The early Embryonic Development of the Argasid tick Ornithodorus moubata (Acarina: Ixodoidea: Argasidae)

The mode of cleavage of the centrolecithal tick eggs has so far been considered to be superficial. Evidence could be obtained from an electron-microscopic study of <i>Omithodoros moubata</i> Murray 1877 that cleavage of this species is total. The early development leads to a diploblastic stage composed of a superficial layer of yolk-free micromeres (ectomesoderm) and a core of yolk-rich macromeres (primary entoderm).