Walk into any pet store and you’ll find axolotls in the fish section, swimming in aquarium tanks alongside goldfish and bettas. This creates massive confusion. Are axolotls actually fish? Are they amphibians? What about salamanders are those different?

The Simple Answer: Axolotls Are Amphibians

Axolotls are amphibians, not fish. More specifically, they’re a type of salamander that stays in water their entire life.

Here’s the classification breakdown:

Kingdom: Animalia (animals)
Phylum: Chordata (animals with backbones)
Class: Amphibia (amphibians)
Order: Urodela (salamanders and newts)
Family: Ambystomatidae (mole salamanders)
Genus: Ambystoma
Species: Ambystoma mexicanum (Mexican axolotl)

So yes, axolotls are salamanders. And salamanders are a type of amphibian. Therefore, axolotls are both salamanders AND amphibians these terms aren’t mutually exclusive.

Why Everyone Thinks They’re Fish

The confusion makes perfect sense when you consider where and how people encounter axolotls.

They live underwater: Unlike most amphibians that split time between water and land, axolotls spend their entire life submerged. This makes them look like fish.

They have gills: Those feathery structures on their head work exactly like fish gills, extracting oxygen from water. Most adult amphibians lose their gills and develop lungs instead.

They’re sold in aquarium stores: Pet stores display axolotls in the fish section with aquarium equipment. This placement reinforces the fish assumption.

They swim constantly: Watching an axolotl glide through water looks identical to fish swimming. They navigate their environment exactly like aquatic fish do.

They need the same equipment as fish: Filters, heaters (or chillers), water conditioners, and testing kits all standard fish-keeping supplies work for axolotls.

The name doesn’t help: “Axolotl” doesn’t sound like any familiar amphibian. It’s an Aztec word (meaning “water dog” or “water monster”) that gives no hints about what type of animal they are.

Despite all these fish-like qualities, axolotls remain amphibians through and through.

What Makes Axolotls Amphibians Instead of Fish

Several key differences separate axolotls from actual fish, even though they live in water.

Skin vs. Scales

Fish have scales covering their body tough, overlapping plates that protect them. Axolotls have smooth, permeable skin without any scales. Their skin absorbs oxygen from water and releases waste products, just like other amphibians.

This permeable skin makes axolotls extremely sensitive to water quality. Fish can tolerate conditions that would severely harm an axolotl.

Skeletal Structure

Axolotls have a bony skeleton similar to other land vertebrates. They possess distinct bones for limbs, a proper spine structure, and a skull designed like other amphibians.

Fish have a different skeletal arrangement. Many have cartilage instead of bone, and their fin structure differs completely from axolotl limbs.

Limbs with Toes

Look at an axolotl’s legs. They have four distinct limbs with individual toes four toes on the front legs, five on the back. These are true legs with joints like knees and elbows.

Fish have fins, not legs. Even bottom-dwelling fish that “walk” on their fins don’t have true limb structures with separate toes.

Reproduction Method

Axolotls lay eggs without hard shells, just like frogs and other amphibians. Females deposit eggs that males fertilize externally. The eggs are soft, jelly-like clusters that stick to plants and surfaces.

Most fish also lay eggs, but the structure and development process differ. Some fish give live birth, which no amphibian does.

Metamorphosis Capability

Here’s where things get really interesting. Axolotls CAN transform into a land-dwelling salamander form under certain conditions, though this rarely happens naturally. This transformation ability even if unused marks them as amphibians.

Fish cannot transform into land animals. They remain aquatic their entire life without any possibility of developing land-living adaptations.

Breathing Adaptations

Axolotls have three ways to breathe: through their gills, through their skin, and with vestigial lungs. Yes, they have small, underdeveloped lungs that work minimally but exist nonetheless.

Fish breathe only through gills. They don’t have lungs or the ability to absorb significant oxygen through skin.

Understanding the Salamander Connection

Now let’s address another point of confusion: the relationship between axolotls and salamanders.

Axolotls ARE salamanders. Specifically, they’re a type of mole salamander that exhibits neoteny a scientific term meaning they retain juvenile features into adulthood.

What makes salamanders different from other amphibians:

Salamanders have tails throughout their entire life. Frogs and toads lose their tails during metamorphosis.

