Destruction of Sertoli cells and disturbance of spermiogenesis in Saduria entomon L. (Crustacea, Isopoda) from the Baltic infected with the ciliate Mesanophrys

Abstract

Summary Pathological lesions were observed by electron microscopy in the testicular tubules of the isopod Saduria entomon naturally infected with the ciliate Mesanophrys. Profound and extensive changes were visible in the ultrastructure of both somatic and germinal cells. The cytoplasm of Sertoli cells was electron transparent and there was a drastic reduction in the rough endoplasmic reticulum and Golgi complexes; in addition, their nuclei showed an abnormal arrangement of chromatin. The damaged protrusions of the cells had lost contact with spermatids. In the lumen of the testicular tubules, spermatids at various stages of destruction lay in a loose, chaotic group, as did spermatozoa, which failed to form bundles. Extracellular tubules were missing. Spermiogenesis, if occurring at all, was disturbed. Determination of the level of infection by analysis of the haemolymph revealed that pathological changes intensified with the progress of infection.