STUDY ON THE EFFECT OF FILAMENTOUS FUNGI ON FINGERLING OF STRIPED CATFISH (Pangasianodon hypophthalmus)

The aim of present study is to investigate fungal infection on striped catfish fingerling cultured in Mekong Delta, Vietnam. Fungi was isolated from the fish diseases and inoculated on two culture media: Glucose Yeast agar and Potato dextrose agar; the inoculated plates were incubated for 5-7 days at 28-30ºC. The result showed that five fungal genera were identified such as Fusarium sp. (40,9%), Aspergillus sp. (27,3%), Achlya sp. (20,5%), Saprolegnia sp. (6,8%) Mucor sp. (4,5%). The results also indicated that Fusarium sp. and Aspergillus sp. were found in most of the organisms of fish; however, Achlya sp., Saprolegnia sp. and Mucor sp. (4,5%) were found only in muscle and gills. The prevalence of infection is various in gills (61,4%), swim bladder (19,3%), muscle (8%) and liver (8%). Fusarium sp. grew at 35⁰C after seven days of inoculation, meanwhile the other fungus grew until 38⁰C. pH from 5.0 to 8.0 is suitable for growing of the strains. Fusarium sp. was especially detected as pathogenic swollen swim bladder in striped catfish fingerling.