VIEWPOINT. Is the Australian subterranean fauna uniquely diverse?

Abstract

Abstract. Australia was historically considered a poor prospect for subterranean fauna but, in reality, the continent holds a great variety of subterranean habitats, with associated faunas, found both in karst and non-karst environments. This paper critically examines the diversity of subterranean fauna in several key regions for the mostly arid western half of Australia. We aimed to document levels of species richness for major taxon groups and examine the degree of uniqueness of the fauna. We also wanted to compare the composition of these ecosystems, and their origins, with other regions of subterranean diversity world-wide. Using information on the number of 'described' and 'known' invertebrate species (recognised based on morphological and/or molecular data), we predict that the total subterranean fauna for the western half of the continent is 4140 species, of which~10% is described and 9% is 'known' but not yet described. The stygofauna, water beetles, ostracods and copepods have the largest number of described species, while arachnids dominate the described troglofauna. Conversely, copepods, water beetles and isopods are the poorest known groups with less than 20% described species, while hexapods (comprising mostly Collembola, Coleoptera, Blattodea and Hemiptera) are the least known of the troglofauna. Compared with other regions of the world, we consider the Australian subterranean fauna to be unique in its diversity compared with the northern hemisphere for three key reasons: the range and diversity of subterranean habitats is both extensive and novel; direct faunal links to ancient Pangaea and Gondwana are evident, emphasising their early biogeographic history; and Miocene aridification, rather than Pleistocene post-ice age driven diversification events

Protecting the innocent: studying short-range endemic taxa enhances conservation outcomes

“…The EPA wishes 'to ensure adequate protection of important habitats for these species' (Environmental Protection Authority 2003), and the onus is on proponents to demonstrate that SRE species, including subterranean fauna, are not irreparably affected by the proposed activity. A positive side effect of these requirements is that we are now gaining insights into a previously poorly known and largely undocumented fauna (see review by Guzik et al 2011a). Collaborative research projects being developed between industry, government and universities foster a unique blend of outcomes that not only document and describe the fauna, but also provide sufficient background data against which regulatory authorities can assess proposals to ensure positive conservation outcomes.…”

“…Leys et al 2003;Edward and Harvey 2008;Guzik et al 2008;Harvey et al 2008;Guzik et al 2011a) and epigean shortrange endemic taxa (e.g. Solem 1979Solem , 1981aSolem , 1981bSolem , 1984Solem , 1985Solem , 1988Solem , 1991Solem , 1993Solem , 1997Johnson et al 2006;Edward and Harvey 2010;Rix and Harvey 2010) provides insights into the diversification of the Western Australian biota under increasingly arid influences since the late Oligocene and Miocene.…”

“…Many species are known to be endemic to individual geological formations, such as pisolitic mesas only a few hundred hectares in area , and no species are known from an area greater than 500 km 2 , clearly conforming to current definitions of short-range endemism (Harvey 2002;Eberhard et al 2009;Environmental Protection Authority 2009). Knowledge of the taxonomy and distribution of different species and genera has been refined with each new discovery, and recent molecular phylogeographic research has highlighted the evolutionary inter-relationships among species ) and the remarkable subterranean biogeography of the region (summarised in Guzik et al 2011a).…”

“…Harvey (2002) suggested a nominal range of less than 10 000 km 2 as a working definition of short-range endemism, but Eberhard et al (2009), considering stygofauna, recommended a reduced area of less than 1000 km 2 . Even this may need further refinement as, for example, groundwater calcrete aquifers of the southern Western Shield (Yilgarn) each have unique faunas largely comprising endemic species (Humphreys 2008;Guzik et al 2011a;and references therein). Of 77 unique calcrete faunas listed as 'priority communities' by the Western Australian Department of Environment and Conservation, the mean area of each calcrete is 90.8 km 2 (range 0.89-2205 km 2 ) and some of these distinct calcretes are only 1 km apart.…”

Two new species of stygobitic Anzcyclops (Copepoda: Cyclopoida: Cyclopidae) from Australia

“…However, it should be recognised that while the Pilbara and adjacent Yilgarn regions in Western Australia appear to support substantially richer stygofauna communities than other parts of Australia (Guzik et al 2010), there has been comparatively little study of stygobitic copepods elsewhere in Australia and the number of described species in Queensland and New South Wales considerably underestimates known stygobitic copepod biodiversity in those states (e.g. Hancock and Boulton 2008;Karanovic and Hancock 2009).…”