Home / Mammals / Cats, dogs and other carnivores / Eurasian otter
Federal restrictions applyEurasian otter
Lutra lutra
Mammals › Cats, dogs and other carnivores (Carnivora) › Mustelidae (Ferrets, weasels and otters)
The Eurasian otter (Lutra lutra), also known as the European otter, Eurasian river otter, European river otter, common otter, and Old World otter, is a semiaquatic mammal native to Eurasia and the Maghreb.
Care at a glance
Species-specific values
Values researched for this exact species. Where they differ from the group guide below, follow these. Air, surface and water temperatures are listed separately, and each source is kept as published rather than averaged.
| Minimum enclosure area | 100 m² For one animal; EAZA recommendation. | 305 |
| Minimum enclosure area | 250 m² For a breeding pair or mother with cubs; EAZA recommendation. | 305 |
| Land to water area ratio | land: 4 ratio; water: 1 ratio | 305 |
| Minimum nest box dimensions | length: 45 cm; width: 45 cm; height: 40 cm Per animal; breeding females need additional nest-box provision. | 305 |
| Typical captive lifespan | 12–14 years | 305 |
| Reported captive lifespan maximum | 18 years | 305 |
| Adult total length | 100–135 cm Male, including tail. | 305 |
| Adult total length | 90–125 cm Female, including tail. | 305 |
| Adult body mass | 7–12 kg Male. | 305 |
| Adult body mass | 4–8 kg Female. | 305 |
Warnings
Care guide
Otters
Applies to most species in this group. Habitat: Rivers and coasts. Individual species can differ, so compare with the species numbers above and the linked sources.
Housing & setup
- Large land and pool areas with excellent filtration; kept by zoos and aquariums.
Diet
- Fish, shellfish and formulated diets.
Social life
- Social housing depends on species. Lutra lutra is naturally solitary; compatible pairs or related groups require management, monitoring and separation facilities.
Health watch
- Bladder stones (Asian small-clawed otters); dental disease.
Understanding the animal
About this animal
About this animal
It is the most widely distributed member of the otter subfamily (Lutrinae) of the weasel family (Mustelidae) and is found in the waterways and on the coasts of Europe, much of Asia, and parts of North Africa. The Eurasian otter eats mainly fish, and is strongly territorial.
Quoted from the Wikipedia article “Eurasian otter” (CC BY-SA 4.0) 174
In the wild
In the wild
Quoted from the matching sections of reputable sources for this exact species. Specialist databases are used first; Wikipedia (community-edited, CC BY-SA 4.0) only fills gaps. Other sources are short credited quotes.
| Overview | The Eurasian otter (Lutra lutra), also known as the European otter, Eurasian river otter, European river otter, common otter, and Old World otter, is a semiaquatic mammal native to Eurasia and the Maghreb. It is the most widely distributed member of the otter subfamily (Lutrinae) of the weasel family (Mustelidae) and is found in the waterways and on the coasts of Europe, much of Asia, and parts of North Africa. The Eurasian otter eats mainly fish, and is strongly territorial. It is endangered in some parts of its range, but is recovering in others. — Wikipedia (community-edited) |
| Where it lives | Lutra lutra forage in water and nest on land. — Animal Diversity Web |
| Wild diet | Lutra lutra individuals eat fish, crustaceans, clams, small mammals and amphibians, birds, eggs, insects, worms, and a small amount of vegetation. — Animal Diversity Web |
| Behavior | River otters can dive for up to two minutes underwater and are most active at dusk and during the night. — Animal Diversity Web |
| Reproduction | Lutra lutra has a continuous breeding cycle and female otters have a continuous estrus cycle. — Animal Diversity Web |
| Appearance and size | The Eurasian otter is a typical member of the otter subfamily. With brown fur on their backs and cream-coloured fur on their bellies, these long, slender creatures are well-equipped for their aquatic lifestyle. Their bones show osteosclerosis, which increases their density and reduces buoyancy. — Wikipedia (community-edited) |
| History and naming | The extinct Japanese otter is sometimes considered a subspecies. However, recent studies have found that it falls outside the subspecific clades comprising L. lutra, so it has been reclassified as a distinct species. Nevertheless, uncertainty remains. — Wikipedia (community-edited) |
| Conservation | IUCN Red List Near Threatened More information Additional Links Encyclopedia of Life Contributors Susan Kennedy (author), University of Michigan-Ann Arbor. — Animal Diversity Web |
Native climate (measured)
Native climate (measured)
| Warm-season highs | about 70°F (up to 82°F in the hottest sampled areas) |
| Cool-season lows | about 24°F (down to 5°F in the coldest sampled areas) |
| Average temperature | 32–55°F across sampled records |
| Relative humidity | 75–81% on average (driest month about 67%) |
| Rainfall | about 660 mm a year, spread fairly evenly |
| Winters | Cool to cold winters (lows around 24°F) in much of its native range. Seasonal slowdown may be relevant, but species-specific biology determines whether brumation or hibernation occurs. |
Measured at 2325 wild occurrence records sampled against WorldClim 2.1 climate data (1970–2000 averages). Air conditions in the range are ecological context, not enclosure settings: microhabitats such as burrows, leaf litter or basking rocks can be cooler, warmer or more humid.
