See text The Calyptraeidae are a family of small to medium-sized marine prosobranch gastropods.
This family has no subfamilies according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005.
Crepidula fornicata was transported to Europe on imported American oysters in the late 19th century and is now considered a significant pest in European oyster beds.
[2] Internally, the shell is distinguished by a shelf-like, cup-like, or half-cup-like structure used for muscle attachment.
Calyptraeids may form a tower of up to 25 animals, sometimes referred to as a mating chain.