海獭

📖 1. 概览

它是一种会把石头放在肚皮上敲碎蛤蜊和海胆进食的使用工具的海洋哺乳动物，也是因仰浮海面手牵手睡觉而闻名的关键种。

🌐 Wikipedia 摘要摘录

The sea otter is a marine mammal native to the coasts of the northern and eastern North Pacific Ocean. Adult sea otters typically weigh between 14 and 45 kg (30–100 lb), making them the heaviest members of the weasel family, but among the smallest marine mammals. Unlike most marine mammals, the sea otter's primary form of insulation is an exceptionally thick coat of fur, the densest in the animal kingdom. Although it can walk on land, the sea otter is capable of living exclusively in the ocean.

🦴 2. 身体结构与特征

每1cm²皮肤上竟长有15万根毛发，是地球上毛发密度最高的动物；它还会把自己心爱的专用石头收进腋下松弛的皮囊里随身携带。

🔍 3. 生态与行为

只有海獭捕食海胆，海藻林（巨藻林）才不至于荒漠化并得以维持，因此在生态学教科书中被列为“关键种（Keystone species）”的首要范例。

🇰🇷 4. 与韩国的关联

它是与韩国河川中的水獭（Lutra lutra）同属鼬科的海洋亲戚。