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Effect of water exchange on water quality and the production of ornamental carp (Cyprinus carpio var. koi L.) cultured in concrete tanks manured with poultry excreta

100%

Jha P., Barat S.

Archives of Polish Fisheries

2005

tom 13

nr 1

The effect of water exchange on water quality, plankton abundance, and the production of koi carp, Cypńnus carpio var. koi L., cultured in outdoor concrete tanks manured with poultry excreta was determined. Individual weight gain and survival rates of fish (initial weight 0.09 ± 0.02 g) were compared among five culture regimes, where a volume of 100 dm³ water was exchanged: (1) every day (WEI); (2) every alternate day (WE2); (3) two times a week (WE3); (4) once a week (WE4); and (5) a control treatment with no water exchange (NE). Significandy higher concentrations (P < 0.05) of conductivity, NH₄ -N, NO₂ -N, NO₃ -N, PO₄ -P and bicarbonate alkalinity were recorded in the NE treatment. Plankton volume was highest in WEI (P < 0.05). The weight gain and number of koi carp of marketable size were significantly higher (P < 0.05) in WEI. There was a significant difference in the survival of koi carp among the treatments ranging from 60.43% (NE) to 95.21% (WEI). The results suggest a water exchange of 100 dm³ daily (WEI) was the most effective for koi carp tanks manured with poultry excreta as better water quality and greater plankton abundance were both maintained in the system.

Behavioural responses of two popular ornamental carps, Cyprinus carpio L. and Carassius auratus [L.], to monoculture and polyculture conditions in aquaria

80%

Jha P., Jha S., Pal B. C., Barat S.

Acta Ichthyologica et Piscatoria

2005

tom 35

nr 2

Experiments were conducted to document behavioural responses of koi carp, Cyprinus carpio L., and goldfish, Carassius auratus (L.) to monoculture and polyculture conditions in aquaria. Two parallel experiments, otherwise involving similar experimental protocols, were carried out with two batches of fish, fed with live tubifex worm (first batch) and live zooplankton (second batch). Each of the trials, randomized with respect to treatment, yielded data on aggressive encounters (chases, nips), both in presence and absence of food. The two species exhibited considerable variation in the extent and type of aggression displayed, koi carp being the more aggressive species. Frequency of attack increased in the presence of food. The impact of aggressive behaviour of koi carp was conspicuous by the increased level of attack on goldfish in polyculture trials in both experimental batches.

Ograniczanie wyników

1 Acta Ichthyologica et Piscatoria

1 Archives of Polish Fisheries

2 Barat S.

2 Jha P.

1 Jha S.

1 Pal B. C.

2 2005

Wyniki wyszukiwania

Effect of water exchange on water quality and the production of ornamental carp (Cyprinus carpio var. koi L.) cultured in concrete tanks manured with poultry excreta

Behavioural responses of two popular ornamental carps, Cyprinus carpio L. and Carassius auratus [L.], to monoculture and polyculture conditions in aquaria