to start looking at biofluorescence more broadly across the various different kinds of amphibian lineages that they may work on, so we can fill in the gaps in knowledge,” Davis says.

“There’s still a lot to learn about animal groups that we think we know,” he adds. “There’s still lots of interesting things out there to find that can help us rethink their life history and biology, and that may point us in new exploratory directions.”

The 10 Best Air Fryers on Amazon

Cosori/Amazon
Cosori/Amazon

When it comes to making food that’s delicious, quick, and easy, you can’t go wrong with an air fryer. They require only a fraction of the oil that traditional fryers do, so you get that same delicious, crispy texture of the fried foods you love while avoiding the extra calories and fat you don’t.

But with so many air fryers out there, it can be tough to choose the one that’ll work best for you. To make your life easier—and get you closer to that tasty piece of fried chicken—we’ve put together a list of some of Amazon’s top-rated air frying gadgets. Each of the products below has at least a 4.5-star rating and over 1200 user reviews, so you can stop dreaming about the perfect dinner and start eating it instead.

1. Ultrean Air Fryer; $76

Ultrean/Amazon

Around 84 percent of reviewers awarded the Ultrean Air Fryer five stars on Amazon, making it one of the most popular models on the site. This 4.2-quart oven doesn't just fry, either—it also grills, roasts, and bakes via its innovative rapid air technology heating system. It's available in four different colors (red, light blue, black, and white), making it the perfect accent piece for any kitchen.

Buy it: Amazon

2. Cosori Air Fryer; $120

Cosori/Amazon

This highly celebrated air fryer from Cosori will quickly become your favorite sous chef. With 11 one-touch presets for frying favorites, like bacon, veggies, and fries, you can take the guesswork out of cooking and let the Cosori do the work instead. One reviewer who “absolutely hates cooking” said, after using it, “I'm actually excited to cook for the first time ever.” You’ll feel the same way!

Buy it: Amazon

3. Innsky Air Fryer; $90

Innsky/Amazon

With its streamlined design and the ability to cook with little to no oil, the Innsky air fryer will make you feel like the picture of elegance as you chow down on a piece of fried shrimp. You can set a timer on the fryer so it starts cooking when you want it to, and it automatically shuts off when the cooking time is done (a great safety feature for chefs who get easily distracted).

Buy it: Amazon

4. Secura Air Fryer; $62

Secura/Amazon

This air fryer from Secura uses a combination of heating techniques—hot air and high-speed air circulation—for fast and easy food prep. And, as one reviewer remarked, with an extra-large 4.2-quart basket “[it’s] good for feeding a crowd, which makes it a great option for large families.” This fryer even comes with a toaster rack and skewers, making it a great addition to a neighborhood barbecue or family glamping trip.

Buy it: Amazon

5. Chefman Turbo Fry; $60

Chefman/Amazon

For those of you really looking to cut back, the Chefman Turbo Fry uses 98 percent less oil than traditional fryers, according to the manufacturer. And with its two-in-one tank basket that allows you to cook multiple items at the same time, you can finally stop using so many pots and pans when you’re making dinner.

Buy it: Amazon

6. Ninja Air Fryer; $100

Ninja/Amazon

The Ninja Air Fryer is a multipurpose gadget that allows you to do far more than crisp up your favorite foods. This air fryer’s one-touch control panel lets you air fry, roast, reheat, or even dehydrate meats, fruits, and veggies, whether your ingredients are fresh or frozen. And the simple interface means that you're only a couple buttons away from a homemade dinner.

Buy it: Amazon

7. Instant Pot Air Fryer + Electronic Pressure Cooker; $180

Instant Pot/Amazon

Enjoy all the perks of an Instant Pot—the ability to serve as a pressure cooker, slow cooker, yogurt maker, and more—with a lid that turns the whole thing into an air fryer as well. The multi-level fryer basket has a broiling tray to ensure even crisping throughout, and it’s big enough to cook a meal for up to eight. If you’re more into a traditional air fryer, check out Instant Pot’s new Instant Vortex Pro ($140) air fryer, which gives you the ability to bake, proof, toast, and more.

Buy it: Amazon

8. Omorc Habor Air Fryer; $100

Omorc Habor/Amazon

With a 5.8-quart capacity, this air fryer from Omorc Habor is larger than most, giving you the flexibility of cooking dinner for two or a spread for a party. To give you a clearer picture of the size, its square fryer basket, built to maximize cooking capacity, can handle a five-pound chicken (or all the fries you could possibly eat). Plus, with a non-stick coating and dishwasher-safe basket and frying pot, this handy appliance practically cleans itself.

Buy it: Amazon

9. Dash Deluxe Air Fryer; $100

Dash/Amazon

Dash’s air fryer might look retro, but its high-tech cooking ability is anything but. Its generously sized frying basket can fry up to two pounds of French fries or two dozen wings, and its cool touch handle makes it easy (and safe) to use. And if you're still stumped on what to actually cook once you get your Dash fryer, you'll get a free recipe guide in the box filled with tips and tricks to get the most out of your meal.

Buy it: Amazon

10. Bella Air Fryer; $52

Bella/Amazon

This petite air fryer from Bella may be on the smaller side, but it still packs a powerful punch. Its 2.6-quart frying basket makes it an ideal choice for couples or smaller families—all you have to do is set the temperature and timer, and throw your food inside. Once the meal is ready, its indicator light will ding to let you know that it’s time to eat.

Buy it: Amazon

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Lead from the 2019 Notre-Dame Cathedral Fire Detected in Paris’s Beehives

Veronique de Viguerie/Stringer/Getty Images
Veronique de Viguerie/Stringer/Getty Images

It's been over a year since a fire destroyed Notre-Dame's iconic spire in April 2019, and we still haven't determined the blaze's full effect on the environment. As Smithsonian reports, evidence of pollution from the incident has been found in an unusual place: Paris's beehives.

A new study published in the journal Environmental Science & Technology Letters explains that hives located downwind from the Notre-Dame fire contained honey with high concentrations of lead. As the cathedral's roof and spire burned, 450 tons of lead melted in the extreme heat, releasing hazardous particles into the air. While lead had clearly settled into the structure itself—making it unsafe to reopen to the public even after it was renovated—the question remains of how far the toxic materials spread beyond the site.

The study shows that at least some lead managed to travel a few miles away from the church. Honey sampled three months after the blaze from hives downwind from the Notre-Dame fire contained four times as much lead as honey from the Parisian suburbs, and 3.5 times as much as Parisian honey collected before April 2019.

This doesn't mean that honey from certain Paris neighborhoods is unsafe to eat. The sample with the highest numbers, taken from a hive 3 miles west of the cathedral, contained 0.08 micrograms of lead per 1 gram of honey. The European Union allows honey to be sold with lead concentrations up to 0.10 micrograms per gram.

“The highest levels of lead that we detected were the equivalent of 80 drops of water in an Olympic sized swimming pool,” study co-author Dominique Weis, director of the University of British Columbia's Pacific Centre for Isotopic and Geochemical Research, said in a statement. But what the findings mean for homes and businesses in Notre-Dame's surrounding area-where environmental lead samples have exceeded the safety guidelines 20 times over in some spots—is still unclear.

[h/t Smithsonian]