Pearl Culture Specialist
For the project Fresh Water Pearl Culture
FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS
Note to Readers:
This Manual was prepared for the purpose of giving information to individuals who would like to engage in pearl culture. The requirements needed for the establishment of a farm are mentioned as well as procedures for the operations. Some illustrations are also presented.
Bangladesh is famous for natural pink pearls, locally known as “mukta”. They are collected from a species of freshwater mussels which are found in abundance in inland bodies of water such as lakes, rivers, ponds and dams. The river gypsies, people who live in houseboats, collect them for the shells which are converted into lime (lime is an ingredient in chewing beetle nuts, which is very popular in Bangladesh). Occasionally, natural pearls are collected and are sold in jewelry and novelty shops in Dhaka and other large towns throughout the country. These pearls are beautiful, with a deep lustre and are expensive. They are commonly termed as pink pearls, although the actual colour is golden.
In Bangladesh, most of the families, especially in the villages, own ponds near their houses which are used for domestic purposes, such as washing clothes, bathing, as a source of drinking water, and also for cultivating fish. On the bottom of these ponds, mussels can be grown for pearls, thereby providing an additional source of income for the families.
Pearls can be classified into three categories: natural, cultured and artificial. Artificial pearls are manufactured in the factory and are not a product of living oysters or mussels. They may be plastic, processed in a way that makes them shiny like natural pearls. They may also be made of rounded material such as glass or plastic, then painted with pearl essence, a silvery extract made from fish scales.
There is little difference between natural and cultured pearls because both are made of calcium carbonate and produced as a secretion of living oysters. The only difference is that natural pearls are formed by accident when a foreign material, such as a grain of sand, enters the oyster and settles on the fleshy part of the body. The tendency of the oyster, if a foreign body enters, is to spit it out, but when not able to do so, especially when embedded, will coat it with pearl secretion to lessen irritation. This results in the formation of natural pearls. As natural pearls are formed by accident, they are rare.
Cultured pearls, however, are produced by inducing the oysters to produce pearls. It was the Japanese who perfected the technique of producing cultured pearls.
In order to undertake the culture of pearls, there are four necessary requirements: a culture area, mussels, instruments and irritants or nuclei.
The site where the mussels will be cultured can be a pond or a portion of a lake, river, irrigation canal or dam. In Bangladesh most facilities own ponds near their dwellings, as mentioned previously and these ponds are good sites for culturing pearls.
There are two genera of pearl mussels in Bangladesh: Lamellidens and Perreysia. From a survey undertaken in 1982, of the various districts in Bangladesh, two species of Lamellidens were identified: Lamellidens marginalis and L. jenkinsianus var. obesus (Hanley and Theobald), while five species of Perreysia were observed: the Perreysia daccaensis (Preston), P. wynegungaensis (Lea). P. (Radiatula) pachysoma (Benson), P. favidens var. assamensis (Preston) and P. favidens var. deltae (Benson). The mussels are commonly called “Jhinuk” a term applying to various shell types.
Of the above species, the one used for pearl culture should be Lamellidens marginalis, for two reasons. First, due to its size (the mature ones range from 7 to 10 cm, measured from anterior to posterior end), it is suitable to operate on. Perreysia are smaller so they would be difficult to operate on. Second, they are common in most inland bodies of water.
To operate on the mussels for culturing pearls, the following special instruments are needed:
Shell Opener: Made of stainless steel. When the handle is pressed, the end opens. This is used to pry open the shells of mussels and prevent them from closing prior to the introduction of nuclei and grafts.
Graft Cutter/Knife: Made of flat stainless steel and used in the preparation of graft tissues made from the mantle of the mussel.
Incision Knife: Made of stainless steel with a plastic handle. It has a rounded, flat sharp tip which is used to make slits on the gonad, through which the nucleus and graft tissues are inserted.
Nucleus Carrier/Lifter: Similar to the incision knife except that the tip is cup-shaped. It is used to carry or lift a piece of nucleus/irritant for insertion into the gonad. In doing so, the tip should first be wet with water, which due to surface tension (a physical property of water), will enable the instrument to lift the nucleus.
Graft Carrier/Lifter: Also similar to that of the incision knife and nucleus lifter except that the tip is pointed. By pricking and lifting a piece of the mantle tissue, it is used to insert the tissue inside the gonad.
