The infected aquafarm Shrimp Penaeus monodon were used for bacteriological examinations. Tissues of carapace, alimentary canal and gills of shrimp were cultured in both Nutrient Agar (NA) and Thiosulfate Citrate Bile Sucrose Agar (TCBS) plate after homogenization and existence of bacterial population were observed. Results showed that there was a significant variation in bacterial flora among the tissues. According to the diagnostic scheme for Vibrio species described by Larsen and Pedersen (1999), three types Vibrio spp such as V.harveyi, V.alginolyticus, V. parahaemolyticus and some of the non – Vibrio spp (Bacillus, Pseudomonas, E.coli, Streptococcus, Staphylococcus, Proteus) were identified. The findings of this study would suggest that there may be a wide range of Vibrio spp in the various tissues and some characteristics of these bacteria are given in this report.
