Filament-like densities in the supra-alveolar space. 10 nm thick sections through the tomograms from three different sporozoites showing the apical end (left panel), central region (middle panel) and the proximal end (right panel). Small filamentous structures (red arrowheads) between the plasma membrane (blue arrowheads) and the IMC (yellow arrowheads) are highlighted. Green arrowheads point to microtubules in the left panel. The direction of the electron beam is perpendicular to the plane of the sections. Scale bars: 100 nm.