Pinctada albina is a species of Pearl oyster

Pearl oyster

Pearl oysters are saltwater clams, marine bivalve molluscs of the genus Pinctada in the family Pteriidae. They have a strong inner shell layer composed of nacre, also known as "mother of pearl"....

, known as the sharks bay shell. Another common name is the Arafura shell. It is called the "Amami gai" in Japan.

Pinctada

Pinctada albina belongs to the genus, Pinctada. These are saltwater clams, marine bivalve mollusks of the genus Pinctada in the family Pteriidae. They have a strong inner shell layer composed of nacre, also known as mother of pearl. Pearl oysters are not closely related to the edible oysters of family Ostreidae, and they are also not closely related to the freshwater pearl mussels of the families Unionidae

Unionidae

Unionidae is a family of freshwater mussels, the largest in the order Unionoida, the bivalve mollusks sometimes known as river mussels, naiads, or simply as unionids.The range of distribution for this family is world-wide...

 and Margaritiferidae

Margaritiferidae

Margaritiferidae is a family of medium-sized freshwater mussels, aquatic bivalve mollusks in the order Unionoida. They are known as freshwater pearl mussels, because they are capable of producing pearls.-Genera within the family Margaritiferidae:...

. Like other members of the genus, Pinctada, they share the physiological properties that can lead to the production of large pearl

Pearl

A pearl is a hard object produced within the soft tissue of a living shelled mollusk. Just like the shell of a mollusk, a pearl is made up of calcium carbonate in minute crystalline form, which has been deposited in concentric layers. The ideal pearl is perfectly round and smooth, but many other...

s of commercial value, and therefore attempts have been made to harvest pearls commercially from many different Pinctada species.

Characteristics

The species is small, only three to four inches in diameter. The shells are either grayish or greenish yellow and surrounded by a few indistinct brownish-green radial bands. Nacre is tinted yellowish-green, with a slight border of pale yellow, and has brown markings.

Habitat/Distribution

Although the population stretches along the northern coast up the Great Barrier Reef, P. albina is predominately found in Shark Bay, Western Australia. P. Albina strives in relatively shallow waters, which contributed to it being the first Australian pearl oyster discovered. When white adventurers first recruited Aboriginals to collect pearl oysters, they found P albina, as it was accessible from wading or swimming offshore.

The distribution of P. albina reaches Northern Australia, from Indonesia through the Philippines and up to Micronesia. The widespread distribution is equal to P. maxima. They can also be found in China, Korea, and Vietnam.

Commercially

Pearls are only occasionally found. They are yellow and small. The nacre is thin and the shells are small, making them of little commercial value. However, before the introduction of the Mississippi shell, their ideal shape for buttons made “Shark Bay” shells critical to the Mother of Pearl Industry in the 19th century. Today, the species is used for culturing blister pearls (Mabe pearls).