sterlet
A species of sturgeon (Acipenser ruthenus). The Japanese name is usually written in katakana.
See also: カワリチョウザメ
The sterlet is a type of sturgeon from which caviar is obtained.
Katakana spelling is standard for this fish name; usually written in kana.
Kanji spelling exists but is rarely used; the katakana form is strongly preferred.
The name コチョウザメ literally means 'small butterfly shark', but the exact origin of the name is uncertain. It is a compound of 小 (ko, 'small') + 蝶鮫 (chōzame, 'sturgeon').