Revisão taxonômica e filogenia molecular da família Cycloposthiidae Poche, 1913 (Ciliophora, Trichostomatia, Entodiniomorphida)

Abstract

The family Cycloposthiidae (Ciliophora, Trichostomatia) includes symbiotic intestinal ciliates of herbivorous mammals known to contribute significantly to the digestive metabolism of their hosts. Currently, it is represented by 69 species, divided into 17 genera. However, because to the absence of a methodological pattern for species descriptions, as well as several other taxonomic incongruities, the systematics of the family Cycloposthiidae requires extensive reformulation. Recent studies have shown that the family Cycloposthiidae is not monophyletic, however, there is a paucity of molecular data to investigate such relationships. This dissertation is divided into two sections. Section 1 presents a brief taxonomic review of the family Cycloposthiidae, with data on taxonomy, morphology, species checklists, hosts and geographic distribution, and discusses the validity of taxa belonging to the family, with the objective to reflect on the group's systematics. Section 2 presents data on molecular phylogeny of representatives of the family Cycloposthiidae and provides ten new sequences, nine of which are representatives of the genus Cycloposthium and one of the genus Monoposthium, with the objective to investigate the relationships between the members of the family Cycloposthiidae and other tricostomatids ciliates, and to investigate the evolution of some characters within the genus Cycloposthium. In this way, it is emphasized the importance of knowing better the family Cycloposthiidae, to consider its diversity, wide spectrum of hosts where the family occurs and its importance in the digestion of these animals.