Enhydra lutris
(Linnaeus, 1758) · speciesAt a glance
Sources14 archives
Databases and archives Enhydra lutris's data was compiled from.
WikipediaWikimedia Foundation21 languages↗
Animal Diversity WebUniv. of Michigan MZspecies account↗
BioWikiNetmultilingual Wikipediamultilingual↗
GBIFGlobal Biodiversity Information Facility9 727 records↗
OBISOcean Biodiversity Information System5 777 records↗
ENAEuropean Nucleotide Archive · EMBL-EBI5 eDNA detections↗
BOLD SystemsCentre for Biodiversity Genomics15 specimens↗
Open Tree of LifeOpenTreephylogeny backbone↗
GoaTGenomes on a Tree · Sangergenome & karyotype↗
NCBIUS National Library of Medicinegenome & karyotype↗
Tree of SexTree of Sex Consortiumgenome & karyotype↗
Paleobiology DatabasePBDB consortiumfossil record↗
WikidataWikimedia Foundationstructured facts↗
GLoBIGlobal Biotic Interactionsbiotic interactions↗Every layer below draws on the sources above — open one to explore it, or use ← → to move between tabs.
The sea otter (Enhydra lutris) is a marine mammal native to the coasts of the northern and eastern North Pacific Ocean. Adult sea otters typically weigh between 14 and, making them the heaviest members of the weasel family, but among the smallest marine mammals. Unlike most marine mammals, the sea otter's primary form of insulation is an exceptionally thick coat of fur, the densest in the animal kingdom. Although it can walk on land, the sea otter is capable of living exclusively in the ocean. The sea otter inhabits nearshore environments, where it dives to the sea floor to forage. It preys mostly on marine invertebrates such as sea urchins, various mollusks and crustaceans, and some species of fish. Its foraging and eating habits are noteworthy in several respects. Its use of rocks to dislodge prey and to open shells makes it one of the few mammal species to use tools. In most of its range, it is a keystone species, controlling sea urchin populations which would otherwise inflict extensive damage to kelp forest ecosystems. Its diet includes prey species that are also valued by humans as food, leading to conflicts between sea otters and fisheries. Sea otters, whose numbers were once estimated at 150,000–300,000, were hunted extensively for their fur between 1741 and 1911, and the world population fell to 1,000–2,000 individuals living in a fraction of their historic range. A subsequent international ban on hunting, sea otter conservation efforts, and reintroduction programs into previously populated areas have contributed to numbers rebounding, and the species occupies about two-thirds of its former range. The recovery of the sea otter is considered an important success in marine conservation, although populations in the Aleutian Islands and California have recently declined or have plateaued at depressed levels. For these reasons, the sea otter remains classified as an endangered species.
No narrative description available for this taxon yet.
Size & morphology6
Life cycle & reproduction9
Diet & foraging4
Habitat & environment4
Physiology & chemistry2
Uses & economy1
Other traits8
A DNA barcode is a short, standardised stretch of genes that works like a fingerprint — enough to tell one species from another. Below is the molecular trace Enhydra lutris has left across the world's sequence archives.
At a glance
★ the standard DNA barcode for this group — the short region actually read to tell this species apart. The rest are extra genes sequenced along the way.
Besides the big genome in the nucleus, cells carry a small, circular loop of DNA inside the cell's energy factories — the mitochondria. It is inherited almost only from the mother and is a leftover from ancient bacteria that moved into the cell. The mitochondrial markers above (ND*, COX, CYTB…) are read from exactly this loop. Outer ring = one strand, inner ring = the other.
The complete instruction manual Enhydra lutris carries — its genome. We read it from three angles — how big it is, how the DNA is packed into chromosomes, and how completely it has been sequenced — and explain how to read each value as you go.
Genome sizehow big the whole instruction manual is
Measured in base pairs (bp) — the individual letters of DNA (human ≈ 3.2 Gb, a bacterium a few million). The chart places this genome on a logarithmic scale — each step to the right is ten times bigger — among reference organisms. Across species a bigger genome loosely tracks with larger cells, slower growth and lower-energy lifestyles (powered flight favours small genomes) — yet it does not imply more genes or a more advanced organism (the long-standing C-value paradox).
Chromosomes & ploidyhow the DNA is packaged
2n is the full chromosome count in a normal body cell; n is a gamete (egg or sperm), which carries half. Ploidy is how many complete chromosome sets each cell holds — 2× (diploid) is typical for animals, while higher levels (polyploidy) are common in plants. Click any value below to see the underlying records and sources.
