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More About Seals and Sea Lions ...
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Pinnipeds are large marine mammals belonging to the Pinnipedia, a suborder of the order Carnivora. The true seals, sea lions, fur seals and Walrus are all pinnipeds.
Pinnipeds are typically sleek bodied and rather large. The smallest pinniped, the Galapagos Fur Seal weighs about 30 kg when full-grown and is 1.2 metres long; the largest, the male Southern Elephant Seal, is over 4 metres long and weighs up to 2,200 kg. All are carnivorous and live on fish, shellfish, squid, and other marine creatures.
It has long been believed that the pinnipeds are descended from a land-based carnivore, something approximately like a dog that has undergone aquatic adaptation. During the 20th Century there was considerable debate about the relationship between them; some taxonomists maintaining the traditional view that they share a common ancestor, others suggesting that the eared seals (sea lions and fur seals) are distinct from the true seals, and that the similarities between the two groups are the result of convergent evolution. If this were so, Pinnipedia would be a paraphyletic grouping with no taxonomic meaning. Recent studies of mitochondrial DNA, however, have strongly supported the monophyletic hypothesis: that is, the evidence is currently on the side of a single-ancestor theory.
The true seals or earless seals are one of the three main groups of mammals within the seal suborder, 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 family Otariidae.
Phocids are the more highly specialized for aquatic life of the two groups and, unlike otariids, lack external ears and cannot bring their hind flippers under their body to walk on them.
They are more streamlined than fur seals and sea lions, and can therefore swim more effectively over long distances than otariids. However, because they cannot turn their hind flippers downward, they are very clumsy on land because they have to wriggle with their front flippers and abdominal muscles; this method of locomotion is called gallumphing.
While otariids are built for speed and maneuverability in the water, phocids are built for efficient, economical movement. This allows most phocids to make long foraging trips to exploit prey resources that are far from land, whereas otariids are tied to rich upwelling zones close to their breeding sites. The phocid reproductive cycle is characterized by temporal and spatial separation between feeding and maternal investment; in other words, a pregnant female spends a long period of time foraging at sea, building up her fat reserves, and then returns to the breeding site and uses her stored energy reserves to provide milk for her pup. (It should be noted that the common seal (harbor seal in the U.S.), Phoca vitulina, does not separate foraging and maternal investment; instead, it displays a reproductive strategy similar to those of otariids, in which the mother makes short foraging trips between nursing bouts.)
Because the pup receives the milk energy from its mother so quickly, its development is typically not complete enough for it to begin foraging on its own as soon as the nursing period is complete. Seals, like all marine mammals, need time to develop the oxygen stores, swimming muscles and neural pathways necessary for effective diving and foraging. Because of this, most phocids undergo a postweaning fast, in which they remain on or near the breeding site and live off of the fat stores they acquired from their mothers until they are ready to begin foraging on their own. These pups typically eat no food and drink no water during the fast, although some polar species have been observed to eat snow. The postweaning fast ranges from 2 weeks in the Hooded Seal to 9-12 weeks in the Northern Elephant Seal. The physiological and behavioral adaptations that allow phocid pups to endure these remarkable fasts, which are among the longest for any mammal, remain an area of active study and research.
