Studies on the culture of the freshwater prawn Macrobrachium rosenbergii at various stocking size and density in ricefields
Experiments were conducted to investigate the possibility of prawn culture in ricefields. The work was undertaken in cooperation with the Farming System Research Institute in Bangkok and the Sakolnakorn Fisheries Station in Sakolnakorn in the North-east Thailand. The experiments were conducted on farmers' fields. Eight farmers participated in the research. They carried out day to day management of the 16 plots. The plots were prepared for the experiments by digging a trench around the ricefiel d. Paddy was planted and tillered before the prawn were stocked. Prawn were of two sizes, just metamorphosed postlarvae (PL 1) measuring 1–1.5 cm in length, others as PL 60 measuring 4.5 – 4.8 cm in length. The latter ones were first nursed for 60 days in ponds before stocking in the ricefield. The PL 1 were stocked at the rate of 1.25/m2 meter and PL 60 at 0.31, 0.63 and 1.25/m2. Thus the rate of stocking varied from 3100 to 12500/hectare. The size of each of the ricefields in this experiment w as about 1600 square meter. After a culture period of 90 to 100 days the prawn were handpicked after draining or pumping the water out of the field. Six plots belonging to three farmers were infested with large predatory fish following heavy rain that flooded the fields and damaged the screening material of 50 cm height put on the dikes surrounding the plots. Flooding and infestation with fish were perhaps the main reasons for very low survival rates of 1 to 9% in these plots. Other fields gav e survival rates of 10 to 89 %. The PL 1 in ricefields grew to 5.4 grammes after a rearing period of 90 days. However 34 % of the population had an average weight of 17.1 grammes indicating clearly that the stocked PL grew extremely well in a ricefield ecosystem.
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| Format: | Project biblioteca |
| Language: | English |
| Published: |
1988
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| Online Access: | https://openknowledge.fao.org/handle/20.500.14283/AC268E http://www.fao.org/3/a-ac268e.htm |
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