How and why do fireflies glow?

Isn’t it fascinating how our world is filled with wonderful magical creatures. Some weigh more than 100 pounds, while others could give you deadly wounds. Some are so fast that they could disappear in a blink of an eye, whereas some could be wild and dangerous ally. But the most fascinating of all are the ones that glow. Yes, you guessed it right. I’m talking about the fireflies. Aren’t they magical? It is truly magnificent to see these creatures sparkle at the dark night sky. But have you ever wondered what makes them glow? And if we had that, could we glow too?


How fireflies glow?

Fireflies glow because they produce light by a chemical reaction. In the lower abdomen of fireflies there is a chemical called luciferin and an enzyme called luciferase along with an extra oxygen electron. The oxygen enters into their abdomen through tracheal tubes and reacts with calcium and adenosine triphosphate and with chemical luciferin, in the presence of luciferase. This reactions emits a burst of light. Through this reaction, they convert chemical energy into light energy. This production and emission of light by living organisms is called bioluminescence. Bioluminescence is a cold light, which means the light produced generates very less heat, preventing the fireflies from getting overheated. This is necessary because if the fireflies light producing organ got overheated, they may not survive.

Image Credit: National Geographic

Why fireflies glow?

Now since it is clear how fireflies glow, lets figure out why do they glow at the first place? Do they just glow for fun or is it a kind of defence mechanism? Let’s find out.

Fireflies glow for a variety of reasons. Some fireflies or their larvae glow to appear distasteful to their predators, while others glow in order to attract a mate. Glow from the fireflies of different species can be different. It can be yellow, green or orange. This  means different species have their unique flash patterns which they use to identify other members of their species, since there are about 2000 different species of fireflies.

Do other organisms glow like fireflies?

Did you know apart from fireflies there many other organisms which are bioluminescent, which means they can glow, although fireflies are the most popular and fascinating ones. For example, plankton, some types of algae, deep water fish and some rare bacteria and fungi also have the ability to glow.

Not only living organisms, but also some plants are gifted to glow in the dark such as kale, arugula, spinach and watercress. They use their glow as a medium of defense mechanism.

Interesting Facts about Fireflies

Here are some cool fun facts about fireflies that you may enjoy:

  • Not only fireflies, but also their egg and larvae are bioluminescent, that is they can glow.
  • Fireflies belong to the family of beetles called lampyridae.
  • They are 100% light givers. For example, when a light bulb lights up it gives 10% of the light, whereas 90% is lost in heat. But when fireflies glow, they give out 100% of the light. A very small amount is lost in heat. Thus, they are considered very efficient light givers,
  • Some fireflies are cannibals, that is they eat other fireflies for food.
  • Some fireflies larvae live underwater. They have gills to help them breathe.
  • Some fireflies do not glow at all.
  • Fireflies have the rare ability to turn their lights on and off voluntarily.
  • Fireflies larvae are also called ‘glow worms’. Larvae are carnivorous and particularly enjoy snails. Adult fireflies often feed on pollen and nectar.
  • Adult fireflies live only two months, spending their summer’s mating and laying eggs.

Interesting Videos : Why Fireflies glow?

Bioluminescent nature of fireflies is not only a treat for the eyes, but it has also helped scientists to perform various medical researches to find the cure of many diseases. Luciferase, that is found in fireflies is an extremely useful chemical in scientific research, food safety testing and forensic tests. It can also be used to detect ATP levels in cells and could possibly lead through a breakthrough in cancer and diabetes research. When luciferase was discovered the only way to obtain the chemical was from fireflies themselves. But today, synthetic luciferase is available, but some companies still harvest fireflies,  which may lead to their decline.

You may have seen or heard a lot about fireflies glow jar or perhaps even planned on creating one for yourself. Here are little things you must remember. Although fireflies in Amazon jar is a pretty sight, make sure to always leave holes on the cap of the jar for them to breathe, and always remember you should not keep them locked up for more than a couple of days. Besides, it is best to keep these magical creatures in the arms of nature itself, instead of capturing them in jar. Their numbers have been already declining at a huge rate in the past few years because of their use in scientific researches. Many even hurt these creatures for entertainment. Thus, there is an increased need to protect these creatures before they go extinct.

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