various cytoplasmic inclusions (Fig. 1E). Mature spores appeared
to contain electron-lucent regions that likely coincided with the
posterior vacuole observed by TEM (see below).
TEM revealed several stages of a microsporidian parasite in
the cytoplasm of hepatopancreatic, tubule epithelial cells. Definitive
early meront stages were not observed but early and late
stage plasmodia were frequent and showed multiple nuclei and
sporogony typical of members of the family Enterocytozoonidae
(Fig. 2A and B). The plasma membrane of some plasmodia was