Comparison on bacterial load of black tiger shrimp (Penaeus monodon) farm in the southwest region of Bangladesh

Abstract

Shrimp farming is a promising sector in Bangladesh since return from export earning of this commodity is considerably high. With the rapid development of grow-out farms, good husbandry and environmental problems developed as the shrimps were stressed and weakened under adverse conditions. The total bacterial load during the sampling period as varied from 7.4*105to 8.1*105 CFU/g of Hepatopancreas, 7.10*105 to 9.11*105CFU/g of digestive tract, 7.1*104 to 6.6*105CFU/ml of water and 8.68*104 to 4.88*105 CFU/g of soil in diseased pond. At this time, the total bacterial load during the sampling period as varied from 9.4*103to 7*104CFU/g of Hepatopancreas, 7.2*103to 4.8*104CFU/g of digestive tract, 6.1*102to 2.8*103CFU/ml of water and 8.1*103 to CFU/g of soil in non-diseased pond. Total number of bacteria in Hepatopancreas, digestive tract of shrimp, and water & soil of the diseased pond are differ distinctly from non-diseased pond. The pathogenic bacteria load during the sampling period as varied from 1.16*103 to 1.9*103CFU/g of Hepatopancreas, 1.29*103 to 1.75*103CFU/g of digestive tract, 1.1*103 to 3.1*103 CFU/ml of water and 7.5*102 to 2.3*103CFU/g of soil in diseased pond. At this time, the pathogenic bacteria load during the sampling period as varied from 1.39*102to 4.3*102CFU/g of Hepatopancreas, 4.2*102 to 7.1*102CFU/g of digestive tract, 7.5*101to 5.1*102CFU/ml of water and 3.2*102to 5.1*102CFU/g of soil in non-diseased pond. Total number of pathogenic bacteria in Hepatopancreas, digestive tract of shrimp, and water & soil of the diseased pond are differ distinctly from non-diseased pond. Early Mortality Syndrome (EMS) or Acute Hepatopancreatic Necrosis Disease (AHPND) is occurring for presence of Vibrio parahaemolyticus. That is a pathogenic bacteria. So, this study shows a positive indication for Early Mortality Syndrome (EMS) or Acute Hepatopancreatic Necrosis Disease (AHPND). Environmental factors such as water temperature, pH, dissolved oxygen, nutrients, organic substances etc. might be the causal factors of these bacterial load variations.