Spatula with a hook: Made of stainless steel with a flat end. It is used to lift the gills of a mussel to allow an unobstructed view of the body prior to the operation. The hook is used to hold the foot when making an incision during the operation.
Mussel Holder: A wooden block ( 10 × 10 × 18 cm ) with a large ordinary paper clip fitted on the end. This holds the mussel to be operated on in place.
Pinchers: An ordinary pincher which is used in the preparation of graft tissues, as in picking up the cut/detached mantle from the mussel.
Graft Cutting Board: A wooden block ( 3 × 10 × 15 cm ) used in cutting the mantle to a desired size and shape.
Wooden Peg: Made of wood (an ordinary pencil cut to size) 0.7 cm in dia and 3.5 cm long. It is placed between the shells of the mussel, after it has been opened by the shell opener, to prevent the shells from closing during the operation.
Miscellaneous Equipment: Other items needed during the operation include basins, trays, rubber sponges, dishes and bowls.
With the use of nuclei or irritants, the pearls can be produced in a shorter culture period as they start from larger material than is naturally found. The best material for nuclei would be made of shell as it has the same composition as that of pearls. Shell nuclei are available in Japan in sizes ranging from 3 to 10 mm, but there are constraints in importing these. Manufacturing them locally is not advisable due to the non-availability of both the equipment for processing and the thick shells used as raw material.
For the culture of pearls, substitute material can be used. Round beads made of ceramic are available at factories in Dhaka. The size should range from 2 to 4 mm for the average local mussel and not any larger. Ceramic is a good substitute nuclei as it has almost the same weight as that of a pearl.
Other materials, such as sand can also be used. The smooth type of sand should be selected. Round objects for nuclei can also be formed out of either ordinary or white cement. When using these they should first be thoroughly dried for several days.
In pearl culture, the technique lies in the use of graft tissue and a nucleus. Graft tissue is a portion of the mantle, which is the part of the mussel which produces the shell. When a portion of this mantle is taken and grafted inside the body of the mussel, it will live by connecting itself on the wall of the organ where it was introduced. It will receive nutrition from there and function as part of the mantle which is secreting shell substance or calcium carbonate and coating the nucleus inserted. This results in a cultured pearl. The graft tissue may also be introduced on the mantle itself to produce seed pearls.
The suitable sites for pearl culture in Bangladesh are the lowland areas such as Sylhet, Mymensingh and Dhaka. The advantage of lowland areas is that water is not a problem, even during the summer months.
Pearl culture can be undertaken in ponds, portions of lakes, rivers, irrigation canals or dams. A pond, as a culture site, will have an advantage as it can easily be controlled as can the condition of water. For the purpose of this manual, the pond will be mentioned as the culture site. In using portions of lakes, rivers, irrigation canals or dams, the area should be fenced, so that the mussel can crawl on the bottom and throughout the area.
The following are factors to be considered in selecting the site for pearl culture:
Presence of mussel stock - The site should have a good stock of thriving mussels, this being a good indication that the area is suitable for pearl culture.
Good sources of water - The site should have sufficient water supply, even during summer, that can be tapped whenever necessary.
Water level - The mussel prefers shallow areas and is usually found in knee-deep waters. A range of 0.5 to 1 m of water level is necessary throughout the culture period.
Protection from flood - The area should be protected from floods as the mussels could be carried away. The area should not have a water level of more than 2 m. Mussels naturally migrate to shallower areas during flooding.
Free from pollution - Culture sites should be free from pollution, such as the industrial waste of factories or tanneries. Polluted water adversely affects the mussels.
Free from the influence of saline water - Areas near the coast which may be affected by the influence of tides coming from the Bay of Bengal, should not be selected. Saline water is detrimental to the life of the mussels.
If the site has no stock of mussels or if the quantity is not sufficient, it will require gathering from other sources. Gathering is not difficult as the mussels are found in shallow areas (usually knee-deep) of ponds, rivers, lakes, irrigation canals and dams. When a gatherer steps on the mussels while wading, their presence can easily be felt, as they are only partly embedded in the sand or mud bottom, and they can be collected. Gathered mussels are then transferred to the culture site.
