---
title: "What the sources say about the Axolotl | AnimalTracks.wiki"
description: "58 claims from the Axolotl profile, each beside the words of the source that backs it."
image: "https://animaltracks.wiki/images/animals/axolotl-1.webp"
canonical: "https://animaltracks.wiki/animals/axolotl/sources/"
---

# What the sources say about the Axolotl (*Ambystoma mexicanum*)

> 58 claims from the Axolotl profile, each beside the words of the source that backs it. A "..." marks a cut in a quote and [brackets] an insertion.

Profile: [Axolotl](https://animaltracks.wiki/animals/axolotl/)

## Ambystoma mexicanum (axolotl). Animal Diversity Web, University of Michigan.

https://animaldiversity.org/accounts/Ambystoma_mexicanum/

| The page says | The source says |
| :--- | :--- |
| keeps its larval gills as an adult | Juvenile and adult axolotls possess feathery, external gills and tail fins suited to an aquatic lifestyle. |
| A cyber-larva with feather-antenna gills it keeps into adulthood | Juvenile and adult axolotls possess feathery, external gills and tail fins suited to an aquatic lifestyle. |
| Lake Xochimilco canal waterways at the southern edge of Mexico City | Lake Xochimilco is now nothing more than a scattering of canals and swamps. |
| Mollusks, fish, insects and other arthropods, even other axolotls | axolotls will eat anything that they can catch, including molluscs, fishes, and arthropods, as well as conspecifics. (note: 'Insects' is from ADW's Animal Foods list (amphibians, fish, insects, mollusks, terrestrial worms, zooplankton); conspecifics means other axolotls.) |
| keeps its larval gills as a breeding adult | A. mexicanum is paedomorphic, which means that it retains larval characteristics in the reproductively mature adult form. Juvenile and adult axolotls possess feathery, external gills |
| It usually keeps its larval features into adulthood and lives its whole life cycle in water, a condition called neoteny | Axolotls are paedomorphic or neotenic aquatic salamanders, meaning they retain certain larval characteristics in the adult, reproductive state. |
| In the wild it rarely, if ever, metamorphoses. | In the wild, axolotls rarely, if ever, metamorphose. |
| feathery external gills | They possess feathery external gills and finned tails for swimming. |
| Through paedomorphosis, often called neoteny: axolotls keep larval features like their feathery external gills and finned tail into breeding adulthood | Axolotls are paedomorphic or neotenic aquatic salamanders, meaning they retain certain larval characteristics in the adult, reproductive state. They possess feathery external gills and finned tails for swimming. |
| in the wild they rarely, if ever, metamorphose | In the wild, axolotls rarely, if ever, metamorphose. |
| Give an axolotl thyroid hormone and it can go through metamorphosis anyway. | Metamorphosis can be induced in axolotls via thyroid hormone injections. |
| now a scattering of canals and swamps at the southern edge of Mexico City | Lake Xochimilco is now nothing more than a scattering of canals and swamps. |

## Ramos et al. (2025). Movement ecology of captive-bred axolotls in restored and artificial wetlands: Conservation insights for amphibian reintroductions and translocations. PLOS ONE.

https://doi.org/10.1371/journal.pone.0314257

| The page says | The source says |
| :--- | :--- |
| Critically Endangered | a critically endangered aquatic species endemic to Lake Xochimilco (note: Ramos et al. cite the IUCN Red List version 2024-1 for the status. iucnredlist.org refuses scripts, so the 2020 assessment itself was not read.) |
| Yes, critically endangered. | a critically endangered aquatic species endemic to Lake Xochimilco (note: Ramos et al. (2025) cite the IUCN Red List version 2024-1.) |
| but in the wild they live only in Lake Xochimilco | A. mexicanum is endemic to Lake Xochimilco, the last remnant of a once-extensive wetland system in the Central Valley of Mexico |
| while untreated wastewater, farm runoff and a spreading city have fouled the water and driven a marked decline | Urban expansion, environmental degradation, invasive species, and a severe decline in water quality—driven by untreated wastewater discharge, agricultural runoff, and surrounding urbanization—have led to a marked decline in axolotl populations |

