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Granular Salamander

Ambystoma granulosum


The granular salamander, unlike many of its close relatives, is a fully metamorphosing species of mole salamander. It therefore develops into an adult form, losing its larval characteristics such as gills and fins, and developing adult traits such as eyelids and functioning lungs.

Mole salamanders belong to the family Ambystomatidae, which is one of the most primitive lineages of salamanders. Ambystomatid salamanders diverged from all other salamanders over 150 million years ago, in the Late Jurassic. This is around the same time kangaroos and humans last shared a common ancestor!

The granular salamander is listed as Critically Endangered by the IUCN Red List as it is known only from a single small area on the periphery of Toluca city, Mexico. There is declining availability and quality of the required habitat for the species, and the population is also thought to be in decline.

Introduced predatory fish are the major threat to this species, but there is also habitat clearance and degradation due to extensive urban and agricultural expansion, leading to the desiccation and pollution of its breeding habitat. This species does not occur in any protected area, and the conservation and restoration of its habitat is urgent. Captive breeding is a possible conservation method.

  • Order: Caudata
  • Family: Ambystomatidae
  • Population: Unknown
  • Trend: decreasing
  • Size: 140-170mm

EDGE Score

EDGE Score: 5.69 (?)
ED Score: 17.52 (?)
GE / IUCN Red List (?)
Not Evaluated Data Deficient Least Concern Near Threatened Vulnerable Endangered Critically Endangered Extinct in the Wild Extinct


This species found in Toluca city, Mexico, at 3,000 metres above sea level.

Habitat and Ecology

This is a metamorphosing species spending most of its time on land in grassland habitat. It breeds in marshes and dams as well as small pools and ponds, both artificial and natural. There is no parental care.

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This wordcloud illustrates the threats facing this species. The size of each word indicates the extent of a species range that is affected by that threat (larger size means a greater area is affected). The colour of the word indicates how much that threat impacts the species (darker shades of red mean the threat is more severe).

Urban development Industrial development Tourism Roads/Rail Recreation Invasive species Wastewater Industry

Threat wordcloud key:

Small area affected
Large area affected
Least severe
Most severe
Severity unknown
Source: The IUCN List of Threatened Species. Version 2017.1.
Available at:

Rafael Alejandro Calzada Arciniega

  • Project name: Determine conservation priorities for Granular salamander
  • Project site: State of Mexico, Mexico
  • Active: 2016 - 2018
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