Cube root powder is a better piscicide than bleaching powder for pre-stocking carp nursery pond preparation

Abstract

Yard and pond applications of cube root powder (CRP) at 2.5 mg L⁻¹ and bleaching powder (BP) at 10 mg L⁻¹ Cl⁻ produced total fish kill within 14–24 h. Safe periods for stocking fingerling and fry of carps were on 8th and 11th day following CRP application against 4th day for BP. Pond chlorophyll concentrations did not change with CRP application, but was markedly affected by BP. Zooplankton population reduced by 88–95% with BP application compared to 70% with CRP. Initial zooplankton densities were revived in ponds up to 84.6 and 120.5% on 12th and 20th day, respectively with CRP application, while similar BP applications failed to reach initial levels even after 20 days. Based on the result, the study revealed CRP to be a better piscicide than bleaching powder for pre-stocking pond preparation.

Keywords:

• rotenone
• chlorine
• toxicity
• plankton
• chlorophyll

Acknowledgments

The authors are thankful to the Director, Central Institute of Freshwater Aquaculture, Bhubaneswar for providing all the facilities to conduct the experiment and M/s AS Aquaculture Pvt. Ltd, Kolkata, India for supplying the cube root powder.