A place should be prepared for conducting the operations. It can be inside the house or outside in the open. It should be as close as possible to the culture site to simplify work activities. A table and a chair are needed to assure the comfort of the pearl technician while operating on the mussels. Trays, pans and buckets are also needed and a container of mussels and the necessary instruments should be ready.
Mussels are brought up from the pond and placed in trays on top of the table. They should be arranged with the ventral side facing up so that when they gape, the opener can be inserted into the mussel to open it prior to the operation.
There are two methods of operating on mussels described in this manual which are applicable to the local freshwater mussels. They are the operations using the gonad for round pearls and the use of the mantle for seed pearls.
The mussel to be used as graft should be properly selected; it should be young and healthy. The two mantles of one mussel will be sufficient for use in operating on 10 to 15 mussels.
To prepare the graft tissues, one mussel will be opened to remove its mantles. This can be done by slipping the pointed, narrower end of the graft knife between the shells to cut the adductor muscles (anterior and posterior). With the shells widely opened, the two mantles can then be cut and separated from the body of the mussel and placed on a wooden board. The slimy fluid on the mantle should be wiped off with a wet synthetic sponge. They should be divided into long strips by cutting or eliminating the outer margin of the mantles which produce the prismatic layer of the shells. They are then cut into 2 to 4 mm squares and are ready for use as graft tissues.
The mussels to be operated on are on trays in water. The end of the shell opener should be inserted into a gaping mussel while the handle is pressed to open the shells approximately 7 mm wide. A wooden peg should be placed between the shell valves and the shell opener removed. With the use of a spatula, the right gills should be lifted up and the left gills pressed down to allow a clear view of the viseral mass. If the body is thin or the gonad full of eggs or sperm, the mussel should be rejected and not operated on and should be returned to the pond to recover. Weak ones, if operated on, will have a lesser chance of surviving the operation, while in those with a full gonad, the graft tissue and nucleus that are inserted may flow out with the gonadal fluid that oozes out during operation.
After the healthy one is selected, the mussel is placed in the holder. With the spatula and hook in the left hand, the foot of the mussel is held in position with the hook for easy manipulation, so that the body will not move. With the incision knife in the right hand, make a cut at the base of the foot toward the gonad, to cut its wall. A piece of graft tissue is then picked up by the graft carrier and inserted inside the gonad through the slit. Using a nucleus carrier, pick up a piece of nucleus and insert in the gonad through the same slit, so that it is in contact with the graft tissue previously inserted. Another incision can be made for the introduction of a second nucleus and graft tissue. The operation is then completed and the mussel is taken out of the holder, the wooden peg removed and the mussel placed on a tray with water. The same procedure is used for the succeeding mussels. After operating on a sufficient quantity in a day, the mussels in the tray can be returned to the pond for recuperation.
Pearls can be grown on the mantle of the mussels. This method has been practised in China and Japan using their freshwater mussels (Anodonta sp. Cristaria plicata). Only pieces of graft tissues were inserted between the layers of the mantle, without any nucleus or irritant. The graft tissue will easily become attached to the mantle, while a nucleus if inserted will be expelled.
The following is the procedure for operating on the mantle of mussels for seed pearls:
First, the graft tissues should be prepared (the same way as when used in the operation of the gonad). Insert the end of the shell opener into the gaping mussel to make a 7 mm opening. Insert a wooden peg between the shells to prevent them from closing and remove the shell opener. Place the mussel in a holder. With the use of a spatula, push the gills upward for a clear view of the lower mantle lobe. Then, with the use of the incision knife, make slits on the mantle, taking extra care not to cut through the other side. The mantles are usually bulging due to the presence of a watery fluid, so when slit, fluid will ooze out. Two to three slits can be made on the mantle. Using the graft carrier, insert one mantle tissue in each of the slits. Turn the mussel in the holder upsidedown so that the other mantle can be operated on. Repeat the procedure for this mantle.
For operating on two mantle lobes, four to six graft tissues may be inserted in one mussel. In some mussels, especially if the size is large, it may be possible to insert up to ten graft tissues in one mussel. The use of larger sized graft tissues is preferable as pearls will develop faster and the culture period will be shorter. It will be difficult, however, to insert these larger-sized graft tissues and the expulsion or rejection rate of the tissues will be higher.
