Bacterial Flora of Freshwater Prawn, Macrobrachium rosenbergii(de Man), Cultured in Concrete Tanks in Saudi Arabia

ABSTRACT

Bacterial counts and the aerobic heterotrophic bacterial flora in the digestive tract of the freshwater prawn, Macrobrachium rosenbergii, in Saudi Arabia were investigated, and the isolates were identified to the species level. Physicochemical characteristics, bacterial counts, and bacterial flora of freshwater prawn culture tank water, tank sediment, and freshwater prawn carapace were also investigated. Total viable bacterial counts ranged from 8.9 ×10³ to 1.4 ×10⁵ cfu/mL; 3.4 ×10⁶to4.1 ×10⁸cfu/mL;2.1 ×10³to4.7 ×10⁴cfu/cm²and3.4 ×10⁵ to 8.7 ×10⁶ cfu/g in prawn culture tank water, tank sediment, carapace, and digestive tract of the freshwater prawn, respectively. In total, eleven bacterial species were identified. Chryseomonas sp., Vibrio diazo-trophicus, Shewanella putrefaciens, and Vibrio cholerae were the most abundant bacterial species (prevalence > 10%) in the tank water; Aeromonas enteropelogenes, Chryseomonas sp., and Pseudomonas alcaligenes in tank sediment; Aeromonas enteropelogenes, Vibrio diazotrophicus, Curtobacterium pusillum, Vibrio alginolyticus, and Chryseomonas sp. on freshwater prawn carapace, and Aeromonas enteropelogenes, Vibrio alginolyticus, and Pseudomonas alcaligenes in the digestive tract of the freshwater prawn.

Key Words:

• Macrobrachium rosenbergii
• bacterial flora
• concrete tank