This specimen was picked up at Gwakji beach, Jeju Island, South Korea on August 17, 2021. Bostrycapulus gravispinosus is a species that lives widely in South Korea. It attaches itself on rocks and Gastrapods. The shell is thick and flat. The exterior of the shell has irregular nodules and color of brown and white. The interior has white color with smooth surface.
SL: 23mm
SW: 18mm