noun
otter; Eurasian otter
General term for otter, especially the Eurasian otter (Lutra lutra).
カワウソは川で魚を捕るのが上手だ。
Otters are good at catching fish in rivers.
noun
Japanese river otter
Specifically the Japanese river otter (Lutra lutra whiteleyi), a subspecies once found in Japan, now considered extinct.
ニホンカワウソは絶滅したと考えられている。
The Japanese river otter is thought to be extinct.