1.
marine mammal; sea creature
A mammal that lives primarily in the ocean, such as seals, sea lions, walruses, and sea otters. A zoological term.
水族館で海獣のショーを見た。
I watched a marine mammal show at the aquarium.
アザラシやセイウチは海獣に分類される。
Seals and walruses are classified as marine mammals.
北海道の海岸では野生の海獣を観察できることがある。
On the coasts of Hokkaido, it is sometimes possible to observe wild marine mammals.
Composed of 海 (sea) + 獣 (beast, animal). Refers specifically to marine mammals — not fish or other sea creatures. Includes animals like アザラシ (seal), アシカ (sea lion), セイウチ (walrus), ラッコ (sea otter), and sometimes クジラ (whale) and イルカ (dolphin). Not to be confused with the homophone 怪獣 (monster, as in Godzilla). Common collocations: 海獣類 (marine mammals as a group), 海獣ショー (marine mammal show). In Japanese aquariums, the 海獣 section typically features pinnipeds (seals and sea lions).