Bearded Seal
Overview
 
The bearded seal also called the square flipper seal, is a medium-sized pinniped
Pinniped
Pinnipeds or fin-footed mammals are a widely distributed and diverse group of semiaquatic marine mammals comprising the families Odobenidae , Otariidae , and Phocidae .-Overview: Pinnipeds are typically sleek-bodied and barrel-shaped...

 that is found in and near to the Arctic Ocean
Arctic Ocean
The Arctic Ocean, located in the Northern Hemisphere and mostly in the Arctic north polar region, is the smallest and shallowest of the world's five major oceanic divisions...

. It gets its generic
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 name from two Greek
Greek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...

 words (eri and gnathos) that refer to its heavy jaw
Jaw
The jaw is any opposable articulated structure at the entrance of the mouth, typically used for grasping and manipulating food. The term jaws is also broadly applied to the whole of the structures constituting the vault of the mouth and serving to open and close it and is part of the body plan of...

. The other part of its Linnaean
Linnaean taxonomy
Linnaean taxonomy can mean either of two related concepts:# the particular form of biological classification set up by Carl Linnaeus, as set forth in his Systema Naturæ and subsequent works...

 name means beard
Beard
A beard is the collection of hair that grows on the chin, cheeks and neck of human beings. Usually, only pubescent or adult males are able to grow beards. However, women with hirsutism may develop a beard...

ed 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.
Encyclopedia
The bearded seal also called the square flipper seal, is a medium-sized pinniped
Pinniped
Pinnipeds or fin-footed mammals are a widely distributed and diverse group of semiaquatic marine mammals comprising the families Odobenidae , Otariidae , and Phocidae .-Overview: Pinnipeds are typically sleek-bodied and barrel-shaped...

 that is found in and near to the Arctic Ocean
Arctic Ocean
The Arctic Ocean, located in the Northern Hemisphere and mostly in the Arctic north polar region, is the smallest and shallowest of the world's five major oceanic divisions...

. It gets its generic
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 name from two Greek
Greek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...

 words (eri and gnathos) that refer to its heavy jaw
Jaw
The jaw is any opposable articulated structure at the entrance of the mouth, typically used for grasping and manipulating food. The term jaws is also broadly applied to the whole of the structures constituting the vault of the mouth and serving to open and close it and is part of the body plan of...

. The other part of its Linnaean
Linnaean taxonomy
Linnaean taxonomy can mean either of two related concepts:# the particular form of biological classification set up by Carl Linnaeus, as set forth in his Systema Naturæ and subsequent works...

 name means beard
Beard
A beard is the collection of hair that grows on the chin, cheeks and neck of human beings. Usually, only pubescent or adult males are able to grow beards. However, women with hirsutism may develop a beard...

ed 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. Distinguishing features of this earless seal
Earless seal
The true seals or earless seals are one of the three main groups of mammals within the seal superfamily, 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...

 include square fore flippers
Flipper (anatomy)
A flipper is a typically flat limb evolved for movement through water. Various creatures have evolved flippers, for example penguins , cetaceans A flipper is a typically flat limb evolved for movement through water. Various creatures have evolved flippers, for example penguins (also called...

 and thick bristle
Bristle
A bristle is a stiff hair or feather. Also used are synthetic materials such as nylon in items such as brooms and sweepers. Bristles are often used to make brushes for cleaning uses, as they are strongly abrasive; common examples include the toothbrush and toilet brush...

s on its muzzle
Snout
The snout, or muzzle, is the protruding portion of an animal's face, consisting of its nose, mouth, and jaw.-Terminology:The term "muzzle", used as a noun, can be ambiguous...

. Adults are greyish-brown in colour, darker on the back; rarely with a few faint spots on the back or dark spots on the flanks. Occasionally the face
Face
The face is a central sense organ complex, for those animals that have one, normally on the ventral surface of the head, and can, depending on the definition in the human case, include the hair, forehead, eyebrow, eyelashes, eyes, nose, ears, cheeks, mouth, lips, philtrum, temple, teeth, skin, and...

 and neck
Neck
The neck is the part of the body, on many terrestrial or secondarily aquatic vertebrates, that distinguishes the head from the torso or trunk. The adjective signifying "of the neck" is cervical .-Boner anatomy: The cervical spine:The cervical portion of the human spine comprises seven boney...

 are reddish-brown. Bearded seal pup
Pup
Pup may refer to:In zoology:*Puppies, younger dogs*Pinniped young*Shark young*Rodent youngIn other uses:* Sopwith Pup, an aircraft used by the British in World War I* Beagle Pup, a 1960s British light aircraft...

s are born with a greyish-brown natal fur with scatter
Scatter
In ordinary English, to scatter is to distribute randomly. Scatter also has the following meanings:*In physics, scattering is the study of collisions, especially of waves and particles...

ed patches of white on the back
Back
- People :* Adam Back, British cryptographer* Charles Back, South African winemaker* Chris Back , Australian politician* Ernst Emil Alexander Back , German physicist* Frédéric Back , Canadian animator...

 and head
Head
In anatomy, the head of an animal is the rostral part that usually comprises the brain, eyes, ears, nose and mouth . Some very simple animals may not have a head, but many bilaterally symmetric forms do....

