Do Axolotls Glow In The Dark? [GFP Axolotl]

In recent years, axolotls – a species of salamander from Mexico – have gained a large global fan base. And it’s easy to see why! Whether it’s because of their cute smiley faces, feathery external gills, colorful morphs, or amazing ability to regenerate body parts…axolotls really are unique creatures.

However, these unusual physical features have brought more than just glowing press! They’ve also caused all sorts of wild rumors to circulate…the most surprising perhaps being that axolotls can glow in the dark. If you’re reading this post, you’re likely wondering: “Do axolotls glow in the dark?.

I’ve shone some light on the mystery!

Axolotls do not glow in the dark. Or, to be precise, axolotls do not naturally glow in the dark. If you were considering buying an axolotl because of its ability to glow in the dark, then you may be disappointed. A wild-type axolotl will not glow if you simply switch off all the lights in the room and make it dark. So, if you watch your axolotl on a normal day, you will notice that they do not glow as they move around inside their tank. But, there’s an exception…The emphasis here is on the word “naturally”. Indeed, certain axolotls have been genetically modified to synthesize a special type of protein that glows in the dark when exposed to UV light.

So, you might be wondering where this myth could have come from. After all, it’s a pretty random thing to say about a creature if they don’t actually glow in the dark…Keep on reading to learn more!

Table of Contents

Do Axolotls Glow In The Dark [GFP Axolotl] Featured Image

What Is a GFP Axolotl?

The source of confusion about whether or not axolotls can glow in the dark is the GFP axolotl. GFP axolotls possess a gene that causes the synthesis of a special type of protein that glows in the dark when exposed to UV light.

GFP (Green Fluorescent Protein)

GFP stands for Green Fluorescent Protein. Green Fluorescent Protein will glow in the dark with a bright green hue when exposed to ultraviolet light – also known as UV light or black light.

The gene that is responsible for the synthesis of the Green Fluorescent Protein naturally exists in many creatures in the wild, most noticeably certain deep-sea marine species such as jellyfish. However, the GFP gene is not naturally present in axolotl DNA.

Do Axolotls Glow Under UV Lights?

The GFP gene is ultimately what gives the axolotl the ability to glow – but only when exposed to UV light. UV lights, often known as black lights, work best when they are used in total darkness. To make GFP axolotls glow you must turn off your regular lights to make the room pitch black and then shine a UV light on them. This is where the glow-in-the-dark axolotl rumors come from.

So, you could argue that, yes, axolotls do glow in the dark. But, they are only able to do so if A) they possess the GFP gene AND B) they are exposed to UV light. Without this combination, your axolotl will not glow in the dark. Instead, when you turn off the lights, you simply won’t be able to see them at all.

Knowing this, why don’t you go ahead and do the test to see if your axolotl has the GFP gene?

Where Do GFP Axolotls Come From?

The gene behind the GFP was originally isolated from bioluminescent jellyfish cells back in the 1960s. Since the 1990s, scientific research has been carried out to try to insert this gene into the cells (and more specifically the genetic material inside the nucleus of the cells) of certain animals, among which the axolotl.

This genetic manipulation was carried out with the hope of giving researchers the ability to observe the development of certain types of cells and their movement/migration throughout the body, by placing their subjects under UV light.

This is how the GFP axolotl came into existence and the GFP gene has been passed down from one generation of axolotl to the next. It is this genetic modification which makes a GFP axolotl glow in the dark.

Are GFP Axolotls Transgenic?

Yes, GFP axolotls are transgenic organisms. Transgenic means that DNA from an unrelated organism has been artificially introduced into another organism’s genetic material.

Are GFP Axolotls Healthy?

Thankfully, GFP axolotls are just as healthy as their wild type or non-GFP peers.

Because GFP axolotls glow in the dark, certain people assume that they aren’t healthy. They associate glowing axolotls with radioactivity or chemical exposure of some sort, and thereby jump to the conclusion that the animals are sick.

How Much Do GFP Axolotls Cost?

Many people wonder if GFP axolotls are expensive because of their ability to glow. The answer is that yes, GFP axolotls are more expensive than axolotls that don’t have the GFP gene. This is due to simple supply and demand.

On average, GFP axolotls tend to cost $40 to $50 more than a typical axolotl – so be prepared to pay anywhere from $50 to $100. Indeed, GFP axolotls are rare. Because GFP axolotls are rarer than so-called normal axolotls they are able to command a higher price as people are ready to pay more in order to buy one.

