On farm trial of freshwater pearl culture

On farm preliminary trial of freshwater pearl culture was done through 20 entrepreneurs in Boilor and Sutiakhali villages of Mymensingh district during 2004. A group of 20 enthusiastic women were selected and trained on the art of mantle tissue dissection, operation for mantle tissue implantation and preparation of ponds for pearl culture. A total of 200 juvenile freshwater mussel, Lamellidens marginalis, were collected from the wild and were used for mantle issue operation. The operated mussels were then transferred to farmer's pond and were subjected to observational trial. Length and weight of each of the test mussels were recorded before hanging them at a depth of 40 cm in net bags (3 mussels/net bag) in ponds at the rate of 24,700 mussels/ha of pond area. Ponds were routinely fertilized with organic and inorganic fertilizers thorough out the mussel rearing period. Water temperature, pH, plankton density and soil organic matter were monitored fortnightly. Growth of pearl is yet to be monitored through sacrifice of the mussels but X-ray photography of a few mussels indicated the initiation of pearl formation in most of them.

A statistical study on weight loss in frozen prawns

This paper deals with an extensive study conducted to estimate the extent of weight loss in frozen prawns. The weight Joss varied from 7 to 12% in peeled and deveined (PD), 5 to 7% in headless (HL) and about 7% in cooked and peeled (CP) prawns from the date of processing to the date of inspection, normally within two weeks. To compensate the weight loss nearly 11% of excess material is being added with every frozen block resulting in an average annual loss of Rs. 2.68 crores in foreign exchange. The relevant data pertain to the period 1971 to 1973 and the annual average loss was estimated for the ten years ending 1973.