Culture of pearl oyster

MOHD SALIM- Culturing of pearl

1. CULTURE OF PEARL OYSTER Presented by : MOHD SALIM 18BTM028 GK7985 Deptt.of botany AMU ,ALIGARH

2. INTRODUCTION Pearls are unique as the only gems produced by a living organism. These structures are secreted by the mantle (i.e., the skin) of pearl oysters in response to irritations caused by stimuli such as sand grains, molluscs eggs, parasites, detritus, and other foreign particles.

3. HISTORY Kokichi Mikimoto, in 1893 created the world’s first culture pearl by manually introducing an irritant into an oyster to stimulate it to form a pearl.

4. Tokishi Nishikawa  and Tatsuhei Mise independently learned the secret to spherical pearl production. Their discovery is commonly known as the "Mise-Nishikawa method". In India, in October 1972 , the CMFRI started a pearl culture research project at Tuticorin. Success came in July 1973 when a perfectly spherical pearl was produced.

5. TAXONOMY Kingdom: Animalia Phylum: Mollusca Class: Bivalvia Order: Pterioida Family: Pteriidae Genus: Pinctada

6. Pinctada maxima Pinctada margaritifera Pinctada fucata

7. DISTRIBUTION Japan China Vietnam Australia Indonesia Myanmar Philippines Tahiti

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9. PEARL FORMATION

10. PROTOCOL FOR MARINE PEARL CULTURE

11. Temperature ( 20 – 25 C° ) Salinity (above 30 ppt) Bottom ( Gravelly) Depth ( Optimum depth at ~ 15 m ) Good phytoplankton production Moderate water currents (I) Environmental conditions for culture:

12. (II) Selection of oysters for operation: age: above 1.5-2 years Weight > 25 g ( 40 mm) Stage of maturity spent resting stage Overall health: Good, free from infections (III) Narcotization : Narcotization of selected oysters by sprinkling menthol in the sea water.

13. (IV) Preparation of graft tissue: 2-3 mm square mantel pieces are prepared . (V) Implantation: Single implantation in the gonad near the intestinal loop. Double implantation-close to hepato-pancreas.

14. (VI) Nursing: Implanted oysters are placed in cages. Healing of operated tissue takes about 3-4 days. Dead oysters are removed. Healthy implanted oysters are transferred to culture cages and suspended at depth of about 2-3 m.  

15. On bottom culture Raft culture Rearing methods Long line culture

16. Rearing methods Raft culture : Most suitable and appropriate one to farm the oysters in the sheltered Bays. Wooden poles lashed with coir ropes and floated with the help of buoys moored by 2-4 anchors tied by means of 15 mm nylon ropes. A raft of 6 5 m is found to be more ideal for the pearl oyster culture .  

17. On bottom culture Possible only on the rocky sea bottom or artificial bottom. In an area of 100×3m,300 oyster cages can be kept . Can be appli Can be applied as a temporary means to accommodate the wild collected oysters before farming into off shore rafts.

18. Collapsible or long line raft Comprised of 16-20 empty PVC a row or 4 rows connecting one another by a chain stretched,and anchored to all the ends. Between the gaps the pearl oyster cages are suspended. Suspended cages get entangled during the rough weather and get damaged due to hitting with one another.

19. ECONOMIC IMPORTANCE Importance to cultivators Sell meat, shells, and mostly pearls. Importance to businesses provides oysters to restaurant. provides pearls for jewelry business. provides oyster shells which can be used as ornamentals. Source of employment

20. STATUS OF PEARL PRODUCTION The world trade of cultured pearl is reported to be  over  3 billion US $ per year .  India is one of the major importers of pearls importing pearls worth US $ 4 million every year.  China is the world's largest producer of freshwater pearls, producing more than 1,500 metric tons per year.

21. South sea cultured pearls Black cultured pearls Akoya cultured pearls

22. REFERANCE THE PEARL OYSTER , Paul Southgate and John Lucas. Wikipedia www.sustainablepearls.org/pearls/global-pearl-industry/ Economic zoology by R.C.SOBTI.

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