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Browsing Environment Institute Leaders publications by Author "Abrams, K."
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Item Metadata only Molecular phylogenetic, morphological and biogeographic evidence for a new genus of parabathynellid crustaceans (Syncarida:Bathynellacea) from groundwater in an ancient southern Australian landscape(C S I R O Publishing, 2013) Abrams, K.; King, R.; Guzik, M.; Cooper, S.; Austin, A.The putatively ancient subterranean crustacean family Parabathynellidae has been poorly studied, in part because of the problem of obtaining material from difficult to access subterranean habitats in which they live. Further, the systematics of the group has been complicated by their generally simplified morphology and isolated descriptions of new taxa in the absence of any phylogenetic framework. Using material from comprehensive field surveys and mitochondrial cytochrome c oxidase subunit I (COI) and nuclear 18S sequence data, plus morphology, a new genus is recognised, Arkaroolabathynella Abrams & King, gen. nov., from underground waters in the Flinders Ranges, South Australia. Arkaroolabathynella contains four genetically and morphologically distinct species, described as A. bispinosa Abrams & King, sp. nov., A. remkoi Abrams & King, sp. nov., A. robusta Abrams & King, sp. nov. and A. spriggi Abrams & King, sp. nov. Phylogenetic analysis also revealed a previously unknown diversity of parabathynellids from southern Australia, and a complex set of relationships with the eastern (New South Wales) and south-western (Western Australia) continental faunas. Additionally, this study showed that deep molecular divergences in parabathynellids are not always reflected in morphological divergence. A checklist to Australian parabathynellid genera and species is also provided.Item Metadata only Phylogeography of the ancient Parabathynellidae (Crustacea : Bathynellacea) from the Yilgarn region of western Australia(C S I R O Publishing, 2008) Guzik, M.; Abrams, K.; Cooper, S.; Humphreys, W.; Cho, J.; Austin, A.The crustacean order Bathynellacea is a primitive group of subterranean aquatic (stygobitic) invertebrates that typically inhabits freshwater interstitial spaces in alluvia. A striking diversity of species from the bathynellacean family Parabathynellidae have been found in the calcretes of the Yilgarn palaeodrainage system in Western Australia. Taxonomic studies show that most species are restricted in their distribution to a single calcrete, which is consistent with the findings of other phylogeographic studies of stygofauna. In this, the first molecular phylogenetic and phylogeographic study of interspecific relationships among parabathynellids, we aimed to explore the hypothesis that species are short-range endemics and restricted to single calcretes, and to investigate whether there were previously unidentified cryptic species. Analyses of sequence data based on a region of the mitochondrial (mt) DNA cytochrome c oxidase 1 gene showed the existence of divergent mtDNA lineages and species restricted in their distribution to a single calcrete, in support of the broader hypothesis that these calcretes are equivalent to closed island habitats comprising endemic taxa. Divergent mtDNA lineages were also observed to comprise four new and 12 recognised morphospecies. These results reflect the findings of previous studies of stygobitic arthropods (beetles, amphipods and isopods) from the Yilgarn region and reinforce the usefulness of using DNA-sequence data to investigate species boundaries and the presence of cryptic species.Item Metadata only Species diversity and genetic differentiation of stygofauna (Syncarida: Bathynellacea) across an alluvial aquifer in north-eastern Australia(C S I R O Publishing, 2012) Cook, B.; Abrams, K.; Marshall, J.; Perna, C.; Choy, S.; Guzik, M.; Cooper, S.Recent research suggests that alluvial aquifers in southern and eastern Australia may contain a diverse subterranean aquatic fauna (i.e. stygofauna). However, to date only a limited number of alluvial aquifers have been studied and little molecular data are available to assess species-level diversity and spatial patterns of genetic variation within stygofaunal species. In this paper, we present the initial results of a stygofaunal survey of the Burdekin River alluvial aquifer in Queensland, extending the northern range of alluvial aquifers along the east coast of Australia that have been investigated. The survey resulted in the collection of bathynellid stygofauna (Syncarida: Bathynellacea) and genetic analyses were conducted to determine species level diversity using the mitochondrial cytochrome oxidase subunit I (COI) gene. We further investigated the phylogenetic relationships of the species with bathynellids from western and southern Australia to assess the generic status of species. Four highly divergent COI lineages within the Parabathynellidae and one lineage within the Bathynellidae were found. These lineages did not group within any described genera, and phylogenetic analyses indicated that both local radiations and the retention of a lineage that was more apical in the genealogy account for the diversity within the Parabathynellidae in the Burdekin River alluvial aquifer. Most COI lineages were sampled from only a single bore, although one taxon within the Parabathynellidae was found to be more widespread in the aquifer. Haplotypes within this taxon were not shared among bores (ΦST = 0.603, P < 0.001). Overall, the high species diversity for bathynellaceans from an alluvial aquifer reported here, and surveys of bathynellaceans in several other alluvial systems in south-eastern Australia, suggests that groundwater ecosystems of eastern Australia may contain high stygofaunal diversity by Australian and world standards, particularly at the generic level for parabathynellids.Item Metadata only What lies beneath: Molecular phylogenetics and ancestral state reconstruction of the ancient subterranean Australian Parabathynellidae (Syncarida, Crustacea)(Academic Press Inc Elsevier Science, 2012) Abrams, K.; Guzik, M.; Cooper, S.; Humphreys, W.; King, R.; Cho, J.; Austin, A.The crustacean family Parabathynellidae is an ancient and significant faunal component of subterranean ecosystems. Molecular data were generated in order to examine phylogenetic relationships amongst Australian genera and assess the species diversity of this group within Australia. We also used the resultant phylogenetic framework, in combination with an ancestral state reconstruction (ASR) analysis, to explore the evolution of two key morphological characters (number of segments of the first and second antennae), previously used to define genera, and assess the oligomerization principle (i.e. serial appendage reduction over time), which is commonly invoked in crustacean systematics. The ASR approach also allowed an assessment of whether there has been convergent evolution of appendage numbers during the evolution of Australian parabathynellids. Sequence data from the mtDNA COI and nDNA 18S rRNA genes were obtained from 32 parabathynellid species (100% of described genera and ~25% of described species) from key groundwater regions across Australia. Phylogenetic analyses revealed that species of each known genus, defined by traditional morphological methods, were monophyletic, suggesting that the commonly used generic characters are robust for defining distinct evolutionary lineages. Additionally, ancestral state reconstruction analysis provided evidence for multiple cases of convergent evolution for the two morphological characters evaluated, suggesting that caution needs to be shown when using these characters for elucidating phylogenetic relationships, particularly when there are few morphological characters available for reconstructing relationships. The ancestral state analysis contradicted the conventional view of parabathynellid evolution, which assumes that more simplified taxa (i.e. those with fewer-segmented appendages and setae) are derived and more complex taxa are primitive.