Chloroplast ultrastructure of Euglena cuneata Pringsheim, E. deses Ehrenberg and E.mutabilis [Euglenophyceae]: taxonomic significance

Summary. For the first time the iunilaterali pyrenoids of Euglena were studied by transmission electron microscopy in three taxa: E. deses var. deses Ehrenberg, E. deses Ehr. var. intermedia Klebs and E. mutabilis Schmitz. The presence of pyrenoids in E. deses var. intermedia has been uncertain. Our investigations show that these three taxa have chloroplasts with pyrenoids. Centrally or laterally located in each plastid, the pyrenoid matrix is penetrated by a few thylakoids (E. deses) or by many (E. mutabilis). The chloroplast morphology and ultrastructure of Euglena cuneata Pringsheim were also studied for the first time. The species has one stellate, axial chloroplast with pyrenoid and the pyrenoid matrix forms a net-like pattern; no thylakoids penetrate the pyrenoid.