Pearl Culture by Kajal Maurya M.Sc. I Year.pptx

culture practices of pearl is discussed

1. PEARL CULTURE

2. CONTENT What is pearl and pearl culture? History of pearl culture Types of pearl culture Pearl producing molluscs Basic structure of pearl formation Pearl culture technique Composition of pearl Enemies of pearl culture Economic importance of pearl and pearl culture

3. PEARL(MOTI):- Pearl is a highly shining and precious gem that is formed inside the shell of certain molluscs (Oysters). PEARL CULTURE :- ‘The rearing of bivalve molluscs in a controlled conditions for obtained a pearl’. The bivalve molluscs are two different groups- the freshwater and saltwater oysters. Pearls are formed inside the shell of certain molluscs as a defence mechanism against a potentially threatening irritant(parasite and injury of mantle tissue). PEARL and PEARL CULTURE

4. The pearl culture technique was first initiated in Japan. Father of Pearl culture- Kokichi Mikimoto (1858-1954), Mikimoto was established a pearl farm in Toba (small island in Japan ). He got pearl in July 1893 in his farm. In 1896, he did pearl patents. Best quality pearl is called Lingha Pearl . In India, the technological breakthrough in pearl culture was achieved in 1973 by the Central Marine fisheries research institute(CMFRI-Kochi, Kerala) at Tuticorin, Tamil Nadu. Pearl Oyster Fisheries In India: Two Main Areas The Gulf of Mannar of Tuticorin coast (Tamil-Nadu) and The Gulf of Kutch (Gujarat). History of Pearl Culture

5. Types of Pearl Three types of pearl: Natural Pearl: may be formed within the oyster or mussels by either accidental entrance of a solid or accidental wound with in the shell tissues. This type of pearl is very rare. Cultured Pearl: are produced by human interference. Artificial Pearl: these are made up of plastic, glass, and fish scales.

6. Pearl Producing Molluscs All bivalve oysters can make a pearl. But for economic purposes, only some oyster species are used. Sl.no. Species Common Name Remarks 1 Pinctada margaritifera Black-lip pearl oyster Best pearl 2 Pinctada fucata Akoya pearl oyster Pinctada vulgaris- Indian pearl oyster (India) Pinctada martensii (Japan ) 3 Placuna maxima Gold-lip or silver-lip pearl oyster 4 Pinctada atropurpurea Fragile pearl shell oyster 5 Pferia penguin Penguin wing oyster

7. Sl.no. Species Common name Remarks 6 Tridacna gigas Giant Clam (Natural) Large size pearl 7 Lamellidens marginalis In India and South Asia is used. Freshwater pearl 8 Lamellidens corrianus In India Fresh water mussels Other genus : Haliothis , and Mytilus (Low quality pearl).

8. Classification of Pearl Oyster Kingdom: Animalia Phylum: Mollusca Class: Bivalvia Order: Pteriida Family: Pteriidae Genus: Pinctada

9. • Two part are found in an Oyster: Shell and Mantle ▪ Mantle : In Bivalve, Mantle layer present just below to Shell, in which outer most layer is columnar epithelium cells (this layer contains Nacre secreting unicellular cells that form Pearl). ▪ Connecting tissue found below to outer layer and innermost layer is formed by ciliated epithelium cells (secretion of Mucous). Shell : Shell made up of 03 layers Peri- ostracum : Prismatic Layer: Nacreous Layer: Basic Structure of Pearl Formation

10. Peri- ostracum : Outermost layer of shell which is made up of organic substance (Conchiolin- a protein). It work as a protective layer. It's formed by epithelium cells in the larval stage and in the adult stage is formed by the edges of the mantle. Prismatic Layer: It is the middle layer secreted by mantle. These crystals are arranged perpendicular to the shell surface. It gives strength and rigidity to the shell. Nacreous Laver: Innermost layer of Shell. This is made up of Calcium carbonate and arranged in parallel form. This layer is called 'Mother of Peral’. Form by secretion of Epithelium ceIls of Mantle.

11. Pearl Formation Pearl is formed due to secretion of mantle part in response to irritations caused by foreign particles (parasite, soil, Marine algae, piece of grass, and micro insect). The Pearl attached with mantle. Mantle epithelium cells secreted calcium carbonate surround to it and form many layer. This structure is will be made a Pearl after dry.

