Enables signaling receptor activity and signaling receptor binding activity. Involved in cell adhesion; fusion of sperm to egg plasma membrane involved in single fertilization; and sperm-egg recognition. Predicted to be located in membrane. Predicted to be anchored component of external side of plasma membrane. Is expressed in several structures, including adrenal gland; gonad; gut; hemolymphoid system gland; and integumental system. Orthologous to human IZUMO1R (IZUMO1 receptor, JUNO). [provided by Alliance of Genome Resources, Apr 2022]