author(s)
Patel MP, Dr. Vadher KH and Dr. Tank PR

abstract
This study was conducted to evaluate the virulence of Vibrio harveyi MTCC 7954, V. parahaemolyticus MTCC 451 and V. vulnificus MTCC 1145 to Pacific white shrimp Litopenaeus vannamei juveniles. Vibrio spp. were injected to juvenile shrimps (2.28 ± 0.19 g) with a lethal dose of 1 x 10⁷ CFU/shrimp while control without Vibrio spp. and reared for 10 days. Significantly higher and earlier mortality was recorded with V. parahaemolyticus than other Vibrio strains and control. Total mortality of juvenile shrimps was recorded in 6 days with V. parahaemolyticus injection followed by V. vulnificus in 7 days while V. harveyi produced 63.33% ± 10.00% mortality in 10 days of the test period. Higher virulence exhibited by V. parahaemolyticus to juveniles shrimp with median lethal time value 4.13 days than V. vulnificus and V. harveyi with values of 4.96 and 8.57 days respectively.