Salamanders have four legs of roughly equal size. Frogs have large back legs and smaller front legs adapted for jumping.

Salamanders walk or swim using side-to-side body movements. Frogs hop and use a completely different movement pattern.

Salamander larvae look similar to adults, just smaller. Frog tadpoles look nothing like adult frogs.

Why axolotls look different from other salamanders:

Most salamanders go through metamorphosis. They start as aquatic larvae with gills, then transform into land-dwelling adults with lungs. Their body changes dramatically during this process.

Axolotls skip this transformation. They become sexually mature and can breed while still in their larval form. This phenomenon neoteny means they keep their feathery gills, tail fin, and aquatic lifestyle forever.

Think of axolotls as salamanders that decided to stay kids. They reach adulthood without “growing up” into the typical adult salamander form.

What Happens If an Axolotl Morphs

Under certain conditions, axolotls can undergo metamorphosis into a terrestrial (land-dwelling) salamander form. This is extremely rare in captivity and doesn’t happen in healthy axolotls.

What triggers morphing:

Severe environmental stress, particularly lowering water levels in their habitat

Exposure to certain hormones, particularly thyroid hormones

Genetic factors some axolotls are more prone to morphing than others

Poor water quality forcing them to leave the water

What changes during metamorphosis:

The external gills shrink and eventually disappear

The tail fin reduces in size

Skin texture changes and becomes less permeable

Coloration often changes they usually become darker

Eyelids develop (axolotls normally lack eyelids)

Body shape becomes more robust and less streamlined

Lungs develop more fully for air breathing

Why morphing is dangerous:

The transformation puts extreme stress on the axolotl’s body. Many don’t survive the process.

Morphed axolotls have a significantly shorter lifespan, often living only 1-2 years compared to 10-15 years for aquatic axolotls.

They require completely different care as terrestrial animals humid terrariums instead of aquariums.

They’re more prone to health problems and injuries.

Responsible breeders avoid encouraging morphing. Axolotls evolved to stay aquatic, and forcing or allowing metamorphosis goes against their natural biology.

How Axolotls Compare to Other Aquatic Creatures

Let’s put axolotls side by side with animals they’re commonly confused with.

Axolotls vs. Fish

Both: Live fully underwater, have gills, swim constantly Axolotls have: Four legs with toes, permeable skin, ability to regenerate limbs Fish have: Fins instead of legs, scales, cannot regenerate complex structures like entire limbs

Axolotls vs. Tadpoles

Both: Aquatic amphibian larval forms with gills and tails Axolotls: Reach sexual maturity, stay in larval form permanently, grow large (up to 12 inches) Tadpoles: Transform into adult frogs/toads, temporary life stage, lose tail and gills

Axolotls vs. Mudpuppies

Both: Neotenic salamanders that keep their gills as adults, fully aquatic Axolotls: Native to Mexico, kept as pets, come in many color varieties Mudpuppies: Native to North America, stay in natural habitat, typically dark colored

Axolotls vs. Newts

Both: Salamanders in the order Urodela Axolotls: Fully aquatic, never leave water, larger size Newts: Most are semi-aquatic, spend time on land, generally smaller

Axolotls vs. Sirens

Both: Permanently aquatic salamanders with external gills Axolotls: Four legs, native to Mexico, common in captivity Sirens: Only two front legs (no back legs), native to North America, rarely kept as pets

Why the Fish Store Connection Makes Sense

Despite being amphibians, selling axolotls in aquarium stores actually makes practical sense.

Care requirements overlap with fish:

They need filtered, temperature-controlled water tanks

Water chemistry (pH, ammonia, nitrites, nitrates) must be monitored exactly like fish tanks

They eat aquatic foods similar to what large carnivorous fish eat

Tank setup uses the same equipment filters, heaters/chillers, decorations

Water changes follow the same schedule as fish tanks

They don’t fit with terrestrial amphibians:

Frogs and toads kept in pet stores need land areas and humidity control

Terrestrial salamanders need moisture but not full submersion

Axolotls would die in a typical frog enclosure they must stay underwater

Fish keepers have the right knowledge:

Anyone who successfully keeps fish understands water chemistry and cycling

The nitrogen cycle works identically in axolotl tanks and fish tanks

Filter maintenance, water testing, and tank cleaning skills transfer directly

From a practical retail perspective, grouping axolotls with fish makes more sense than putting them with frogs or lizards.

