Pinctada fucata
Akoya Pearl Oyster
The small marine oyster famous for producing classic round akoya pearls, treasured for centuries.
About the Species
Pinctada fucata (commonly called the Akoya pearl oyster) is a bivalve mollusc found in warm coastal waters of the Indo-Pacific, from the Persian Gulf and India to Japan and Australia. It is the species behind the classic white, round "akoya" saltwater pearls and has been farmed for pearl production since the early 20th century.
The shell is thin, slightly rounded and typically 6–10 cm across, with a nacreous (mother-of-pearl) interior. Like other bivalves it is a filter feeder, drawing plankton-rich water through its gills. Pearls form when the animal coats an irritant with layers of nacre — the same material that lines its shell.
Note for editors: the taxonomy of the Pinctada fucata/martensii/imbricata complex is actively debated; verify current classification before publication.
Classification
Characteristics
01Shell Structure
A thin, almost circular to slightly oblique shell, 6–10 cm across, with distinctive hinge teeth and a nacre-lined interior. The outside is marked with growth rings and may show green, brown or red-brown rays.
02Pearl Production
Pearls form when mantle tissue or an irritant is coated with successive layers of nacre (aragonite platelets in conchiolin). In pearl farms a small shell bead plus donor mantle tissue is grafted into the oyster; a marketable akoya pearl typically develops over 10–24 months.
03Feeding Behaviour
A suspension filter feeder: cilia on the gills draw in water and trap phytoplankton, detritus and bacteria in mucus, which is sorted and carried to the mouth. Water is pumped at up to several litres per hour.
04Habitat
Clear, shallow, well-oxygenated coastal waters (roughly 2–20 m deep) with firm substrates and moderate currents: bays, gulfs and lagoons of the Indo-Pacific. Often cultured on nets, rafts or longlines suspended in the water column.
05Economic Importance
The foundation of the cultured pearl industry — akoya pearls dominate the classic white pearl jewellery market. Also significant for coastal livelihoods; shell by-products are used in craft and inlay work.