Giant Otter - Origin, Characteristics, Feeding and Conservation

Giant otter: find out what this animal is like, its physical characteristics, character, behavior, etc. The giant otter or Brazilian giant otter (Pteronura brasiliensis) is...

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The giant otter or Brazilian giant otter (Pteronura brasiliensis) is a mammal belonging to the family Mustelidae and the genus Pteronura. It is the only species of this genus and also the largest of the family. It has several common names depending on the region where it is found, so it is known as ariraí (Argentina, Bolivia and Paraguay), ariranha (Brazil), tie wolf (Uruguay), lobo de rio (Peru and Bolivia) , lobo de rio grande (Argentina and Paraguay), water dog (Colombia, Venezuela and Guyana) and watradagoe (Suriname).

She has a great affinity for human beings, hence probably the origin of one of her common names, the water dog. Due to its large size and type of fur, it has been hunted for decades in a terrible and disproportionate way for use in the fur industry. Currently, the factors that endanger the giant otter have increased significantly, so its population is decreasing. At PlanèteAnimal, we want to introduce you to various aspects of the giant otter, so that you can learn more about this absolutely incredible animal!


  • America
  • Argentina
  • Bolivia
  • Brazil
  • Colombia
  • Ecuador
  • Guyana
  • Paraguay
  • Peru
  • Suriname
  • Uruguay
  • Venezuela

Origin of the Giant Otter

Although there are disagreements, it has been proposed that the giant otter be subdivided into two subspecies: Pteronura brasiliensis brasiliensis and Pteronura brasiliensis paranensis. The first would be located in Suriname, the Guianas, southern Venezuela, southern Colombia, eastern Ecuador, eastern Peru, Bolivia, Paraguay and Brazil; while the second is found in the Paraguay and Paraná rivers in Brazil, northern Argentina and Uruguay. Subsequently, the subspecies P. b. paranensis has been treated as a synonym of a different subspecies, P. b. paraguensis.

Subsequent genetic studies support the subdivision of this species into four different evolutionary units, located in:

  • The Madre de Dios River with the Madeira River.
  • The Pantanal.
  • The Amazon with the drains of the Orinoco and the Guianas.
  • The Itenez - Guaporé basin.

The undisputed thing is that the giant otter lives exclusively in South America and its populations vary by region, however, they have disappeared from some areas. The possibility that the giant otter is related to the Asiatic otter (Lutrogale perspicillata), with which it has some morphological relationship, as well as its behavior, has been suggested and documented.

Characteristics of the Giant Otter

As an adult, it can reach 2 meters and weigh up to 30 kilos. Its color is intense brown, with the presence of creamy white spots in the lower part of the neck; curiously, the shape of this spot is unique in each individual, which facilitates their identification for research purposes. Its legs are broad and webbed, but the front legs are shorter than the hind legs, although they are all adapted for swimming; as well as its robust and flat tail, which greatly facilitates its movements under water.They have five toes on each paw, with strong non-retractable claws, which are extremely useful in capturing and tearing the prey they devour. In addition, they have membranes that reach the tip of each finger.

The giant otter has well-developed muscles and jaws and has between 34 and 36 teeth. The ears and nostrils are small and she can close them when she goes underwater. The muzzle is short and wide, its nose is completely covered with hair, in addition, it has whiskers that are very sensitive and allow them to perceive their prey under water.

The coat is extremely dense, so much so that the skin does not get wet when submerged in water due to the barrier formed by its hair. Males are generally larger and heavier than females.

Giant Otter Habitat

The giant otter occupies a wide variety of freshwater bodies and is not used to living in s alt water.It inhabits slow flowing rivers and streams, lagoons, swampy or rocky areas, swamp forests and flooded forests; on the other hand, it avoids very large and deep water flows, as well as those close to the Andes. The availability of food is a determining aspect for the presence of the species in the mentioned ecosystems.

These animals need dense vegetation around water bodies for the construction of their burrows. During the dry season, giant otters remain clustered in streams and are dispersed during the rainy season through flooded forested areas. They can possibly be seen in canals associated with agricultural land. When inhabiting areas such as lakes, they can maintain a not so large distribution area, while in the case of rivers, they show greater variations in terms of expansion.

