What makes a firefly glow

  • There are over 2,000 individual firefly species, all within the taxonomic family of Lampyridae.
  • But the answer to the lightning bug’s light all happens in the same organ in its abdomen: the lantern.
  • While the firefly may have evolved its lantern as a form of protection, today the lightning bugs use their light as a species-specific mating ritual.
  • Visit Business Insider’s homepage for more stories.

Following is a transcript of the video.

Narrator: There are over 2,000 individual firefly species, all within the taxonomic family of Lampyridae, which is pretty easy to remember. And these lightning bugs with their flickering light shows make summer nights feel all the more magical and romantic. But how did fireflies manage to catch lightning in a bottle? The answer is found in the bug’s butt, or more specifically in its abdomen, in an organ called the lantern. This organ is a set of specialized light cells, all encased in a translucent exoskeleton. And those light cells are where the magic happens: the phenomenon of bioluminescence, when a chemical reaction in a living thing emits light. Fireflies aren’t the only creatures that have this power. Glowworms and certain deep-sea fish species are some of the creatures capable of producing and emitting light. But the firefly is probably the Earth’s most famous bioluminescent species. So what’s happening inside the firefly’s light cells? What’s the secret to its glow?

In the 19th century, French pharmacologist Raphaël Dubois, working with bioluminescent clams, discovered that there are two essential components to these creatures’ light show. He named them luciferin and luciferase, based on the Latin term lucifer, for “light-bringer.” Luciferin is the compound that generates light, and luciferase is the enzyme that acts on it. Today, we know that the firefly’s bioluminescent reaction plays out like this. A firefly diverts oxygen to its light cells through its tracheoles. And those oxygen molecules react to luciferin, catalyzed with the help of luciferase and energy in the form of ATP. The luciferin then becomes agitated and excited, elevating its energy level. And when the excited luciferin drops back to its normal state, it releases that energy in the form of light, creating the “fire” in fireflies. It’s a remarkable phenomenon that’s also remarkably efficient. In a light bulb, 90% of the energy consumed is given off as heat, with only the remaining energy, a mere 10%, given off as visible light. In a firefly, on the other hand, nearly 100% of the energy is given off as light. That luminescence, or “cold light,” as it’s also called, is produced in the light cells and then focused by a layer of reflector cells, which direct that beam outward through that translucent exoskeleton.

But why do fireflies do what they do? As it turns out, bioluminescence has a number of evolutionary benefits, helping certain marine species lure prey to their mouths or serving as a defense against predators.

Sara Lewis: Fireflies are beetles, and so the juvenile fireflies live underground. So, we think that firefly light first evolved as a warning. It’s like a neon sign that shouts out, “Don’t eat me, I’m toxic.”

Narrator: But in adult fireflies, the purpose is a bit more romantic. Those yellow flashes lighting up our warm summer nights are actually part of the fireflies’ complex mating rituals, with male fireflies attracting female fireflies of the same species by flashing a distinctive, recognizable pattern. So those lights twinkling around you, switching on and off seemingly at random – they’re just the opposite: a highly intricate, specialized form of species-specific seduction.

Lewis: In North America, males might flash, like, just one flash. Wait, wait, wait, wait, wait, wait, wait, bleep, another flash, wait, wait, wait, wait, wait, bleep, another flash. Some species, the males actually give paired flashes, so they’ll fly along and then go bleep, bleep, wait, wait, wait, wait, wait, wait, wait. Bleep, bleep, wait, wait, wait, wait, wait. And so on. And so females who are kind of hanging around on grass down below can see these flashes, and they can recognize a male of their own species.

Narrator: But for all the romance and magic they add to our summer evenings, firefly populations around the globe are at serious risk. Those finely tuned mating rituals? Thanks to light pollution, those love letters get a little lost in translation.

Lewis: In areas where there’s a lot of bright lights, it’s been shown that it’s much, much more difficult for the male fireflies to find the females and for the females to see the flashes, the advertisement flashes of the male fireflies.

Narrator: And other threats like habitat loss and pesticide use have also put the population at risk.

Lewis: Sadly, in many parts of the world, there are other firefly species that aren’t doing so well. In fact, they are flickering out. And some of these fireflies are restricted to a very specific habitat. If that habitat goes away, the fireflies disappear. They can’t live anywhere else.

Narrator: It’s a story playing out all over the planet and across the animal kingdom. But as Lewis explains, education is absolutely key to conservation of fireflies and of all at-risk species.

