Pearl Formation

Introduction,Production of Pearls, chemical composition of Pearl, Pearls oyster and their Distribution, Stages in the pearl formation

1. KUNAL
17373016
MSc. 1
ST
Year
Taxonomy of marine organisms
Dr. T. GANESH
SUBMITTED TO SUBMITTED BY
PEARL FORMATION

2. INTRODUCTION
IT IS ALSO KNOWN AS “MOTI”.
A ROUND CONCRETION OF SKELETAL MATERIAL.
BIOCHEMICAL PRODUCT OF MOLLUSC.
ONLY GEM PRODUCED BY THE LIVING ANIMALS.
HIGHLY SHINING GLOBULAR IN SHAPE.
PEARL CONSISTS OF A CENTRAL NUCLEUS SURROUNDED BY A SERIES OF
PEARLY NACREOUS MATTER.
NACRE/MOTHER-OF-PEARL IS A SHINY,HARD PEARLY IRIDESCENT SUBSTANCE
FORMING THE INNER LAYER OF A MOLLUSC SHELL.
SHELL CONSISTS OF 3LAYERS, NAMELY AN OUTER ORGANIC LAYER OF
CONCHIN AND TWO INNER CALCAREOUS LAYERS

3. PRODUCTION OF PEARLS
NATURAL WAY
NATURALPEARLSAREFORMED
DUETONATURALPROCESSESOR
DISTURBANCES IN THE
ENVIRONMENWHERETHEOYSTER
LIVES.
ARTIFICIAL WAY
ARTIFICIALLYINDUCING THE
MOLLUSCTOSECRETENACREOUS
MATTERAROUNDANINSERTED
NUCLEUS.ITISPRODUCEDBY
HUMANINTERFERENCEANDIS
KNOWNASCULTUREDPEARL.CHIEF
IMITATIONSMADEOFPLASTICS
THATHAVEAARTIFICIALLUSTREARE
KNOWNASARTIFICIALPEARL.

4. CHEMICAL COMPOSITION OF PEARL
1.WATER -3.97%
2.ORGANIC MATTER -3.83%
3.ALCITE & ARAGONITE -91.53%
4.LOSS -0.67%
QUALITY OF PEARL IS DETERMINED BY ITS KERATIN CONTENT AND COLOR. THE
LATTER IS INFLUENCED BY THE COLOR OF THE SHELL OF DONOR MOLLUSCFROM
WHICH PALLIUM (Graft-tissue) HAD BEEN TAKEN AND THE PART FROM WHERE
IT IS EXTRACTED AND IMPLANTED.

5. PEARL OYSTERS AND THEIR DISTRIBUTION
1. Pinctadaanomioides–Bombay, Madras Harbour, Andaman.
2. P. atropurpurea–Madras Harbour, Andaman.
3. P. chemnitzi-Madras Harbour, Palk Bay.
4. P. fucata–Common indianpearl oyster, Gulf of Kachch.
5. P. margaritifera–Common in Andaman and Nicobar.
6.P. sugillata–Gujarat, Tuticorin, Andaman.

6. STAGES IN THE PEARL FORMATION
1. PREPARATION OF HOST SHELL
2. NUCLEUS INSERTION
3. CONVALESCENCE
5.HARVESTING
6.PROCESSING OF PEARLS
4. PEARL FORMATION
Fig.Removingtheoystersfrom
theirshell.

7. PREPARATION OF HOST SHELL
IN NATURE PEARLS MAY BE FORMED IN DIFFERENT REGIONS OF THE BODY NAMELY THE REGION OF ADDUCTOR
MUSCLES, MANTLE MARGIN, PALLIAL ZONE.
THE BEST SITE FOR PEARL PRODUCTION IS CONSIDERED TO BE THE GONADIAL REGION,SPENT INDIVIDUALS
(individuals whose gonads are devoid of gametes) SERVES AS GOOD HOSTS.
NUCLEUS IS INSERTED IN THE GONADIAL REGION.

8. NUCLEUS INSERTION
IT INVOLVES SELECTION OF A SUITABLE DONOR SHELL OR ANY OTHER OBJECT FOR OBTAINING THE NUCLEAR
MATERIAL AND DONOR OYSTER OR MUSSEL FOR OBTAINING GRAFT TISSUE.
THE SIZE OF THE NUCLEUS DETERMINES THE SIZE OF THE GRAFT TISSUE.
AFTER OBTAINING THE NUCLEUS AND GRAFT TISSUE THE RECIPIENT OYSTER WILL BE OPERATED UPON AND THE
NUCLEUS IS IMPLANTED IN THE GONADIAL REGION.
THE TIME AND NUMBER OF NUCLEI TO BE IMPLANTED WILL BE DETERMINED IN ADVANCE.

9. CONVALESCENCE (PERIOD OF TIME SPENT HEALING)
AFTEROPERATIONTHEMUSSELAREALLOWEDTOBERECOVERFROMTHEDISTURBANCECAUSED.
THEOYESTERAREKEPTINCAGES.
PEARL FORMATION
THEGRAFTTISSUEONTHENUCLEUSGROWSINTOAPEARLSAC.
THEEPITHELIALCELLSOFTHEPEARLSACDEPOSITNACREOUSLAYERAROUNDTHENUCLEUS,WHICHULTIMATELY
LEADSTOTHEFORMATIONPFAPEARL.
INPEARLOYSTERSITTAKESTO3-4YEARSOFCOMMERCIALVALUETODEVELOP.
INFRESHWATERMUSSELPEARLSAREHARVESTED2-3YEARSAFTERIMPLANTATION.

10. HARVESTING
OYESTERSORMUSSELSWITHPEARLSARE
BROUGHTTOTHELABORATORY.THEVALVES
AREOPENEDANDTHEFLESHYPARTSARE
EXTRACTEDOUT.THEPEARLSARE
OBTAINEDBYPULVERISINGTHEEXTRACTED
PART.
PROCESSING OF PEARLS
SOON AFTER THEIR SEPARATION FROM THE MEAT, PEARLS ARE WASHED WITH WATER TO
REMOVE THE MUCILAGINOUS MATTER AND MAINTAIN THE LUSTER. THE PEARLS ARE THEN
GRADED ACCORDING TO SIZE.

11. REFERENCEs
1.N.V. Subba Rao.,Records of the Zoological Survey of india, Indian seashells
2.Rebecca stott, Oyster
3.R.L. Kotpal, Invertebrates zoology
4. www.google.com