The southern giant salamander (''Isthmura maxima'') is a species of

salamander Salamanders are a group of amphibians typically characterized by their lizard-like appearance, with slender bodies, blunt snouts, short limbs projecting at right angles to the body, and the presence of a tail in both larvae and adults. All t ...

in the family

Plethodontidae Plethodontidae, or lungless salamanders, are a family of salamanders. With over 500 species, lungless salamanders are by far the largest family of salamanders in terms of their diversity. Most species are native to the Western Hemisphere, from B ...

. It is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to Mexico and known from the

Sierra Madre del Sur The Sierra Madre del Sur is a mountain range in southern Mexico, extending from southern Michoacán east through Guerrero, to the Isthmus of Tehuantepec in eastern Oaxaca. Geography The Sierra Madre del Sur joins with the Eje Volcánico Transv ...

of western and southern

Oaxaca Oaxaca, officially the Free and Sovereign State of Oaxaca, is one of the 32 states that compose the political divisions of Mexico, Federative Entities of the Mexico, United Mexican States. It is divided into municipalities of Oaxaca, 570 munici ...

and eastern

Guerrero Guerrero, officially the Free and Sovereign State of Guerrero, is one of the 32 states that compose the administrative divisions of Mexico, 32 Federal Entities of Mexico. It is divided into Municipalities of Guerrero, 85 municipalities. The stat ...

. It is the largest tropical salamander; the holotype had a total length of about and weighed .

Description

Adult males measure and females in Snout–vent length, snout–vent length (SVL). The tail is moderately long, on average 99% of SVL in males and 85% SVL in females. The coloration is variable, but in general it is uniformly black, with markings consisting of parallel rows of vivid red-orange to pale orange spots on the head, body, and proximal part of the tail. The body is robust, and the head is large and relatively broad but with short snout. The limbs are long and robust. The fingers and toes are well developed but relatively short and without appreciable webbing.

Habitat and conservation

This little-known salamander has been found in a banana field and a roadside bank at elevations of above sea level. It appears to live in permanent burrows. Although it seems to tolerate some habitat modification, urbanization and changed agricultural practices are potential threats. It is not known from any protected areas.

References

{{Taxonbar, from=Q28056199 Isthmura, maxima Endemic amphibians of Mexico Fauna of the Sierra Madre del Sur Amphibians described in 2005 Taxa named by David B. Wake Taxonomy articles created by Polbot