CONCLUSIONS
Pacific white shrimp were first observed
to be infected with the microsporidian between
20-25 days after stocking PL into the ponds. The
highest infection prevalence of between 25-28%
was found at day 60. Shrimp infected with
microsporidian in both the hepatopancreas and
abdominal muscle had the lowest body weights,
which were significantly different from either the
shrimp infected in only the muscle or the
uninfected shrimp. The histopathological changes
in heavily infected shrimp revealed that most of
the vital organs, including the hepatopancrease,
lymphoid organ, stomach and other organs were
infested by microsporidian parasites. This study
clearly indicated that the severity of
microsporidian infection negatively affected the
growth and survival of white shrimp.