The graft tissue will join with the inner epithelial cells or with the connective tissue between the external and the internal epithelial cells of the mantle. This will have the same function as when it is part of the mantle, and will therefore secrete the shell substance or calcium carbonate and eventually result in seed pearls. In China and Japan, the seed pearls grown on the mantle are commonly called rice pearls due to their rice-like shape.
Each mussel operated on should be properly marked by etching a coded letter and number on the outer shell to identify the person who operated on it and the date of the operation. For example, the mussels operated on by Mrs Momtaz Begum in April 1986 will be marked 4M6 - 4 for April, M for Momtaz and 6 for 1986. This marking is important in recording and estimating the probable date of harvest.
After the operation is completed, the mussel operated on should be returned to the pond as soon as possible. To determine if the operation was successful, the mussels should be placed in a cage for observation. The cage can be made out of wood with netting on the sides, the size depending on the quantity of mussels (Figure 5). The mussels move or crawl on the pond bottom to seek a suitable place to burrow. The cage will prevent them from spreading throughout the pond, making it easier to locate them during inspection, which is done after one or two weeks. During inspection, the mussels should be collected from the cage, brought up and the dead mussels (mortality due to the operation) separated from the surviving ones. They should be properly counted and recorded and after the live mussels should be returned to the pond for culturing.
Extreme care should be practised to minimize mortality during the operation. Following are suggestions to minimize the mortality rate of mussels operated on:
Mussels die whenever a vital organ is damaged during operation. Vital organs include intestines, the stomach, the liver or kidney. These organs are adjacent to the gonad, where the nucleus is inserted. One way to avoid touching them is to insert the nucleus in the gonad as close as possible to the base of the foot.
Forcing the mussels to open the shells during operation can damage the adductor muscles. Only gaping mussels should be opened for operation. Opening of the shells should be done gently by pressing the shell opener. If the shell is tightly closed, the mussel should not be opened.
Opening the shells of the mussels too wide can damage the adductor muscles, causing mortality. Shells should not be opened more than 7 mm wide.
Weak or thin mussels should not be operated on as they will probably not survive the operation; instead, healthy ones should be selected.
As experienced in foreign countries, mortality is higher when using larger-sized nuclei. The size of nuclei to be used must be proportionate to the size of the gonad.
The mussels can expel or spit out the foreign body introduced. The following are procedures to minimize the expulsion of nuclei or graft tissues:
The freshwater mussel crawls along the pond bottom by using its protruding foot. In so doing, the body is somewhat compressed and the nucleus inserted inside the gonad may be expelled. Also, the nucleus may be emitted through the wound opening made during the operation, or the nucleus may come out if the skin gives way. As experienced in the pilot pearl farm in Mymensingh, this expulsion rate can be minimized by inserting the nucleus deep inside the gonad, almost reaching its other side (Figure 6).
Another cause of expulsion of the nuclei is when the mussel to be operated on has a gonad full of eggs or sperm. When making a slit on the gonad for insertion of the nucleus into a mussel with a full gonad, fluid will ooze out. Nucleus and graft tissue may be carried out in this way immediately after the operation. Mussels with full gonads should therefore be rejected and returned to the pond, to be operated on only after they have undergone spawning.
The mussels operated on are cultured in ponds which takes from two to three years. Therefore it is necessary to maintain the ponds in suitable condition. Submerged and floating plants should not be allowed to grow in abundance as they will impede penetration of the light thereby diminishing the plankton content of the water. Plankton, whether plants or animals, are an important food of mussels. They are strained together with other organic matters by the gills of the mussels and taken in as food. The plankton content of water can be increased through the application of fertilizers, either organic or chemical.
During dry months, water levels usually go down due to evaporation. Water loss should be replaced by pumping water from the ground, river or other ponds.
The pearls can be harvested after two to three years of culture depending on the quality of pearls desired and the size of the nuclei inserted. The longer the culture period, the better the quality of pearls.
It is necessary to make a trial harvest to determine whether the pearls have a sufficient coating. If it is not sufficient then an additional six months to a year of culturing is necessary.
To harvest pearls, the mussels should be brought up from the bottom of the pond. Each one has to be opened by cutting the adductor muscles and exposing the body. The gonad of the mantles (whichever was operated on) is then inspected for pearls. Collected pearls should be thoroughly dried after the harvest to prevent loss of lustre.
