Fig. 4

Exo-erythrocytic stages of Leucocytozoon parasites: meronts (a, b) and megalomeronts (c–h). Hepatic meronts of Leucocytozoon simondi in a liver section of an experimentally infected Pekin duck Anas platyrhynchos domestica (note numerous meronts and the much haemorrhagic and disorganized liver tissue, a). Maturing hepatic meront of L. simondi (the same preparation as in a; note numerous cytomeres, in which division of parasite nuclei occurs and non-changed size of the infected hepatocyte nucleus, in comparison to nuclei size in the adjacent non-infected hepatocytes, b). Megalomeronts of Leucocytozoon sakharoffi in different stages of growth in spleen of a naturally infected the hooded crow Corvus cornix (note numerous roundish megalomeronts in different stages of growth, c). Maturing megalomeront of L. sakharoffi (the same preparation as in c; note a markedly enlarged host cell nucleus or the ‘central body’ of megalomeront, capsular-like wall surrounding the parasite, and numerous cytomeres, d). A fragment of the L. sakharoffi megalomeront (the same preparation as in c; note cytomeres containing numerous roundish subcytomeres, in which nuclear division occurs, a well-evident ‘central body’ and capsular-like wall surrounding the megalomeront, e). Megalomeront of L. simondi in hart of a naturally infected mallard Anas platyrhynchos (note numerous cytomeres, a well-evident ‘central body’, and capsular-like wall, f). Megalomeront of Leucocytozoon sp. in a section of spleen in a naturally infected Australian magpie Cracticus tibicen (note a large ‘central body’ and numerous roundish cytomeres in a parasite developing in a vessel, g). Megalomeront of Leucocytozoon sp. in a section of skeletal muscle of a naturally infected tawny frogmouth Podargus strigoides (note a large ‘central body’ and numerous roundish developing cytomeres; the muscle fibres surrounding the parasite are swollen, h). Simple long arrows meronts, simple wide long arrows megalomeronts, triangle wide long arrows cytomeres, simple wide short subcytomeres, simple short arrows megalomeront wall, triangle wide short arrow a nucleus of infected hepatocyte, simple arrowhead a nucleus of non-infected hepatocyte, stars host cell nucleus or ‘central body’ of megalomeront. Scale bars 10 μm (b), 50 μm (a, d–h), 200 μm (c)