Fig. 39

Examples of marked variation in morphological characters of different Haemoproteus species during sporogony (a–l) and exo-erythrocytic development (m–p). Microgametes (a, b), zygotes (c, d), developing ookinetes (e, f), fully grown ookinetes (g, h), oocysts (i, j), sporozoites (k, l), exo-erythrocytic meront (o) and megalomeronts (m, n, p) of H. minutus (a, g), H. tartakovskyi (b, c, h, k), H. fringillae (d, i), H. palumbis (j, l), H. majoris (m), H. mansoni (n), H. attenuatus (o) and H. passeris (p). Note that these Haemoproteus species are readily different not only on gametocyte stages (see Figs. 13, 17, 31, 34, 35), but also due to the following characters of their sporogonic and exo-erythrocytic stages: length of microgametes (a, b), mode of the cytoplasm vacuolization in zygotes (c, d), mode of elongation during initial stage of ookinete development (e, f), size and form of fully grown ookinetes (g, h), oocyst structure (i, j), size and form of sporozoites (k, l), form of exo-erythrocytic stages (m–p). Microgametes (a, b), ookinetes (g, h), sporozoites (k, l), oocysts (i, j) and exo-erythrocytic meronts (m–p) are clearly different in size. A large conspicuous vacuole (d) is present in zygote of H. fringillae, which is not a case in zygote of H. tartakovskyi (c). A long outgrowth appears in apical end of developing H. tartakovskyi ookinete (f), which is not a case in H. minutus ookinete (e). Developing oocyst of H. palumbis (j) contains numerous germinative centres (j), which is not a case in small oocyst of H. fringillae (i). One end of H. palumbis sporozoite is rounded (l), which is not the case in H. tartakovskyi sporozoite (k). Morphology of exo-erythrocytic meronts is markedly variable in different species of Haemoproteus (m–p). These examples show that different Haemoproteus and other haemosporidian species can be distinguished due to many characters of sporogonic and exo-erythrocytic stages, which remain unexplored in taxonomy. Long simple arrows—capsular-like wall of megalomeronts. Short simple arrows—parasite nuclei. Simple arrowheads—pigment granules. Simple wide arrowheads—apical end of ookinetes. Simple wide short arrows—vacuoles. Simple small arrowhead—merozoites. Simple wide long arrows—megalomeront cytomeres. Triangle wide short arrows—oocysts. Scale bars 10 µm (a–i, k, l), 50 µm (j, m–p). Other explanations are given in the text