Plasmodium gallinaceum: a novel morphology of malaria ookinetes in the midgut of the mosquito vector

Malaria ookinetes invade midgut epithelial cells of the mosquito vector from the bloodmeal in the lumen of the mosquito midgut, but the cellular interactions of ookinetes with the mosquito vector remain poorly described. We describe here a novel morphology of Plasmodium gallinaceum ookinetes in which the central portion of the ookinete is an elongated narrow tube or stalk joining the anterior and posterior portions of the parasite. We propose that the previously undescribed stalkform ookinete may be an adaptation to facilitate parasite locomotion through the cytoplasm of mosquito midgut epithelial cells.