Do Axolotls Have Blood? Understanding Axolotl Circulatory System

Abdul Wasay Khatri | Administrator

Last updated: 18 January, 2026

If you’ve ever watched an axolotl closely, especially a light-colored one, you might wonder: do these creatures actually have blood? It’s a valid question. Unlike fish, you don’t see red gills. Unlike mammals, you can’t feel a pulse. And those pale pink or white axolotls look almost translucent. So what’s going on inside these mysterious salamanders?

The straightforward answer is yes, axolotls absolutely have blood. They have a complete circulatory system with a functioning heart, blood vessels, and blood that contains the same basic components found in most vertebrates. But the way their circulatory system works is quite different from mammals, which is probably why this question comes up so often.

Let’s clear up the confusion and dive into how axolotl blood and circulation actually work.

Yes, Axolotls Have Real Blood

Axolotls possess a fully functional blood-forming system (hematopoietic system) that generates blood cell lineages similar to other vertebrates, including lymphocytes, monocytes, and other major blood cell types.

Their blood serves the same essential functions as blood in any animal: transporting oxygen and nutrients to cells, removing waste products like carbon dioxide, fighting infections through immune cells, and helping with temperature regulation and healing.

The reason people sometimes question whether axolotls have blood comes down to their appearance. Light-colored axolotls—particularly leucistic (pink) and albino (white) varieties—have nearly transparent skin. When you look at them, you’re not seeing the vivid red coloration you’d expect from a creature with blood.

But the blood is definitely there. It’s just harder to see through their unique physiology.

What Color Is Axolotl Blood?

Axolotl blood is red, just like human blood, because it contains hemoglobin—the iron-based protein that gives blood its color and carries oxygen.

However, the concentration of red blood cells in axolotl blood may be lower than in mammals, which can make the blood appear less intensely red. This is partly because axolotls don’t rely solely on blood to transport oxygen. They also absorb oxygen directly through their skin and gills, reducing the need for extremely high concentrations of red blood cells.

If you’ve ever seen an axolotl with an injury, you’d notice red blood. It’s unmistakable. The misconception exists mainly because their skin is so effective at hiding what’s underneath.

The Unique Axolotl Heart: Three Chambers Instead of Four

Here’s where axolotl circulation gets interesting. An axolotl’s heart has only three chambers: two atria (right and left) and one ventricle. Mammals and birds have four-chambered hearts with two separate ventricles.

This three-chamber design is typical for amphibians, but it works differently than the four-chamber hearts we’re more familiar with.

The right atrium receives deoxygenated blood from the body, while the left atrium receives oxygenated blood from the lungs and gills. Both atria contract and send their blood into the single ventricle. This means oxygenated and deoxygenated blood mix together in the ventricle.

You might think this would be a problem—and in mammals it would be—but the spiral valve helps keep the blood from completely mixing, and the conus arteriosus directs the correct blood flow to different parts of the body.

Axolotls have a double circulatory system with a three-chamber heart that contains mixed oxygen-rich and oxygen-depleted blood. They don’t prioritize oxygenating blood to high concentrations, but rather focus on transferring whatever oxygen they have to cells that need it.

How Axolotl Circulation Works

The axolotl circulatory system follows this basic path:

Step 1: Deoxygenated blood from the body flows into the sinus venosus, which receives blood before it enters the heart.

Step 2: Blood moves from the sinus venosus into the right atrium.

Step 3: Meanwhile, oxygenated blood from the gills and lungs enters the left atrium.

Step 4: Both atria contract simultaneously, pushing blood into the single ventricle where it partially mixes.

Step 5: The ventricle contracts, sending blood through the conus arteriosus and out to the body through blood vessels.

The blood pressure in axolotls is much lower than in humans—around 20-30 mmHg compared to the typical human range of 120/80 mmHg. This lower pressure is sufficient for their needs because they’re cold-blooded and have a much slower metabolism than warm-blooded animals.

Why Three Chambers Instead of Four?

The three-chamber heart design is perfectly adequate for axolotls because of how they breathe. Unlike mammals that rely exclusively on lungs, axolotls primarily absorb oxygen through their skin using passive diffusion through thin, moist skin with surface capillaries.

They also breathe through their feathery external gills and have small internal lungs they occasionally use by swimming to the surface for air. With three different methods of oxygen intake, they don’t need the super-efficient four-chamber heart that mammals require.

The mixed blood in their single ventricle isn’t a flaw—it’s an adaptation that works perfectly for their amphibian lifestyle.

Blood Production in Axolotls

Research shows that axolotl blood cells are produced primarily in the liver and spleen during adulthood, with the embryonic liver being the first organ to harbor blood stem cells capable of long-term production.

This is similar to humans, where bone marrow produces most blood cells, though the specific organs differ. The important point is that axolotls have a sophisticated system for continuously producing fresh blood cells throughout their lives.

Their blood-forming system is particularly interesting to scientists because it plays a role in their incredible regenerative abilities. When an axolotl regrows a limb, blood vessels must regrow along with it, requiring the production of new blood cells and circulatory structures.

Can You See Axolotl Blood?

In most cases, no—you can’t see the blood circulating inside a healthy axolotl. Their skin, even on pale varieties, is opaque enough to conceal the blood vessels beneath.

However, there are situations where you might observe their blood:

During injuries: Any cut or wound will produce visible red blood.

