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

semiaquatic In biology, semiaquatic can refer to various types of animals that spend part of their time in water, or plants that naturally grow partially submerged in water. Examples are given below. Semiaquatic animals Semiaquatic animals include: * Verte ...

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

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 almost 608 species, it is the second-largest family of mammals, and has m ...

. It has a restricted range in the state of

Oaxaca Oaxaca ( , also , , from nci, Huāxyacac ), officially the Free and Sovereign State of Oaxaca ( es, Estado Libre y Soberano de Oaxaca), is one of the 32 states that compose the political divisions of Mexico, Federative Entities of Mexico. It is ...

in southern

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

, Threatened by

deforestation Deforestation or forest clearance is the removal 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. The most concentrated d ...

and

water pollution Water pollution (or aquatic pollution) is the contamination of water bodies, usually as a result of human activities, so that it negatively affects its uses. Water bodies include lakes, rivers, oceans, aquifers, reservoirs and groundwater. Water ...

, 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 and inva ...

by the

International Union for Conservation of Nature The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

(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 (abbreviated as AMNH) is a natural history museum on the Upper West Side of Manhattan in New York City. In Theodore Roosevelt Park, across the street from Central Park, the museum complex comprises 26 inter ...

New York City New York, often called New York City or NYC, is the List of United States cities by population, most populous city in the United States. With a 2020 population of 8,804,190 distributed over , New York City is also the L ...

, 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 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 found elsew ...

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 foothill ...

, San José Lachiguirí,

Unión Hidalgo Unión Hidalgo is a town and municipality in Oaxaca in south-western Mexico. It is part of the Juchitán District Juchitán District is located in the east of the Istmo de Tehuantepec region of the State of Oaxaca, Mexico, covering the southern p ...

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 peri ...

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. It contains the following species: * Mexican water mouse, ''Rheomys mexicanus'' * Goldman's water mouse, ''Rheomys raptor'' * Thomas's water mou ...

'' 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 adverse change. Pollution can take the form of any substance (solid, liquid, or gas) or energy (such as radioactivity, heat, sound, or light). Pollutants, the ...

, 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 and inva ...

References

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