Lewis: If fireflies disappeared, a lot of the world’s wonder would disappear with them. Would you wanna live in a world without fireflies? I would not.

Narrator: By increasing awareness of these risk factors, Lewis hopes to shine a little light on firefly conservation, ensuring that these little bugs will be able to dazzle us for years to come, giving future generations the chance to spend their summer nights trying to catch lightning in a bottle.

EDITOR’S NOTE: This video was originally published in August 2020.

Read the original article on Business Insider

What’s inside the ‘world’s ugliest animal,’ the blobfish

  • The blobfish was crowned the world’s ugliest animal in 2013 – a title it still defends today.
  • But drop this fellow 9,200 feet below sea level, and the water holds up all that flab like a push-up bra, making the fish a little more handsome.
  • Between the skin and the muscles is a lot of fluid. And that’s the secret to the fish’s distinct appearance – and its survival.
  • Visit Business Insider’s homepage for more stories.

Following is a transcript of the video.

Narrator: This creature was crowned the world’s ugliest animal in 2013, a title it still defends today. On land, he’s got a body like Jell-O and a big old frown. But drop this fellow 9,200 feet below sea level, and the water holds up all that flab like a push-up bra, making the fish a little more handsome. Same old fish, but with a little more support. So, what is all that water pressure holding together?

David Stein: Between the skin, that flabby skin, and the muscles is a lot of fluid.

Narrator: This is David Stein, a deep-sea-fish biologist who was lucky enough to dissect 19 blobfishes in the 1970s. Blobfish look blobby because they are full of water. Under their skin, blobfish have a thick layer of gelatinous flesh that floats outside their muscles.

Stein: If you pick up a blobfish by the tail, then it kind of flows to the head.

Narrator: This water-filled, Jell-O-like layer allows the blobfish to stay somewhat buoyant, which is important because blobfishes don’t have a swim bladder.

Stein: And fishes that have swim bladders are able to adjust their buoyancy. They can secrete gas into the swim bladder or remove it. A fish that lives on the bottom doesn’t need to be able to maintain its buoyancy.

Narrator: So, the Jell-O layer isn’t a perfect substitute, but the blobfish doesn’t need to be a strong swimmer. The predator has a highly specialized hunting strategy that’s perfect for the rocky barrens of the deep sea.

Stein: It just sits there and waits for dinner to come by.

Narrator: If all you do is sit, you don’t need much under your skin. Just watery tissue, some yellow pockets of fat, and a smidgen of muscle. In case you hadn’t guessed, blobfishes aren’t exactly yoked. They have very little red muscle, the kind that allows you, a human, to run a mile or a tuna fish to migrate across oceans. Instead, blobfish have a lot of white muscle, which allows them to swim in short bursts and lunge at prey that on occasion ramble by.

This is a baby blobfish. It’s a cleared and stained specimen, meaning all its tissue has been dissolved to show only the bones and cartilage. Those thin red lines you see, they’re the blobfish’s bones dyed red. If you’re having trouble seeing the bones, you’re not the only one. Blobfish have poorly ossified skeletons, meaning they’re thinner and more fragile than the bones of most shallow-water fish. This is another handy deep-sea adaptation, as it takes a lot of precious energy to build strong bones.

But the blobfish saves its energy to develop what might be the most important bone in its body: its jaws, which also happened to be the reason it looks so gloomy. The fish needs enormous jaws so it can snap up any prey that passes by and swallow it whole, maybe even smacking its blubbery lips as it eats. And that brings us to its stomach. If you’re the kind of creature that eats anything that swims by, some surprising things can wind up in your stomach. Stein found a wide range of foods and not-foods in the blobfish he dissected. Fish, sea pens, brittle stars, hermit crabs, an anemone, a plastic bag, and also lots of rocks.

Stein: Their stomach contents kind of bear out the fact that they’re probably not too bright.

Narrator: He also found octopus beaks, the cephalopods’ hard, indigestible jaws. This means that one of the world’s flabbiest fishes has been able to eat one of the sea’s most cunning predators. If you’re surprised, just think about the blobfish’s thick skin. What would it be harder to grab in a fight: a sack of bones or a sack of Jell-O? Stein suspects it might be the latter.

Stein: If the skin is loose, perhaps the suckers can’t really get a good grip on it.

Narrator: Stein found sucker marks across the blobfish’s body, a hint that the fish might’ve been in some deep-sea fights. So while all of this Jell-O might look a little unconventional, well, it seems to have served its purpose. The blobfish is perfectly suited to life in the deep sea, where beauty standards are probably quite different. After all…

Stein: Ugly is kind of in the eye of the beholder.

