Enables calcium ion binding activity and identical protein binding activity. Involved in cell-cell recognition and homophilic cell adhesion via plasma membrane adhesion molecules. Located in membrane. Is integral component of plasma membrane. Is expressed in alimentary system; autopod; nervous system; and sensory organ. Orthologous to human PCDHA7 (protocadherin alpha 7) and PCDHA9 (protocadherin alpha 9). [provided by Alliance of Genome Resources, Apr 2022]