## Voss, Woodcock & Zambrano (2015). A Tale of Two Axolotls. BioScience.

https://doi.org/10.1093/biosci/biv153

| The page says | The source says |
| :--- | :--- |
| Axolotls are a much-loved aquarium pet and lab animal around the world | The Mexican axolotl (Ambystoma mexicanum) is an icon of culture, a revered aquarium pet, and a highly valued animal model in biomedical research. |
| Axolotls are a much-loved aquarium pet and lab animal around the world | the laboratory populations that are needed to sustain research efforts around the world |

## Contreras et al. (2009). Recent decline and potential distribution in the last remnant area of the microendemic Mexican axolotl (Ambystoma mexicanum). Biological Conservation.

https://doi.org/10.1016/j.biocon.2009.07.008

| The page says | The source says |
| :--- | :--- |
| Lake Xochimilco canal waterways at the southern edge of Mexico City | The last remnant of its distribution is in a highly heterogeneous urban-rural water system in the Xochimilco region, at the southern edge of Mexico City. |
| now a scattering of canals and swamps at the southern edge of Mexico City | in the Xochimilco region, at the southern edge of Mexico City |
| A 2009 habitat model picked out just 11 sites there still suitable for them, and surveys at the time had found only one axolotl in the whole study area. | Results indicated that potential distribution of the axolotl in Xochimilco is limited to 11 sites in six reduced, isolated, and scattered areas ... Recent surveys found only a single organism in the whole study region, in one of the predicted sites |

## Zambrano, Valiente & Vander Zanden (2010). Food web overlap among native axolotl (Ambystoma mexicanum) and two exotic fishes: carp (Cyprinus carpio) and tilapia (Oreochromis niloticus) in Xochimilco, Mexico City. Biological Invasions.

https://doi.org/10.1007/s10530-010-9697-8

| The page says | The source says |
| :--- | :--- |
| Introduced carp and tilapia came to dominate the canals and overlap heavily with axolotls in what they eat | Two exotic fishes, common carp (Cyprinus carpio) and tilapia (Oreochromis niloticus), were introduced more than 20 years ago into Xochimilco for aquaculture, and now dominate the system in terms of biomass and numbers. |
| Introduced carp and tilapia came to dominate the canals and overlap heavily with axolotls in what they eat | Stable isotope analysis revealed substantial trophic niche overlap among axolotl and the exotics. |

## Crowner et al. (2019). Rediscovering the Axolotl as a Model for Thyroid Hormone Dependent Development. Frontiers in Endocrinology.

https://doi.org/10.3389/fendo.2019.00237

| The page says | The source says |
| :--- | :--- |
| While its close relative the tiger salamander is known to always go through metamorphosis and head for a boring, mostly land-based adult life | The ancestral mode of development in salamanders is generally thought to include a single, obligate metamorphosis which partitions the life cycle between an early aquatic phase and a more terrestrial adult phase. Indeed, close tiger salamander ... relatives of the axolotl are known to invariably undergo a metamorphosis |
| It usually keeps its larval features into adulthood and lives its whole life cycle in water, a condition called neoteny | the axolotl does not typically undergo a metamorphosis. Instead, the axolotl exhibits a paedomorphic mode of development that enables a completely aquatic life cycle. |
| Thyroid hormone drives amphibian metamorphosis, and in the tiger salamander a rise in it triggers the change. | Metamorphosis in the tiger salamander is regulated by the hypothalamus-pituitary-thyroid (HPT) axis. At a critical time during larval development, corticotrophin releasing hormone (CRH) from the hypothalamus stimulates thyrotrophic cells in the pituitary to release thyroid stimulating hormone (TSH), which in turn stimulates the thyroid gland to secrete thyroid hormone (TH). Increasing TH (+) triggers metamorphic changes in target cells. |
| Thyroid hormone drives amphibian metamorphosis | Thyroid hormones play a central role in regulating amphibian metamorphosis |
| An axolotl's thyroid hormone stays low through larval development and doesn't rise at the point where its close relative, the tiger salamander, metamorphoses. | TH levels in the axolotl remain low throughout larval development and do not increase at the time metamorphosis occurs in related tiger salamanders. |
| Studies suggest a fault in the chain of signals from the hypothalamus to the pituitary to the thyroid gland, perhaps at the hypothalamus or pituitary, but the exact mechanism is still unknown. | Collectively, these and other results suggest a defect in the regulation of the HPT axis, perhaps at the level of the hypothalamus or pituitary |
| Studies suggest a fault in the chain of signals from the hypothalamus to the pituitary to the thyroid gland, perhaps at the hypothalamus or pituitary, but the exact mechanism is still unknown. | the mechanism associated with its unique paedomorphic mode of development remains unknown |
| Give an axolotl thyroid hormone and it can go through metamorphosis anyway. | the axolotl is capable of initiating and completing metamorphosis when thyroid hormone and other endocrine factors of the HPT axis are administered |

