Pearl

The Akoya pearl and penguin’s wing oyster used in production of pearls

Pteria penguin Oyster, commonly known as the penguin’s wing oyster, is a species of marine bivalve mollusc in the family Pteriidae, the pearl oysters. It is native to the western and central Indo-Pacific region and is used for the production of cultured pearls. The generic name comes from Greek πτερον (pteron) meaning wing

Pteria penguin  Pearl culture

Wild oysters of this species seldom contain pearls. When they do, they tend to be irregular in shape and have the same range of pinkish hues that are typical of the nacre lining the shells. The maximum diameter of the pearls is about 13 mm (0.5 in). Because the shell valves of this species are so thin, it was beyond the competence of nineteenth century oyster culturists to use it for pearl production.

With modern techniques, seeding has become easier and Pteria penguin has joined Pteria sterna, another member of the genus Pteria, as being a major producer of cultured pearls. Most of the pearls produced by Pteria penguin are “mabé pearls”, also known as bubble or half pearls, formed between the mantle and the shell valve and having one flattened side. The production of round pearls is possible but requires more advanced techniques in seeding. Naturally occurring spat can be collected on spat collectors for growing on into mature oysters, and there are some hatcheries producing spat on a commercial scale. These oysters are cultured on the Ryukyu Islands, along the southern coast of China, on Phuket Island in Thailand and on Vava’u in Tonga

Pinctada fucata Oyster

Pinctada fucata oyster, the Akoya pearl oyster, is a species of marine bivalve mollusk in the family Pteriidae, the pearl oysters. Some authorities classify this oyster as Pinctada imbricata fucata (Gould, 1850). It is native to shallow waters in the Indo-Pacific region and is used in the culture of pearls.

pearl

Pinctada fucata Pearl culture

Japan and Australia are the largest producers of cultured pearls. The process takes place within the tissues of living oysters, the species Pinctada fucata and Pteria penguin being mainly used for this purpose in Japan and Pinctada maxima in Australia. The oyster spat is grown on in barrels immersed in the sea for two or three years until large enough to seed. Then a tiny mother-of-pearl bead is inserted into the shell and layers of nacre become deposited around this. The oysters are kept in wire nets suspended from rafts while both oysters and pearls grow. Readiness for harvest is often determined by x-ray. Not only is the pearl gathered, but the nacre lining the inside of the valves of the shell is used in jewellery and in the manufacture of ornamental objects.