(Last Updated On: March 20, 2021)

The coypu, scientific name Myocastor coypus, also called the nutria, is a big, herbivorous, semiaquatic rodent. Classified for a long time as the one member of the family Myocastoridae, Myocastor is now included inside Echimyidae, the family of the spiny rats.

The coypu, Myocastor coypus lives in burrows alongside stretches of water and feeds on river plant stems. Originally native to subtropical and temperate South America, it has since been introduced to North America, Europe, Asia, and Africa, primarily by fur farmers.

Although it’s nonetheless hunted and trapped for its fur in some areas, its harmful burrowing and feeding habits usually carry it into battle with people, and it’s thought of as an invasive species.

Myocastor coypus Distribution

Native to subtropical and temperate South America, it has since been launched to North America, Europe, Asia, and Africa, primarily by fur ranchers. The distribution of coypus outdoors in South America tends to contract or develop with successive chilly or gentle winters. During chilly winters, coypus usually endure frostbite on their tails, resulting in an infection or dying.

As an outcome, populations of coypus usually contract and even grow to be regionally or regionally extinct as within the Scandinavian nations and such US states as Idaho, Montana, and Nebraska throughout the 1980s.

During gentle winters, their ranges are inclined to develop northward. For instance, lately, range expansions have been famous in Washington and Oregon, in addition to Delaware.

Myocastor coypus Description

The coypu, Myocastor coypus considerably resembles a really giant rat or a beaver with a small tail. Adults are usually 4–9 kg (9–20 lb) in weight, and 40–60 cm (16–24 in) in body size, with a 30 to 45 cm (12 to 18 in) tail.

It is possible for coypu to weigh as much as 16 to 17 kg (35 to 37 lb), though adults normally average 4.5 to 7 kg (10 to 15 lb). They have coarse, darkish brown outer fur with delicate dense gray below fur, additionally referred to as the nutria.

Three distinguishing options are a white patch on the muzzle, webbed hind feet, and huge, vivid orange-yellow incisors. The nipples of feminine coypu are high on her flanks, to permit their younger to feed whereas the feminine is within the water.

A coypu is usually mistaken for a muskrat, one other broadly dispersed, semiaquatic rodent that occupies the same wetland habitats.

The muskrat, nevertheless, is smaller and more tolerant of chilly climates and has a laterally flattened tail it makes use of to help in swimming, whereas the tail of a coypu is round.

It will also be mistaken for a small beaver, as beavers and coypus have very comparable anatomies. However, beavers’ tails are flat and paddle-like, versus the round tails of coypus.

Myocastor coypus Body Features

Myocastor coypus seem like a big, sturdy rat. Its body is very arched, and the pinnacle is giant and virtually triangular. The ears and eyes are small and are positioned within the higher part of the pinnacle.

The incisors are broad, with orange-pigmented anterior surfaces. The legs are brief. The hind feet are for much longer than the forefeet, and comprise 5 digits; the first 4 are linked by webbing, and the fifth is free.

The forefeet have 4 long, versatile, unwebbed digits and a vestigial thumb. The tail is long and rounded. Females have 4 pairs of thoracic mammae which can be located nicely up on the perimeters of the body.

The pelage consists of two sorts of hair, delicate dense underfur, and long coarse guard hairs that fluctuate from yellowish-brown to reddish-brown. The underfur is darkish grey, and it’s denser on the stomach. The chin is roofed by white hairs, and the tail is scantily haired.

Myocastor coypus coypu

Myocastor coypus Behavior

Myocastor coypus is semiaquatic. Individuals can stay submerged for more than 10 minutes. They are most energetic at night. Most of the energetic interval is spent feeding, grooming, and swimming.

They generally make platforms of vegetation, the place they feed and groom themselves. For shelter, nutria assemble burrows, which can be an easy tunnel or a fancy system containing passages that reach 15 meters or more and chambers that maintain crude nests of vegetation.

Nutria additionally makes runways by means of the grass and wander inside a radius of about 180 meters of their dens. Myocastor coypus are very gregarious. Groups normally consist of 2- 13 animals and are composed of associated adult females, their offspring, and a big male. Young adult males are often solitary. Generally, nutrias stay in a single space all through their lives.


Besides breeding shortly, every coypu consumes giant quantities of vegetation. An individual consumes about 25% of their body weight every day and feeds year-round.

Being one of many world’s bigger extant rodents, a mature, wholesome coypu averages 5.4 kg (11 lb 14 oz) in weight, however, they’ll attain as a lot as 10 kg (22 lb).

They eat the bottom of the above-ground stems of crops and sometimes dig by means of the natural soil for roots and rhizomes to eat. Their creation of “eat-outs”, areas where a majority of the above- and below-ground biomass has been eliminated, produces patches within the surroundings, which in flip disrupts the habitat for different animals and people depending on marshes.


Nutria most likely communicates by means of tactile, chemical, and auditory channels. Their eyesight is restricted.


Coypus, Myocastor coypus are discovered mostly in freshwater marshes, but additionally inhabit brackish marshes and barely salt marshes. They both assemble their very own burrows or occupy burrows deserted by beaver, muskrats, or different animals. They are additionally able to develop floating rafts out of vegetation.

Nutrias inhabit marshes, lake edges, and sluggish streams, particularly in areas with emergent or succulent vegetation alongside the banks. They are mainly lowland animals, however might range as much as 1,190 meters within the Andes. Although they typically choose contemporary water, the inhabitants of the Chonos Archipelago in Chile happens in brackish and saltwater.

Myocastor coypus coypu


The potential longevity of Myocastor coypus is 6 years.

Myocastor coypus Life cycle

Coypus can reside as much as six years in captivity, however people uncommonly reside previous three years old; in accordance with one research, 80% of coypus die throughout the first year, and fewer than 15% of wild inhabitants is over three years old.

Male coypus attain sexual maturity as early as 4 months, and females as early as three months; nevertheless, each can have chronic adolescence, as much as the age of 9 months.

Once a feminine is pregnant, gestation lasts 130 days, and he or she might give start to as few as one or as many as 13 offspring. They typically line nursery nests with grasses and delicate reeds.

Baby coypus are precocial, born totally furred and with open eyes; they’ll eat vegetation with their parents inside hours of start. A feminine coypu can grow to be pregnant once more the day after she provides start to her younger.

If timed correctly, a feminine can grow to be pregnant 3 times inside a year. Newborn coypus nurse for seven to eight weeks, after which they go away their moms.

Myocastor coypus coypu


Myocastor coypus is polyestrus. The size of the estrus cycle is variable; intervals between cycles might range from 5 to 60 days. Nutrias are nonseasonal breeders. The gestation interval is long, various from 127 to 139 days.

There is a post-partum estrus within 2 days of parturition. Mean litter size generally varies from three to 6, though it could range from 1 to 13. Factors affecting the reproductive potential of nutria are meals sort and availability, climate situations, predators, and illness.

Sexual maturity is attained when younger are solely 6 months old.

Females Myocastor coypus care completely for the younger. Newborns are totally furred and have their eyes open. They weigh roughly 225 grams each and quickly acquire weight throughout the first 5 months. The lactation interval extends for about eight weeks.

Other recommended Reading

Leave a Reply

Your email address will not be published. Required fields are marked *