Pinctada

Pinctada is a genus of saltwater oysters. These oysters are bivalve mollusks in the family Pteriidae. They are special because they make pearls. Their shells have a strong inner layer made of nacre, also called "mother of pearl." This shiny material makes pearls glow and the shells very strong.

Unlike the oysters we eat, which are in the family Ostreidae, pearl oysters are different. They are not related to freshwater pearl mussels in families like Unionidae and Margaritiferidae. Pinctada oysters are unique because they make some of the world's most valuable pearls.

Two important species, Pinctada margaritifera and P. maxima, are used to make South Sea and Tahitian pearls. These pearls grow through a process called culturing. They are mainly found in the central and eastern parts of the Indo-Pacific region. Because these pearls are rare and beautiful, they are often a symbol of wealth. You can see a pearl oyster on the back of the 1,000-peso note from the Philippines.

Species of commercial value

All species in the genus Pinctada make pearls. The species that are important for making pearls include:

• Gulf pearl oyster, Pinctada radiata; found in the Persian Gulf, Red Sea, Mediterranean Sea, and the Indo-Pacific up to Japan and Australia.
• Black-lip oyster, Pinctada margaritifera; found in the Persian Gulf, southwestern Indian Ocean, Fiji, Tahiti, Myanmar, Baja California, and the Gulf of Mexico
• Gold-lip oyster, Pinctada maxima; found in Australia, Fiji, and Tahiti
• White-lip oyster, Pinctada maxima; found in Australia, Cygnet Bay Pearl Farm, Fiji, Tahiti, and Myanmar
• Pinctada mazatlanica; found in Mexico and Panama
• Akoya pearl oyster, Pinctada fucata (also called P. martensii); found in the Red Sea, Sri Lanka, Persian Gulf, Indian Ocean, the western Pacific Ocean, Australia, China, and Venezuela
• Shark Bay pearl oyster Pinctada albina; found in Australia

These species make pearls of different sizes and colors, based on the natural nacre color of their shells. Pearls can also come from some species of the related winged oyster genus Pteria and from certain freshwater mussel species.

Species list

The World Register of Marine Species lists many types of pearl oysters in the genus Pinctada. Some well-known species are the Shark Bay pearl oyster Pinctada albina, the Akoya pearl oyster Pinctada fucata, and the Black-lipped oyster Pinctada margaritifera. Others include the Gulf pearl oyster Pinctada imbricata and the gold-lipped oyster Pinctada maxima. There are nineteen species in this group.