Fig. 22

Morphological features of gametocytes, which are used for identification of Haemoproteus species parasitizing Piciformes birds. Macrogametocytes (a–e, i–l, n, p) and microgametocytes (f–h, m, o) of Haemoproteus xantholaemae (a), H. cornuata (b), H. velans (c), H. homovelans (d), H. bennetti (e–g), H. bucconis (h), H. thereicerycis (i–k), H. bilobata (l, m), H. indicator (n, o) and H. borgesi (p). Note that H. velans gametocytes contain numerous prominent volutin granules and/or distinct volutin clumps (c), but this is not the case in H. homovelans (d). The advanced gametocytes of H. bennetti, H. bucconis and H. thereicerycis markedly displace nuclei of infected erythrocytes to the erythrocyte poles (f, i, k) and can enucleate the infected erythrocytes (e, g, h). Fully grown gametocytes of H. bilobata assume a unique dumbbell-like or bilobed form (l, m) and cause a readily visible flattening of nuclei of infected erythrocytes at the nuclei side, which is opposite to the gametocytes (l, m). Images f–h, j–m are from the type material, which is fading, resulting in pale staining and the poorly recognizable pigment granules and nuclei, however the overall form of the gametocytes is readily visible. Long simple arrows—host cell nuclei. Short simple arrows—parasite nuclei. Simple arrowheads—pigment granules. Simple wide long arrows—unfilled spaces between gametocytes and the envelope of infected erythrocytes or/and between gametocytes and nuclei of the erythrocytes. Triangle wide arrowhead—volutin granule. Other explanations are given in the text