Taxonomy, phylogenomics and morphometry of Neotropical species of the genus Idiops Perty, 1833 (Mygalomorphae, Idiopidae)

Author(s)

Rafael da Fonseca Ferreira

• Document type: Doctoral Thesis
• Press: Rio Claro. 2023-06-30.
• Institution: Universidade Estadual Paulista (Unesp). Instituto de Biociências. Rio Claro
• Defense date: 2023-02-10
• Advisor: José Paulo Leite Guadanucci; Millke Jasmine Arminini Morales

Abstract

The Idiopidae family, composed exclusively of trapdoor spiders, comprises the second most diverse family among Mygalomorphae spiders, a group characterized by a generally sedentary lifestyle, normally limited dispersal, and apparent morphological uniformity. Among the genera of Idiopidae, the most specious is the genus Idiops Perty, 1833 (Idiopinae), the subject of this doctoral thesis. Focused on the Neotropical species of the genus, this work explores different aspects of the morphological and molecular systematics of the genus Idiops, based on three chapters: 1. Taxonomic revision of Neotropical spiders of the genus Idiops Perty, 1833 (Araneae, Idiopidae), describing four new species; 2. Phylogenetic analysis of the genera of Idiopinae 1889 (Idiopidae), with emphasis on Neotropical species of Idiops Perty 1833, based on Ultraconserved Elements (UCE); and 3. Geographic variation of trapdoor spiders (Araneae, Idiopidae) across different Brazilian biomes reveals morphometric differentiation of spiders from the Brazilian Caatinga biome. In Chapter 1, the results of the taxonomic revision of the Neotropical species are presented, which, among other results, presents a new diagnosis for the Neotropical species of the genus, based on the dentition pattern of the chelicerae, in addition to updated distribution maps for all species, which now total 24 taxa in South America. In Chapter 2, the results of the first molecular phylogeny focused on Idiops and Idiopinae are presented, which aimed to test the monophyly of Idiops genus and the subfamily Idiopinae, and to investigate the evolutionary relationships between the genera of the subfamily, based on phylogenomic analyzes of Ultraconserved Elements (UCEs) of DNA. According to the results, both the subfamily Idiopinae and the clade composed of neotropical species of Idiops were recovered as monophyletic. Despite this, due to the most closely phylogenetic proximity between the African species of Idiops with the other African genera of the subfamily, Idiops genus was retrieved as paraphyletic. According to Ancestral Character Reconstruction, analyses carried out for different morphological characters, and distinct patterns of chelicerae dentition found in Neotropical and Afrotropical specimens of Idiops support the hypothesis of paraphyly of the genus. The phylogenetic relationships between the genera of Idiopinae, as well as the family Idiopidae, are also discussed in this chapter. Chapter 3, focused on the species Idiops pirassununguensis, which has continental distribution and covers different Brazilian biomes, a series of morphometric analyzes were carried out, based on measurements of linear structures and morphogeometric shapes of specimens from different locations within the Amazon, Caatinga, and Cerrado biomes. Aiming to investigate whether there is geographic variation and morphological structure in relation to biomes, the results are presented, which suggest the presence of morphological structuration among the specimens originating from the Caatinga when compared with other biomes. The main factors that may be involved in the observed structuring patterns are discussed. Based on different levels of approaches and analysis methods, the results presented in this thesis reinforce the importance of studies that investigate mygalomorph spiders, especially trapdoor spiders, from different perspectives, to solve different questions, direct future research, and expand the scope of research knowledge about these taxa. (AU)

• FAPESP's process: 18/02842-2 - Phylogeographic analysis of three species of the genus Idiops Perty 1833 (Araneae, Idiopidae)
• Grantee: Rafael da Fonseca Ferreira
• Support Opportunities: Scholarships in Brazil - Doctorate