Chytrid survey carried out between 2007 and 2011 in M. rosenbergii culture pond.
High prevalence rate of infection was in November and low in June.
LD50 dose of 105 zoospores/prawn produced 50% mortality from 4 to 6 days.
After 2nd week of infection the THCs significantly decreased.
All immunological parameters registered a significant increase (p < 0.05) to Bd challenge.