Fig. 1 Freshwater Mussel - Lamellidens marginalis
Fig. 2 Instruments for Pearl Culture
Step 1 - Make slits on the gonad near base of foot
Step 2 - Insert graft tissues and nuclei inside gonad
Fig. 3 Culture of Pearls inside the Gonad
Step 1 - Make slits on the mantle
Step 2 - Insert graft tissues inside the mantle
Fig. 4 Culture of Seed Pearls inside the Mantle
Fig. 5 Wooden Cage for Pearl Culture
Fig. 6 Diagram showing the correct location of inserted nucleus and graft tissue
Fig. 7 A model Pearl Culture Farm
In keeping with the desire of the Government to develop its fishery resources, a project on pearl culture was planned and implemented by the Aquaculture Experiment Station (AES) now Freshwater Aquaculture Research Station (FARS), Mymensingh, with the assistance of the Food and Agriculture Organization (FAO). Project TCP/BGD/2308 was implemented for one year, from 10 March 1984 to 9 March 1985. As a follow-up project, TCP/BGD/4508 was started on 25 August 1985 and continued until 24 August 1986.
With the prospect of pearl culture as an income-generating industry in the rural areas, a training programme is planned. Pearl mussels abound in the bodies of freshwater in Bangladesh and each rural family usually owns a small pond adjacent to their dwellings. These ponds are now being used for domestic purposes as well as for growing fish; the bottom of these ponds could be utilized for pearl culture.
The purpose is to train rural families/individuals in pearl culture. Once the technique is learned, pearl culture can be a small family undertaking and this can generate additional income to the rural families.
The training will concentrate on the practical application of the technique. A brief lecture on the biology of mussel and pearl culture techniques will be given, field visits will be made to culture ponds and natural grounds, and time will be devoted to the actual operation on mussels in the laboratory.
B. Training Plan/Programme in Pearl Culture for Rural Farmers
Purpose - To train individuals/rural farmers in pearl culture techniques.
Implementing Agency - Freshwater Aquaculture Research Station (FARS), Mymensingh.
Cooperating Agency - Fishery Advisory Services Project (Pearl Culture Project, TCP/BGD/4508), FAO Dhaka
Participants/Trainees - Rural Farmers 1 (preferably women)
Number of Participants - 15 persons/group
Training Site - FARS Building, Mymensingh
Training Dates - 15–19 June 1986
Programme Duration - Five days
Hours - 10.00 h to 14.00 h daily
Staff Support - Mr Abdul Bazak, Field and Laboratory Aide
Mr Bellal Hossain, Field and Laboratory Aide
Mr Abul Kalam, Driver
1 See qualifications of participants
Working lunch provided for participants and trainers
SCHEDULE - Training on Pearl Culture for Rural Farmers
15 June 1986
09.00 – 10.00 h - Registration of Participants
10.00 – 10.15 h - Opening remarks, Dr Md. Saifuddin Shah, CSO, Training Coordinator
10.15 – 10.30 h - Short talk, Dr Asadur Rahman, Director FRI
10.30 – 10.45 h - Short talk, on training schedule, Mrs Nurun Nahar Begum
10.45 – 11.00 h - Tea break
11.00 – 11.30 h - Lecture on the Biology of Mussels, University Professor
11.30 – 14.00 h - Lecture on Pearl Culture, Mrs Nurun Nahar Begum
- Tour of laboratory/pond with Support staff, Trainer
16 June 1986
10.00 – 11.00 h - Demonstration in Pearl culture - Mrs Nurun Nahar Begum
Mrs Momtaz Begum
Mrs Jahirul Islam
11.00 – 14.00 h - Actual training in Pearl culture Laboratory work - Mrs Nurun Nahar Begum
Mrs Montaz Begum
Mr Jahirul Islam
17–18 June 1986
10.00 – 14.00 h - Actual training in Pearl culture - Mrs Nurun Nahar Begum
Mrs Montaz Begum
Mr Jahirul Islam
19 June 1986
10.00 – 10.30 h - Short talk, Mrs Nurun Nahar Begum
10.30 – 11.00 h - Short talk, Response of participants (to be selected)
11.00 – 11.30 h - Short talk, Dr Md. Asadur Rahman, Director FRI
11.30 – 12.00 h - Closing remarks, Dr Md. Saifuddin Shah
Consultant - R. Pagcatipunan
Pearl Culture Specialist, FAO
Principal Counterpart - Dr A.K.M. Nuruzzaman
Chief Scientific Officer
Fisheries Aquaculture Research Station
Working Counterparts - Mrs Momtaz Begum, Scientific Officer
Mrs Nurun Nahar Begum, Scientific Officer
Mr Jahirul Islam, Research Officer
All assigned to the Fisheries Aquaculture Research Station, Mymensingh
Terms of Reference:
Under the general supervision of the Senior Fishery Adviser of BGD/81/034, the Pearl Culture Specialist will be responsible for training and transfer of techniques of pink pearl culture on a scientific basis. He will prepare a manual on the culture of pink pearls in Bangladesh.
