Integrative taxonomy of the taxon Ophiothrix (Ophiothrix) angulata (Ophiotrichidae, Ophiuroidea), cryptic species that occurs in two Brazilian ecoregions

Abstract

The aim of this project is to realize a taxonomic study to consistent recognition and delimitation of Ophiothrix (Ophiothrix) angulata (Ophiotrichidae, Ophiuroidea). This taxonomic review is necessary because this taxon exhibit huge morphological variation and studies evolving specimens from Brazilian coast are scarce. Therefore, for the first time in literature, integrative taxonomy of this group will combine external and internal morphological characters, morphometry and molecular analysis, with specimens from two ecoregions, (1) Southeastern Brazil and (2) Trindade and Martin Vaz Islands. The molecular aspects will be measure based on genetic analysis of mitochondrial DNA (CO1 and 16S) and in relation to morphological aspects, besides the morphometry, diagnostic structures of the disc and arms will be analyzed, described and illustrated, including vertebral ossicles and arm plates, arms elements that have shown consistent in the study and lineage delimitation of Ophiuroidea. Due to peculiarities of each ecoregion, the specimens will be compared to verify if they represent different lineages and clarify the species delimitation in the Brazilian coast. At the end of the analysis, the results will be evaluated by integration, enabling more precise delimitation of the taxon, contributing to the knowledge of Ophiuroidea biodiversity in Brazil and understanding of the speciation process along the continental shelf.