Cleavage in Ixodes ricinus (L.) (Acari: Ixodidae)

The author analyzed the first 5 days of embryonic development of Ixodes ricinus. The cleavage takes 4 days, being terminated on the 5th day of embryogenesis, when the cells start to invaginate and differentiate. The karyomeres play a role in the initial mitotic divisions. Cellularization occurs on the 2nd and 3rd day of embryogenesis. The blastoderm cells maintain their potential for division, and as from the 5th day cellular differentiation starts.