sistemática filogenética do gênero Rhacodiaptomus Kiefer, 1936 (Crustacea: Copepoda: Diaptomidae)

Abstract

The species of the genus Rhacodiaptomus were reviewed through the detailed study of all the appendices. The specimens were obtained from scientific collections and field samples. After the appointment of R. calamensis as the type-species of the genus, the measurement, dissection and drawings of the appendices of the typespecies were performed. Regarding the pther species of the genus, only the appendices that were different from those found in species-type were drawn. The software DeLTa-IntKey, version 1.04, was used for the generation of descriptions, keys of identification and matrices of characthers. The softwares TNT and Windclada were used to test the relationships between species, searching for he most parcimonious tree. Six species of Rhacodiaptomus were re-described along with the first description of the unknown female of R. calatus and a new species. A total of 448 items, among characters and attributes was listed with Delta and a matrix of 80 informative characters and with Nexus output was obtained. The outside-group selected included Notodiaptomus deitersi, Aspinus acicularis and 8 species of Argyrodiaptomus. The search revealed a tree with length (L) = 272, consistency index (CI) = 0.52 and retention index (RI) = 0.72. The monophyly of Rhacodiaptmus was supported by 28 synapomorphies and the relationships among the species are: (Rhacodiaptomus calamensis (Rhacodiaptomus retroflexus (Rhacodiaptomus sp. n. (Rhacodiaptomus calatus, Rhacodiaptomus ringueleti) (Rhacodiaptomus insolitus, Rhacodiaptomus besti))))). Rhacodiaptomus calamensis is the most basal species within the group. An updated record of distribution of each species has also been done