Definition
The genus *Enhydra* consists of the sea otter (*Enhydra lutris*) – the smallest marine mammal in North America. They reside in the Pacific Ocean, from Alaska to California and Russia. This genus is unique because sea otters lack a blubber layer; they rely on their dense fur for warmth. They are known for their tool usage, especially using rocks to open shellfish. As a keystone species, their presence is vital for maintaining kelp forest ecosystems. Protecting *Enhydra* is essential for ocean biodiversity.