It discuss about what is pearl culture, classification, history of pearl culture, STEPS INVOLVED IN PEARL CULTURE - Construction of farm, Collection of oysters, Rearing of oysters. Preparation of the graft tissue, Insertion of nucleus, Harvesting of pearl, economic importance of pearl culture Clearing of pearls.

1. PEARL CULTURE
DR. C. BEULAH JAYARANI
M.Sc., M.A, M.Ed, M.Phil (Edn), M.Phil (ZOO), NET, Ph.D (Edn)
ASST. PROFESSOR,
LOYOLA COLLEGE OF EDUCATION, CHENNAI - 34

2. INTRODUCTION
Pearl is a white, highly shining globular
found within the shell of an oyster.
Sedentary animals.
First cultured in 1973 in Tuticorin.
Found along the coast of kanyakumari
and in Gulf of kutch.
Genus(Pinctada, Lamellidens).
“Lingha pearl”.
7/14/2021 Dr. C. Beulah Jayarani 2

3. CLASSIFICATION
• Kingdom: Animalia
• Phylum : Mollusca
• Class : Bivalvia
• Order : Ostreida
• Superfamily : Ostreoidea
• Family : Ostreidae
• Genus :Crassostrea
• Species : rhizophorae
7/14/2021 Dr. C. Beulah Jayarani 3

4. ANATOMY OF PEARL OYSTER
7/14/2021 Dr. C. Beulah Jayarani 4

5. PEARL CULTURE
• A cultured pearl is a pearl initiated by a mussel or
oyster farmer under controlled conditions using two
very different groups of bivalve mollusks - the
freshwater river mussels and saltwater pearl oysters
MOLLUSKS
7/14/2021 Dr. C. Beulah Jayarani 5

6. PEARL FORMATION
• A natural pearl (often called an Oriental pearl)
forms when an irritant works its way into a
particular species of oyster, mussel, or clam.
As a defense mechanism, the mollusk
secretes a fluid to coat the irritant such as
sand grains, mollusks eggs, parasites &
other foreign bodies. The oyster or mussel
slowly secretes layers of aragonite and
conchiolin materials that also make up its
shell it goes on until a lustrous pearl is
formed..
7/14/2021 Dr. C. Beulah Jayarani 6

7. 7/14/2021 Dr. C. Beulah Jayarani 7

8. HISTORY OF PEARL CULTURE
• The history of Japan's pearl culturing
industry started with Kokichi Mikimoto,
who dreamed of producing gem-
quality pearls using the Akoya oyster. In
1899 he started selling ornaments using
Hanen blisters for the first time and
carved out a new market in which
cultured pearls were handled as jewelry.
7/14/2021 Dr. C. Beulah Jayarani 8

9. IMPLANTATION
• Single implantation in the gonad near the intestinal loop.
• Double implantation close to hepato-pancreases.
7/14/2021 Dr. C. Beulah Jayarani 9

10. STEPS INVOLVED IN PEARL CULTURE
Construction of farm.
Collection of oysters.
Rearing of oysters.
Preparation of the graft tissue.
Insertion of nucleus.
Harvesting of pearl.
Clearing of pearls.
7/14/2021 Dr. C. Beulah Jayarani 10

11. 1. CONSTRUCTION OF PEARL FARM
Construction of a pearl farm includes three steps.
They are,
• Selection of farm site
• Construction of farm
• Well-planned work schedule
7/14/2021 Dr. C. Beulah Jayarani 11

12. CLIMATIC CONDITION FOR THE CULTURE
Temperature – 20 to 25° C
Salinity (above 30 ppt)
Bottom (Gravelly)
Depth (Optimum depth – 15 m)
Good phytoplankton production
Moderate water current
7/14/2021 Dr. C. Beulah Jayarani 12

13. NARCOTIZATION
• Narcotization of selected oysters by sprinkling Menthol in the
sea water
7/14/2021 Dr. C. Beulah Jayarani 13

14. 2. COLLECTION OF OYSTERS
From July to November, the spats are easily
available.
7/14/2021 Dr. C. Beulah Jayarani 14

15. Special type of cages
(84 ×54 × 20 cm)
7/14/2021 Dr. C. Beulah Jayarani 15

16. The divers set out to the bottom of the sea, to collect the oysters.
7/14/2021 Dr. C. Beulah Jayarani 16

17. NURSING
7/14/2021 Dr. C. Beulah Jayarani 17

18. 3.REARING OF OYSTERS
The collected oysters are
The collected oysters are
cleaned and placed in culture
cages.
10-20 days
Stocked and reared in special
type of cage called as rearing
cage.
7/14/2021 Dr. C. Beulah Jayarani 18

19. 4.INSERTION OF NUCLEUS
Following steps are done in
insertion of nucleus
a. Fitness of oyster for operation
b. Insertion of graft tissues
c. Preparation of nucleus
d. Insertion of nucleus
e. Post operation care
7/14/2021 Dr. C. Beulah Jayarani 19

20. A. FITNESS OF OYSTER FOR OPERATION
AGE: 1.5 to 2 years
WEIGHT: 25g (40mm)
STAGE OF MATURITY- spent resting stage
OVER ALL HEALTH: Good & free from infections
7/14/2021 Dr. C. Beulah Jayarani 20

21. b. INSERTION OF GRAFT TISSUE
• The piece of tissue which is
inserted inside the mantle is
called as “Graft tissue”.
• A donor oyster is sacrificed
to obtain mantle.
• 2-3 mm of square mantel
pieces are prepared
• Mantle is needed by the
host oyster to accept the
nucleus.
7/14/2021 Dr. C. Beulah Jayarani 21

22. C. THE NUCLEUS - HEART OF THE PEARL
Any small particle may function as nucleus.
7/14/2021 Dr. C. Beulah Jayarani 22

23. D. INSERTION OF NUCLEUS
STEP 1: oysters are fixed in a desk clamp position of right valve facing
upward.
7/14/2021 Dr. C. Beulah Jayarani 23

24. STEP 2: mantle folds are touched smoothly, followed by incision in
the epithelium of the foot.
7/14/2021 Dr. C. Beulah Jayarani 24

25. STEP 3: in the slender channel, one graft tissue which functions as
the bed for the nucleus.
7/14/2021 Dr. C. Beulah Jayarani 25

26. E. POST OPERATION CARE
Suspended in the floating rafts to a depth of 2 to 3 meters for about 6-7 days to
recover from the shock. This period is called as the recovery period.
7/14/2021 Dr. C. Beulah Jayarani 26

27. 4. HARVESTING OF PEARL
Pearls are harvested after 3 years of the insertion of nucleus from
December to February
7/14/2021 Dr. C. Beulah Jayarani 27

28. 5. CLEARING OF PEARLS
After taking out the pearls from the oyster shell, they are washed,
cleared with soap solution.
7/14/2021 Dr. C. Beulah Jayarani 28

29. COMPOSITION OF PEARL
• Pearl comprises of
Water 2-4%
organic matter 3.5-5.9%
calcium carbonate 90%
Residue 0.1-0.8%
7/14/2021 Dr. C. Beulah Jayarani 29

30. ECONOMIC IMPORTANCE
• 1. Importance to cultivators
Sells meat, shells & mostly pearls
• 2. Importance to businesses
• Provide oysters to restaurant
• Provides pearls for jewellery
• Provides oysters shells can be used as ornamental
• 3. Importance to employment
7/14/2021 Dr. C. Beulah Jayarani 30

31. REFERENCE
“SCIENCE READER”
 Tamil Nadu text book
 NCERT Books
7/14/2021 Dr. C. Beulah Jayarani 31