Fine structure of merozoites ofEimeria ? beauchampiLeger and Duboscq, 1917 inGlossobalanus minutus(Kow.) (Enteropneusta)

Abstract

SUMMARY. Merozoites of Eimeria? beauchampi Leger and Duboscq, 1917 from the digestive epithelium of the hepatic region of the enteropneust Glossobalanus minutus (Kow.) have been studied by electron microscopy lor the first time. The merozoites show typical coccidian features with a trilaminate pellicle, an apical polar ring, a conoid with two accessory rings, micronemes, and two rhoptries whose ductules are directed along a central intra-conoidal microtubule, above which a spherical vesicle occurs. Approximately 50 subpellicular microtubules run from the apical end to the nuclear region of the parasites. Lipid droplets, amylopectin granules and a large mito chondrion also occur in the cytoplasm. The presence of a refractile-like body is a remarquable feature of the merozoites studied. The present data are discussed in the light of the available literature. Key