Southwestern Australia has been recognized as a biodiversity hot spot of global significance, and it is particularly well known for its considerable diversity of flowering plant species. Questions of interest are how this region became so diverse and whether its fauna show similar diverse patterns of speciation. Here, we carried out a phylogeographic study of trapdoor spiders (Migidae: Moggridgea), a presumed Gondwanan lineage found in wet forest localities across southwestern Australia. Phylogenetic, molecular clock and population genetic analyses of mitochondrial (mtDNA) COI gene and ITS rRNA (internal transcribed spacer) data revealed considerable phylogeographic structuring of Moggridgea populations, with evidence for long-term (>3 million years) isolation of at least nine populations in different geographic locations, including upland regions of the Stirling and Porongurup Ranges. High levels of mtDNA divergence and no evidence of recent mitochondrial gene flow among valley populations of the Stirling Range suggest that individual valleys have acted as refugia for the spiders throughout the Pleistocene. Our findings support the hypothesis that climate change, particularly the aridification of Australia after the late Miocene, and the topography of the landscape, which allowed persistence of moist habitats, have been major drivers of speciation in southwestern Australia.
Earth is currently experiencing the sixth mass extinction of complex multi-cellular life, the first at the hands of a single species. The documented extinctions of iconic (mostly vertebrate and plant) taxa dominate the discourse, while poorly known invertebrate species are disappearing ‘silently’, sometimes without having ever been described. Here, we highlight the decline of elements of the trapdoor spider (Mygalomorphae: Idiopidae) fauna of southern Australia – a taxonomically poorly documented yet diverse assemblage of long-lived fossorial predators. We show that a number of trapdoor spider species may be threatened after a century of intensive land clearing and stocking, and that remaining populations in some areas may be experiencing serious contemporary population declines. So, how do we conserve this fauna? We suggest that baseline systematic studies are crucial, and that follow-up surveys, including integrative citizen science solutions, should be used to assess where remnant populations still exist, and whether they can persist into the future. Detailed population genetic research on a handful of carefully chosen taxa could be broadly informative, and ongoing natural history studies remain invaluable. Although solutions may be limited in the face of ongoing habitat degradation and other threats, urgently quantifying declines has implications not just for spiders but for mitigating against the mass extinction of poorly known invertebrate taxa across the globe
Summary1. Developing a predictive understanding of how species assemblages respond to fire is a key conservation goal. In moving from solely describing patterns following fire to predicting changes, plant ecologists have successfully elucidated generalizations based on functional traits. Using species traits might also allow better predictions for fauna, but there are few empirical tests of this approach. 2. We examined whether species traits changed with post-fire age for spiders in 27 sites, representing a chronosequence of 0-20 years post-fire. We predicted a priori whether spiders with ten traits associated with survival, dispersal, reproduction, resource-utilization and microhabitat occupation would increase or decrease with post-fire age. We then tested these predictions using a direct (fourth-corner on individual traits and composite traits) and an indirect (emergent groups) approach, comparing the benefits of each and also examining the degree to which traits were intercorrelated. 3. For the seven individual traits that were significant, three followed predictions (body size, abundance of burrow ambushers and burrowers was greater in recently burnt sites); two were opposite (species with heavy sclerotisation of the cephalothorax and longer time to maturity were in greater abundance in long unburnt and recently burnt sites respectively); and two displayed response patterns more complex than predicted (abdominal scutes displayed a U-shaped response and dispersal ability a hump shaped curve). However, within a given trait, there were few significant differences among post-fire ages. 4. Several traits were intercorrelated and scores based on composite traits used in a fourth-corner analysis found significant patterns, but slightly different to those using individual traits. Changes in abundance with post-fire age were significant for three of the five emergent groups. The fourthcorner analysis yielded more detailed results, but overall we consider the two approaches complementary. 5. While we found significant differences in traits with post-fire age, our results suggest that a traitbased approach may not increase predictive power, at least for the assemblages of spiders we studied. That said, there are many refinements to faunal traits that could increase predictive power.
The Australasian spiny trapdoor spiders of the family Idiopidae (subfamily Arbanitinae) are revised at the generic level, using a multi-locus molecular phylogenetic foundation and comprehensive sampling of all known lineages. We propose a new family- and genus-group classification for the monophyletic Australasian fauna, and recognise 10 genera in four tribes. The Arbanitini Simon includes Arbanitis L. Koch, 1874 (61 species), Blakistonia Hogg, 1902 (one species) and Cantuaria Hogg, 1902 (43 species). The Aganippini Simon includes Bungulla Rix, Main, Raven & Harvey, gen. nov. (two species), Eucanippe Rix, Main, Raven & Harvey, gen. nov. (one species), Eucyrtops Pocock, 1897 (two species), Gaius Rainbow, 1914 (one species) and Idiosoma Ausserer, 1871 (14 species). The Cataxiini Rainbow and Euoplini Rainbow include just Cataxia Rainbow, 1914 (11 species) and Euoplos Rainbow, 1914 (12 species), respectively. Two distinctive new genera of Aganippini are described from Western Australia, and several previously valid genera are recognised as junior synonyms of existing genus-group names, including Misgolas Karsch, 1878 (= Arbanitis; new synonymy), Aganippe O. P.-Cambridge, 1877 (= Idiosoma; new synonymy) and Anidiops Pocock, 1897 (= Idiosoma; new synonymy). Gaius stat. rev. is further removed from synonymy of Anidiops. Other previously hypothesised generic synonyms are supported by both morphology and molecular phylogenetic data from 12 genes, including the synonymy of Neohomogona Main, 1985 and Homogona Rainbow, 1914 with Cataxia, and the synonymy of Albaniana Rainbow & Pulleine, 1918, Armadalia Rainbow & Pulleine, 1918, Bancroftiana Rainbow & Pulleine, 1918 and Tambouriniana Rainbow & Pulleine, 1918 with Euoplos. At the species level, the identifications of Eucy. latior (O. P.-Cambridge, 1877) and I. manstridgei (Pocock, 1897) are clarified, and three new species are described: Bungulla bertmaini Rix, Main, Raven & Harvey, sp. nov., Eucanippe bifida Rix, Main, Raven & Harvey, sp. nov. and Idiosoma galeosomoides Rix, Main, Raven & Harvey, sp. nov., the latter remarkable for its phragmotic abdominal morphology. The Tasmanian species Mygale annulipes C. L. Koch, 1842 is here transferred to the genus Stanwellia Rainbow & Pulleine, 1918 (family Nemesiidae), comb. nov., Arbanitis mestoni Hickman, 1928 is transferred to Cantuaria, comb. nov. and Idiosoma hirsutum Main, 1952 is synonymised with I. sigillatum (O. P.-Cambridge, 1870), new synonymy. In addition to the morphological synopses and an illustrated key to genera, molecular diagnoses are presented for all nominal taxa, along with live habitus and burrow images to assist in field identification. The Australasian idiopid fauna is highly diverse, with numerous new species known from all genera. As a result, this study provides a taxonomic and nomenclatural foundation for future species-level analyses, and a single reference point for the monographic documentation of a remarkable fauna. http://zoobank.org/?lsid=urn:lsid:zoobank.org:pub:BACE065D-1EF9-40C6-9134-AADC9235FAD8
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