Author(s): Sampa Baidya and Arun Bhai Patel

Abstract: The main objective of the study was to evaluate the effects of area of Wolffia-growing zone as percentage of total water surface area of the culture system on the overall water quality of the culture system. Three levels of Wolffia-zones viz. 10% (T1), 20% (T2), 30% (T3) of the total surface area were evaluated against control without any Wolffia (C). The culture period was 75 days & stocking density was 2 fish m2 involving Rohu (Labeo rohita), Catla (Catla catla), Mrigal (Cirrhina mrigala), puntius (Puntius javanicus), Grass carp (Ctenopharyngodon idella) and Amur carp (Cyprinus carpio haematoperus). The seeding rate of Wolffia (0.5kg m-2), feeding regime (constant feeding rate @2% d-1 offered once a day) and fertilization rate involving cow dung, urea and single super phosphate were the same in all treatments throughout the study period. Presence of Wolffia in the culture system had a positive influence with regards to somewhat increase in crude protein content with concomitant reduction in crude lipid in case of in Rohu, Catla and Mrigal compared to their counter parts in control. On the other hand, substantial increase (p<0.05) in crude lipid content with concomitant decrease in ash content was observed for grass carp and puntius. Further, organoleptic evaluation did not indicate any significant variation in color, odour, gill, eye, body surface of whole fish.

Pages: 327-333  |  1122 Views  264 Downloads

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