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The is an aquatic mammal thought to have become extinct in the 1970s.〔〔 (''Zalophus californianus japonicus'' (CR) ), Red Data Book, Japan Integrated Biodiversity Information System, Ministry of the Environment (Japan). "The Japanese sea lion (''Zalophus californianus japonicus'') was common in the past around the coast of the Japanese Archipelago, but declined rapidly after the 1930s from overhunting and increased competition with commercial fisheries. The last record in Japan was a juvenile, captured in 1974 off the coast of Rebun Island, northern Hokkaido."〕 Prior to 2003, it was considered to be a subspecies of California sea lion as ''Zalophus californianus japonicus''. However, it was subsequently reclassified as a separate species.〔 Some taxonomists still consider it as a subspecies of the California sea lion. It has been argued that ''Z. japonicus'', ''Z. californianus'', and ''Z. wollenbaeki'' are distinct species because of their distant habitation areas and behavioral differences. They inhabited the Sea of Japan, especially around the coastal areas of the Japanese Archipelago〔 ("ニホンアシカ剥製標本" ), Shimane University Museum, Shimane University, Japan.〕 and the Korean Peninsula.〔 (en abstract available) Itoo Tetsuro, Fujita Akiyoshi, Kubo Kin-ya, ("Pinniped records on the neighbouring waters of the Korean Peninsula: Japanese sea lions and larga seals recorded in the ancient literature of Korea" ), 野生生物保護 (Wildlife conservation Japan),Vol.6, No.2 (20010731), 51-66, Wildlife Conservation Society ISSN 13418777.〕 They generally bred on sandy beaches which were open and flat, but sometimes in rocky areas. Currently, several stuffed specimens can be found in Japan〔 ("天王寺動物園で「絶滅の危機にある動物展」を開催します" ) Tennoji Zoo, Osaka, Japan.〕 and in the National Museum of Natural History, Leiden, the Netherlands, bought by Philipp Franz von Siebold.〔 The British Museum possesses a pelt and four skull specimens.〔 ==Physical description== Male Japanese sea lions were dark grey and weighed about 450 to 560 kg, reaching lengths of 2.3 to 2.5 m; these were larger than male California sea lions. Females were significantly smaller at 1.64 m long with a lighter colour than the males.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Japanese sea lion」の詳細全文を読む スポンサード リンク
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