Galemys pyrenaicusPyrenean desman

Geographic Range

The Pyrenees mountains in France, and the northern portion of the Iberian peninsula (Spain and Portugal)


Iberian desmans are usually found in cold mountain lakes and rivers with abundant crustaceans and insect larvae.

  • Aquatic Biomes
  • lakes and ponds
  • rivers and streams

Physical Description

Iberian desmans have many adaptations to their aquatic habitat. These include a long tail, verticaly flattened at the end, and the ability to close their ears and nostrils.

  • Average mass
    57.5 g
    2.03 oz


The gestation period is about thirty days. Populations have three estrus peaks in a given breeding season (January-May). Litter size can be from one to five. Sexual maturity is reached in the second year of life.

  • Key Reproductive Features
  • gonochoric/gonochoristic/dioecious (sexes separate)
  • sexual
  • Average number of offspring
  • Average gestation period
    30 days
  • Average age at sexual or reproductive maturity (female)
    Sex: female
    730 days
  • Average age at sexual or reproductive maturity (male)
    Sex: male
    730 days



Iberian desmans have no sexual size dimorphism. They seek shelter in rock crevices, the burrows of water rats, or in caves. Only rarely do they dig their own burrows. They are typically monogamous with a male's territory completely encompassing that of a female. There are solitary adults of both sexes. Territories are defended and marked with scent produced with specialized scent-glands. Iberian desmans are nocturnal. It has been suggested that Iberian desmans slap the surface of the water to produce noises useful in echolocation, although this is only speculation. Their are no known predators in normal circumstances, although one was attacked by a weasel while in a trap.

Communication and Perception

Food Habits

Iberian desmans eat larval aquatic insects, crustaceans, and terrestrial insects. They will eat appropriate food whether it is alive or dead. Some people have claimed that Iberian desmans forage away from water, but this is uncertain.

Conservation Status

IUCN "vulnerable" due to habitat destruction


Bret Weinstein (author), University of Michigan-Ann Arbor.



living in the northern part of the Old World. In otherwords, Europe and Asia and northern Africa.

World Map

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.


uses smells or other chemicals to communicate


animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.


forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.


having the capacity to move from one place to another.


This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.

native range

the area in which the animal is naturally found, the region in which it is endemic.


reproduction that includes combining the genetic contribution of two individuals, a male and a female


uses touch to communicate


Mammalian Species #207

Walker's Mammals of the World, fifth edition; Nowak, R. ed.; 1991; Johns Hopkins University Press. pp. 170-171