Enables cation channel activity and purinergic nucleotide receptor activity. Acts upstream of or within several processes, including activation of cysteine-type endopeptidase activity involved in apoptotic process; regulation of ion transport; and serotonin secretion by platelet. Located in external side of plasma membrane and postsynaptic membrane. Is expressed in several structures, including bladder; foregut-midgut junction; heart; liver lobe; and midgut. Orthologous to human P2RX1 (purinergic receptor P2X 1). [provided by Alliance of Genome Resources, Apr 2022]