Please use this identifier to cite or link to this item: http://hdl.handle.net/2440/120494
Type: Thesis
Title: [EMBARGOED] Contributions to the systematics and biogeography of the mygalomorph spider families Migidae and Idiopidae in Australia
Author: Harrison, Sophie Ellen
Issue Date: 2018
School/Discipline: School of Biological Sciences
Abstract: The genus Blakistonia Hogg, 1902 is a member of the spiny trapdoor spider family Idiopidae, and has a mostly semi-arid, southern Australian distribution. Prior to the publications in this thesis, Blakistonia contained only two species: B. rainbowi (Pulleine, 1919) and the type species B. aurea Hogg, 1902, with a third species, B. exsiccatus (Strand, 1907), being recently designated a nomen dubium. Here, I undertook a systematic revision of Blakistonia, using a combined molecular and morphological approach. This firstly required a review of the taxonomic history of the genus and a reappraisal of the enigmatic species ‘Blakistonia’ rainbowi, which was originally described in the idiopid genus Aganippe O. P.-Cambridge, 1877, and then mistakenly transferred to Blakistonia. Following the timely rediscovery of this species on Kangaroo Island, we demonstrated that ‘B.’ rainbowi is in fact a valid species and member of the otherwise African genus Moggridgea O. P.-Cambridge, 1875 (family Migidae) and, accordingly, the species is transferred to that genus and family. The trapdoor spider genus Moggridgea is widespread across the Afrotropical region, and the rediscovery and redescription of M. rainbowi from Kangaroo Island was a highlight of this project. I also investigated the biogeographic history and phylogenetic relationships of M. rainbowi within the family Migidae. Specimens of Moggridgea were sampled from Africa, and Bertmainus, a related Australian genus, were sampled from south-western Australia. Sanger sequencing methods were used to generate a robust six marker molecular dataset consisting of the nuclear genes 18S rRNA, 28S rRNA, ITS rRNA, XPNPEP3 and H3, and the mitochondrial gene COI. Bayesian and maximum likelihood phylogenetic methods were used to analyse the dataset, and the key nodes were dated using BEAST. The resulting trees showed that M. rainbowi from Kangaroo Island is deeply nested within African Moggridgea and is unrelated to Australian members of the family. Significantly, the inter-specific divergence of M. rainbowi from African congeners significantly post-dates the separation of Africa from Gondwana and therefore does not support a vicariant origin for Australian Moggridgea. It also substantially pre-dates human colonisation of Kangaroo Island, a result which is further supported by phylogeographic structuring between separate populations on Kangaroo Island. These results provide strong support for the hypothesis that Moggridgea colonised Australia via long-distance trans-Indian Ocean dispersal. To revise the taxonomy of Blakistonia, i.e. to redescribe the widespread type species, and to describe all new taxa, species limits were determined using both freshly collected and museum specimens for morphological characterisation. Sequence data from the COI barcoding gene were analysed using Bayesian, RAxML and neighbour-joining approaches. The type species, B. aurea, is redescribed and 19 species are described as new. These species are B. bassi sp. n., B. bella sp. n., B. birksi sp. n., B. carnarvon sp. n., B. emmottiorum sp. n., B. gemmelli sp. n., B. hortoni sp. n., B. mainae sp. n., B. maryae sp. n., B. newtoni sp. n., B. nullarborensis sp. n., B. olea sp. n., B.parva sp. n., B. pidax sp. n., B. plata sp. n., B.raveni sp. n., B. tariae sp. n., B. tunstill sp. n., and B. wingellina sp. n. An illustrated key is provided for both male and females, and molecular diagnoses are supplied for all species for which molecular data are available. Wherever possible, live habitus and burrow photos are provided for each species, and a discussion of their conservation status is presented. Finally, my general discussion provides a synopsis of recent research and its impact on providing a better understanding of the diversity, biogeography and conservation of mygalomorph spiders in Australia, and opportunities for future research.
Advisor: Austin, Andy
Cooper, Steve
Harvey, Mark
Dissertation Note: Thesis (Ph.D.) -- University of Adelaide, School of Biological Sciences, 2019
Keywords: Mygalomorph
dispersal
systematics
biogeography
taxonomy
Provenance: This thesis is currently under Embargo and not available.
Appears in Collections:Research Theses

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