Pearls, one of the highly esteemed gems, are very valuable due to the high demand and
prices for them. Several countries bordering the Indian and Pacific Oceans and some
countries along the Eastern Atlantic Ocean have pearl oyster resources. Many of these
countries, particularly those in Asia, are very much interested in pearl oyster farming and
pearl culture. Japan stands foremost in the two fields having developed technologies and
innovations in the field.
The techniques of pearl oyster farming and pearl culture are not widely known. There is a
need to promote more widely the techniques and relevant information on the bionomics of
In India, interest in pearl culture began at the start of this century. Several studies have been
conducted by the Madras Fisheries Department in the 1930s. In 1972, the Central Marine
Fisheries Research Institute (CMFRI) took up intensive research on pearl culture at Tuticorin
achieving a breakthrough in July 1973 when it produced free spherical cultured pearls by
employing the mantle graft implementation technique. Since then intensive research has
been carried out by the Institute on pearl formation, pearl oyster biology and ecology, and
hatchery techniques for production of pearl oyster seed. Considerable information of applied
value has been obtained.
The development of the pearl oyster hatchery technology in India in 1981 opened the way
for large and commercial scale culture of this bivalve species. Based on the technical know-
how provided by the CMFRI, a company has been established at Tuticorin to produce
In view of the keen-interest shown by countries in the region, the FAO/UNDP Regional
Seafarming Development and Demonstration Project (RAS/90/002) requested the Indian
Council of Agricultural Research (ICAR), New Delhi to conduct a training programme on
“Pearl Oyster Farming and Pearl Culture” at the Central Marine Fisheries Research Institute
in Tuticorin, to train personnel from different countries. In line with this training course, this
training manual was prepared. This manual deals with various aspects of pearl oysters, pearl
oyster farming, pearl production technology, etc.
Pearls have been known to mankind since the beginning of civilization. They are highly
esteemed as gems for their beauty and splendour. These structures are secreted by the
mantle (i.e., the skin) of pearl oysters in response to irritations caused by external or internal
stimuli such as sand grains, molluscs eggs, parasites, detritus, and other foreign particles.
Many attempts have been made to culture pearls in freshwater mussels. In the 13th century
the Chinese fixed small Buddha figures inside freshwater mussels which became covered
with a pearly layer. After considerable perseverance and study on the mode of pearl
formation, success was achieved early in this century in Japan on the production of spherical
cultured pearls. The Japanese grafted a piece of mantle with a small bead in a pearl oyster
and reared the oyster in protected coastal waters with favourable environmental conditions.
India has one of the highest demand for pearls for setting in jewellry, and is particularly
famous for its pearl oyster resources which yield superb pearls. The pearl oyster fisheries
are located in two main areas: 1) in the Gulf of Mannar off Tuticorin coast and 2) in the Gulf
of Kutch on the northwest coast of the country. The pearl oysters are found in two different
environments in the two localities, at depths up to 23 meters in the Gulf of Mannar, in the
intertidal zone in the Gulf of Kutch. These bivalves form large beds on hard substrata in the
Gulf of Mannar, while they are sparsely distributed in the Gulf of Kutch. The pearl oyster
resources in the two areas have been fished for pearls until the early 1960’s.
After surveying the pearl oyster resources and fisheries in the two Gulfs at the beginning of
the century, Hornell (1916) recommended that in order to maintain pearl fisheries profitably it
was necessary to develop techniques to induce the Indian pearl oysters to form pearls by
artificial means. In response, the then Madras Government Fisheries Department carried out
preliminary research at the Marine Biological Station in Krusdai Island, Gulf of Mannar.
Research focused mainly on the biology and ecology of several species. The oysters were
reared in cages and induced to form pearls. That work managed to produce only two poorly
shaped pearls and a half-pearl attached to the shell. Efforts in Gujarat did not meet success
In October 1972 the Central Marine Fisheries Research Institute started a pearl culture
research project at Tuticorin. Success came in July 1973 when a perfectly spherical pearl
was produced. This breakthrough was achieved by introducing a graft of the oyster mantle in
the gonad of an adult specimen together with a shell bead nucleus. This is a delicate
Following this success an Ad-hoc Research Scheme on pearl culture under the Indian
Council of Agricultural Research (ICAR) was implemented (from 1973–78) by the CMFRI in
association with the Department of Fisheries, Government of Tamil Nadu. During this
Research Scheme, production of cultured pearls by multiple implantation was successfully
achieved. Several aspects of pearl formation and pearl oyster biology and ecology — highly
important for successful pearl culture — were investigated.
The CMFRI also succeeded in artificially spawning Pinctada fucata, rearing of larvae, and
producing seed in the laboratory by hatchery techniques. This breakthrough is very
important in light of the difficulty in obtaining sustained supplies of oysters from natural
banks for culture purposes. Recently the CMFRI also produced seed of the black-lip pearl
oyster, Pinctada margaritifera which produces the highly valuable black pearl.
To follow-up on the development of pearl culture technology, the Tamil Nadu Fisheries
Development Corporation and the Southern Petro-chemical Industries Corporation Ltd.
established in 1983 a company to produce cultured pearls, with the farm at Krusadai and the
nucleus implantation centre at nearby Mandapam. Since then other companies have
became interested in taking up pearl culture on a commercial scale.
The CMFRI is making efforts to promote the pearl culture technology by conducting short-
and long-term training programmes. Scientific and technical personnel from fisheries
institutes in all of the maritime states as well as from the Fisheries Faculties of Agricultural
Universities are given the opportunity to be trained in these programmes.