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Glow in the Dark Animals

 
By Josie F. Turner, Journalist specialized in Animal Welfare. June 25, 2020
Glow in the Dark Animals

Have you every heard of bioluminescence? It is the phenomenon whereby a living organism can produce light from its own body. This means they are animals which can glow in the dark. It is something which is seen most commonly in the world's oceans as the vast majority of glow in the dark animals live in the depths of the sea. There are bioluminescent animals which live in the land also, but regardless of where they live, the ability to grow in the dark makes them a phenomenon of nature.

If you are interested in knowing more, AnimalWised brings you our list of the top 10 glow in the dark animals. We also show you some surprising pictures so you can see this incredible natural phenomenon for yourself.

You may also be interested in: Why do Cats' Eyes Glow in the Dark?

Why do some animals glow in the dark?

The reason why some bioluminescent animals glow in the dark is due to chemical reactions which occur in the body. This type of chemical reaction is known as chemiluminescence. Generally, a light emitting molecule reacts with a certain enzyme and the reaction causes light to emanate from the part of the body where it takes place. However, the type of molecules differ between organisms and they may need other factors to support the reaction.

Our top 10 animals that glow in the dark are:

  1. Jellyfish
  2. Scorpion
  3. Firefly
  4. Firefly squid
  5. Antarctic krill
  6. Horned lantern fish
  7. Comb jelly
  8. Siphonosphores
  9. Railroad worm
  10. Quantula striata

Now we know what animals glow in the dark, the question remains as to what purpose it serves. The reasons are believed to be varied and include:

  • Warning: certain animals, such as poisonous frogs and toads, are brightly colored to tell potential predators eating them is not a good idea. Bioluminescence can work in a similar way, notifying something not to attack otherwise they're could be trouble. Some animals may be bioluminescent to give them the look of a predator themselves, even if they are actually a prey animal.
  • Mimicry: some predators may do the opposite of give a warning. By mimicking the look of a prey animal with light, they can attract smaller predators and attack when they are vulnerable. They may also camouflage themselves so they can surprise prey or evade predators themselves.
  • Defense: some bioluminescent animals can also give off bioluminescent material. This creates a shroud which allows them to escape a potential threat.
  • Communication: although it is very difficult to know what they are saying, there are some bioluminescent animals which use their light to communicate. Glow in the dark bacteria might use it to attract predators to their host and allow them to move on.

Since so many of the animals that glow in the dark live in the depths of the ocean, our knowledge about them is very limited. What we do know is that they can be incredibly beautiful as our list of glow in the dark creatures shows.

1. Jellyfish

The first on our list is not really an animal, but a large group of different animals which have some of the most incredible adaptations in nature. Some of them have the property of being able to glow in the dark. The reason for this is due to the green florescent protein or aequorin proteins which allow they to glow.

Jellyfish likely use their light emission to attract prey. At night, agitation can cause the bioluminescent proteins to react and attract prey. They can they use their tentacles to envelop and/or sting their prey. Some glow in the dark jellyfish include Aequorea victoria and the atolla jellyfish.

Glow in the Dark Animals - 1. Jellyfish

2. Scorpion

Scorpions do not glow in the dark, as such. Instead, they glow florescent blue or green when placed under UV light or certain wavelengths of light. In fact, if the moon is particularly intense on a clear night, the moonlight can be sufficient for them to glow in the dark.

Although experts have studied this phenomenon in scorpions for years, the reason for this reaction is still unknown. However, it is believed that they likely use this mechanism to measure light levels at night. In turn, this allows them to determine if it is appropriate to go hunting. It may also be used to recognize each other.

While scorpions don't look bright in normal light, there are some blue animals in nature which do.

Glow in the Dark Animals - 2. Scorpion

3. Firefly

We move on to the minority of glow in the dark animals which live on land. Or at least some of the time. Fireflies are the little insects that light up gardens and forests. They live in temperate and tropical environments and more than 2000 species of them have been discovered.

Fireflies glow due to chemical processes that occur in their body caused by oxygen consumption. This process releases a lot of energy and transforms it into a glowing cold light. This light is emitted by the organs below their abdomen and can emit in various colors such as: yellow, green and red. They are quite magical, especially when flying in a swarm.