## McCusker, Bryant & Gardiner (2015). The axolotl limb blastema: cellular and molecular mechanisms driving blastema formation and limb regeneration in tetrapods.

https://doi.org/10.1002/reg2.32

| The page says | The source says |
| :--- | :--- |
| can regrow whole legs | The axolotl is one of the few tetrapods that are capable of regenerating complicated biological structures, such as complete limbs, throughout adulthood. |
| Regrows whole limbs | capable of regenerating complicated biological structures, such as complete limbs, throughout adulthood |
| The new limb comes from a blastema, a mass of stem-like cells that grows, lays out the pattern and turns into the missing parts. | Upon injury the axolotl generates a population of regeneration-competent limb progenitor cells known as the blastema, which will grow, establish pattern, and differentiate into the missing limb structures. (note: 'stem-like cells' paraphrases 'progenitor cells' for the 11-14 audience.) |
| Cut off a limb and cells from the stump form a blastema of stem-like cells that rebuilds the whole thing. | Multiple cell types from the mature limb stump contribute to the blastema at different stages of regeneration |
| Scientists study them in the hope of better regenerative treatments for humans. | with the goal of translating these concepts to developing better human regenerative therapies |
| At a lost limb, cells from the stump form a blastema, a mass of stem-like cells that grows, lays out the pattern and turns into the missing parts. | Upon injury the axolotl generates a population of regeneration-competent limb progenitor cells known as the blastema, which will grow, establish pattern, and differentiate into the missing limb structures. |

## Andersson, Dittrich & Lauridsen (2023). Continuous anesthesia for 60 days in an isosmotic environment does not impair limb or cardiac regeneration in the axolotl. Scientific Reports.

https://doi.org/10.1038/s41598-023-42339-z

| The page says | The source says |
| :--- | :--- |
| parts of its own brain and heart | No differences were detected in the axolotl's ability to regenerate amputated limbs and cardiac cryo-injury while anesthetized |
| able to regrow its limbs and parts of its heart and brain | No differences were detected in the axolotl's ability to regenerate amputated limbs and cardiac cryo-injury while anesthetized |
| In one lab study, most adult axolotls had regrown a complete front leg by 60 days after amputation. | Representative photos of amputated right front limb in anesthetized and unanesthetized axolotls at 0, 10, 24, 35, 48 and 60 days post amputation (dpa). Most axolotls showed complete limb regeneration except from one animal from each of the anesthetized and unanesthetized groups |
| In one lab study, most adult axolotls had regrown a complete front leg by 60 days after amputation. | the present study was performed using adult axolotls |
| part of a damaged heart | All groups showed functional regeneration of the heart expressed as a decrease in the non-contraction fraction |
| part of the heart's ventricle | The non-contraction fraction of the ventricle in axolotls with a cardiac cryoinfarction housed in either tap water or Ringer's solution with or without feeding for 60 days. All groups showed functional regeneration of the heart |
| Sixty days to a new leg | Representative photos of amputated right front limb in anesthetized and unanesthetized axolotls at 0, 10, 24, 35, 48 and 60 days post amputation (dpa). Most axolotls showed complete limb regeneration except from one animal from each of the anesthetized and unanesthetized groups (note: blockquote lead-in; 60 days from the same study) |

## Godwin et al. (2017). Heart regeneration in the salamander relies on macrophage-mediated control of fibroblast activation and the extracellular landscape. npj Regenerative Medicine.

