title: Ultrastructural observations on merogony of Protoentospora ptychoderae Sun, 1910 (Apicomplexa, Coccidia) from the enteropneust Glossobalanus minutus (Kowalewsky, 1866).
abstract: The ultrastructure of the merogony of Protoentospora ptychoderae Sun, 1910 from the coelom of the enteropneust Glossobalanus minutus (Kowalewsky, 1866) is described. Trophic forms dedifferentiated into meronts by losing components of both the apical complex and the pellicle. Prior to merozoite formation, multinucleate meronts showed a discontinuous pellicle inner membrane complex. Merozoites formed by ectomerogony or external budding. In daughter merozoites the subpellicular microtubules were the first apical complex structures that were differentiated; rhoptries, conoid and polar ring differentiated later, and lastly micronemes appeared. The new merozoite had a trilaminate pellicle with a micropore, and showed approximately 60 subpellicular microtubules, a short conoid, at least five rhoptries, one paranuclear Golgi apparatus and one nucleus including one nucleolus. No parasitophorous vacuole was found at any stage of merozoite development. The organellogenesis events are discussed and compared with already known data from other Coccidia.
authors.affiliation: Departamento de Biología Animal I, Facultad de Biología, Universidad Complutense, Madrid, España.
authors.forename: J
authors.initials: J
authors.lastname: Benito
authors.forename: I
authors.initials: I
authors.lastname: Fernández