Duration - One year from 24 August 1985 to 23 August 1986
Preparation of tentative work plan/schedule. The consultant, working with the government counterparts, will prepare the work plan for implementation in one year.
Laboratory preparation. For use in the operation of mussels to produce pearls, a laboratory will be prepared, complete with equipment, furniture and other facilities.
Pond preparation. Ponds will be used for the culture of mussels operated on and for the rearing of newly-collected specimens. These ponds need to be prepared by: cleaning the sides and bottom of weeds and grasses, supplying with water, settling suspended matter and silt by the application of lime and fertilizing to produce plankton which is the food of mussels.
Collection of mussels. Mussels will be collected from ponds and pools at the University area. Others will be collected from outlying lakes when supply at the University area is exhausted. Collected mussels will be stocked in ponds for acclimation/growth until they are operated on.
Operation of mussels for pearl production. Matured or operable-sized mussels will be taken from the stock pond and brought to the laboratory for operation. Each mussel has to be opened slightly for insertion of irritants and graft (mantle piece). The graft will develop into a sac enclosing the irritant and secreting the pearl substance to coat or be deposited on the irritant.
Care of mussels. Mussels operated on will be returned to the pond for observation. In a week, the dead mussels (mortality due to the operation) will be separated. Surviving mussels will be stocked in a prepared pond for culturing until harvest. The pond should be properly managed and maintained to ensure the growth of the cultured pearls.
Training of counterparts on the technique of pearl culture. The government counterparts will be trained in the proper procedures for insertion of irritants and grafts and on the care after the operation. To learn the technique will require the practice of performing operations, so a large quantity of mussels should be operated on regularly by each pearl technician.
Training of interested individuals in pearl culturing. Private individuals will be trained on a regular basis beginning February 1986.
Trial harvest of pearls. Pearls will be ready for harvest after two to three years of culture. To evaluate or assess the progress of the project a trial harvest will be undertaken in July 1986.
Oyster culture. The consultant will also assist and advise the Directorate of Fisheries in the programme of oyster and mussel culture at Cox's Bazar.
Writing of the report and manual for the culture of pearls in Bangladesh.
Submitted and signed by:
Pearl Culture Specialist
Noted and signed by:
Dr A.K.M. Nuruzzaman
Chief Scientific Officer/counterpart
Approved and signed by:
Prof P.C. George
Project Manager/Senior Fisheries Adviser
|1985||25 August||-||Arrival in Dhaka|
|26 August-4 September||-||Dhaka, FAO Office|
|5–10 September||-||Mymensingh - Pearl Culture Project|
|11–14 September||-||Dhaka, FAO Office|
|15–27 September||-||Mymensingh - Pearl Culture Project|
|28–30 September||-||Dhaka, FAO Office|
|1–21 October||-||Mymensingh - Pearl Culture Project|
|22–27 October||-||Dhaka, FAO Office|
|28 October-12 November||-||Mymensingh - Pearl Culture Project|
|13–15 November||-||Dhaka, FAO Office|
|16–24 November||-||Mymensingh - Pearl Culture Project|
|25 November||-||Dhaka, FAO Office|
