freshwater black snail; marsh snail
A small freshwater snail native to East Asia, often found in clean streams and rivers. Semisulcospira bensoni is a specific species, but the term may be used broadly for similar snails.
Freshwater black snails live in clean rivers.
Firefly larvae eat freshwater black snails.
Katakana spelling is standard for this species name; the word is usually written in kana.
Rare kanji form; 蜷 is a non-jōyō character meaning 'spiral shell'.
Rare kanji form; 貝子 is an old term for shellfish.
The name likely derives from 川 (kawa, 'river') and 蜷 (nina, an old word for spiral-shelled snails). The exact origin is uncertain.