Sequencing statusassembly quality — how far to trust these numbers
Assembly level tells you how finished the sequence is — from fragmented contigs, through scaffolds, up to a full chromosome-level assembly. BUSCO % estimates completeness: the share of genes expected to be present that were actually found. These describe the data quality, not the organism.
How far back this lineage goes — and how we know. Everything here is measured in Ma, short for “mega-annum”: millions of years ago. The chart reads left to right like a calendar of the Earth, from the deep past on the left to today at the right edgetop to bottom like a core drilled through the Earth, from the deep past at the top down to today at the bottom.
At a glance
When this lineage existed
How to read this: the coloured strip along the bottomdown the left is the geological calendar — the standard epochs (Pliocene, Pleistocene…) every museum uses, shown so you can see which chapter of Earth's history this lineage lived in. This lineage is a young one, so the strip is zoomed in to epochs — the finer subdivisions inside a period. The solid bar is the fossil range: the span between the oldest and the youngest fossil that palaeontologists have assigned to Enhydra lutris. Above itBeside it, the bars count how many dated finds fall in each slice of time; the tallest bar is labelled, and heights use a square-root scale so that thin slices stay visible next to rich ones. Read this as how well each stretch of time is preserved and studied — thick bars mean plenty of the right kind of rock and plenty of collectors, which is related to, but not the same as, how common it actually was. The orange marker is the DNA clock: DNA accumulates mutations at a roughly steady rate, so comparing this species' DNA with its relatives estimates when the lineage split off — independently of any fossil. Where the DNA reaches further back than the oldest fossil, the gap is hatched: the ghost lineage. It means the lineage was already out there, but has left us nothing we have dug up yet.
How it livedPBDB
Record type15 524 records
Origin
Range
Wildobservation + sensor
Human sightings and records, or camera-trap / sensor detections — someone (or a device) saw or captured the species in the wild.
Museum / Voucheredphysical evidence
Backed by a physical specimen — a herbarium sheet, sample or voucher held in a collection. “Vouchered” means supported by material evidence, not just an observation.
Wildobservation + sensor
Human sightings and records, or camera-trap / sensor detections — someone (or a device) saw or captured the species in the wild.
Holding institutions21 of 32 geolocated
Institutions and collections holding physical, vouchered specimens of this species — click a row to fly to it on the map.
| Institution | Specimens |
|---|---|
| Edmonton, CA | 3 957 |
| Seattle, US | 146 |
| Tacoma, US | 40 |
| CASlocation not on record | 23 |
| Berkeley, US | 17 |
| University of Wisconsin, Zoological Museumlocation not on record | 14 |
| Provo, US | 12 |
| Los Angeles, US | 12 |
| München, DE | 10 |
| Washington State University, Charles R. Conner Museumlocation not on record | 7 |
| University of Victorialocation not on record | 6 |
| Geneva, CH | 5 |
| Zacatecas, MX | 5 |
| San Diego, US | 3 |
| Science Museum of Minnesotalocation not on record | 3 |
| Fort Hays State University, Sternberg Museumlocation not on record | 2 |
| Denver, US | 2 |
| Chicago, US | 2 |
| Florida Museum of Natural History- Zoology, Paleontology & Paleobotanylocation not on record | 2 |
| Ohio State University - Mammal Division, Columbus, OH (OSUM)location not on record | 2 |
| Washington, US | 1 |
| Bonn, DE | 1 |
| ASUlocation not on record | 1 |
| 1 | |
| University of Wyoming Museum of Vertebrateslocation not on record | 1 |
| Toronto, CA | 1 |
| Santa Cruz, US | 1 |
| Cambridge, US | 1 |
| NTNU-VMlocation not on record | 1 |
| EL PASO, US | 1 |
| Ann Arbor, US | 1 |
| Ithaca, US | 1 |
Where the DNA of Enhydra lutris was picked up in samples of water, soil or air — nobody saw the organism, only its DNA left behind. A trace is a clue that the species was near, not a confirmed sighting.
Signal
Where its DNA was found
How strong is each trace?
How to read this: each dot is one detection of this species' DNA in an environmental sample. The confidence meter weighs how many independent studies and places back up the signal — one detection in one study is a hint; many across several studies is solid. Records dated before 2008 (when eDNA methods began) are treated as likely mislabeled and left off the map.