Optimisation of stocking density of Thai silver barb (Barbodes gonionotus Bleeker) in the duckweed-fed four species polyculture system

The optimisation of stocking density of Thai silver barb (Barbodes gonionotus) in the polyculture with Labeo rohita, Catla cat/a and Cyprinus cmpio was investigated in seasonal ponds. Three different stocking densities of Thai silver barb i.e., 5,000, 6,000 and 7,000 fingerlings ha-1 were tested with stocking density of carps fixed at the rate of 10,000 fingerlings ha-1 Duckweed was applied to all ponds supplemented with rice bran and oil cake. There were no significant variations on either water quality parameters or abundance of planktonic organisms due to the different stocking densities of silver barb. A significantly higher fish production (p

Towards optimisation of bridle lengths in bottom trawls

Apart from increasing the swept area of the trawls, the importance of bridles as a herding device based on fish behaviour is discussed. The results of 10, 20 and 30m bridles when rigged with a 15m bulged belly trawl in combination with 114x57cm flat rectangular otter boards are presented. The net with 20m bridle landed better catches.