Corbicula leana

Corbicula leana, known as chamjaecheop (; "true "jaecheop"") in Korean and as mashijimi (; "true "shijimi"") in Japanese, is a species of freshwater and brackish water clams, distributed in the Korean Peninsula and the Japanese archipelago.
Culinary use.
In Korean cuisine, "Corbicula leana" are used in a clam soup known as "jaecheop-guk".