What is pearl farming?
Pearl farming is the industry in which farm-raised pearl mollusks and cultured pearls are produced. These cultured pearls compose nearly 100% of the pearls sold today.
Pearl formation
Pearl formation is a rare and accidental phenomenon. Pearls are the result of a biological procedure– the oyster’s method of safeguarding itself from foreign substances. It takes about 2-6 years for attaining a good diameter.
The longer the time the larger would be the dimension of the pearl which establishes within a period of 3-4 years are very good in luster whereas those which develop for more than 6 years, lose their shine and luster.
This is because of the extreme deposition of calcium carbonate, which is deposited in concentric rings. Pearls cannot be produced in all the seas (only warmer water seas).
Collection of Oysters
The oysters are collected from the bottom sea by divers. Divers are drawn by big luger boats towards the tidal flow. Oysters are normally situated on a seabed and are generally covered with aquatic animals as well as a thin layer of silt.
The best time for diving is from the early morning to midday. The best duration for the collection of oysters is of two months in the summer period when the water is nearer and calm.
Rearing of Oysters
The collected oysters are stocked and reared in a special type of cages called rearing cages. These cages are well protected from all-natural enemies of oysters like Octopus, Eel, Devilfishes, and so on.
The collected oysters are first cleansed and after that placed into cages for a period of about 10 to 20 days to recuperate the strain because of extreme handling as well as for the physical modification to shallow water conditions.
Insertion of Nucleus
The insertion of the nucleus as a foreign substance is quite a technological process as well as is of fantastic importance for the pearl market. A number of techniques are designed yet the most practicable as well as reliable technique is one taken on by Nishikows.
In this approach, a piece of the mantle of a living oyster is removed and placed together with the nucleus center inside the living cells of another oyster. Following actions are taken for the insertion of the nucleus;
1.Health and fitness of oyster for the procedure
The chosen oysters for the insertion of the nucleus must be healthy as well as strong sufficient to get over the shocks throughout the procedure. Before the operation, oysters are kept under stress of suffocation. Consequently, they begin to open their coverings and at the same time, a bamboo piece is placed in between the gaps of two shells because of which coverings may not be shut again.
2.Preparation of graft tissue
The piece of cells which is placed inside the mantle is called ‘Graft’ tissue. A strip of about 7 x 0.75 cm is cut from the edge of the mantle of healthy oysters by a sharp blade. This piece is smoothed clean and cleaned off. The border gill item is eliminated by a sharp scalpel.
These cells are trimmed to 2 to 3 centimeters long and cut transversely into tiny squares according to the dimension of the nucleus for insertion. These squares are kept in seawater at 22 degrees centigrade where they can survive for about 40 hours.
The outer sides of these graft squares should be known due to the fact that these nacre secreting cells are discovered only on the external surface area of the mantle so it is essential to keep the outer surface area touching the inserted nucleus.
3.Preparation of Center
Although any little particle may function as a nucleus to initiate the pearl development yet it was reported that ‘calcareous center’ is the best due to the fact that the deposition of nacre was found to be more satisfactory on calcareous nucleus as contrasted to any other particle. The finest nucleus is created by the covering of mollusks with hefty deposition of calcareous coverings.
4.Insertion of Nucleus
For the insertion of the nucleus, oysters are placed in a desk clamp. Mantle folds up are efficiently touched to expose the foot and the body mass, followed by incision into the epithelium of the foot and a slender network right into the primary mass.
Now, one graft tissue piece is placed into the channel and the nucleus is put over the plethora of tissue that works as a bed for the nucleus. For the insertion of the second nucleus, a similar operation is carried out from the left side in the gonadial cells and the third insertion should never be attempted.
5.Post Operational treatment
Nucleated oysters are placed into cages and put on hold into seawater, attached with floating rafts to a deepness of 2 to 3 meters for around 6 to 7 days to recuperate from shocks as a result of the procedure.
Sometimes, a couple of oysters expel out the nucleus from the body as a result of hefty shock. Nowadays, it is checked out by X-rays whether oysters are having a nucleus or not.
Harvesting of Pearls
Pearls are collected in the months of December to February which may somewhat differ according to weather conditions of the industrial area. After the completion of 3 years of insertion of the nucleus, pearl oysters are collected from the sea, and pearls are secured from the shell. Accumulated peals ought to be extensively dried out after the harvest to prevent loss of luster.