Pinctada mazatlanica is a species of tropical marine bivalve mollusc in the family Pteriidae, the pearl oysters. It is native to shallow waters on the Pacific coast of Central America where its range includes both northern and southern Mexico and Panama.
This oyster along with the Pacific wing-oyster (Pteria sterna) has been the subject of a pearl fishery in the Gulf of California since before the arrival of Hernando Cortez in 1535; the Spaniards quickly appreciated the value of the harvest and in 1586 declared the gathering of oysters to be a right of the Spanish crown. By the 1840s, the export of the shells was as valuable as the pearls extracted from them, and in 1874, compressed air diving equipment made harvesting the oysters easier. By the early 1900s, some 200,000 to 500,000 oysters were being harvested annually. This over-exploitation caused populations of both species of oyster to become depleted and in 1940 the fishery was closed by the Mexican Government, a ban that still remains in force.