The Sangre de Cristo peaclam (Pisidium sanguinichristi) was thought to occur exclusively in the Sangre de Cristo Mountains in Taos County, New Mexico. Rigorous genetic and morphological evidence strongly indicates that this clam is a member of a widely dispersed cosmopolitan species, likely Euglesa casertana or E. variabilis, and is not a valid species. As such, this freshwater clam does not meet the statutory definition of a species under the Endangered Species Act. For more information on the Service’s decision to not list the Sangre de Cristo peaclam, visit the Federal Register, docket number FWS–R2–ES–2026–1453.