Distribution profile of Vibrio harveyi in Panulirus homarus

Microbiological studies in lobster culture rearing system at Kovalam laboratory, Chennai was carried out for a period of 150 days. The infected tissues, gills, gut and the exoskeleton of the diseased animal were subjected to various microbial analysis to study the distribution profile of luminous bacterial. The total heterotrophic bacteria in the water, sediment and animal samples were also determined. The total heterotrophic bacterial counts ranged from 1.6 x 103 to 26.3 x 103 cfu/ml in water, 2.4 x 105-24.2 x 105 cfu/ml in sediment and 3.4 x 106 to 4.2 x 106 cfu/ml in infected animals. The Vibrio harveyi population density varied between 0.8 x 103 to 9.6 x 103 LCFU/ml in water, 1.8 x 105 to 12.5 x 105 LCFU/ml in sediment and 1.3 x 106 to 2.2 x 106 LCFU/ml in animal. The high amount of luminescent bacteria accounted to the outbreak of tail fan necrosis in Panulirus homarus when grown in artificial rearing system