Northern elephant seal (English name: Mirounga angustirostris; northern elephant seal)

Japanese: キタゾウアザラシ（英語表記）Mirounga angustirostris; northern elephant seal

The elephant seal is a member of the genus Phocidae, suborder Pinnipedia, family Phocidae, and genus Phocidae. Males reach a body length of about 5 m and a weight of 1.8 to 2.2 t, while females reach a body length of about 3 m and a weight of 400 to 800 kg, with a marked difference in size between males and females. The length at birth is about 1.2 m, and the birth weight is 30 to 40 kg. The fur of the seal is uniformly gray, tan, or brown, and generally fades with annual molting. The fur of the calf is black-brown at birth, but is replaced by silver-gray fur about three weeks after birth. The body is long and muscular, with a very thick neck. The head, muzzle, and lower jaw are wide. Mature males have a fleshy nose like an elephant's trunk, which usually hangs down in front of the mouth, but can inflate it. The tips of the fingers of the forelimbs have large black-brown claws. They have four incisors on the upper jaw and two on the lower jaw, two canines on each side, and ten cheek teeth on each side. They do not have territories, but form large polygamous groups. Males fast during the breeding season and repeatedly fight while barking to secure many females. They can perform the longest and deepest dives of any pinniped. They prey on small sharks and deep-sea fish, mainly Japanese flying squids. They are found in the eastern and central North Pacific Ocean. Their breeding grounds include the continent and offshore islands from the central Baja California Peninsula to northern California, and they visit them twice a year during the breeding and molting seasons. At the end of the breeding and molting seasons, they migrate northward or westward to the ocean areas of the North Pacific Ocean and the Gulf of Alaska.

Source: Encyclopaedia Britannica Concise Encyclopedia About Encyclopaedia Britannica Concise Encyclopedia Information

Japanese:

食肉目鰭脚亜目アザラシ科ゾウアザラシ属。雄は体長約 5m，体重 1.8～2.2t，雌は体長約 3m，体重 400～800kgに達し，雌雄の体格に著しい差がある。出生体長は約 1.2m，出生体重は 30～40kgである。体毛の色は，一様に灰色，黄褐色，茶色を呈し，一般に毎年の換毛で色があせる。出生仔の毛色は黒茶色であるが，生後約3週間ほどで銀灰色の毛に抜け替る。体は長くたくましく，頸部は非常に太い。頭部，鼻口部および下顎は幅が広い。成熟した雄はゾウの鼻のような肉厚の鼻を有しており，通常は口の前で垂れ下がっているが，ふくらませることができる。前肢の指先には大きな黒茶色の爪がある。門歯は上顎4本，下顎2本，犬歯は上顎と下顎に各2本，頬歯は上顎と下顎に各 10本である。なわばりはないが，大きな一夫多妻の集団をつくる。雄は繁殖期には絶食し，多くの雌を確保するために吠えながら闘争を繰返す。鰭脚類中，最長かつ最深の潜水を行う。スルメイカ類を中心に小型のサメ類や深海性魚類を捕食する。北太平洋東部と中央部に分布する。繁殖場はバハカリフォルニア半島中部からカリフォルニア北部までの大陸や沖合いの島々などで，繁殖期と換毛期に年2回訪れる。繁殖期および換毛期の終盤には北太平洋とアラスカ湾の大洋域の北方ないし西方へ回遊する。

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