바이오플락(Biofloc) 사육수가 잉어(Cyprinus carpio)와 어병세균에 미치는 영향

Abstract

This study was conducted to obtain basic information on the control capability of bacterial fish pathogens and water quality for biofloc technology (BFT), environmental friendly system based on zero or minimum water exchange, applying to culture of common carp (Cyprinus carpio). Biofloc breeding water from catfish farm was applied to investigate the influence of biofloc on the pathogenic fish bacteria, Listonella anuguillarum and Aeromonas hydrophila and to test for application of biofloc system to juvenile of common carp. Although biofloc breeding water was maintained in zero water exchange model over a long period of time, it was observed that toxic nitrogen did not reached as harmful level to carp. The tested biofloc was investigated as composed of more than 28 species of heterotrophic bacteria. The biofloc showed the effective control ability on L. anguillarum and the inhibition effect on proliferation of A. hydrophila through interaction with fish pathogenic bacteria. The fish in biofloc water allowed to higher growth rate with increased lysozyme activities in the skin mucus and stable level of spleen somatic index (SI) compared with control group in common breeding water. From these results, it would be suggested that SI could be one of the useful indicator of fish culturing conditions related stress such as change in water quality. Furthermore, it was read off that biofloc water had buffering capacity for changing of toxic nitrogen concentration in culturing water and microbiota unlike control fresh water. In conclusion, biofloc breeding water used in this study indicated positive effect on growth of juvenile of common carp and control activity to fish pathogenic bacteria. Therefore, biofloc technology is expect to be a new way in carp culture.