white-spotted char; Japanese char
A freshwater fish native to Japan, Salvelinus leucomaenis leucomaenis. Often referred to by its katakana name.
I caught a white-spotted char in a river in Hokkaido.
Katakana spelling is common for this fish name; usually written in kana.
Kanji spelling exists but is rarely used; the katakana form is preferred.
The name likely derives from 雨 (ame, 'rain') and 鱒 (masu, 'trout'), but the exact origin is uncertain.