. The bearded seal is unique in the subfamily Phocinae in having two pairs of nipple
Nipple
In its most general form, a nipple is a structure from which a fluid emanates. More specifically, it is the projection on the breasts or udder of a mammal by which breast milk is delivered to a mother's young. In this sense, it is often called a teat, especially when referring to non-humans, and...

s, a feature it shares with monk seals
Monachus
Monachus is a genus containing the monk seals, a group of three Pinniped species. They are the only earless seals which are found in tropical climates...

.

The bearded seal reaches about 2.1 m (6.9 ft) to 2.7 m (8.9 ft) in nose-to-tail length and from 200 kg (441 lb) to 430 kg (948 lb) in weight. Both sexes are about the same size.

The bearded seal is a primary food source for the polar bear
Polar Bear
The polar bear is a bear native largely within the Arctic Circle encompassing the Arctic Ocean, its surrounding seas and surrounding land masses. It is the world's largest land carnivore and also the largest bear, together with the omnivorous Kodiak Bear, which is approximately the same size...

 and for the Inuit
Inuit
The Inuit are a group of culturally similar indigenous peoples inhabiting the Arctic regions of Canada , Denmark , Russia and the United States . Inuit means “the people” in the Inuktitut language...

 of the Arctic coast. The Inuktitut
Inuktitut
Inuktitut or Eastern Canadian Inuktitut, Eastern Canadian Inuit language is the name of some of the Inuit languages spoken in Canada...

 name for the seal is Ugyuk or Oogrook or Oogruk. The seal's skin is used to cover a wooden frame boat (Umiak
Umiak
The umiak, umialak, umiaq, umiac, oomiac or oomiak is a type of boat used by Eskimo people, both Yupik and Inuit, and was originally found in all coastal areas from Siberia to Greenland. First arising in Thule times, it has traditionally been used in summer to move people and possessions to...

).

The body fat content of a bearded seal is 30–40%.

Hunting and Diet

Primarily benthic, the bearded seal feeds on a variety of small prey found along the ocean floor, including clam
Clam
The word "clam" can be applied to freshwater mussels, and other freshwater bivalves, as well as marine bivalves.In the United States, "clam" can be used in several different ways: one, as a general term covering all bivalve molluscs...

s, squid
Squid
Squid are cephalopods of the order Teuthida, which comprises around 300 species. Like all other cephalopods, squid have a distinct head, bilateral symmetry, a mantle, and arms. Squid, like cuttlefish, have eight arms arranged in pairs and two, usually longer, tentacles...

, and fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...

. Its whiskers serve as feelers in the soft bottom sediments. Adults tend not to dive very deep, favoring shallow coastal areas no more than 300 m (984.3 ft) deep. Pups up to one year old, however, will venture much deeper, diving as deep as 450 m (1,476.4 ft).

Reproduction and Lifecycle

The bearded seal gives birth in the spring. In the Canadian Arctic, seal pupping occurs in May. Further south, in Alaska
Alaska
Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...

, most pups are born in late April. Pups are born on small drifting ice floes in shallow waters, usually weighing around 30–40 kg. They enter the water only hours after they are born, and quickly become proficient divers. Mothers care for the pups for 18–24 days, during which time the pups grow at an average rate of 3.3 kg per day. During this time, pups consume an average of eight liters of milk a day. By the time they are weaned, the pups have grown to about one hundred kilograms.

Just before the pups are weaned, a new mating cycle takes place. Females ovulate at the end of their lactation period, but remain close to their pups, ready to defend them if necessary. During the mating season, male seals will "sing," emitting a long-drawn-out warbling note that ends in a sort of moan or sigh. This sound may attract females, or may be used by the males to proclaim their territory or their readiness for breeding. Males occupy the same areas from one year to the next.

Like many Arctic mammals, the bearded seal employs a reproductive strategy known as delayed implantation. This means that the blastocyst
Blastocyst
The blastocyst is a structure formed in the early embryogenesis of mammals, after the formation of the morula. It is a specifically mammalian example of a blastula. It possesses an inner cell mass , or embryoblast, which subsequently forms the embryo, and an outer layer of cells, or trophoblast,...

 is not implanted for two months after fertilization, most often becoming implanted in July. Thus, the seal's total gestation
Gestation
Gestation is the carrying of an embryo or fetus inside a female viviparous animal. Mammals during pregnancy can have one or more gestations at the same time ....

 period is around eleven months, though its active gestation period is nine months.

Conservation status

On March 28, 2008, the U.S. National Marine Fisheries Service
National Marine Fisheries Service
The National Marine Fisheries Service is a United States federal agency. A division of the National Oceanic and Atmospheric Administration and the Department of Commerce, NMFS is responsible for the stewardship and management of the nation's living marine resources and their habitat within the...

 initiated a status review under the Endangered Species Act
Endangered Species Act
The Endangered Species Act of 1973 is one of the dozens of United States environmental laws passed in the 1970s. Signed into law by President Richard Nixon on December 28, 1973, it was designed to protect critically imperiled species from extinction as a "consequence of economic growth and...

(ESA) to determine if listing this ice seal species under the ESA is warranted.

Subspecies

There are two recognized subspecies of this seal:
  • Erignathus barbatus barbatus
  • Erignathus barbatus nautica

Further reading


External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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