Axolotl (Ambystoma mexicanum) Fact Sheet: Taxonomy & History

Nomenclature

• Genus: Ambystoma
  • From the Greek ambyls for “blunt, dull, or wide” and stoma for “mouth” (Smith and Smith 1971)
• Species: mexicanum
  • Found only in Central Mexico (Tschudi, 1838)

Synonyms

See Frost (2021) for complete list of synonyms and Smith (1989) for name history.

• Gyrinus mexicanus (Shaw and Nodder, 1798)
• Siren pisciformis (Shaw, 1802)
• Triton mexicanus (Oppel, 1811)
• Siredon axolotl (Wagler, 1830)
• Axolotl pisciformis (Guérin-Méneville, 1838)

Common names

• Axolotl (English) (IUCN SSC Amphibian Specialist Group 2020; Frost 2021)
• Axolote, salamandra axolote (Mexican Spanish) (IUCN SSC Amphibian Specialist Group 2020; Frost 2021; ITIS 2022; Diana Laura Vázquez-Mendoza, personal communication, 2023)
  • Less commonly today, but sometimes used to refer to other tiger salamander species living in Mexico (Brandon 1989)

Indigenous names

• “Axolotl” originates from ancient Aztec language, Nauatal (or Náhuatl) (McKay et al. 2008)
  • Pronounced ashlotl (McKay et al. 2008; Abelardo de la Cruz, personal communication, 2023)
• Translated to mean “water dog,” “water sprite,” “water monster,” “water slave,” “water twin,” etc. (Smith 1989; McKay et al. 2008; Wanderer 2018)
  • Derived from Aztec mythology (Smith 1989)
    • Xolotl watched over the dead and resurrected, taking the form of a dog (hence “water dog”)
  • Also see Culture and folklore

Evolutionary relationships

• Axolotl is a member of Ambystomatidae, a large and diverse clade of New World salamanders (Brandon 1989)
• Axolotl divergence
  • Possibly diverged very recently or has not completely diverged from its closest relatives (David W. Weisrock, personal communication, 2023)
    • Also see "Closest extant/living relatives" below
• A. tigrinum complex divergence from other species of Ambystoma (David W. Weisrock, personal communication, 2023, and as noted below)
  • Comprehensive, time-calibrated analysis of all Ambystoma species not yet available
  • Best estimate: probably diverged at least 5 mya (Shaffer and McKnight 1996)
    • Likely no older than 10–12 mya (Hime et al. 2021)
• Divergence of ambystomatids (Ambystomitidae) (David W. Weisrock, personal communication, 2023, and as noted below)
  • No complete data set but some general estimates available
  • Findings of Hime et al. (2021) indicate a common ancestor of all ambystomids no older than 22–23 mya
    • Ambystoma and its sister genus Dicamptodon may have split as long ago as 65-70 mya
• Paedomorphy
  • Life histories where juvenile traits are retained into adulthood (paedomorphy) evolved multiple times among ambystomid salamanders (Shaffer 1984; Shaffer 1993; Shaffer and McKnight 1996; Everson et al. 2021)
    • Also see "Youthful Looks"

Closest extant/living relatives

• Other tiger salamanders living in Central Mexico (e.g., Ambystoma tigrinum complex) (Shaffer 1984; Schaffer 1989; Shaffer 1993; Williams et al. 2013; Everson et al. 2021)
  • Related news article

