Pinctada is a genus of saltwater oysters, marine bivalve mollusks in the family Pteriidae. These pearl oysters have a strong inner shell layer composed of nacre, also known as "mother of pearl".
Pearl oysters are not closely related to either the edible oysters of family Ostreidae or the freshwater pearl mussels of the families Unionidae and Margaritiferidae.
Opening and extracting pearls from farmed pearl oystersCultivated pearl oyster (from JapanShima, Mie)
All species within the genus produce pearls. Attempts have been made to harvest pearls commercially from many Pinctadaspecies. However, the only species that are currently of significant commercial interest are:
The various species of Pinctada produce different maximum sizes and colors of pearls, depending on the size of the species and the natural color of the nacre inside the shell. Black South Sea pearls, or Tahitian pearls come from the black-lip oyster; gold and silver South Sea pearls from the gold-lip and silver-lip oysters; and Akoya cultured pearls from Pinctada fucata martensii, the Akoya pearl oyster.
Pearls are also obtained in commercial quantities from some species of the closely related winged oyster genus Pteria.
Pearls are also produced from freshwater mussel species unrelated to pearl oysters. These freshwater species include Hyriopsis cumingii, Hyriopsis schlegelii, and a hybrid of the two species.
At danger from the large demand for pearls, the typical lifespan of a pearl oyster is usually around 3 years to 14 years. Pinctada maxima are seeded at about 2 years of age and take 2 years to fully develop a pearl. They can be reseeded up to 3 or 4 times. Akoya pearls are harvested after about 9 to 16 months.
Research carried out by biologist Aldemaro Romero Jr. allowed him to discover that the first animal population depleted by Europeans in the American continent was a pearl oyster species (Pinctada imbricata) off the coast of Venezuela. He analyzed historical records and used information about the biology of these and other species to explain its rapid disappearance.
