Spermatophore Formation and Sperm Transfer in <i>Ornithodoros</i> Ticks

Abstract

In seven species of Ornithodoros and two species of Argas ticks the spermatophore is formed outside the male body in three consecutive stages: (i) the outer bulb, the ectospermatophore, is formed; (ii) it is filled with sperm; and (iii) the inner capsules, the endo-spermatophore, are extruded into the ecto-spermatophore. The morphologies of the ecto-spermatophore and the endo-spermatophore are related to their biological functions. Eversion and evagination of the endo-spermatophore after deposition of the spermatophore on the female genital opening, as well as transfer of sperm from ecto-spermatophore to endo-spermatophore, are described.