History

• Axolotl remains known to archaeologists from at least 8,000 years ago (McKay et al. 2008)
• As early as 1,000 BC: Aztecs and pre-Aztec peoples begin engineering a system of wetland agriculture from Xochimilco’s aquatic habitats; axolotl occupied deep excavated canals (Fox 1965; Rabiela 1991; Griffiths et al. 2003; Voss et al. 2015; Zambrano et al. 2020)
  • Chinampas (raised farming plots of mud and vegetation bordered by willow trees) expanded as the capital city, Tenochtitlan, was built
    • Used to grow vegetables and flowers today
• 1500s: urbanization of Xochimilco district grows after Spanish conquest, reducing axolotl lake habitat (Vance 2017)
• 1577: Naturalist Francisco Hernández completes a 16-volume work of natural history containing an early scientific (though only partly accurate) description of the axolotl (von Hagen 1944; Newth 1960)
  • Partially published decades later
• Circa 1803: Naturalist Alexander von Humboldt sent 2 preserved axolotl specimens to Georges Cuvier for taxonomic study (Muséum d'Histoire Naturelle, Paris) (Reiß et al. 2015)
• 1863 or 1864: about 35 live axolotls collected from Xochimilco and shipped to Paris’ Museum of Natural History for display and study (Duméril 1866; Smith 1989; Griffiths et al. 2003; Tate 2010; Voss et al. 2015; Vance 2017; Reiß et al. 2015; Reiß 2022)
  • Auguste Duméril began early research on anatomy and life history (Reiß et al. 2015)
  • Thousands of axolotls bred and distributed to scientists throughout Europe by the 1870s (Reiß et al. 2015)
    • Helped establish the axolotl as a prominent experimental animal (Smith 1989)
• 1867: first scientific papers on regeneration in the axolotl published (Reiß 2022)
• 1868: first white mutant axolotl appears in Paris (Newth 1960)
• Early 1950s: water supply challenges in Mexico City exacerbated, as springs and rivers that previously fed Xochimilco’s water table were diverted to urban areas and away from wetlands (Fox 1965; Rabiela 1991; Voss et al. 2015)
• 1950 to 1975: aquatic salamander habitats decline as Mexico City becomes much more urbanized (Ezcurra 1990 cited by Voss et al. 2015)
  • Increasing demand for water due to the growth of industry and human populations (Fox 1965)
• 1957: treated wastewater discharged into Xochimilco canal system to restore a higher water table (Rabiela 1991; Griffiths et al. 2003; Griffiths, Graue, et al. 2004)
• 1970s and 1980s: tilapia and carp introduced to Xochimilco ecosystem to alleviate hunger in local community; prey on axolotl, harming populations (Tapia and Zambrano 2003)
• 1987: Xochimilco listed as a UNESCO World Heritage site (Griffiths, Graue, et al. 2004)
• 1990s: biologists begin monitoring wild axolotl populations, finding drastic declines from 1998 to 2008 (Zambrano et al. 2007; Contreras et al. 2009; Voss et al. 2015)
• 2000s: scientists begin genetically modifying axolotls for studies on vertebrate developmental biology (Sobkow et al. 2006; Echeverri et al. 2022; Reiß 2022)
• 2001-2002: Mexican and British scientists begin a conservation partnership (e.g., Griffiths, Graue, et al. 2004)
  • 3-year project focused on biology, legislation, public education/engagement, local economics, and habitat restoration
    • Also see Management Actions
  • Culminated in a Darwin Initiative conservation workshop resulting in a species–habitat action plan (published in 2004) (Griffiths, Graue, et al. 2004; Griffiths, Bride, et al. 2004; Bride et al. 2008)
• 2004: Xochimilco recognized as a Ramsar Convention on Wetlands of International Importance site (Griffiths, Graue, et al. 2004)
• 2005: Senate of the Mexican government urges action to prevent the axolotl’s extinction (Bride et al. 2008)
• 2008: start of axolotl conservation projects focused on use of chinampa culture in Xochimilco (Valiente et al. 2010)
• 2014: new axolotl refuges built around Xochimilco chinampas (Zambrano et al. 2020)

Culture and folklore

• Mexican culture
  • Modern era
    • Axolotls embedded in Mexican history and Latin American identity (Wanderer 2018)
    • Pop culture icon and source of national pride (Griffiths, Graue, et al. 2004; Vance 2017)
      • Depicted on tourist souvenirs (Bride et al. 2008; Vance 2017)
      • Illustrated on 50 peso note by Bank of Mexico (Cenisio 2022)
      • Official emoji for Mexico City (Vance 2017)
    • Ingredient in Mexican traditional medicines, particularly for respiratory ailments (Sciences et al. 2006; McKay et al. 2008)
      • Illegal collection presumed to have ceased due to rarity of this species in wild habitats (IUCN SSC Amphibian Specialist Group 2020)
    • A prized pet (Bride et al. 2008; Vance 2017)
  • Mexica, or Aztec, traditions
    • Axolotls were important to local economies (Newth 1960; Smith 1989; McKay et al. 2008; Tate 2010)
      • Considered a delicacy and an important protein source (large fish were uncommon) (Griffiths, Graue, et al. 2004; Sciences et al. 2006; Tate 2010)
      • Traded as food and medicine (Griffiths et al. 2003; Bride et al. 2008; Voss et al. 2015)
        • Mid-1800s: vendors sold roasted and live axolotls in a number of Central Mexican markets
    • Axolotls represented in Aztec art and mythology (Voss et al. 2015)
    • Considered transfigurations of the Aztec god, Xolotl (twin brother of Quetzacoatl) (Smith 1989; McKay et al. 2008; Tate 2010; Wanderer 2018; Cenisio 2022)
      • Xolotl disguised himself in various forms to avoid death, until captured by other gods and sacrificed to nourish the sun and moon; took final form as an axolotl
      • Xolotl known for powers over the dead and resurrected; also games, twins (possibly alluding to regeneration, or fertility in plants), and irregular traits in nature
• Japanese culture
  • Pokémon character, “Wooper” (Adamson et al. 2022)
  • Certain restaurants serve axolotl deep-fried (Vance 2017)
• International pop culture icon
  • Image used in art, coloring books, cartoons, memes and social media, as well as for avatars (Vance 2017; Adamson et al. 2022)
  • Axolotl characters in video games, including Fortnite and Minecraft (Adamson et al. 2022; Needleman and Rodriguez 2022)
    • Driver of pet ownership demand (Needleman and Rodriguez 2022 Mar 7)
  • Build-A-Bear created an axolotl plush toy (Adamson et al. 2022)

