abdominal muscle resulting in decreased normal
physiological function and finally consumption by
the healthy shrimp. The histopathological changes
in this study resembled microsporidian infection
in pond-cultured P. monodon in Malaysia
(Anderson et al., 1989). Microsporidian A. penaei
was reported to infect the blood vessels, heart,
gonads, gills, hepatopancreas, gut and connective
tissues, as well as muscle of white shrimp, P.
setiferus (Rigdon et al., 1975; Kelly, 1987).