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.
Single-character kanji form; also read うそ, おそ, or だつ in restricted contexts.
Hiragana spelling, also common.
Kanji spelling using 川 (river) and 獺 (otter). Rarely used.
Alternate kanji spelling using 河 (river). Rarely used.
ラッコ refers to the sea otter (Enhydra lutris), a different species that lives in the ocean, while カワウソ lives in rivers.
Compound of 川 (kawa, 'river') and 獺 (uso, 'otter'). The reading うそ is an older native Japanese word for otter, now mostly replaced by かわうそ.