Habits of the Giant Otter

These animals define well-established territories and form family groups of 2 to 15 individuals, forming stable and dominant pairs, young non-breeding individuals and offspring. It is also common for sexually mature individuals to cross established territories. Finally, a family can accept a young person from another family group. They are diurnal animals, a little clumsy to move on land, but very agile underwater.

These animals have a life expectancy of 8 years when living in the wild, while in captivity they can live up to 10 years. Some studies have reported that they seek rocky or sandy bottoms rich in s alts to rest. A special feature of this species is that it has a specific place where the family group defecates, which is why the giant otter is known to make latrines.

They tend to prepare large spaces of up to 28 meters for their dens, in which they dig or create several entrances under the vegetation that compose them. Interestingly, burrows should be located in higher areas to stay dry and avoid flooding. They also usually mark boundaries with their urine to keep other animals away. On the other hand, they have a complex communication system through sounds, which emit different types of messages. On top of that, also being a fairly trusting species, it usually doesn't go unnoticed in the places it dwells.

Giant Otter Feeding

The giant otter is a voracious and almost insatiable carnivore, its prey will have a hard time escaping when chased. In addition, an adult individual is able to consume up to 4 kilograms of food per day. Fish are their main food source, especially those belonging to the families Pimelodidae, Serrasalmidae, Curimatidae, Erythrinidae, Characidae, Anostomidae, Cichlidae and Loricariidae.However, they can also feed on:

  • Crabs
  • Small mammals.
  • Birds.
  • Alligators
  • Snakes
  • Molluscs.

These animals have different hunting strategies and can do it alone, in pairs or in groups. They usually make quick, jerky movements, turning in the water. They have a sharp vision under this environment, which helps them to identify food, which they capture easily with the support of their claws. The giant otter, when hunting in groups, is capable of capturing large individuals, such as alligators or anacondas. Another very special characteristic is that this species has been observed in association with the pink river dolphin (Inia geoffrensis) to collect fish together.

Reproduction of the giant otter

Although they reach sexual maturity at two and a half years old, they reproduce on average after five years. After courtship, the act of reproduction occurs in water and the gestation period lasts between 64 and 77 days. In addition, each pair generally has one litter per year which is made up of 1 to 6 young, but on average there are two. At birth, the young are blind and dependent on maternal care, at least until the fourth week when they open their eyes. At two months they begin to swim, and at three they begin their first hunting attempts, mostly fishing. Adults play a vital role in teaching their children to hunt. Weaning of the young can occur after nine months after birth.

These otters form quite close family bonds. In fact, younger ones can stay with their families until they reach sexual maturity.Males and siblings actively participate in caring for and teaching the young. Once a new litter is born, parents lessen their interest in the young and focus on the newborns.

State of conservation of the giant otter

Initially, the main threat factor for the species was hunting to obtain its skin and market it to the fur industry. However, over time, other things have come to light that have endangered the giant otter, such as habitat destruction associated with water bodies, overfishing, contamination of rivers by mining and the use agrochemicals such as fertilizers and pesticides. Mining is a very disturbing action of the giant otter ecosystem, which in addition to polluting and destroying ecosystems, contributes to the sedimentation of these river bodies, which occurs mainly in the Guiana Shield region (Suriname , Guyana, Guyana, southern Venezuela and northern Brazil) and also in southeastern Peru.In addition, the construction of dams and the alterations of waterways are also important causes of the affectation of these animals.

The giant otter is listed on Appendix I of the Convention on International Trade in Endangered Species (CITES) and is listed as endangered by the International Union for Conservation of Wildlife. nature. Despite the proposal of various actions, such as the protection of their habitat, mining continues to cause alarming devastation in the aforementioned areas.

The giant otter is an animal that has virtually no natural predators in the ecosystems it inhabits, however, humans are its main and most dramatic threat, perhaps not so much because direct hunting, but because of the significant modification of their habitat.

Pictures of Giant Otter

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