In the gills: If you look very closely at the gill filaments of a light-colored axolotl, you might see a slight pink tinge from blood vessels, though this is subtle.

Through very thin skin: In rare cases with extremely pale albino axolotls, you might detect a faint pinkish coloration in areas with particularly thin skin.

Under specialized lighting: Researchers sometimes use special imaging techniques to visualize blood flow in axolotls for scientific studies.

Common Misconceptions About Axolotl Blood

Let’s address some widespread confusion:

Myth 1: Pink axolotls don’t have blood—they’re just pink naturally.

False. The pink coloration in leucistic axolotls comes from their skin pigmentation (or lack thereof) and the slight visibility of blood vessels beneath. They absolutely have blood.

Myth 2: Axolotls have blue blood like some sea creatures.

False. Axolotl blood is red due to iron-based hemoglobin. Some marine animals have blue blood because they use copper-based hemocyanin instead, but axolotls use the same iron-based system as mammals.

Myth 3: Axolotls can survive without blood because they breathe through their skin.

False. While skin respiration is important, axolotls still need blood to transport oxygen to internal organs and carry nutrients throughout their body. They absolutely require a functioning circulatory system to live.

Myth 4: You can’t take blood samples from axolotls.

False. Veterinarians and researchers can draw blood from axolotls for testing, though it requires specialized knowledge due to their delicate nature and small size.

What Happens When Axolotls Lose Blood?

Like any animal, axolotls can suffer from blood loss due to injury. However, thanks to their remarkable regenerative abilities, they can often recover from injuries that would be fatal to other creatures.

If an axolotl experiences blood loss:

• Their clotting mechanisms will work to seal the wound
• Their immune system will fight off potential infections
• Their regenerative abilities will begin repairing damaged tissue
• Their blood-forming organs will produce new blood cells to replace what was lost

That said, severe blood loss can still be dangerous or fatal. Maintaining excellent water quality and handling your axolotl carefully are crucial for preventing injuries.

Frequently Asked Questions

Do axolotls have blood types like humans?

Axolotls do have different blood cell characteristics, but the blood typing system for amphibians is not as well-defined as the ABO system in humans. Research into axolotl blood types is ongoing, particularly for studies involving blood cell transplantation.

Can you see an axolotl’s heartbeat?

In some light-colored axolotls, particularly young ones with very translucent skin, you might be able to see a faint pulsing movement near the throat area where the heart is located. However, this is uncommon and not visible in most adults.

How much blood does an axolotl have?

The total blood volume varies with the size of the axolotl, but generally, amphibians have a blood volume of about 5-8% of their body weight. For a typical adult axolotl weighing 200 grams, that would be roughly 10-16 milliliters of blood.

Do axolotls need oxygen-rich water because of their blood?

Yes, but not just for their blood. Axolotls absorb oxygen through their gills and skin, so well-oxygenated water is essential. Poor oxygen levels stress their entire system, not just their circulatory system.

Can axolotls get anemia?

Yes, axolotls can develop anemia (low red blood cell counts) due to poor nutrition, parasites, or disease. Signs include pale gills, lethargy, and reduced appetite. A specialized exotic vet can diagnose and treat this condition.

Why are my axolotl’s gills pale?

Pale gills can indicate several issues including poor water quality, low oxygen levels, stress, anemia, or illness. The gills should normally appear a healthy pink or red color due to blood vessels near the surface. If your axolotl’s gills look consistently pale, check your water parameters and consult a vet if the problem persists.

Is it normal to never see blood on my axolotl?

Yes, completely normal! In a healthy axolotl with no injuries, you shouldn’t see any blood. The circulatory system is entirely internal and well-protected by their skin.

Can axolotls regenerate blood vessels?

Yes! When an axolotl regenerates a limb or organ, it also rebuilds the complete network of blood vessels needed to supply that tissue. This includes arteries, veins, and tiny capillaries—all perfectly integrated with the existing circulatory system.

Do different colored axolotls have different colored blood?

No. All axolotls have red blood regardless of their external color. Their skin pigmentation doesn’t affect their internal blood color.

Should I worry if my axolotl seems to have no pulse?

Axolotl heart rates are naturally very slow—around 20-30 beats per minute when resting. This is completely normal for cold-blooded animals. You probably won’t be able to detect a pulse by touching them like you would with a dog or cat.

The Bottom Line

Do axolotls have blood? Absolutely. They have a complete, functional circulatory system with red blood, a three-chambered heart, and all the necessary components to keep them alive and healthy.

The confusion exists because their unique physiology—transparent skin, external gills, multiple breathing methods, and three-chamber heart—differs so dramatically from the mammals we’re most familiar with. But different doesn’t mean absent.

Understanding that axolotls have real blood and a functioning circulatory system helps you appreciate just how complex and fascinating these creatures are. Their blood-forming system, heart structure, and circulation methods represent millions of years of evolution perfectly adapted to their aquatic amphibian lifestyle.

So the next time someone asks if axolotls have blood, you can confidently explain not only that they do, but exactly how their remarkable circulatory system works!

Abdul Wasay Khatri
Administrator
Abdul Wasay is the founder and lead author of Axolotl Portal, a trusted site for axolotl care. He spent almost nine months learning about axolotls, including their tanks, feeding, water care, and common health problems. His knowledge comes from trusted vets, research, and real experience from long term axolotl owners. All Posts by