The earless seals, phocids, or true seals are one of the three main groups of mammals within the seal lineage, Pinnipedia. All true seals are members of the family Phocidae. They are sometimes called crawling seals to distinguish them from the fur seals and sea lions of the family Otariidae. Seals live in the oceans of both hemispheres and, with the exception of the more tropical monk seals, are mostly confined to polar, subpolar, and temperate climates. The Baikal seal is the only species of exclusively freshwater seal.
Fur seals are any of nine species of pinnipeds belonging to the subfamily Arctocephalinae in the family Otariidae. They are much more closely related to sea lions than true seals, and share with them external ears (pinnae), relatively long and muscular foreflippers, and the ability to walk on all fours. They are marked by their dense underfur, which made them a long-time object of commercial hunting. Eight species belong to the genus Arctocephalus and are found primarily in the Southern Hemisphere, while a ninth species also sometimes called fur seal, the Northern fur seal, belongs to a different genus and inhabits the North Pacific. The fur seals in Arctocephalus are more closely related to sea lions than they are to the Northern fur seal, but all three groups are more closely related to each other than they are to true seals.
The walrus is a large pinniped marine mammal with discontinuous distribution about the North Pole in the Arctic Ocean and subarctic seas of the Northern Hemisphere. It is the only extant species in the family Odobenidae and genus Odobenus. This species is subdivided into two subspecies: the Atlantic walrus, which lives in the Atlantic Ocean, and the Pacific walrus, which lives in the Pacific Ocean.
An eared seal, otariid, or otary is any member of the marine mammal family Otariidae, one of three groupings of pinnipeds. They comprise 15 extant species in seven genera and are commonly known either as sea lions or fur seals, distinct from true seals (phocids) and the walrus (odobenids). Otariids are adapted to a semiaquatic lifestyle, feeding and migrating in the water, but breeding and resting on land or ice. They reside in subpolar, temperate, and equatorial waters throughout the Pacific and Southern Oceans, the southern Indian, and Atlantic Oceans. They are conspicuously absent in the north Atlantic.
The Bering Sea is a marginal sea of the Northern Pacific Ocean. It forms, along with the Bering Strait, the divide between the two largest landmasses on Earth: Eurasia and the Americas. It comprises a deep water basin, which then rises through a narrow slope into the shallower water above the continental shelves. The Bering Sea is named after Vitus Bering, a Danish navigator in Russian service, who, in 1728, was the first European to systematically explore it, sailing from the Pacific Ocean northward to the Arctic Ocean.
Pinnipeds, commonly known as seals, are a widely distributed and diverse clade of carnivorous, fin-footed, semiaquatic, mostly marine mammals. They comprise the extant families Odobenidae, Otariidae, and Phocidae, with 34 extant species and more than 50 extinct species described from fossils. While seals were historically thought to have descended from two ancestral lines, molecular evidence supports them as a monophyletic lineage. Pinnipeds belong to the suborder Caniformia of the order Carnivora; their closest living relatives are musteloids, having diverged about 50 million years ago.
The Steller sea lion is a large, near-threatened species of sea lion, predominantly found in the coastal marine habitats of the northeast Pacific Ocean and the Pacific Northwest regions of North America, from north-central California to Oregon, Washington and British Columbia to Alaska. Its range continues across the Northern Pacific and the Aleutian Islands, all the way to Kamchatka, Magadan Oblast, and the Sea of Okhotsk, south to Honshu's northern coastline. It is the sole member of the genus Eumetopias, and the largest of the so-called eared seals (Otariidae). Among pinnipeds, only the walrus and the two species of elephant seal are bigger. The species is named for the naturalist and explorer Georg Wilhelm Steller, who first described them in 1741. Steller sea lions have attracted considerable attention in recent decades, both from scientists and the general public, due to significant declines in their numbers over an extensive portion of their northern range, notably in Alaska.
The crabeater seal, also known as the krill-eater seal, is a true seal with a circumpolar distribution around the coast of Antarctica. They are medium- to large-sized, relatively slender and pale-colored, found primarily on the free-floating pack ice that extends seasonally out from the Antarctic coast, which they use as a platform for resting, mating, social aggregation and accessing their prey. They are by far the most abundant seal species in the world. While population estimates are uncertain, there are at least 7 million and possibly as many as 75 million individuals. This success of this species is due to its specialized predation on the abundant Antarctic krill of the Southern Ocean, for which it has uniquely adapted, sieve-like tooth structure. Indeed, its scientific name, translated as "lobe-toothed (lobodon) crab eater (carcinophaga)", refers specifically to the finely lobed teeth adapted to filtering their small crustacean prey. Despite its common name, crabeater seals do not eat crabs. As well as being an important krill predator, the crabeater seal's pups are an important component of the diet of leopard seals (H. leptonyx). They are the only member of the genus Lobodon.
