Figure 1

Shapes and dwellings of microfilariae. (A) Head of microfilaria Chabfilaria jonathani Bain, Purnomo & Dedet, 1983, a parasite of edentate, left lateral view with hook and right lateral view with transversal rows of cuticular points, respectively. (B) Onchocerca volvulus, head, apical view with the hook half inserted in the left amphidial pocket (in 19). (C) Diplotriaena bargusinica Skrjabin, 1917, an oviparous filaria from a bird showing the primitive cephalic anatomy of the stage 1 in spirurids, ventral view, with numerous rows of spines (in 64). (D) Acanthocheilonema viteae: when the hook is raised, the vestigial cephalic spines placed on the right side clutch its basis (in 65). (E) Waltonella sp., from an Asiatic frog, with helical body (original). (F) Onchocerca suzuki Yagi, Bain & Shoho, 1994 from a wild caprine, with helical posterior region (in 66). (G) Cercopithifilaria kenyensis Eberhard, 1980, a parasite of an African monkey, with a dorsoventrally flattened body, lateral view (left) and median view (right) (in 67). (H) In Cercopithifilaria tumidicervicata, the thick lateral alae of the cuticle of the caudal extremity are helically switched (in 68). (I) O. volvulus inside a subcutaneous lymphatic vessel (in 69). (J) Initial lymphatics (IL, transversal section) are identified among the connective fibres of a subcutaneous tissue (SEM micrograph, in 8; arrows indicate transitional zones in which the endothelial lining becomes discontinuous; sparse endothelial cells are present). (K) Mansonella (Tetrapetalonema) colombiensis Esslinger, 1982 in a subcutaneous vessel of a saimiri: this microfilaria stays in vessels of ear lobe and tail extremity and is extremely rare in blood recovered from the vessels of the flank (in 12). Scales: the width of the mentioned microfilariae varies from 4 to 8 μm according to the species; the head of Diplotriaena is 15 μm wide.