12. Pearl formation is a complex and technical process. Pearl culture is done by trained and specialists. Cultivation or culture of pearl is in controlled conditions. Whole process is divided in to following steps: Collection of Oysters: Insertion of Nucleus: Post operational care of Oysters: Harvesting of Pearls: Pearl Culture Technique

13. Collection of oysters rearing of oysters selection of oysters preparation of nuclear shell beads preparation of graft tissue insertion of nucleus nursing the oyster harvesting

14. COLLECTION OF OYSTERS: This is first step. Spats (young one oysters) are collected from spat-falling areas. Oysters are reared in marine water and fresh water bodies. The divers, collect the oysters to the bottom of the sea. Collection of oysters shall be done from July to November due to spats are easily available. These collected oysters are now transferred to rearing cages. The young ones are reared until they are mature enough to undergo the grafting procedure. Rearing cages are suspended in the sea at a depth of 6- meters. Pearl culture technique

15. 2. INSERTION OF NUCLEUS: This process is fully technical. Nucleus is a special structure that will be inserted in to mantle part of oysters. After the insertion of nucleus in to an oyster, nacre layer will be start for secretion. The shape of pearl is depend on the graft that is inserted. For insertion of nucleus, Nishikawa method is used- (A healthy oyster will be put into hot and warm water in an alternate, so the shell will be opened). Reproductive organs also removed.

16. 2. INSERTION OF NUCLEUS: The oyster is opened with special wedges and pliers, then a scalpel slit is made in the soft tissue near the reproductive organ. The graft (1-2) is inserted into mantle. Insertion process of nucleus will be completed with in 3 minutes). Oysters that accepted the implanted are transferred to the pearl farm .

17. 3.POST OPERATIONAL CARE OF OYSTER : The oysters are transferred to the pearl farm where they are rearing baskets or cages that attached to long lines connected to the floating rafts. The rafts are dropped down 2-3 meter into the water just after the nucleus insertion. With in 6-7 days, the wound will be filled, so rearing cages take out from water and check (dead oyster will be removed). Then it must be 14 meter depth in ocean. Regular cleaning of the shells to remove seaweed results in better pearls. The cleaning is done by a machine which uses water jets and brushes to clean off any seaweed.

18. 4. HARVESTING OF PEARLS: The whole process of pearl culture taken 03-06 years. The harvesting process shall be done from December to January month or it depends on the weather. For obtained Peral, the oyster two shell valves must be opened (cutting the adductor muscle, making an incision on the gonad) and then push out the pearl by pressure. Finally, the harvested pearls are washed in distilled water, polished with refined salt and sorted for sale according to size, colour , shape, lustre and other external characteristics.

19. • Pearl consists of water, organic matter, calcium carbonate and the residue. Calcium carbonate : 85-90% Organic matter (Conchiolin protein): 05-07% Water: 02-04% Residue: 0.1-0.8% Composition of pearl

20. Boring organisms: Boring organisms comprising polychaetes, sponges, molluscs and isopods (crustaceans) may cause considerable damage to the pearl oyster shell. Predator organisms: Predators in wild beds are mainly benthic fish which feed on young oysters below one year of age, while rays, octopods and starfish feed on adult oysters. Cymatium cingulatum and Murex virgeneus have been found to be serious predators in natural oyster beds. Usually in the culture sites crabs are the worst predators. Biofouling: Barnacles: The cirriped Balanus amphitrite is one of the major fouling organism. Heavy settlement of barnacles cause physical obstruction to the opening and closing of the oyster valves. Ascidians, Bryozoans, Molluses , Sponges and other organisms such as amphipods, hydroids algae, anthozoans, crabs, tubicolous polychaetes, Pycnogonids, and polyclad worms. Enemies of pearl culture

21. Economic importance of pearl and pearl culture Used as an ornament and a symbol of grandeur. Used in ornamental handicraft. By-Products of Pearl : The by-products of pearl culture are seed pearls, shell and flesh. Medicinal values (tiny seed pearls which are unsuitable as a gem) are used as: Use as Laxative, sedative, emetic and nutrition. Pearl powders act as an antacid. It is also used in heartburn and bilious affections. The pearl is used in formation of calcium tablets, and in allergic rection treatment. Large oyster shells are used in shell craft. Small and broken shells of oysters are used as food ingredients in poultry. The flesh of oysters is used for human consumption and feeding fishes.

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