The ringed seal is an earless seal inhabiting the Arctic and sub-Arctic regions. The ringed seal is a relatively small seal, rarely greater than 1.5 m in length, with a distinctive patterning of dark spots surrounded by light gray rings, hence its common name. It is the most abundant and wide-ranging ice seal in the Northern Hemisphere, ranging throughout the Arctic Ocean, into the Bering Sea and Okhotsk Sea as far south as the northern coast of Japan in the Pacific and throughout the North Atlantic coasts of Greenland and Scandinavia as far south as Newfoundland, and including two freshwater subspecies in northern Europe. Ringed seals are one of the primary prey of polar bears and killer whales, and have long been a component of the diet of indigenous people of the Arctic.
The bearded seal, also called the square flipper seal, is a medium-sized pinniped that is found in and near to the Arctic Ocean. It gets its generic name from two Greek words that refer to its heavy jaw. The other part of its Linnaean name means bearded and refers to its most characteristic feature, the conspicuous and very abundant whiskers. When dry, these whiskers curl very elegantly, giving the bearded seal a "raffish" look.
The hooded seal is a large phocid found only in the central and western North Atlantic, ranging from Svalbard in the east to the Gulf of St. Lawrence in the west. The seals are typically silver-grey or white in color, with black spots that vary in size covering most of the body. Hooded seal pups are known as "blue-backs" because their coats are blue-grey on the back with whitish bellies. This coat is shed after 14 months of age when the pups molt. It is the only species in the genus Cystophora.
The harp seal, also known as Saddleback Seal or Greenland Seal, is a species of earless seal, or true seal, native to the northernmost Atlantic Ocean and Arctic Ocean. Originally in the genus Phoca with a number of other species, it was reclassified into the monotypic genus Pagophilus in 1844. In Greek, its scientific name translates to "ice-lover from Greenland," and its taxonomic synonym, Phoca groenlandica translates to "Greenlandic seal." This is the only species in the genus Pagophilus.
The northern fur seal is an eared seal found along the north Pacific Ocean, the Bering Sea, and the Sea of Okhotsk. It is the largest member of the fur seal subfamily (Arctocephalinae) and the only living species in the genus Callorhinus. A single fossil species, Callorhinus gilmorei, is known from the Pliocene of Japan and western North America.
The Guadalupe fur seal is one of eight members of the fur seal genus Arctocephalus. They are the northernmost member of this genus. Sealers reduced the population to just a few dozen by the late 19th century, but the species had recovered to 10,000 in number by the late 1990s. Many individuals can be found on Mexico's Guadalupe Island.
Phoca is a genus of the earless seals, within the family Phocidae. It now contains just two species, the common seal and the spotted seal. Several species formerly listed under this genus have been split into the genera Pusa, Pagophilus, and Histriophoca. Until recently, Phoca largha has been considered a subspecies of Phoca vitulina but now is considered its own species. For this reason, the fossil history of the genus is unclear, and it has formerly been used as wastebasket taxon for a number of fossils of uncertain affinity.
The Weddell seal is a relatively large and abundant true seal with a circumpolar distribution surrounding Antarctica. The Weddell seal was discovered and named in the 1820s during expeditions led by British sealing captain James Weddell to the area of the Southern Ocean now known as the Weddell Sea. The life history of this species is well documented since it occupies fast ice environments close to the Antarctic continent and often adjacent to Antarctic bases. It is the only species in the genus Leptonychotes.
The spotted seal, also known as the larga seal or largha seal, is a member of the family Phocidae, and is considered a "true seal". It inhabits ice floes and waters of the north Pacific Ocean and adjacent seas. It is primarily found along the continental shelf of the Beaufort, Chukchi, Bering and Okhotsk Seas and south to the northern Yellow Sea and it migrates south as far as northern Huanghai and the western Sea of Japan. It is also found in Alaska from the southeastern Bristol Bay to Demarcation Point during the ice-free seasons of summer and autumn when spotted seals mate and have pups. Smaller numbers are found in the Beaufort Sea. It is sometimes mistaken for the harbor seal to which it is closely related and spotted seals and harbor seals often mingle together in areas where their habitats overlap.
Hauling-out is a behaviour associated with pinnipeds temporarily leaving the water. Hauling-out typically occurs between periods of foraging activity. Rather than remain in the water, pinnipeds haul-out onto land or sea-ice for reasons such as reproduction and rest. Hauling-out is necessary in seals for mating and giving birth. Other benefits of hauling-out may include predator avoidance, thermoregulation, social activity, parasite reduction and rest.
Pagophily or pagophilia is the preference or dependence on water ice for some or all activities and functions. The term Pagophila is derived from the Ancient Greek pagos meaning "sea-ice", and philos meaning "-loving".
The Arctic ringed seal is a subspecies of ringed seals. Arctic ringed seals inhabit the Arctic Ocean, and are the most abundant and wide-ranging seal in the Northern Hemisphere. The ringed seal species is the smallest true seal, and gets its name from a distinctive patterning of light spots on dark grey colored fur. The ringed seal is commonly preyed upon by Polar bears, Arctic foxes, and Killer whales. Population estimates and survival rates are unknown, but average life expectancy is 15-28 years. Ringed seals have long been a component of the diet of indigenous people of the Arctic. Arctic ringed seals have been listed as threatened on the Endangered Species Act since 2012, and increasingly face loss of their habitat due to shrinking ice and snow cover.
