Table of Contents
- What is Bioluminescence?
- 1. Anglerfish
- 2. New Zealand Glowworm
- 3. Firefly Squid
- 4. Crystal Jellyfish
- 5. Motyxia Millipedes
- 6. American Pocket Shark
- 7. Phylliroe
- 8. Velvet Belly Lanternshark
- 9. Sea Firefly
- 10. Fireflies
What is Bioluminescence?
Bioluminescence is a chemical light created by living creatures, usually animals who have adapted to living in darkness, like insects and deep-sea fishes. However, the purpose of the light is generally for mating, baiting, and camouflaging. Here are ten amazing animals that glow in the dark and how they use the bioluminescence light.
1. Anglerfish
You can be happy deep-sea creatures like the anglerfish live at depths 6600 feet below the water surface. However, you don’t want one of these alien-looking creatures nibbling on your toes while you are trying to enjoy a day at the beach with your family.
This monstrous creature is a killing machine, luring its prey with its bioluminescent bait right in front of its mouth. Over millions of years, it has developed one of nature’s finest traps in the dark.
The Anglerfish Bioluminescent Lure
The anglerfish lure like a fishing rod with bait at the end of the line. The bait is filled with bacteria, and it is exactly these bacteria that are bioluminescent.
Because of the complete darkness at the bottom of the sea, they also use the lure to attract mating partners. So, the typical anglerfish you see is actually the female one. Once they meet, the male will attach to the female like a parasite with sharp teeth.
As freaky as it sounds, the both of them will start fusing together, and the only thing left of the male after a while is his testes for reproduction.
2. New Zealand Glowworm
The New Zealand Glowworm is known as the larval stage of the fungus gnat. The fungus gnat is a pest fly that is quite hardy and can tolerate freezing temperatures. However, they are much more incredible insects in the larval stage than in the adult stage. Here’s why.
The glowworm produces a blue-green bioluminescent light from its body. The glowworm uses its body as bait while it sits between a minefield of hanging webs that it has produced.
The New Zealand glowworm thrives inside dark caves where they are sheltered and where the climate is humid.
This larva’s ability to create silk threads hanging down to capture flying species makes it unique from the rest in this top ten list. In addition, they are the only light source inside these dark caves, which makes them attractive to other flying insects inside the cave.
3. Firefly Squid
You can’t make a list of animals that grow in the dark without mentioning the firefly squid.
This fantastic creature uses blue and green bioluminescent light to blend in with the blue light coming from the ocean surface. This is a survival strategy because it makes it less likely to be seen and targeted by other squid-eating animals from depths.
4. Crystal Jellyfish
On the west coast of North America in the Pacific Ocean, you can find crystal jellyfish – also known as Aequorea victoria.
The crystal jellyfish is a small species, typically growing to around 20 mm in diameter. It has a transparent bell-shaped body with bioluminescent light around the outer ring.
The crystal jellyfish diet is based on small planktonic animals and other jellies.
The crystal jellyfish is not harmful to humans. However, contact with the tentacles can cause skin irritation.
Crystal jellyfish is also used as part of interesting scientific experiments. For example, thanks to the jellyfish GFP gene, scientists have used this unique gene to create ‘green mice’ that glow when exposed to blue light.
5. Motyxia Millipedes
The ocean is rich in glowing creatures, but interestingly enough, the planet Earth offers many glowing insects on the ground. For example, let’s look at the glowing millipede called Motyxia, which can be found around California.
These tiny creatures live most of the day, hiding beneath the soil. Once the day turns into the night, these nocturnal millipedes crawl up to feed on decaying vegetation.
Even though they prefer hiding, nature has its ways of surprising us. The low illumination from their body is not because they want to look cool but to scare off potential predators.
Predators have a good reason to fear biting into one of these because, as scary as it sounds, their body produces hydrogen cyanide. They don’t contain a deadly dose of cyanide, but it is not pleasant for whoever takes a bite into one of these.
6. American Pocket Shark
As you have seen so far in the list, the ocean is filled with bioluminescent species. It is estimated that 76% of the animals in the sea are bioluminescent. Because of these vast amounts, it might not surprise you that there is also a glowing shark.
The American Pocket Shark is a newly discovered species that also uses bioluminescence as a lure to draw prey toward itself. The shark releases a glowing substance that can attract other deep-sea creatures looking for a meal or mating partner.
7. Phylliroe
Strange animals interest me, and Phylliroe is for sure one of them. Phylliroe is a bioluminescent slug that can actually swim. If you are lucky enough to see one, the phylliroe is easy to mistake for a fish.
In the video below, you can see them in action.
8. Velvet Belly Lanternshark
Around the Norwegian coast in the northeastern Atlantic Ocean, we find the velvet belly lanternshark. This is not the typical dangerous shark we all know about. Thus, it is around 18 inches long (45 cm).
The shark’s bioluminescence abilities appear around its belly. Hence its name. They are not the most pretty-looking sharks and often carry parasites.
9. Sea Firefly
On the coast of Japan, there is a sight to behold. The small sea firefly, also known as vargula hilgendorfii, is a small glowing crustacean. These small creatures only have a size of around 3 mm, but together, they create this beautiful sight. Check out the two pictures below!
Vargula hilgendorfii, sea fireflies in Okayama, Japan. 📸 Trevor Williams and @Jonathangalione. Vargula collect in buckets and then thrown over rocks to get these beautiful bioluminescent images. Awesome images #46 and 47 pic.twitter.com/iW5gYdKz9d
— Marc Zimmer (@LightUpScience) December 2, 2019
10. Fireflies
The firefly is the most famous bioluminescent species known for glowing in the dark. It is not unusual to spot these little insects flying on a warm summer night. There are an estimated 2000 firefly species in the Lampyridae family.
When you see a glowing firefly, you see them in the last days of their lives. Their final purpose in the adult stage is to find a mating partner.
It is the male firefly you see fly around looking for a female to mate with. The female is either lying on the ground or in the tree, judging the male’s glow intensity and pattern before deciding who to mate.
If you are interested in learning more about these incredible flying beetles – we have an article that covers a lot of interesting facts about fireflies.
In conclusion, bioluminescence is a fascinating natural phenomenon. In nature, we also find glowing fungi and plankton, but now you know ten more animal species that glow in the dark.
