Sexual Differentiation of Merozoites of Barrouxia schneideri (Butschli)

Abstract

SCHELLACK¹ in a study of Coccidia from Lithobius and Scolopendra recognized the presence of moie than one type of merozoite in Barrouxia schneideri. He nevertheless concluded they did not represent sexually dimorphic forms. In recent cytochemical investigations cf the same parasite two types of merozoite were recognized, which differed in the amount of carbohydrate reserve stored in the cytoplasm and in nuclear structure. Using the periodic acid–Schiff test, some bundles of merozoites were shown to have no carbohydrate reserves other than a few fine granules. These correspond to the microgametocytes which have sparse reserves of fine, discrete granules occupying the central cytoplasm. Other merozoites, often shorter and broader in form, have considerable reserves already in the form of large granules merging together. There is no difficulty in tracing a series of developmental stages between these and the macro-gametocytes with their abundant carbohydrate reserves. Furthermore nuclear differences existing between the two types of merozoite can be traced to the gametocytes. The conspicuous polar nucleolus of the ‘female’ merozoite persists throughout the development of the macrogametocyte. A nucleolus is absent from the nuclei of the ‘male’ merozoite and the micro-gametocyte.