https://doi.org/10.1038/s41536-017-0027-y

| The page says | The source says |
| :--- | :--- |
| A patch of heart damaged by freezing heals without a permanent one too, as long as immune cells called macrophages are there early on: remove them and the heart scars for good. | Using a cardiac cryo-injury model we show that heart regeneration is dependent on the innate immune system, as macrophage depletion during early time points post-injury results in regeneration failure. In contrast to the transient extracellular matrix (ECM) that normally accompanies regeneration, this intervention resulted in a permanent, highly cross-linked extracellular matrix scar |

## McHedlishvili et al. (2012). Reconstitution of the central and peripheral nervous system during salamander tail regeneration. Proceedings of the National Academy of Sciences.

https://doi.org/10.1073/pnas.1116738109

| The page says | The source says |
| :--- | :--- |
| its tail and spinal cord | after tail amputation in Ambystoma mexicanum (Axolotl) the correct number and spacing of dorsal root ganglia are regenerated ... implantation of a clonally derived spinal cord neurosphere can result in reconstitution of all examined cell types in the regenerating central spinal cord |
| Axolotls can also regrow a tail with its spinal cord | implantation of a clonally derived spinal cord neurosphere can result in reconstitution of all examined cell types in the regenerating central spinal cord |

## Kramer et al. (2024). Axolotl mandible regeneration occurs through mechanical gap closure and a shared regenerative program with the limb. Disease Models & Mechanisms.

https://doi.org/10.1242/dmm.050743

| The page says | The source says |
| :--- | :--- |
| a missing section of lower jaw | Axolotls, unlike humans, are capable of regenerating their lower jaws ... we used morphological, histological and transcriptomic approaches to analyze the regeneration of lateral resection defects in the axolotl mandible. We found that this structure can regenerate all missing tissues in 90 days |

## Amamoto et al. (2016). Adult axolotls can regenerate original neuronal diversity in response to brain injury. eLife.

https://doi.org/10.7554/eLife.13998

| The page says | The source says |
| :--- | :--- |
| parts of its own brain and heart | The axolotl can regenerate multiple organs, including the brain. |
| parts of its heart and brain | upon mechanical injury to the adult pallium, axolotls can regenerate several of the populations of neurons present before injury |
| several kinds of neuron lost from an injured patch of brain | upon mechanical injury to the adult pallium, axolotls can regenerate several of the populations of neurons present before injury |
| several kinds of neuron lost from an injured patch of the pallium | upon mechanical injury to the adult pallium, axolotls can regenerate several of the populations of neurons present before injury |
| a forebrain region likely to hold basic versions of some neuron types found in our cerebral cortex | the gross neuroanatomy of the axolotl pallium, organized around two ventricles, shows clear similarities to that of the mammalian telencephalon. In addition, while the evolutionary origin of the mammalian cerebral cortex remains controversial ( Molnár, 2011 ), it is likely that the axolotl pallium contains a basic representation of several of the neuronal subtypes found in the mammalian cerebral cortex |
| The brain has a limit: its new neurons don't rebuild their old long-distance connections. | newborn neurons organize within altered tissue architecture and fail to re-establish the long-distance axonal tracts and circuit physiology present before injury |

## Seifert et al. (2012). Skin Regeneration in Adult Axolotls: A Blueprint for Scar-Free Healing in Vertebrates. PLoS ONE.

https://doi.org/10.1371/journal.pone.0032875

| The page says | The source says |
| :--- | :--- |
| heals deep skin wounds without a scar | we have investigated the wound repair process in adult axolotls and demonstrate that they are capable of perfectly repairing full thickness excisional wounds made on the flank |
| Mammals like us patch a deep skin wound with a permanent scar | the skin is injured more frequently than any other tissue and resulting damage, while repairable, leads to permanent scarring in mammals |
| an adult axolotl regrows the skin with no scar at all | Here we demonstrate that both aquatic and terrestrial axolotls are capable of perfect, scar-free skin regeneration. |
| Deep skin wounds heal without a scar. | they are capable of perfectly repairing full thickness excisional wounds made on the flank |