ASSOCIATION OF ASYMPTOMATIC MORTALITIES IN CULTURED WHITE SHRIMP, PENAEUS INDICUS WITH DOMINANCE OF NON-LUMINESCENT VIBRIO HARVEYI BIOTYPES IN MARICULTURE ENVIRONMENT

Document Type : Original Article

Author

Department of Fish Diseases, Animal Health Research Institute, Agricultural Research Centre. Dokki, Giza, Egypt

Abstract

Asymptomatic mortalities among cultured Penaeus indicus adults and postlarvae were recorded in summer season. Two non-luminescent Vibrio harvevi biotypes (V. harveyi- 1 and V. harveyi- 2) were dominantly identified along with other bacterial species mainly Pseudomonas fluorescencs, Aeromonas hydrophila and Staphylcoccus species. The incidences of recovery of V. harveyi- I V. harveyi- 2 P.fluorescencs, A. hydrophila and Staphylcoccus spp. In infected adults and postlar- vae reached 63.3 %, 26.7%, 6.7 %, 3.3 %, 0 % and 76.7%, 53.3%, 10%, 6.7%, 13.3 %, respec- lively.
The disease condition was found to be associated with the existance of stressful environmental role 2xpressed by the recorded increase in values of Water quality parameters especially ammonia and nitrite in affected ponds. However, the incidences of recovery of harveyi IV. Harveyi 2 P.fluorescencs, A. hydrophila and Staphylcoccus spp. In alfected pond water samples reached 93.3 %, 76.7 %, 13.3 %, 6.7 % and 23.3 %, respectively. Experimental pathogenicity of V. harveyi- IV. Harveyi- 2 in healthy shrimps confirmed the naturally existed disease condition. Recovered V. harveyi biotypes were shown to be sensitive to oxy- tetracycline, chloramphenicol, enrofloxacin. Nalidixic acid and oxolinic acid while they were resistant to ampicillin, novobiocin, kanamicin, Gentamycin and sulfonamide. Recommendations and preventive measures are also discussed.

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