Akoya pearl cultivation requires a large number of Akoya oysters. Otsuki Pearl breeds seeds oysters at a dedicated facility in Mie Prefecture. Excellent oysters are artificially crossbred to produce new oysters.

Parent oysters are carefully hung from a raft to grow. On the day of seeding, they are pulled up. Now the process can finally start.

The potential parent oysters are opened, and about 3 in 100 are selected.

Parent oysters are determined by checking the condition of each oyster. Oysters with beautiful insides are differentiated, and those in excellent health are selected.

Sperm and eggs are removed from each of the selected parent oysters and mixed in a tank to fertilize them.

Baby oysters that were fertilized in the morning are happily floating around in the afternoon. White granular baby oysters can be seen when the lights are dimmed and a flashlight is pointed at them.

The oysters are kept in tanks at the facility for about 1month after fertilization. After that, the oysters are shipped to aquaculture companies in different places.

The young oysters that we use are transferred to the sea as they grow.

After they are transferred to the sea, they are grown for about 1–2 years.

There are various organisms in the sea that can sometimes interfere with the growth and development of an Akoya oyster. When organisms such as other types of oysters, barnacles, and sea anemones attach to the oysters, they prey on the plankton on which they feed. The pearl oysters are regularly cleaned to prevent this, and any attached sea creatures are removed.

From spring to fall, nucleus insertion is performed to insert the piece of mantle tissue and the nucleus into Akoya oysters. During this period, the factory works all day from morning to evening.

The shell of the oyster in which the nucleus is to be inserted is opened in advance. This is to reduce the time required to perform nucleus insertion.

The nucleus is a spherical object carved from the shell of a freshwater bivalve that has the same structure as the layers of nacre, and nuclei come in various sizes. The size of the nucleus is determined based on the size of the pearl to be created and the size of the oyster in which the nucleus is to be inserted.

The piece of mantle particle is from an Akoya oyster. An oyster secretes components that produce the pattern (nacre) inside the oyster’s shell.

The most important aspect of this process is to make sure that the piece of mantle is attached to the nucleus in the Akoya oyster’s shell.

This process is all done by hand. Each oyster is picked up one by one to determine the oyster’s condition.

The size and health of the oyster will determine the size of the pearl that will be produced.

This procedure involves inserting a knife into the oyster using a special tool and implanting the nucleus and piece of mantle tissue. This requires delicate movements of the fingertips as well as the entire body.

After nucleus insertion is complete, the oysters are placed in a special cage and returned to calm waters. The oysters are laid out in rows close together since their recovery will be delayed if they can easily move around.

The wound caused by nucleus insertion fully heals. Occasionally, the cage is pulled up and the inside of the oyster is inspected to check the healing of the wound.

When the oysters have recovered their strength, they are transferred to nets and moved to offshore fishing grounds. This is to allow the oysters to grow larger in offshore waters where food is plentiful. They are carefully grown for a while until the pearls are harvested.

Until harvest, nacre is secreted by the mantle inside the oyster, gradually coating the nucleus. The condition of the oyster is checked regularly and anything attached to the oyster is periodically removed. Secretion of nacre components is also promoted by stimulating the oyster from the outside with water currents.

In the winter, the water temperature drops and the growth of Akoya oysters slows.

The secretion of nacre components thus slows, and fine layers of nacre are formed.

At the same time, the luster of the pearl increases. At this point, the oysters are pulled from the sea.

Extracting the pearls from the oysters is very difficult because of the large amount of attached material, but the shells are opened one by one using a knife. The mollusk is removed and placed in a mixer to filt the pearl.

Some of the pearls are harvested directly from the oysters and they are checked to see if they are fully formed.

This moment when a beautiful pearl is created is the culmination of the cultivation process. Sometimes things may go wrong, so the moment of witnessing this result is very nerve-wracking.

These are pearls right after harvest. Pearls have various quality qualities. The pearls are roughly selected and sent to the Head Office for further sorting.