Using the Integrative Approach to Update a Gap of One Century: Redescription and New Distribution Records of the South American Tarantulas Grammostola pulchra (Araneae: Mygalomorphae: Theraphosidae).

Abstract

Taxonomic researchers have used multiple sources of evidence to support species hypotheses and delimitations. Grammostola Simon (Mygalomorphae: Theraphosidae) comprises 20 valid species endemic to South America, six occurring in Brazil. The classical morphological approach based mainly on genitalia may be misleading in recognizing species in this genus. Thus, we used morphology, geographical distribution, genetic distance, and phylogeny to support the redescription of Grammostola pulchra from southern Brazil, a species described a century ago. We also diagnosed and illustrated the species. Males have a developed apical keel at the apex of the embolus; for the first time, this type of structure has been reported in a species of Grammostola. The molecular analyses using the partial sequence of Cytochrome c oxidase subunit I showed 7% of genetic distance (p-distance) between G. pulchra and Grammostola anthracina. Distance and tree-based methods (ASAP and bPTP, respectively) assigned G. pulchra as a valid species. The gene-tree under Bayesian and Maximum-Likelihood recovered a similar topology, placing G. pulchra as closely related to Grammostola burzaquensis and G. anthracina. Morphological characters which could be important in the taxonomy of the genus are further discussed.