EDITOR’S NOTE: This video was originally published in December 2020.

Read the original article on Business Insider

What’s inside a blobfish, the ‘world’s ugliest animal’

  • The blobfish was crowned the world’s ugliest animal in 2013 — a title it still defends today.
  • But drop this fellow 9,200 feet below sea level, and the water holds up all that flab like a push-up bra, making the fish a little more handsome.
  • Between the skin and the muscles is a lot of fluid. And that’s the secret to the fish’s distinct appearance — and its survival.
  • Visit Business Insider’s homepage for more stories.

Following is a transcript of the video.

Narrator: This creature was crowned the world’s ugliest animal in 2013, a title it still defends today. On land, he’s got a body like Jell-O and a big old frown. But drop this fellow 9,200 feet below sea level, and the water holds up all that flab like a push-up bra, making the fish a little more handsome. Same old fish, but with a little more support. So, what is all that water pressure holding together?

David Stein: Between the skin, that flabby skin, and the muscles is a lot of fluid.

Narrator: This is David Stein, a deep-sea-fish biologist who was lucky enough to dissect 19 blobfishes in the 1970s. Blobfish look blobby because they are full of water. Under their skin, blobfish have a thick layer of gelatinous flesh that floats outside their muscles.

Stein: If you pick up a blobfish by the tail, then it kind of flows to the head.

Narrator: This water-filled, Jell-O-like layer allows the blobfish to stay somewhat buoyant, which is important because blobfishes don’t have a swim bladder.

Stein: And fishes that have swim bladders are able to adjust their buoyancy. They can secrete gas into the swim bladder or remove it. A fish that lives on the bottom doesn’t need to be able to maintain its buoyancy.

Narrator: So, the Jell-O layer isn’t a perfect substitute, but the blobfish doesn’t need to be a strong swimmer. The predator has a highly specialized hunting strategy that’s perfect for the rocky barrens of the deep sea.

Stein: It just sits there and waits for dinner to come by.

Narrator: If all you do is sit, you don’t need much under your skin. Just watery tissue, some yellow pockets of fat, and a smidgen of muscle. In case you hadn’t guessed, blobfishes aren’t exactly yoked. They have very little red muscle, the kind that allows you, a human, to run a mile or a tuna fish to migrate across oceans. Instead, blobfish have a lot of white muscle, which allows them to swim in short bursts and lunge at prey that on occasion ramble by.

This is a baby blobfish. It’s a cleared and stained specimen, meaning all its tissue has been dissolved to show only the bones and cartilage. Those thin red lines you see, they’re the blobfish’s bones dyed red. If you’re having trouble seeing the bones, you’re not the only one. Blobfish have poorly ossified skeletons, meaning they’re thinner and more fragile than the bones of most shallow-water fish. This is another handy deep-sea adaptation, as it takes a lot of precious energy to build strong bones.

But the blobfish saves its energy to develop what might be the most important bone in its body: its jaws, which also happened to be the reason it looks so gloomy. The fish needs enormous jaws so it can snap up any prey that passes by and swallow it whole, maybe even smacking its blubbery lips as it eats. And that brings us to its stomach. If you’re the kind of creature that eats anything that swims by, some surprising things can wind up in your stomach. Stein found a wide range of foods and not-foods in the blobfish he dissected. Fish, sea pens, brittle stars, hermit crabs, an anemone, a plastic bag, and also lots of rocks.

Stein: Their stomach contents kind of bear out the fact that they’re probably not too bright.

Narrator: He also found octopus beaks, the cephalopods’ hard, indigestible jaws. This means that one of the world’s flabbiest fishes has been able to eat one of the sea’s most cunning predators. If you’re surprised, just think about the blobfish’s thick skin. What would it be harder to grab in a fight: a sack of bones or a sack of Jell-O? Stein suspects it might be the latter.

Stein: If the skin is loose, perhaps the suckers can’t really get a good grip on it.

Narrator: Stein found sucker marks across the blobfish’s body, a hint that the fish might’ve been in some deep-sea fights. So while all of this Jell-O might look a little unconventional, well, it seems to have served its purpose. The blobfish is perfectly suited to life in the deep sea, where beauty standards are probably quite different. After all…

Stein: Ugly is kind of in the eye of the beholder.

Read the original article on Business Insider