Systematics, ecomorphological evolution and biogeography of the tropical wandering spiders (Araneae, Ctenidae)
Open AccessWandering spiders (Ctenidae) are a worldwide distributed diverse group with more than 500 species in 48 genera, having its highest species richness in the tropics. Ctenidae are medium to large (5–50 mm) wandering spiders that usually inhabit the forest floor and low vegetation, although a few species are arboreal. Wandering spiders are nocturnal, cursorial predators that do not build webs to capture prey. Some ctenids are restricted to forests and their population densities decrease significantly when forested habitats suffer fragmentation and disturbance. Their large size and predominant abundance in most tropical forests suggest that ctenids play an important role in tropical ecosystems as top generalist predators of invertebrates and small vertebrates. In the first chapter of this work, I test the monophyly of the family Ctenidae and infer the phylogenetic relationships of the ctenid subfamilies based on nucleotide sequence data, including representatives of all ctenid subfamilies (Acantheinae, Cteninae, Acanthocteninae and Calocteninae). Our molecular phylogeny was inferred using five nuclear (histone H3, 28S, 18S, Actin and ITS-2) and four mitochondrial (NADH, COI, 12S and 16S) markers for a total of 9123 base pairs. In addition, I inferred a dated phylogenetic tree to estimate the diversification times of Ctenidae and its main clades. Ocular arrangement has been an important diagnostic feature of several RTA (retrolateral tibial apophysis) clade families, including Ctenidae, although its phylogenetic distribution across families suggests that this pattern (2–4–2) is homoplastic. The time-calibrated analysis indicated that Ctenidae and its main lineages originated during the Paleocene–Eocene and have diversified in the tropics since then. However, in some analyses Ctenidae was recovered as polyphyletic as the genus Ancylometes Bertkau, 1880 was placed as sister to Oxyopidae. Except for Acantheinae, in which the type genus Acantheis Thorell, 1891 is placed inside Cteninae, the four recognized subfamilies of Ctenidae are monophyletic in most analyses. The ancestral reconstruction of the ocular conformation in the RTA clade suggests that the ocular pattern of Ctenidae has evolved convergently seven times and that it has originated from ocular conformations of two rows of four eyes (4–4) and the ocular pattern of lycosids (4–2–2). We also synonymize the monotypic genus Parabatinga Polotov & Brescovit, 2009 with Centroctenus Mello-Leitão, 1929. However, in this study several of the phylogenetic relationships of Lycosoidea and nodes within Ctenidae remained with low support and/or unstable position. Therefore, in the second chapter, I expanded phylogenetic sampling of Ctenidae using genome scale data (UCEs) and discuss the phylogenetic relationships of the ctenid subfamilies. I inferred a dated molecular phylogeny for morphospace analyses and ancestral character reconstruction, to address the effect of habitat shifts on ecomorphological adaptations. Specifically, I aim to answer the following three questions: 1) What is the evolutionary history of habitat transitions in Ctenidae?, 2) Did independent shifts of habitat result in the repeated origin of similar morphologies?, and 3) do macroevolutionary rates of phenotypic evolution correlate with the habitat specialization?. Finally, I reconstructed the global historical biogeography of Ctenidae to test whether the ecomorphotypes assembly in each continent have arisen independently by in situ diversification or colonization from other regions. The ancestral reconstruction of the habitat suggests that ancestral ctenids were arboreal and colonized the ground independently at least five times. In addition, there were three independent events, reversals back, of colonization from the ground to low vegetation. Phylomorphospace analyses indicated a clear morphological separation between arboreal and ground species, and low vegetation species occupying an intermediate morphospace between the two other habitat types. Using Ornstein- Uhlenbeck stabilizing selection models we were able to detect morphological shifts in the phylogeny associated with habitat transitions, but these analyses also indicate that different morphological types originated from repeated habitat transitions, therefore suggesting incomplete morphological convergence. Using State-Dependent models of morphological evolution, we determined that species adapted to arboreal habitats present higher rates of morphological evolution than species that inhabit on the floor, and species in lower vegetation have intermediate rates. Ctenids originated in the Indomalayan region, and from that area dispersed to the Neotropics and Africa. The different Ctenidae ecomorphotypes in Asia arose independently by in situ diversification, while the Neotropical ctenid ecomorphotypes assembly was driven by a combination of in situ diversification and dispersal of ground-adapted forms from Asia. Thus, the evolutionary shifts to different habitats and dispersal from to other regions has promoted the diversification of ctenids, resulting in layers of morphologically convergent forms and morphotype assembly in each continent. In the third chapter, to revalidate the medically important wandering spider species, P. depilata (Strand, 1909), which had been erroneously synonymized with P. boliviensisis (F.O. Pickard-Cambridge, 1897), I used morphological and nucleotide sequence data (COI and ITS-2) together with species delimitation methods. I also provide species distribution models for both species of Phoneutria and test hypotheses of niche conservatism under an allopatric speciation model. My phylogenetic analyses support the monophyly of the genus Phoneutria and recover P. boliviensis and P. depilata as sister species, although with low nodal support. In addition, the tree-based species delimitation methods also supported the separate identities of these two species. Phoneutria boliviensis and P. depilata present allopatric distributions separated by the Andean Mountain system. Species distribution models indicate lowland tropical rain forest ecosystems as the most suitable habitat for these two Phoneutria species. In addition, this study demonstrates the value of citizen science platforms like iNaturalist to improve species distribution information based on occurrence records. In the fourth and last chapter, I review the systematics of Central America wandering spider genus Kiekie. In this study, I described five new species and the unknown females of K. barrocolorado Polotow & Brescovit, 2018 and K. garifuna Polotow & Brescovit, 2018, and the unknown male of K. verbena Polotow & Brescovit, 2018. In addition, we described the female of K. montanensis which Polotow & Brescovit (2018) incorrectly assigned a female of K. griswoldi Polotow & Brescovit, 2018 (both species are sympatric). We inferred a molecular phylogeny using four nuclear (histone H3, 28S rRNA, 18S rRNA and ITS-2) and three mitochondrial genes (cytochrome c oxidase subunit I or COI, 12S rRNA and 16S rRNA) to test the monophyly of the genus and the evolutionary relationships of its species. Furthermore, we reconstructed the historical biogeography and mapped diversity and endemism distributional patterns of this genus. I the highest diversity and endemism for Kiekie in the montane ecosystems of Costa Rica followed by the lowland rainforest of the Pacific side (Limon Basin). Kiekie originated in the North America Tropical region and dispersed to Lower Central America where it started diversifying during the Late Miocene. In Central America, Kiekie colonized independently several times the montane ecosystems corresponding to periods of uplifting of Talamanca and Central Cordilleras. Therefore, this study increased the number of known species of Kiekie from 11 to 16 and documented a new genus, Eldivo which is sister lineage of Kiekie.
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