Enables calcium sensitive guanylate cyclase activator activity. Acts upstream of or within phototransduction; regulation of guanylate cyclase activity; and visual perception. Predicted to be located in cone photoreceptor outer segment and photoreceptor inner segment. Is expressed in retina outer nuclear layer. Human ortholog(s) of this gene implicated in retinitis pigmentosa 48. Orthologous to human GUCA1B (guanylate cyclase activator 1B). [provided by Alliance of Genome Resources, Apr 2022]