|27–29 November||-||Cox Bazar Oyster Farm|
|30 November-2 December||-||Dhaka, FAO Office|
|3–20 December||-||Mymensingh - Pearl Culture Project|
|21–22 December||-||Dhaka, FAO Office|
|23–24 December||-||Mymensingh - Pearl Culture Project|
|24–27 December||-||Dhaka, FAO Office|
|28–30 December||-||Mymensingh - Pearl Culture Project|
|1986||31 December-2 January 1986||Dhaka, FAO Office|
|3–13 January||-||Mymensingh - Pearl Culture Project|
|14–15 January||-||Dhaka, FAO Office|
|17–21 January||-||Cox Bazar Oyster Farm|
|23 January-3 February||-||Mymensingh - Pearl Culture Project|
|4–5 February||-||Dhaka, FAO Office|
|6–17 February||-||Mymensingh - Pearl Culture Project|
|18–19 February||-||Dhaka, FAO Office|
|20 Febaury-2 March||-||Mymensingh - Pearl Culture Project|
|3–4 March||-||Dhaka, FAO Office|
|5–13 March||-||Mymensingh - Pearl Culture Project|
|14–15 March||-||Dhaka, FAO Office|
|16 March-18 April||-||Mymensingh - Pearl Culture Project|
|19–20 April||-||Dhaka, FAO Office|
|21 April-19 May||-||Mymensingh - Pearl Culture Project|
|20–22 May||-||Dhaka, FAO Office|
|23 May-20 June||-||Mymensingh - Pearl Culture Project|
|21–22 June||-||Dhaka, FAO Office|
|23 June-7 July||-||Mymensingh - Pearl Culture Project|
|8–9 July||-||Dhaka, FAO Office|
|10–17 July||-||Mymensingh - Pearl Culture Project|
|18–19 July||-||Dhaka, FAO Office|
|20–30 July||-||Mymensingh - Pearl Culture Project|
|1–5 August||-||Dhaka, FAO Office|
|6–8 August||-||Cox Bazar Oyster Farm|
|9–23 August||-||Dhaka, FAO Office|
|24 August||-||Depart Dhaka for Manila via Bangkok|
Mr L.I.J. Silva - Ex-FAO Representative, Bangladesh
Mr J.A. Hoskins - FAO Representative, Bangladesh
Ms Shireen Lutfunnessa - Project Assistant, FAO Fisheries
Dr V. Zon - Project Manager, BGD/83/010
Dr M.V. Gupta - Aquaculture Expert
Prof P.C. George - Project Manager, BGD/81/034
Dr A.N. Ghosh - Shrimp Culture Expert
Mr F. Rajts - Fish Breeding Specialist
Mr T. Shimura - Statistician, BGD/79/015
Mr Darrel Deppart - Aquaculture Adviser
Dr Peter Perschbacher - Aquaculture Expert
Mr Kai Thorn - Project Engineer, Mymensingh
From Ministry and Directorate of Fisheries (DOF):
Mr A. Q. Chowdhury - Director
Mr M.A. Syed - Secretary
Mr Md. Farooq Ahmed
Mr Ataur Rahman - Principal Scientific Officer, DOF
Mr Liaquat Ali - Project Director, Resource Survey
From Fisheries Research Institute:
Dr Md. Asadur Rahman - Director
Dr Latif Sarker - ADDL. Director
Dr A.K.M. Nuruzzaman - Ex-Chief Scientific Officer (transferred to BARC)
Dr Saifuddin Shah - Chief Scientific Officer, FARS
Mr Golam Hossain - Principal Scientific Officer, FARS
Mr Abdul Rahman - Deputy Director
Mr Abdul Malek - Senior Scientific Officer (SSO)
Mr Abdul Khaleque - SSO
Mr Abdul Latif - SSO
Mr Abdul Rab - SSO
Mr Abdul Khair - SSO
Mr Nurun Nabi - Scientific Officer (SO)
Mr Azizur Rahman - SO
Mr Jahangir Alam - SO
Mr Shabuddin - SO
Mr Goutom Barua - SO
Mr Safiqur Rahman - SO
Mr Jafar Sarker - SO
Mr Obidullah - SO
Mr Rafiqul Islam - SO
Mr Zahirul Haque - SO
Ms Nurun Nahar Begum - SO
Ms Momtaz Begum - SO
Ms Rawsan Ara Begum - SO
Mr Iqbal Hossain - SO
Mr Muhamad Ali - SO
Mr Basiduddin Akhand - Librarian
Alagarswami, K. and S.Z. Qasim. 1973 Pearl culture - Its potential and implications in India, India J. of Fisheries, 2(11): 533-50
Anon. 1965 Study on pink pearls. Dhaka, Bangladesh Small Cottage Industries Corporation, 70p.
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