Ambystoma mexicanum
(Shaw & Nodder, 1798) · speciesAt a glance
Sources11 archives
Databases and archives Ambystoma mexicanum's data was compiled from.
WikipediaWikimedia Foundation21 languages↗
BioWikiNetmultilingual Wikipediamultilingual↗
GBIFGlobal Biodiversity Information Facility319 records↗
BOLD SystemsCentre for Biodiversity Genomics17 specimens↗
Open Tree of LifeOpenTreephylogeny backbone↗
GoaTGenomes on a Tree · Sangergenome & karyotype↗
NCBIUS National Library of Medicinegenome & karyotype↗
Paleobiology DatabasePBDB consortiumfossil record↗
WikidataWikimedia Foundationstructured facts↗
Amphibian Species of the WorldAMNHamphibian catalog↗
GLoBIGlobal Biotic Interactionsbiotic interactions↗Every layer below draws on the sources above — open one to explore it, or use ← → to move between tabs.
The axolotl (; from ), Ambystoma mexicanum, is a paedomorphic salamander closely related to the tiger salamander. Axolotls are unusual among amphibians in that they reach adulthood without undergoing metamorphosis. Instead of taking to the land, adults remain aquatic and gilled. The species was originally found in several lakes underlying what is now Mexico City, such as Lake Xochimilco and Lake Chalco. These lakes were drained by Spanish settlers after the conquest of the Aztec Empire, leading to the destruction of much of the axolotl’s natural habitat. Axolotls should not be confused with the larval stage of the closely related tiger salamander (A. tigrinum), which are widespread in much of North America and occasionally become paedomorphic. Neither should they be confused with mudpuppies (Necturus spp.), fully aquatic salamanders from a different family that are not closely related to the axolotl but bear a superficial resemblance. , wild axolotls were near extinction due to urbanization in Mexico City and consequent water pollution, as well as the introduction of invasive species such as tilapia and perch. They are listed as critically endangered in the wild, with a decreasing population of around 50 to 1000 adult individuals, by the International Union for Conservation of Nature and Natural Resources (IUCN) and are listed under Appendix II of the Convention on International Trade in Endangered Species (CITES). Axolotls were also sold as food in Mexican markets and were a staple in the Aztec diet.
No narrative description available for this taxon yet.
Size & morphology1
Life cycle & reproduction7
Habitat & environment3
Other traits1
A DNA barcode is a short, standardised stretch of genes that works like a fingerprint — enough to tell one species from another. Below is the molecular trace Ambystoma mexicanum has left across the world's sequence archives.
At a glance
★ the standard DNA barcode for this group — the short region actually read to tell this species apart. The rest are extra genes sequenced along the way.
Besides the big genome in the nucleus, cells carry a small, circular loop of DNA inside the cell's energy factories — the mitochondria. It is inherited almost only from the mother and is a leftover from ancient bacteria that moved into the cell. The mitochondrial markers above (ND*, COX, CYTB…) are read from exactly this loop. Outer ring = one strand, inner ring = the other.
The complete instruction manual Ambystoma mexicanum carries — its genome. We read it from three angles — how big it is, how the DNA is packed into chromosomes, and how completely it has been sequenced — and explain how to read each value as you go.
Genome sizehow big the whole instruction manual is
Measured in base pairs (bp) — the individual letters of DNA (human ≈ 3.2 Gb, a bacterium a few million). The chart places this genome on a logarithmic scale — each step to the right is ten times bigger — among reference organisms. Across species a bigger genome loosely tracks with larger cells, slower growth and lower-energy lifestyles (powered flight favours small genomes) — yet it does not imply more genes or a more advanced organism (the long-standing C-value paradox).
Chromosomes & ploidyhow the DNA is packaged
2n is the full chromosome count in a normal body cell; n is a gamete (egg or sperm), which carries half. Ploidy is how many complete chromosome sets each cell holds — 2× (diploid) is typical for animals, while higher levels (polyploidy) are common in plants. Click any value below to see the underlying records and sources.
Sequencing statusassembly quality — how far to trust these numbers
Assembly level tells you how finished the sequence is — from fragmented contigs, through scaffolds, up to a full chromosome-level assembly. BUSCO % estimates completeness: the share of genes expected to be present that were actually found. These describe the data quality, not the organism.
How far back this lineage goes — and how we know. Everything here is measured in Ma, short for “mega-annum”: millions of years ago. The chart reads left to right like a calendar of the Earth, from the deep past on the left to today at the right edgetop to bottom like a core drilled through the Earth, from the deep past at the top down to today at the bottom.
At a glance
When this lineage existed
How to read this: the coloured strip along the bottomdown the left is the geological calendar — the standard epochs (Pliocene, Pleistocene…) every museum uses, shown so you can see which chapter of Earth's history this lineage lived in. This lineage is a young one, so the strip is zoomed in to epochs — the finer subdivisions inside a period. The orange marker is the DNA clock: DNA accumulates mutations at a roughly steady rate, so comparing this species' DNA with its relatives estimates when the lineage split off — independently of any fossil.
How it livedPBDB
Record type319 records
Origin
Range
Wildobservation + sensor
Human sightings and records, or camera-trap / sensor detections — someone (or a device) saw or captured the species in the wild.
Museum / Voucheredphysical evidence
Backed by a physical specimen — a herbarium sheet, sample or voucher held in a collection. “Vouchered” means supported by material evidence, not just an observation.
Wildobservation + sensor
Human sightings and records, or camera-trap / sensor detections — someone (or a device) saw or captured the species in the wild.
Holding institutions15 of 20 geolocated
Institutions and collections holding physical, vouchered specimens of this species — click a row to fly to it on the map.
| Institution | Specimens |
|---|---|
| Cambridge, US | 101 |
| Chicago, US | 77 |
| Mexico City, MX | 39 |
| Washington, US | 18 |
| 14 | |
| Champaign, US | 11 |
| Mexico City, MX | 9 |
| 6 | |
| ASUlocation not on record | 6 |
| Ciudad de México, MX | 4 |
| Chongqing Museumlocation not on record | 4 |
| CASlocation not on record | 3 |
| Los Angeles, US | 3 |
| Ann Arbor, US | 2 |
| Universidad Católica de Manizaleslocation not on record | 2 |
| Toronto, CA | 2 |
| Auckland, NZ | 2 |
| San Francisco, US | 1 |
| Strecker Museum, Baylor Universitylocation not on record | 1 |
| Berkeley, US | 1 |