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Taxonmony
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Phylum: chordata
Class: mammalia
Order: Carnivora
Family: Phocidae
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Source: Wikipedia Read more about Seals and Sea Lions
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VIDEO CLIPS
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Elephant seal
0.550MB MOV View Movie
Ocean stock footage
Elephant seals fighting
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Hooded Seal
0.340MB MOV View Movie
Whalenet
Hooded Seal "Stephanie" gets her Satellite Tag
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Hooded Seal
0.850MB MOV View Movie
Whalenet
Hooded Seal "Stephanie" goes into water
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Sea Lion
1.960MB MOV View Movie
KZU-Geographie: WERKSTATT AUSTRALIEN (In German)
Sea lions in 'Seal Bay Conservation Park', South coast of Kangaroo Island, Australia
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Sea Lion
1.320MB MOV View Movie
KZU-Geographie: WERKSTATT AUSTRALIEN (In German)
Sea lions in Flinders National Park
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Leopard seal
Streaming RAM View Movie
BBC Nature: Wildfacts
Leopard seal Video
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South American Fur Seal
Streaming RAM View Movie
BBC Nature: Wildfacts
South American fur seal Video
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California Sea Lion
0.020MB MPG View Movie
theBigZoo.com
California Sea Lion Swimming
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Fur Seal
Streaming RAM View Movie
National Geographic
Fur seals jughandling
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Crabeater Seal
Streaming RAM View Movie
National Geographic
Crabeater Seal video
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Sea Lion
Streaming RM View Movie
PBS
View a clip about the San Francisco sea lions.
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Elephant Seal
Streaming RM View Movie
PBS
Male elephant seals have truly memorable battles over females, butting their massive chests against one another -- or, if no competing seals are nearby, the nearest equivalent.
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California Sea Lions
11.610MB WMV View Movie
California VideoDiver
"California Sea Lions shows the humor, grace and beauty of these wonderful marine mammals of the California coast"
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Galapagos Sea Lion
0.250MB MOV View Movie
NOAA
This curious sea lion has a good time with the Galapagos diver.
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Monk Seal
Streaming RAM View Movie
NOAA
This video is taken from a small camera attached to a monk seal swimming in shallow coral reef habitat.
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Sea Lion
27.330MB MOV View Movie
RaceRocks.com
Sea Lions and Divers
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Sea Lion
8.420MB MOV View Movie
RaceRocks.com
Ecotourism effects on sea lion behaviour.
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Sea Lion
59.090MB MOV View Movie
RaceRocks.com
Northern Sea Lions on Great Race Rock island
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Elephant Seal
6.210MB MOV View Movie
RaceRocks.com
Male Elephant seal hauled out on South Race Rocks .
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Elephant Seal
6.370MB MOV View Movie
RaceRocks.com
Elephant seals often haul out at the docks at Race Rocks
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Elephant Seal
16.420MB MOV View Movie
RaceRocks.com
Female elephant seal with moulting evidence on coat
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Harbor Seal
17.360MB MOV View Movie
RaceRocks.com
Harbour Seal underwater at West Race Rocks
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Grey seal
MOV View Movie
Arkive.org
Nice selection of Grey seal video clips available in various formats
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Common seal
MOV View Movie
Arkive.org
Nice selection of Common seal video clips available in various formats
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Sea Lion
6.590MB MPG View Movie
jellitot.com
Sealions - Galapagos
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Seal
0.480MB MPG View Movie
jellitot.com
Seal swimming underwater - Farne Islands
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Seal
1.310MB MPG View Movie
jellitot.com
Seal swimming underwater - Farne Islands
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Seal
1.030MB MPG View Movie
jellitot.com
Seal swimming underwater - Farne Islands
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Sea Lion
1.420MB MPG View Movie
jellitot.com
Playful sealion - Galapagos
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Sea Lion
0.460MB MOV View Movie
FreeStockFootage.com
Sea Lions in Bolinas Lagoon
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New Zealand Fur Seal
1.080MB MOV View Movie
Tasmania - Dept. of Primary Industries, Water, and Environment
New Zealand Fur Seal movie
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Elephant Seal
0.550MB MOV View Movie
Ocean Stock Footage
Elephant seals fighting
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Fur Seal
0.560MB WMV View Movie
R&C Photography
Fur Seals at Gold Harbor South Georgia
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Elephant Seal
1.140MB WMV View Movie
R&C Photography
Elephant Seals at Gold Harbor South Georgia
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Fur Seal
1.830MB WMV View Movie
R&C Photography
Baby Fur Seals at Prion Island
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Seal
0.960MB MOV View Movie
Creatas
Seals on iceberg
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