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Pinnipeds, normally referred to as seals, are web-footed aquatic mammals. There are 32 species of
seals, contained within 4 subfamilies, in two families, Phocidae and Otariidae. Seals are divided into two
groups, earless seals, or true seals, in the family Phocidae, and the eared seals: sea lions and fur seals in
the Family Otariidae. Apart from
the tropical monk seals, seals are found in
both hemispheres in the polar and subpolar
regions of the oceans. The exception is the
Baikal seal (Phoca sibirica) of Lake Baikal
in Russia, which is exclusively a freshwater
seal. Seals range in size, but a representa-
tive of the smallest is the Baikal seal at 1.0
to 1.4 metres in length and 50 to 120kg in
weight. The largest is believed to be the ele-
phant seal (genus Mirounga leonina) being
around 5.5 to 6.5 metres in length and
SUBORDER PINNIPE- weighs about 3,700kg.
DIA (pinnipeds)
Family Odobenidae (walrus) True seals (phocids) are often referred to as crawling seals, a
Genus Odobenus name reflecting their clumsy movement on land. Unlike fur
Family Phocidae seals and sea lions, which use all four flippers to ‘walk’ on land, true
seals cannot bend their rear flippers downward, rendering them use-
(true or Earless seals) less for walking so they are forced to undulate or wriggle their body
Subfamily Monachinae while pulling themselves forward with their front flippers. At sea how-
Genus Monachus (Monk seal) ever, the roles are reversed. Their sleek sparsely haired body is more
Genus Neomonachus (Monk agile and streamlined than the fur seal and sea lions. They use their
seal) body and rear limbs to create fast forward movement and their front
Genus Mirounga (Elephant Seal) flippers for steering. They can hold their breath longer and dive much
Genus Ommatophoca (Ross deeper. The Weddell seal and elephant seal, for instance, have on rec-
seal) ord dived to over 600 metres for up to 73 minutes. They also spend
Genus Lobodon (Crabeater seal) most of their time at sea and venture much farther from land then
Genus Hydrurga (Leopard seal) their eared counterparts, but will always return to land to mate. Alt-
Genus Leptonychotes (Waddell hough true seals are found in both hemispheres, they are more nu-
seal) merous in the Southern hemisphere.
Subfamily Phocinae
Genus Cystophora (Hooded seal) Eared seals (otariid, or otary) are found throughout the Pacific
Southern Oceans and the southern Indian, and Atlantic Oceans but
Genus Erignathus (Bearded seal) are not found in the north Atlantic. They are less aquatic than true
Genus Phoca (Common seal) seals spending a lot of time on land, especially at mating time. They
Genus Pusa (3 Ringed, Baikal, Cas- have four large flexible flippers allowing them to ‘walk’ on land with
pian) relative ease. In the water they can attain incredible bursts of speed,
Genus Pagophilus (harp seal) by simply giving their large flippers a powerful backward flip, and
Genus Histriophoca (Ribbon seal) holding them close to their body, they slice forwards through the wa-
Genus Halichoerus (Grey Seal) ter. With several successive flips some, like the sea lion, can reach
Family Otariidae (Eared speeds of 48km/h. They also differ in appearance from true seals;
seals) they have a dog-like head with earflaps and sharp canines. The sea li-
on has a lion-like mane of coarse guard hair and the fur seal a thick
Subfami- and very dense fur coat.
ly Arctocephalinae (fur seals)
Genus Arctocephalus 8 species All seals are carnivores and live on a wide variety of aquatic life,
Genus Callorhinus (N/Fur seal) the leopard seal however, supplements its aquatic diet with large ver-
Subfamily Otariinae (sea li- tebrates such as penguins. Seals have poor daylight vision but good
ons) night vision and their ears are adapted to hear in water. Their snout
Genus Eumetopias (Sellers sea bristles with highly sensitive whiskers, capable of detecting prey
lion) through vibrations and movement. Vocalization takes place, but it’s
Genus Neophoca (Seals+ Fur wide and varied across species, and occurs both in and out of the wa-
seals) ter. For instance, True seals will usually, bark to communicate danger
Genus Otaria (S/American sea lion) while Fur seals and Sea lions will slap their flippers. Seals have many
Genus Phocarctos (N/Zealand sea predators such as polar bears, sharks and whales, even the leopard
lion) seal is known to prey on many seal species, especially the crabeater
Genus Zalophus 3 Species seal. (See: Walrus)