Profile
Profile
Researched for this exact species. Sources are listed under In the wild above.
History
The extinct Japanese otter is sometimes considered a subspecies. However, recent studies have found that it falls outside the subspecific clades comprising L. lutra, so it has been reclassified as a distinct species. Nevertheless, uncertainty remains.
Data and studies
The numbers
The numbers
Each bar is what one source reports. Where several sources weigh in, the dashed gold band marks their average.
Maximum recorded lifespan
Longest recorded lifespan reported by each database; typical lifespans are usually shorter. The AnAge record comes from an animal in human care.
Typical adult weight
Average adult body mass in each database (FishBase gives the maximum recorded weight).
Veterinary & husbandry research
Veterinary & husbandry research
- First description of adiaspiromycosis in an Eurasian otter (Lutra lutra) in Italy Malatesta D et al., Veterinaria italiana 2014
- Occurrence and molecular genotyping of Giardia duodenalis and Cryptosporidium spp. in wild mesocarnivores in Spain Mateo M et al., Veterinary parasitology 2017
- Energy metabolism of underwater swimming in river-otters (Lutra lutra L.) Pfeiffer P et al., Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology 1998
- XANTHINE NEPHROLITHIASIS IN JUVENILE CAPTIVE GIANT OTTERS (PTERONURA BRASILIENSIS) Barratclough A et al., Journal of zoo and wildlife medicine: official publication of the American Association of Zoo Veterinarians 2020
Peer-reviewed papers that mention this species alongside captivity, zoos, veterinary care or aquaculture. Some cover several species or mention it only in passing, so check the abstract. See all 37 on PubMed → 170
Sources for this sheet
- AnAge: The Animal Ageing and Longevity Database (Human Ageing Genomic Resources) Peer-reviewed researchCurated, referenced longevity and life-history records for thousands of species; maximum lifespans are often from zoo animals.
- Myhrvold et al. (2015). An amniote life-history database. Ecology 96: 3109 Peer-reviewed researchPeer-reviewed compilation of life-history data for over 21,000 birds, mammals and reptiles.
- Species+ (UNEP-WCMC and the CITES Secretariat) Zoo, university or veterinaryThe official database of species listed under CITES.
- USFWS International Affairs: CITES Zoo, university or veterinaryFederal agency that issues CITES permits.
- 9 CFR 2.1: Animal Welfare Act licensing (USDA) Zoo, university or veterinaryWho needs a USDA license to breed, sell or exhibit animals.
- Merck Veterinary Manual: Management of zoo animals Zoo, university or veterinaryThe Merck Veterinary Manual: a standard veterinary reference written and reviewed by veterinary specialists.
- Merck Veterinary Manual: Nutrition: exotic and zoo animals Zoo, university or veterinaryThe Merck Veterinary Manual: a standard veterinary reference written and reviewed by veterinary specialists.
- Merck Veterinary Manual: Management of marine mammals Zoo, university or veterinaryThe Merck Veterinary Manual: a standard veterinary reference written and reviewed by veterinary specialists.
- EAZA Best Practice Guidelines — European otter, fifth edition (2016) Zoo, university or veterinaryAdded in the 2026 source-checked care-guide review.
- Wikipedia (species article) Community referenceFree encyclopedia; useful overviews with their own citations. Intro text is quoted under CC BY-SA 4.0.
- PubMed (U.S. National Library of Medicine) Peer-reviewed researchIndex of peer-reviewed veterinary, zoo and husbandry research.
- iNaturalist (captive observations) Community referenceCommunity observation platform run by the California Academy of Sciences and National Geographic; observations marked captive show animals living in homes, zoos and aquariums.
