Comparative analysis of spermatids of Rhipicephalus sanguineus sensu lato (Ixodidae) and Ornithodoros rostratus ticks (Argasidae): morphophysiology aimed at systematics

摘要: The phylogenetic relationships among tick species (Acari: Ixodida) have been revisited by several researchers over the last decades. Two subfamilies, Rhipicephalinae (Ixodidae) and Ornithodorinae (Argasidae), deserve special attention. male reproductive system morphology, as well ultrastructure of germ cells, may provide important information for phylogeny systematics metazoan groups, with spermatozoa exhibiting characters that can be used this purpose. With in mind, study aimed at evaluating, through a comparative analysis, morphology systems cells ticks Rhipicephalus sanguineus Ornithodoros rostratus. In order to do that, histology scanning electron microscopy techniques were used. results shown despite similarities general studied Ixodida so far, there are morphological differences herein, mainly U-shaped testis (ancestral character) O. rostratus pair testes (derived R. sanguineus, (spermatids V). Besides changes observed during spermiogenesis appear different between here, probably characterizing two families considered. data generated showed importance internal studies, regard spermatology, obtained herein not being enough product cladogram (sperm cladistics), it was already possible observe clear Argasidae Ixodidae organization their concerning external spermatids. Data yet transmission will allow application spermiocladistics spermiotaxonomy tools systematics.