The Unique Biology That Causes Confusion

Several aspects of axolotl biology create the fish-or-amphibian confusion.

Neoteny (keeping juvenile features):

This is rare among vertebrates. Most animals grow up and change form. Axolotls broke this rule, remaining in a juvenile state while developing reproductive maturity.

Humans find this fascinating and confusing it challenges our understanding of normal development.

Exclusive aquatic lifestyle:

When most people think “amphibian,” they picture frogs hopping between water and land, or salamanders hiding under logs in forests.

Axolotls never leaving water breaks this mental model. They’re as committed to aquatic life as any fish.

Incredible regeneration:

Axolotls can regrow entire limbs, portions of their brain, heart tissue, and even parts of their spinal cord. This almost magical ability seems more like something from science fiction than reality.

While some fish and amphibians can regenerate, axolotls do it better than almost any other vertebrate. This unique trait adds to their mysterious nature.

Ancient lineage:

Axolotls represent an ancient evolutionary line. They existed before many modern fish species evolved. Their unusual biology reflects adaptations from millions of years ago.

Understanding them requires thinking about evolution in a non-linear way. They’re not “primitive” fish that never evolved they’re advanced amphibians that evolved to stay aquatic.

What This Means for Care

Knowing that axolotls are amphibians rather than fish affects how you should care for them.

Water quality requirements are stricter:

Their permeable amphibian skin absorbs everything from the water. Chemicals, medications, and toxins affect them more severely than fish.

You must be more careful about water conditioners, ensuring they’re amphibian-safe.

Chlorine and chloramine must be completely removed even small amounts can harm them.

Temperature needs differ from tropical fish:

Most popular aquarium fish are tropical, preferring 75-80°F water. Axolotls need much colder water, 60-64°F.

Housing them with tropical fish would stress or kill the axolotl from heat.

You often need chillers rather than heaters, opposite of most fish tanks.

They’re more sensitive to handling:

Their amphibian skin has a protective slime coat that’s easily damaged. Handling should be minimal and done with wet hands.

Fish also have protective slime, but axolotl skin is more delicate.

Never grab or squeeze them their soft bodies bruise and injure easily.

Tank mates must be chosen carefully:

Most fish will nip at axolotl gills, which look like fancy food to them.

Even peaceful fish may be eaten by axolotls if small enough.

The best practice is keeping axolotls in species-only tanks without any fish.

Substrate choices matter more:

Axolotls can swallow gravel while feeding, causing impaction and death.

Fish can live safely over gravel axolotls cannot.

Fine sand or bare bottom tanks work best for axolotls.

Common Misconceptions Cleared Up

Let’s address several persistent myths about what axolotls are.

Myth: Axolotls are baby salamanders Truth: They’re sexually mature adult salamanders that happen to look like larvae. They can breed and are fully grown.

Myth: All axolotls will eventually become land salamanders Truth: Healthy axolotls in proper conditions never morph. Transformation only happens under stress or with hormone intervention.

Myth: Axolotls are a type of fish that evolved legs Truth: They’re amphibians that evolved to stay aquatic. They didn’t evolve FROM fish they evolved to stay IN water.

Myth: Axolotls are reptiles because they have smooth skin Truth: Reptiles have scales or scutes. Axolotls have permeable amphibian skin.

Myth: Axolotls are related to eels or fish with weird faces Truth: They share no close relationship with any fish. Their closest relatives are other mole salamanders.

Myth: The gills mean they’re definitely fish Truth: Many amphibian larvae have gills. Axolotls just keep theirs into adulthood.

Frequently Asked Questions

Can axolotls breathe air like fish that jump out of water?

Axolotls have small lungs and can gulp air at the surface, but they can’t survive out of water. They’ll die within hours if left on land. Fish that jump can usually survive longer out of water than axolotls can.

Are axolotls more closely related to fish or frogs?

Axolotls are much more closely related to frogs. Both are amphibians. Fish are an entirely different class of animal. Axolotls and frogs share a common ancestor that fish don’t share.

