Effects of Sodium, Potassium, Calcium and Magnesium Ions on Flexibacter columnaris Infection in Fish

Abstract

The experimental infection ofFlexibacter columnaris to juvenile common carp (Cyprinus carpio) and loach (Misgurnus anguillicaudatus) was studied in respect of the influence of water media containing 4 cations, Na⁺, K⁺, Ca⁺⁺ and Mg⁺⁺. The occurrence of columnaris disease varied with the different environmental waters as well as with the fish species. In the case of common carp, infection occurred in every fish in both the formulated water (0.03% NaCl, 0.01 % KCl, 0.002% CaCl₂·2H₂O2 and 0.004% MgCl₂·6H₂O) and tap water at the exposure density of 4-6 × 10⁸ CFU/ml of F. columnaris. At a lower exposure density of 4-6 × 10⁷ CFU/ml, an 80% inflection was observed in the formulated water but no infection occurred in tap water. In loach, infection occurred in every fish at the exposure density of 4-6 × 10⁶ CFU/ml in both the formulated water and tap water. No infection was observed in distilled water and the percentage of infection in the individual salt solutions were lower than the occurrence of infection in either the formulated water or tap water. Overall, the formulated water was detected as the most suitable water among the tested media for F. columnaris infection in both fish species.