Price may also vary depending on the color or morph of the axolotl. Indeed, whilst the most common GFP axolotls tend to be white albinos, it’s also possible to get GFP axolotls with other colors such as leucistic, golden, golden albino, and many more.

What Parts Of The GFP Axolotl’s Body Glow?

Many people think that only the GFP axolotl’s mouth can glow. This is incorrect. Indeed, the entire GFP axolotl’s body can glow, with the exception perhaps of its eyes.

However, it’s worth noting that only the underside of the Firefly axolotl will tend to glow.

Are Axolotls Bioluminescent?

The fact that GFP axolotls have the ability to glow in the dark also has many people wondering if this means that they are bioluminescent.

What Is Bioluminescence?

Bioluminescence is the production and emission of light by living organisms. Bioluminescence is achieved through specific chemical reactions, and therefore can be categorized as a form of chemiluminescence.

Are GFP Axolotls Bioluminescent?

GFP axolotls are not bioluminescent. There is no such thing as a bioluminescent axolotl. Indeed, GFP axolotls do not produce and emit their own light. Instead, as seen above, they simply glow a bright shade of green when exposed to UV light.

What Species Are Bioluminescent?

So, now that you know that GFP axolotls are not bioluminescent as such, you might be wondering what animals actually are

We’ve done a little bit of research and discovered that there are in fact quite a few species of animals that can emit light in the darkness. The first that comes to mind is of course the firefly, also known as the lightning bug or glow worm.

However, the majority of light-emitting creatures live in the depths of our oceans. Here’s a short list of some of these amazing species:

  • Anglerfish
  • Firefly Squid
  • Big Fin Reef Squid
  • Flashlight Fish
  • Dinoflagellates
  • Jellyfish
  • Comb Jellie

Finally, certain fungi and bacteria are also bioluminescent.

Axolotls And Darkness

Do Axolotls Like Total Darkness?

With all this discussion of axolotls and darkness, you might be wondering do axolotls like the dark.

As human beings, we can often find it difficult to accept that animals enjoy living in dark conditions, simply because we cannot see in the dark ourselves. But, while we lack this skill, many creatures have this. This is why a lot of animals are able to live nocturnal lifestyles.

While axolotls are not purely nocturnal animals, they are most active during the nighttime. This is part of the reason why axolotls actually like total darkness. Similar to how house cats are typically active during the nighttime while we sleep.

Axolotls are exotic pets, and for this reason, you have to remember that they live in natural habitats. At the bottom of lakes in Mexico, there aren’t any artificial lights to help axolotls see. For this reason, your pet axolotl probably quite likes total darkness.

Of course, it likely isn’t possible to keep your axolotl in total darkness all the time for lots of different reasons. But, axolotls do enjoy the darkness, so ensure that you always allow them a certain amount of time in the dark every day.

Is It Okay To Leave Axolotls In The Dark?

Following on from everything we have just said about axolotls liking the dark, you have probably already guessed that, yes, it is okay to leave axolotls in the dark. However, your axolotl should not spend all of their time in the dark. Instead, they should spend most of their days in dimmed light.

Dim lighting or mood lighting as a lot of people refer to it, is better for axolotls because axolotls have poor eyesight. This is primarily caused by the fact that axolotls are born without eyelids, so this makes them a lot more sensitive to light than humans. This is why it is recommended that you do not get incredibly bright lights for your axolotl’s tank.

In fact, a lot of the time it is recommended to have a dimly lit tank and to just use your normal house lighting to see your axolotl. If you do have lights installed in your axolotl’s tank, it is important to create dark areas too.

Axolotls shouldn’t be left in the dark constantly. But, it is essential to create dark areas for them to visit as and when they want to. Alternatively, you could simply ensure that the lighting is always dimmed in the room where you keep your axolotl to ensure that they are comfortable at all times.


In short, no, axolotls do not glow in the dark. At least not on their own. It is possible for axolotls to glow in the dark if they possess the GFP gene and will only do so when exposed to UV light.


Hello and welcome to Pets From Afar. I'm Glen. My daughter Siri and I are mad about axolotls. I created this website to document our findings and experiences, as we learn more about these amazing amphibians. Follow along and enjoy the fun!

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