Glow in the Dark Animals - 3. Firefly

4. Firefly squid

We go back to marine animals which can glow in the dark by investigating the firefly squid. They are an animal that causes one of the most dramatic and glorious displays in the animal kingdom. Every year, off the coast of the Japanese Toyama Bay area firefly squid provide this display.

During the mating season in the months of March to May, the firefly squid descend on the bay and search for partners. These squid are monogamous, although this may be due to shorter lifespans rather than love. Their whole body lights up and causes the bay to become incredibly beautiful. The light comes from bioluminescent reactions in their outer membranes.

Glow in the Dark Animals - 4. Firefly squid
Image: animalesfantasticosysuscaracteristicas.files.wordpress.com

5. Antarctic krill

This marine creature is a crustacean whose length varies between 8 and 70 mm. They are among the most important animals in the Antarctic food chain. This is because as they are a major food source for many other predatory animals such as seals, penguins and birds.

Krill have numerous organs that can give off a yellow-green light for 3 seconds at a time. This crustacean is said to light up to avoid predators from the deep, blending in to the reflective water and ice surfaces they inhabit. This can also provide a beautiful display, even if the predators don't know what's going on.

Glowing isn't the same as changing color. This is a different process and we explain it in this article on animals that can change color.

Glow in the Dark Animals - 5. Antarctic krill

6. Horned lantern fish

This animal was the inspiration for one of the evil characters in the famous Disney animated movie Finding Nemo. And it is not surprising when you consider their large jaws and teeth can frighten anyone. This poor fish is listed as one of the ugliest animals in the world, but at AnimalWised, we simply consider it very interesting.

However, they do deserve their reputation as being frightening if you are another sea animal. The lantern fish carry on their heads a kind of flashlight with which they shine on the dark ocean floor and attract both their prey and their sexual partners.

Glow in the Dark Animals - 6. Horned lantern fish

7. Comb jelly

Although little known, this type of ctenophore is a close cousin of the jellyfish. They are very abundant in oceans across the world and feed on a large portion of its plankton biomass. They are very strange. Although some have a jellyfish shape, most appear like flattened worms. Unlike jellyfish, they do not sting and produce bioluminescence as a defense mechanism. Many comb jellyfish have a single pair of tentacles that leave behind a kind of light trail. The species Bathocyroe fosteri is one example of glow in the dark jelly combs.

Glow in the Dark Animals - 7. Comb jelly

8. Siphonosphores

Siphonosphores are not technically an animal that glows. There are animals that glow. Although they appear to be only one organism, they are actually made up of something known as zooids, multicellular organisms which group together to form a colonial animal. Some of them exhibit bioluminesence to attract prey. While the other animals on our list glow blue, green or yellow, this is only the second one to have been found to glow red.

Glow in the Dark Animals - 8. Siphonosphores

9. Railroad worm

Leaving the ocean again for a moment, we look at an animal which starts off as bioluminescent in their larvae form. They are known as railroad worms. Their bioluminescence comes from eleven pairs of glowing organs which line their body and then two more which appear on their head. They eventually turn into beetles, but they look like this during their larval stage. The railroad worm's name comes from the fact their glowing parts make them look like a strip of railroad.

Glow in the Dark Animals - 9. Railroad worm
Image: Aaron Pomerantz

10. Quantula striata

A type of land snail, this does not glow as much as some of the other creatures on our list. Their eggs glow a lot, but once they develop into snails their bioluminescence is minimal. It does appear in flashes of green, but it can be difficult to see in certain lights. They can be found in different parts of Asia and measure between 1.5 to 3 cm in the shell and up to 6 cm long in their body. Why these snails glow is not well known.

While you can find various glowing animals in the ocean, they may not be the weirdest you can find. Some of the rarest animals in the sea are also some of the most peculiar (and fascinating) to us:

If you want to read similar articles to Glow in the Dark Animals, we recommend you visit our Facts about the animal kingdom category.

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Image: animalesfantasticosysuscaracteristicas.files.wordpress.com
Image: Aaron Pomerantz
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