Books

• Scientific/environmental books
  • Xochimilco en el Siglo XXI [Xochimilco in the 21st Century] by Luis Zambrano and Ruben Rojas (2021) [in Spanish]
    • Explores the history of Xochimilco and axolotl conservation
• Adult literature
  • The End of the Game: Julio Cortázar wrote a well-known short story titled “Axolotl” (McKay et al. 2008; Tate 2010)
    • A man in Paris fixates on an aquarium-housed axolotl, eventually changing into one himself (Wanderer 2018)
    • Based on the author’s experience in the Jardin des Plantes
  • The Cage of Melancholy: Roger Bartra explores the cultural and mythological importance of the axolotl (Wanderer 2018)
  • El Ajolote: Biología del Anfibio más Sobresaliente del Mundo [The Axolotl: Biology of the World's Most Outstanding Amphibian] by Andres Cota (2016) [in Spanish]
  • Essay in World of Wonders: in Praise of Fireflies, Whale Sharks, and Other Astonishments by Aimee Nezhukumatathil (2020)
  • The Little Book of Axolotl Wisdom: Live Your Life Like the World's Weirdest, Cutest Salamander by Jessica Allen (2022)
• Children’s literature (examples)
  • My Life at the Bottom: The Story of a Lonesome Axolotl by Linda Bondestam (2022)
  • Full Throttle Axolotl : Daredevil Amphibian by Elsie Edelbrook (2021)
  • Axolotl Finds a Bottle by Lesley Sims (2019)

Poetry

• “Salamandra” by Octavio Paz (Paz 1971; Tate 2010)
• “The Axolotl and the Ammocoete” by Walter Garstang (Garstang 1951)

Art

• Early art
  • Numerous illustrations from natural history books (ex. Animate Creation)
  • Some ceramic vessels and other objects from eastern Valley of Mexico (1400–1150 BC) possess gill-like traits that might portray the axolotl (Tate 2010)
    • Motif spread through Mesoamerica by 1000 BC
• Performances
  • “Axolotl Odyssey”
    • Performed at London’s Natural History Museum
    • Inspired by the Zoological Society of London’s axolotl conservation initiatives
• Murals
  • Diego Rivera depicted axolotls in a scene of a Tenochtitlan market of (McKay et al. 2008)

Kingdom: Animalia

Phylum: Chordata

Class: Amphibia — amphibians

Order: Caudata &mash; salamanders

Family: Ambystomatidae (Gray, 1850) — mole salamanders

Genus: Ambystoma (Tschudi, 1838)

Species: Ambystoma mexicanum (Shaw and Nodder, 1798) — axolotl, Mexican axolotl, salamandra axolote

Sources: Frost 2020; ITIS 2022; Diana Laura Vázquez-Mendoza, personal communication, 2023

In Aztec mythology, the axolotl was considered a transfiguration of the god Xolotl (depicted above), the twin brother of Quetzacoatl.

The name “axolotl” originates from the ancient Nauatal (or Náhuatl) language of the Aztecs. Translated from mythology, its name means “water dog,” “water sprite,” “water monster,” “water twin,” etc.

Image credit: Unknown artist. Made available by Wikimedia Commons. Public domain.

Illustration of an axolotl from an 1860s natural history book.

Around the time this illustration was published, more than 30 live axolotls were shipped from Xochimilco to Paris, where museum scientists began studying their biology in earnest. This included early regeneration research.

Curators shipped offspring from this axolotl group around the world, launching the axolotl's worldwide use as a model organism in biomedical, developmental, and evolution research.

Plate 191; Bilder Atlas zur wissenschaftlich populären Naturgeschichte der Wirbelthiere, 1868. Made available by the Biodiversity Heritage Library. Public domain.