Ultrastructure and light microscopic cytology of Agglomerata lacrima n. sp. (Microspora, Duboscqiidae), a microsporidian parasite of Acanthocyclops vernalis (Copepoda, Cyclopidae)

Abstract

Agglomerata lacrima n. sp. is the first species of the genus described from a copepod host ( Acanthocyclops vernalis .) It was studied using light- and electron-microscopy. All stages of the life-cycle had isolated nuclei. The earliest stages found were uninucleate merozoites. Sporogony produced 4–12 (mostly 8) pyriform spores by rosette-like budding within a fragile sporophorous vesicle. Live spores measured 4.4 ± 0.2 × 2.6 ± 0.2 μm, and fixed spores measured 3.7 ± 0.2 × 1.6 ± 0.2 μm. The exospore was constructed of 4 layers. The anisofilar polar filament made 5–6 coils in the posterior half of the spore. The polaroplast had an anterior part with wide lamellae (chambers), followed by a second zone of narrow lamellae. Tubule-like structures which might constitute a third polaroplast region were present immediately anterior to the first filament coil. Cytological characteristics and the generic position of the species are discussed, and it is compared to related or resembling species, and to all previously reported microsporidian species from copepods.