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Koenders A.,Edith Cowan University | Martens K.,Royal Belgian Institute Of Natural Sciences | Martens K.,Ghent University | Halse S.,Bennelongia Environmental Consultants | And 2 more authors.
Biological Invasions | Year: 2012

Eucypris virens, an ostracod with mixed reproduction and Holarctic distribution, forms a species complex with more than 35 cryptic species in Europe. Here, we analysed COI and LSU DNA sequence data from Western Australian E. virens to distinguish between the possibilities that vicariant processes have led to the formation of Australian E. virens species or that these ostracods have been introduced into Western Australia. Phylogenetic reconstructions, genetic networks and estimates of genetic distances all show clearly that Western Australian and European E. virens are very closely related. Some haplotypes are identical, others are only separated by one or two mutational steps. Among the Western Australian representatives of E. virens, three phylogenetic clades can be distinguished. We identified three European cryptic species as ancestors for two of the Western Australian clades and one close relative to the third Western Australian clade. We therefore conclude that E. virens has been introduced into Western Australia, most likely from western Europe, and did not diverge in Australia. In Europe, E. virens shows a typical pattern of geographic parthenogenesis while we found only asexual populations in Western Australia. © 2012 Springer Science+Business Media B.V. Source

Schon I.,Royal Belgian Institute Of Natural Sciences | Schon I.,Hasselt University | Shearn R.,Edith Cowan University | Martens K.,Royal Belgian Institute Of Natural Sciences | And 3 more authors.
Hydrobiologia | Year: 2015

South-western Australia holds an exceptional number of endemic taxa and has been recognized as a biodiversity hotspot at a global scale. We report a much higher diversity in the genus Bennelongia (Ostracoda) in Western than in eastern Australia. Using mitochondrial COI sequence data for phylogenies, relative age estimates, lineage-through-time plots, and reconstructions of ancestral distributions, we test four hypotheses that might explain the higher diversity and endemicity in Western Australia. (1) We find no evidence for ancient relictualism as most Bennelongia species are probably of Miocene age. (2) There are also no apparent links to vicariant events: speciation has mostly taken place in Western Australia and has been ongoing through the evolutionary history of Bennelongia. (3) Dispersal has apparently not negatively affected Western Australian Bennelongia endemicity although these ostracods produce drought-resistant eggs. We report one case of recent long distance dispersal in B. dedeckkeri with genetically identical populations occurring more than 2,000 km apart. (4) Since speciation has been ongoing, there is no evidence of recent explosive speciation through genetic isolation. The underlying mechanisms of Bennelongia speciation thus remain elusive, although speciation has mostly occurred during a period of increasing aridification of Australia. © 2015, Springer International Publishing Switzerland. Source

Shearn R.,Edith Cowan University | Halse S.,Bennelongia Environmental Consultants | Koenders A.,Edith Cowan University | Scho I.,Royal Belgian Institute Of Natural Sciences | And 3 more authors.
Zootaxa | Year: 2014

In this paper, we redescribe six species of the genus Ilyodromus Sars, 1894: I, stanleyanus (King, 1855), I. varrovillius (King, 1855), I. smaragdinus Sars, 1894, I. obtusus Sars, 1894, I. substriatus Sars, 1894 and I. viridulus (Brady, 1886) using materials stored in the Oslo museum (Norway) and (re-) described by G.O. Sars. For each species examined, we have identified a number of additional diagnostic characters to those used by Sars and earlier authors. In particular, the length of setae, claws and segments of the antennule, antenna, sixth limb, and caudal ramus appear to be important for species delineation in the genus, as does the internal structure of the valves. Copyright © 2014 Magnolia Press Source

Martens K.,Royal Belgian Institute Of Natural Sciences | Martens K.,Ghent University | Halse S.,Bennelongia Environmental Consultants | Schon I.,Royal Belgian Institute Of Natural Sciences | Schon I.,Hasselt University
European Journal of Taxonomy | Year: 2015

The ostracod genus Bennelongia De Deckker & McKenzie, 1981 occurs in Australia and New Zealand. We redescribe B. nimala from the Northern Territory and describe six new species from Western Australia belonging to the B. nimala (five species) and B. triangulata sp. nov. (one species) lineages: B. tirigie sp. nov., B. koendersae sp. nov., B. pinderi sp. nov., B. muggon sp. nov., B. shieli sp. nov. and B. triangulata sp. nov. For six of these seven species, we could construct molecular phylogenies and parsimonious networks based on COI sequences. We tested for specific status and for potential cryptic diversity of clades with Birky’s 4 theta rule. The analyses support the existence of these six species and the absence of cryptic species in these lineages. Bennelongia triangulata sp. nov. is a common species in the turbid claypans of the Murchison/ Gascoyne region. Bennelongia nimala itself is thus far known only from the Northern Territory. Bennelongia tirigie sp. nov., B. pinderi sp. nov. and B. muggon sp. nov. occur in the Murchison/ Gascoyne region, whereas B. koendersae sp. nov. and B. shieli sp. nov. are described from the Pilbara. With the six new species described here, the genus Bennelongia now comprises 31 nominal species. © 2015, Museum National d'Histoire Naturelle. All rights reserved. Source

Halse S.A.,Bennelongia Environmental Consultants | Pearson G.B.,Bennelongia Environmental Consultants
Subterranean Biology | Year: 2014

Most sampling of troglofauna occurs in caves but troglofauna species are widespread across the vadose zone in Western Australia in iron ore deposits and calcretes. Other than in karstic calcrete, the subterranean spaces in the Western Australian vadose zone are small and often of similar size to the troglofauna inhabiting them. Here we describe how troglofauna can be sampled in the vadose zone using a technique called scraping, in which a haul net is dropped down a hole drilled for geological exploration. We analysed of the results of 10,895 sampling events in which both the scraping and trapping techniques were used. In the Pilbara region of Western Australia, where most of the fieldwork occurred, scraping collected approximately three-quarters more troglofaunal animals than trapping and more than twice as many troglofauna species per sample. Most orders of troglofauna were collected in greater numbers by scraping than trapping. However, the yields from both troglofauna sampling techniques are low and, even when the results of both techniques are combined to constitute a single unit of sample effort, the currently prescribed effort for environmental impact assessment will document only about half the species present at a site. It is suggested that a larger number of samples should be collected. Source

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