The illustrations on the right show that a parasite coming into the shell stimulates the ciliary epithelial cells of the mantle to migrate into the soft tissues,and then a pearl sack is formed.
The pearl sack secretes a liquid,which crystallizes and grows layer by layer.
A natural pearl is formed in the body of a shellfish in this way.
The illustrations on the right page explain how a cultured pearl is produced.
Mantle cells are implanted into the gonads or other soft tissues of the mother oyster and a pearl sack grows around them.
When cells are implanted at cultivating farms, a nucleus which become the core of a pearl is also inserted, in order to produce a pearl of a desired size.
But in cultured freshwater pearls, using Ikechogai, freshwater mussels, mantle cells alone are implanted.
of a Natural Pearl
of a Cultured
Pearl
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1)A foreign object stimulates ciliary epithelial cells to migrate into the soft tissues. | |
| 2)The cells generate a sack of tissue. | |||
| 3)A pearl sack is formed. | |||
| 4)Nacre is secreted and a pearl is created. | |||
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1)A piece of outer epithlial tissue of the mantle and a nucleus is transplanted into the gonad of a mother oyster. | |
| 2)The cells generate a sack of tissue. | |||
| 3)A pearl sack is formed. | |||
| 4)Nacre is secreted and a pearl is created. | |||