Management induced changes in food selection, growthandsurvivalofkoicarp,Cyprinuscarpiovar.koi l.,Intropicalponds

The effects of different management regimes on the feeding habits and food selection of koi carp (Cyprinus carpio var. koi L.) larvae were examined. Weight gain, fish deformities, and survival were compared in an 11-week growth trial conducted in tropical ponds maintained according to four culture regimes: (1) live food system; (2) poultry manure treated system; (3) cow dung treat- ed system; and (4) a control. The Ivlev’s Electivity Index showed that koi larvae avoided phyto- plankton and preferred cladocerans, an important source of natural food in all the regimes. In the poultry and cow manured ponds, the larvae were negatively elective towards copepods although they were more abundant than cladocerans. Weight gain and survival was significantly higher in the live-feed system (p<0.05) than in the other systems. Fish deformities were significantly high- er (p<0.05) in the control

Tank size and aquaculture management influence on the production of gold fish, Carassius auratus (L.), under tropical conditions

Growth performance of gold fish Carassius auratus (L.) produced in tanks of different size and treated under different management regimes were compared. Tanks of two different size and make were used (concrete; capacity: 2000 l and earthen; capacity: 59650 l) for four management regimes: (1) live zooplankton fed to fish larvae in concrete (CLF) and earthen tanks (ELF); (2) application of poultry manure in concrete (CPM) and earthen tanks (EPM); (3) application of cow manure in concrete (CCD) and earthen tanks (ECD); and (4) a control treatment for concrete (CC) and earthen tanks (EC). Fish larvae (0.10 ± 0.007 g) were cultured for 11 weeks. Weight gain of gold fish was highest in the ELF treatment. There was a significant difference in the survival of gold fish among the treatments, ranging from 64.83% in CC to 93.40% in ELF. Significantly higher values of pH and dissolved oxygen were obtained in the live food and control treatments (for both concrete and earthen tanks), compared to the manured treatments. The concentration of total alkalinity, BOD, PO4 – P, NO3 – N and specific conductivity were significantly higher in EPM and ECD, compared to other treatments. The results indicate that introduction of live zooplankton into culture units resulted in higher growth of fish larvae. Better growth of cultured fish were obtained in larger earthen tanks compared to smaller concrete tanks through maintenance of superior water quality and greater abundance of plankton

2005 b. Management induced changes in food selection, growth and survival of koi carp, Cyprinus carpio var. koi L., in tropical ponds. The Israeli

Abstract The effects of different management regimes on the feeding habits and food selection of koi carp (Cyprinus carpio var. koi L.) larvae were examined. Weight gain, fish deformities, and survival were compared in an 11-week growth trial conducted in tropical ponds maintained according to four culture regimes: (1) live food system; (2) poultry manure treated system; (3) cow dung treated system; and (4) a control. The Ivlev&apos;s Electivity Index showed that koi larvae avoided phytoplankton and preferred cladocerans, an important source of natural food in all the regimes. In the poultry and cow manured ponds, the larvae were negatively elective towards copepods although they were more abundant than cladocerans. Weight gain and survival was significantly higher in the live-feed system (p&lt;0.05) than in the other systems. Fish deformities were significantly higher (p&lt;0.05) in the control

Fish Production, Water Quality and Bacteriological Parameters of Koi Carp Ponds Under Live-food and Manure Based Management Regimes

To test the effectiveness of introducing live zooplankton against direct manuring in ornamental fish ponds upon their survival and production, larvae of koi carp, Cyprinus carpio L., were cultured for 11 weeks in earthen ponds maintained according to four management regimes: (1) live zooplankton fed to carp larvae (LF); (2) direct fertilization with poultry manure (PM); (3) direct fertilization with cowdung (CD); and (4) a control treatment (C). There were three replicates for each treatment. The growth of heterotrophic bacteria and pathogenic microorganisms like Aeromonas sp. and Pseudomonas sp. were also examined in response to pond management. Values of dissolved oxygen were significantly higher (P<0.05) in the water of LF ponds, compared to other treatments, while the PM and CD treatments recorded were significantly higher (P<0.05) values of PO4 – P, NH4 – N, NO3 – N, NO2 – N, specific conductivity, alkalinity, and BOD, compared to the LF and C treatments. The percentages of organic carbon and total nitrogen in the bottom sediments were higher in the PM and CD treatments compared to LF (P<0.05). Average counts of heterotrophic bacteria in the water of PM and CD ponds were significantly higher than other treatments (P<0.05). The development of Aeromonas sp. and Pseudomonas sp. were significantly higher (P<0.05) in the PM and CD treatments. Weight gain of koi carp stocked in LF was significantly higher (P<0.05) than that of fish in the other treatments. There was a significant difference in the survival rate of koi carp among the treatments ranging from 67.21% in C to 90.11% in LF. The results suggest that raising koi carp larvae in ponds and feeding them exogenously with zooplankton would support high rates of survival and production through maintenance of better water quality and greater abundance of zooplankton in the system. Significantly lower abundance of Aeromonas sp. and Pseudomonas sp. in the LF treatment considerably lowered any possibility of occurrence of bacterial disease