noun
Margaritifera laevis; freshwater pearl mussel
A species of freshwater mussel found in Japan. Scientific name: Margaritifera laevis.
カワシンジュガイは日本の清流に生息する。
The freshwater pearl mussel inhabits clear streams in Japan.
この川ではカワシンジュガイが絶滅の危機にある。
In this river, the freshwater pearl mussel is endangered.
Compound of 川 (kawa, 'river') + 真珠 (shinju, 'pearl') + 貝 (kai, 'shellfish'). The exact derivation is uncertain, but the name describes a river pearl mussel.