Một trường hợp nhiễm nặng Trypanosoma sp. trên cá rô đồng (Anabas testudineus) nuôi thâm canh

Diseased climbing perch (Anabas testudineus), 100-150 g/fish, with sign of dark body were sampled from intensive fish ponds in An Giang Province in two samplings (20 fish/sampling) in April and May, 2011. Quality of pond water such as DO, temperature and NH3 were checked during sampling fish. The results showed that water quality was not affect to fish health. Sampled fish were examined for ex- and internal clinical signs, parasites and isolated bacteria from the liver, kidney and spleen. External sign was only dark skin color. Internally, the liver, kidney and spleen were swollen and softened. The liver was also pale and edge of the liver was not in regular shape. Bacteria were isolated from the internal organs and identified as Aeromonas hydrophila, Edwardsiella ictaluri and Streptococcus agalactiae. All sampled fish was infected with Trypanosoma sp. in the blood and mean intensity of this parasite was up to 1103 parasite/cover slip. Fish were also infected with other ex- and internal parasites such as Trichodina sp., Apiosoma sp., Myxobolus sp. and Capillaria sp. but their intensity were insignificant. The results of this study showed that Trypanosoma sp. probadly caused the disease with clinical sign of dark body in sampled climbing perch.