02487nam a2200265   450000500170000000800410001703500150005810000160007324500580008926000520014730000140019949000270021350001550024050200570039552014560045265000170190865000140192565000090193970000300194870000430197870000450202171000310206681000590209785600650215620260817172953.0               th                  eng    a.b116995771 aRai, Sunila10aCo-culture of walking catfish with Indian major carps  aBangkok :bAsian Institute of Technology,c1997  a85 leaves1 aThesis ;vno. AS-97-03  aA thesis submitted in partial fulfillment of the requirements for the degree of Master of  Science,  School of Environment, Resources and Development   aThesis (M.Sc.) - Asian Institute of Technology, 1997  aAn experiment was conducted for 112 days to evaluate the growth performance of hybrid  catfish and carps (silver carp, rohu and mrigal) in three different stocking ratios of 3.2:1, 4.8:1  and 6.4:1, and their impact on water quality and nutrient budget. Hybrid catfish were stocked  in 1.2 m3 cage, at a density of 100, 150 and 200 fish/cage. Fish were fed on pellet feed, at a  rate of 2% body weight. Carps were stocked at a rate of 5,000 fish/ha in 250 m2 ponds. The  ratio of carps was 1: 1 : 1. The carps were grown solely on natural food produced by nutrients  wastes from caged catfish. Ponds were fertilized prior to stocking at a rate of 4 kg N/ha/day  and 1 kg P/ha/day.  Net fish yield of hybrid catfish (28.7 kg/cage), net yield of carps (13.3 kg/pond) and combined  net yield of caged catfish and pond carps (127.9 kg/pond) were significantly higher (P<0.05)  in higher stocking density of catfish. Stocking ratio of 6.4: 1 appeared to be the best stocking  ratio. Stocking ratio did not affect water quality. Hybrid catfish culture released 61-64% N and  76-79% P, out of which carps recovered 3.1-3.8% N and 2.4-2.9% P, and 1.5-2.3% N and 1.3- 14.0% P were lost to the water column. Rest nutrients were unaccounted for. Nutrients derived  from the wastes equal to fertilization rate of 0.9-1.6 kg N/ha/day and 0.3-0.5 kg P/ha/day,  which were grossly inadequate for phytoplankton production to support the growth of  herbivorous carps. 10aFish-culture10aCatfishes10aCarp1 aLin, C. K., eChairperson1 aEdwards, Peter,eExamination Committee1 aLittle, David C.,eExamination Committee2 aNORAD, eScholarship donor2 aAsian Institute of Technology.tThesis ;vno. AS-97-03  3Full-Textuhttp://203.159.5.9/ait-thesis/detail.php?q=B13776