Why don’t pet stores label them as amphibians?

Many stores do label them correctly, but they’re displayed with fish because they need aquarium setups. The “fish department” has the right equipment and knowledge for aquatic animal care.

Can axolotls live with fish?

Generally no. Temperature requirements differ, axolotls eat small fish, larger fish attack axolotl gills, and stress levels increase for both species. Some people successfully house them with specific fish species, but it’s risky.

Do axolotls have teeth like fish?

Axolotls have tiny teeth, but they’re very different from fish teeth. They use them more for gripping than chewing. They swallow food whole by suction, similar to how some fish feed but using a different mechanism.

Are axolotls endangered like some fish species?

In the wild, yes axolotls are critically endangered. Wild populations in Mexican lakes have nearly disappeared. However, millions exist in captivity. All pet axolotls are captive-bred, not taken from wild populations.

If axolotls are salamanders, why don’t they look like the salamanders I see outside?

The salamanders you see outside are terrestrial (land-dwelling) species that completed metamorphosis. Axolotls keep their aquatic larval appearance throughout life. If an axolotl morphed, it would look more like those salamanders.

Can I keep axolotls in a pond like goldfish?

Only if you live in a climate that keeps water between 60-64°F year-round, with no risk of freezing or overheating. The pond must be escape-proof and protected from predators. Most areas aren’t suitable for outdoor axolotl ponds.

Do axolotls need land areas like turtles?

No, axolotls never leave the water. Adding land areas is pointless and reduces their swimming space. They’re fully aquatic unlike turtles, which are reptiles that need to bask.

Are there other animals like axolotls that stay as “babies”?

Yes, several salamander species exhibit neoteny including mudpuppies, olms, and some siren species. This trait appears in various salamander groups but is rare in other animal types.

Why are axolotls used in science if they’re not special fish?

Scientists study axolotls BECAUSE they’re amphibians with incredible regeneration abilities. Their amphibian biology and salamander genetics make them perfect for research on healing, development, and regeneration.

If someone says “water dragon,” are they talking about axolotls?

Maybe. “Water dragon” can refer to axolotls (translation of their Aztec name) or to certain aquatic lizards (which are reptiles, not amphibians). Context matters in aquarium circles, it usually means axolotls.

The Scientific Importance of Being Amphibians

Understanding that axolotls are amphibians matters for more than just trivia.

Research applications:

Scientists study axolotls to understand how amphibians regenerate tissue. This research might someday help humans heal from injuries.

Their amphibian genes contain information about vertebrate development and evolution.

Cancer researchers study axolotls because they rarely develop tumors despite their regeneration abilities.

Conservation implications:

As amphibians, axolotls face threats similar to other amphibians habitat loss, water pollution, climate change.

Protecting their native habitat requires understanding their amphibian ecology and needs.

Captive breeding programs aim to eventually reintroduce them to the wild, requiring knowledge of amphibian reintroduction techniques.

Educational value:

Axolotls help people understand that amphibians aren’t just frogs and toads.

They demonstrate that evolution doesn’t always mean getting more complex sometimes staying “simple” is an advanced adaptation.

They show how one group of animals (amphibians) can occupy niches usually filled by another group (fish).

The Bottom Line

Axolotls are amphibians, specifically a type of salamander that exhibits neoteny retaining juvenile characteristics throughout life. They are not fish, despite living fully underwater and having gills.

The confusion is understandable given their appearance and care requirements, but scientifically there’s no debate. They belong to the class Amphibia, order Urodela (salamanders), and their biology clearly marks them as amphibians in every meaningful way.

They’re sold in aquarium stores and kept like fish because their care requirements overlap heavily with aquarium fish, not because they are fish. The classification as amphibians doesn’t change the fact that aquarium equipment and fish-keeping knowledge work perfectly well for maintaining them.

Understanding what axolotls truly are helps you provide better care, appreciate their unique biology, and explain to others why these amazing creatures deserve special consideration in the pet trade.

Next time someone asks if axolotls are fish, you can confidently explain: “They’re aquatic salamanders a type of amphibian that lives in water like fish but is completely different biologically. They’re basically salamanders that decided to stay in the water forever.”