''Pinctada fucata'', the Akoya pearl oyster (), is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of marine

bivalve Bivalvia () or bivalves, in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class (biology), class of aquatic animal, aquatic molluscs (marine and freshwater) that have laterally compressed soft bodies enclosed b ...

mollusk Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The ...

in the family

Pteriidae Pteriidae, also called the feather oysters, is a family (biology), family of medium-sized to large saltwater oysters. They are pearl oysters, Marine (ocean), marine bivalve mollusks in the order Pteriida. Some of the species in this family are i ...

, the pearl oysters. Some authorities classify this oyster as ''Pinctada fucata martensii'' (Gould, 1850). It is native to shallow waters in the

Indo-Pacific The Indo-Pacific is a vast biogeographic region of Earth. In a narrow sense, sometimes known as the Indo-West Pacific or Indo-Pacific Asia, it comprises the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the ...

region and is used in the culture of pearls.

Description

''Pinctada fucata'' has two

valves A valve is a device or natural object that regulates, directs or controls the flow of a fluid (gases, liquids, fluidized solids, or slurries) by opening, closing, or partially obstructing various passageways. Valves are technically fittings, ...

connected by a long straight hinge. The length of the shell is slightly greater than its width, and the latter is about 85% of the length of the hinge. The right valve is flatter than the left and there are hinge teeth in both valves. The

anterior Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position pro ...

ear is larger than that in other members of the genus and there is a slit-like notch for the

byssus A byssus () is a bundle of filaments secreted by many species of bivalve mollusc that function to attach the mollusc to a solid surface. Species from several families of clams have a byssus, including pen shells ( Pinnidae), true mussels (Mytili ...

threads to pass through at the junction of the ear and the rest of the shell. The posterior ear is large. The outer surface of the valves is scaly and reddish or golden brown with pale radiating streaks. The inner surface of the valve is lined with a thick layer of golden-yellow

nacre Nacre ( , ), also known as mother-of-pearl, is an organicinorganic composite material produced by some molluscs as an inner shell layer. It is also the material of which pearls are composed. It is strong, resilient, and iridescent. Nacre is ...

with a metallic sheen.

Distribution

''Pinctada fucata'' is native to the Indo-Pacific region. Its range includes the

Red Sea The Red Sea is a sea inlet of the Indian Ocean, lying between Africa and Asia. Its connection to the ocean is in the south, through the Bab-el-Mandeb Strait and the Gulf of Aden. To its north lie the Sinai Peninsula, the Gulf of Aqaba, and th ...

, the

Persian Gulf The Persian Gulf, sometimes called the Arabian Gulf, is a Mediterranean seas, mediterranean sea in West Asia. The body of water is an extension of the Arabian Sea and the larger Indian Ocean located between Iran and the Arabian Peninsula.Un ...

, and coastal waters of India, China, Korea, Japan, and the Western Pacific Ocean. It has been introduced in coastal waters of Venezuela

Biology

Like other bivalve mollusks, ''Pinctada fucata'' is a

filter feeder Filter feeders are aquatic animals that acquire nutrients by feeding on organic matters, food particles or smaller organisms (bacteria, microalgae and zooplanktons) suspended in water, typically by having the water pass over or through a s ...

. Water enters the shell through an opening in the mantle, passes over the gills where food particles are filtered out and gas exchange takes place, and passes out through another opening. These pearl oysters feed on

infusoria Infusoria is a word used to describe various freshwater microorganisms, including ciliates, copepods, Euglena, euglenoids, planktonic crustaceans, protozoa, unicellular algae and small invertebrates. Some authors (e.g., Otto Bütschli, Bütschli) ...

ns,

foraminifers Foraminifera ( ; Latin for "hole bearers"; informally called "forams") are unicellular organism, single-celled organisms, members of a phylum or class (biology), class of Rhizarian protists characterized by streaming granular Ectoplasm (cell bio ...

radiolaria The Radiolaria, also called Radiozoa, are unicellular eukaryotes of diameter 0.1–0.2 mm that produce intricate mineral skeletons, typically with a central capsule dividing the cell into the inner and outer portions of endoplasm and ect ...

ns and other small

plankton Plankton are the diverse collection of organisms that drift in Hydrosphere, water (or atmosphere, air) but are unable to actively propel themselves against ocean current, currents (or wind). The individual organisms constituting plankton are ca ...

ic organisms. The sexes are separate in ''Pinctada fucata'' and gametes are released into the sea where fertilisation takes place. In India, spawning peaks from June to September and again in November and December, during the

monsoon A monsoon () is traditionally a seasonal reversing wind accompanied by corresponding changes in precipitation but is now used to describe seasonal changes in Atmosphere of Earth, atmospheric circulation and precipitation associated with annu ...

periods. The developing larvae pass through a

veliger A veliger is the planktonic larva of many kinds of sea snails and freshwater snails, as well as most bivalve molluscs (clams) and tusk shells. Description The veliger is the characteristic larva of the gastropod, bivalve and scaphopod taxono ...

stage and after about twenty-four days settle on the seabed and become juvenile oysters known as spat.

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 in mesh baskets immersed in the sea for two or three years until large enough to seed. Then a tiny

mother-of-pearl Nacre ( , ), also known as mother-of-pearl, is an organicinorganic composite material produced by some molluscs as an inner shell layer. It is also the material of which pearls are composed. It is strong, resilient, and iridescent. Nacre is ...

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 jewelry and in the manufacture of ornamental objects.

As food

Akoya oysters can be eaten raw, cooked or cured. Its flavor is subtle when eaten raw, and more buttery and creamy when cooked. The texture is described as similar to

abalone Abalone ( or ; via Spanish , from Rumsen language, Rumsen ''aulón'') is a common name for any small to very large marine life, marine gastropod mollusc in the family (biology), family Haliotidae, which once contained six genera but now cont ...

References

{{Taxonbar, from=Q420600 Pteriidae Bivalves described in 1850