The Mexican water mouse, Mexican fishing mouse or Goodwin's water mouse (''Rheomys mexicanus''), is a species of

semiaquatic In biology, being semi-aquatic refers to various macroorganisms that live regularly in both aquatic and terrestrial environments. When referring to animals, the term describes those that actively spend part of their daily time in water (in ...

rodent Rodents (from Latin , 'to gnaw') are mammals of the Order (biology), order Rodentia ( ), which are characterized by a single pair of continuously growing incisors in each of the upper and Mandible, lower jaws. About 40% of all mammal specie ...

in the family

Cricetidae The Cricetidae are a family of rodents in the large and complex superfamily Muroidea. It includes true hamsters, voles, lemmings, muskrats, and New World rats and mice. At over 870 species, it is either the largest or second-largest family ...

. It has a restricted range in the state of

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 ...

in southern

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

, Threatened by

deforestation Deforestation or forest clearance is the removal and destruction of a forest or stand of trees from land that is then converted to non-forest use. Deforestation can involve conversion of forest land to farms, ranches, or urban use. Ab ...

and

water pollution Water pollution (or aquatic pollution) is the contamination of Body of water, water bodies, with a negative impact on their uses. It is usually a result of human activities. Water bodies include lakes, rivers, oceans, aquifers, reservoirs and ...

, it is listed as

Endangered An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching, inv ...

by the

International Union for Conservation of Nature The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the stat ...

(IUCN).

Taxonomy

The Mexican water mouse was first described as ''Rheomys mexicanus'' in 1959 by the American zoologist George Gilbert Goodwin. He was the assistant curator of mammals at the

American Museum of Natural History The American Museum of Natural History (AMNH) is a natural history museum on the Upper West Side of Manhattan in New York City. Located in Theodore Roosevelt Park, across the street from Central Park, the museum complex comprises 21 interconn ...

New York City New York, often called New York City (NYC), is the most populous city in the United States, located at the southern tip of New York State on one of the world's largest natural harbors. The city comprises five boroughs, each coextensive w ...

, and went on a number of collecting expeditions, including one to Iran in 1938.

Distribution

The species 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 has a very restricted range in the state of

on the Pacific slope of the mountains, being known from sites in the vicinity of

San Pablo Guelatao San Pablo Guelatao is a town and the seat of the Municipality of Guelatao de Juárez, in the Mexican state of Oaxaca. It is part of the Ixtlán District in the Sierra Norte de Oaxaca region. Guelatao, as it is often called, is in the foothills ...

San José Lachiguirí San José Lachiguirí is a town and municipality in Oaxaca in south-western Mexico. The municipality covers an area of 132.7 km2. It is part of the Miahuatlán District Miahuatlán District is located in the south of the Sierra Sur Region o ...

Unión Hidalgo Unión Hidalgo is a town and municipality in Oaxaca in south-western Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the n ...

and

Tehuantepec Tehuantepec (, in full, Santo Domingo Tehuantepec) is a city and municipality in the southeast of the Mexican state of Oaxaca. It is part of the Tehuantepec District in the west of the Istmo Region. The area was important in pre-Hispanic per ...

Ecology

This rodent is found in and near the headwater streams of rivers in tropical forested areas. Its natural history is poorly known, but it seems to rely on finding its food in the small streams among closed canopy forests in which it lives. Other members of ''

Rheomys ''Rheomys'' is a genus of Mexican and Central American semiaquatic rodents in the family Cricetidae The Cricetidae are a family of rodents in the large and complex superfamily Muroidea. It includes true hamsters, voles, lemmings, muskrat ...

'' are also semiaquatic, with carnivorous diets and similar riparian habitats.

Status

''R. mexicanus'' has a total area of occupancy of less than , and within this distribution, it seems to have a fragmented range, being known from only four locations. It has a habitat requirement for pure, unpolluted water, and the quality and quantity of suitable habitat is declining. This habitat is under threat from deforestation and from water

pollution Pollution is the introduction of contaminants into the natural environment that cause harm. Pollution can take the form of any substance (solid, liquid, or gas) or energy (such as radioactivity, heat, sound, or light). Pollutants, the component ...

, including from such human activities as household clothes-washing. As a result of these threats, the

has listed the conservation status of this mouse as "

endangered An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching, inv ...

References

{{Taxonbar, from=Q1765827 Endemic mammals of Mexico Mexican water mouse Mammals described in 1959 Taxonomy articles created by Polbot