The evolution of epigean and stygobitic species of Koonunga Sayce, 1907 (Syncarida: Anaspidacea) in Southern Australia, with the description of three new species

Three new species of Koonunga were discovered in surface and subterranean waters in southern Australia, and were defined using mtDNA analyses and morphology. The new species are: Koonunga hornei Leijs & King; K. tatiaraensis Leijs & King and K. allambiensis Leijs & King. Molecular clock analyses indicate that the divergence times of the species are older than the landscape that they currently inhabit. Different scenarios explaining this apparent discrepancy are discussed in the context of the palaeography of the area. A freshwater epigean origin for Koonunga is considered the most likely hypothesis, whereby some lineages made the transition to the subterranean environment within the last few million years influenced by significant climatic cooling/drying. We discuss the possibility that one stygobitic lineage secondarily regained some of its body pigmentation as adaptation to increased photic conditions after cave collapse and forming of cenotes during the last glacial maximum.Remko Leijs, Tessa Bradford, James G. Mitchell, William F. Humphreys, Steven J. B. Cooper, Peter Goonan, Rachael A. Kin

Re-evaluation of the distribution of Geocrinia Laevis (Anura: Leptodactylidae) in South Australia

Steven J. Walker & Peter M. Goona

The definition of species richness used by species sensitivity distributions approximates observed effects of salinity on stream macroinvertebrates

The risk of chemicals for ecological communities is often forecast with species sensitivity distributions (SSDs) which are used to predict the concentration which will protect p% of species (PC value). However, at the PC value, species richness in nature would not necessary be p% less than at uncontaminated sites. The definition of species richness inherent to SSDs (contaminant category richness) contrasts with species richness typically measured in most field studies (point richness). We determine, for salinity in eastern Australia, whether these definitions of stream macroinvertebrate species richness are commensurable. There were strong relationships (r ≥ 0.87) between mean point species, family and Ephemeroptera, Trichoptera and Plecoptera species richness and their respective contamination category richness. Despite differences in the definition of richness used by SSDs and field biomonitoring, their results in terms of relative species loss from salinity in south-east Australia are similar. We conclude that in our system both definitions are commensurable

Temporal Patterns and Environmental Correlates of Macroinvertebrate Communities in Temporary Streams

<div><p>Temporary streams are characterised by short periods of seasonal or annual stream flow after which streams contract into waterholes or pools of varying hydrological connectivity and permanence. Although these streams are widespread globally, temporal variability of their ecology is understudied, and understanding the processes that structure community composition in these systems is vital for predicting and managing the consequences of anthropogenic impacts. We used multivariate and univariate approaches to investigate temporal variability in macroinvertebrate compositional data from 13 years of sampling across multiple sites from autumn and spring, in South Australia, the driest state in the driest inhabited continent in the world. We examined the potential of land-use, geographic and environmental variables to predict the temporal variability in macroinvertebrate assemblages, and also identified indicator taxa, that is, those highly correlated with the most significantly associated physical variables. Temporal trajectories of macroinvertebrate communities varied within site in both seasons and across years. A combination of land-use, geographic and environmental variables accounted for 24% of the variation in community structure in autumn and 27% in spring. In autumn, community composition among sites were more closely clustered together relative to spring suggesting that communities were more similar in autumn than in spring. In both seasons, community structure was most strongly correlated with conductivity and latitude, and community structure was more associated with cover by agriculture than urban land-use. Maintaining temporary streams will require improved catchment management aimed at sustaining seasonal flows and critical refuge habitats, while also limiting the damaging effects from increased agriculture and urban developments.</p></div

Results of general linear models for the relationships of the biodiversity indices to site, season (site nested within season) and year (site nested within year).

<p><i>df</i> represents the degrees of freedom for the sources of variation. Bold numbers indicate significant <i>P</i>-values.</p><p>Results of general linear models for the relationships of the biodiversity indices to site, season (site nested within season) and year (site nested within year).</p

RELATE results (ρ and <i>P</i>-value) reported for seriation of macroinvertebrate composition at each site for each season.

<p>Sites names with “Ck” and “R” represent creeks and rivers respectively. ρ signifies Spearman’s correlations in the seriation test; if |0.8 ≤ <i>ρ</i> ≤ 1.0|, then there is a clear trend in the trajectories of the community composition [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0142370#pone.0142370.ref028" target="_blank">28</a>].</p

Results of permutational multivariate analysis of variance (PERMANOVA).

<p><i>df</i> represents degrees of freedom. Bold numbers indicate significant <i>P</i>-values.</p

Map of South Australia, showing the distribution of major land-uses and the sampling sites.

<p>Circles represent study sites; heavy black lines represent catchment area upstream of study sites; grey lines represent coastline and state borders; thin black lines represent boundaries to NMR regions. Land-use South Australia layer was sourced from Australian Natural Resources Data Library and their classifications were based on the Australian Land-use and Management (ALUM) classification.</p

Results of general linear models for the relationships of the biodiversity indices to geographic, environmental and land-use predictor variables in autumn and spring.

<p>S.E. represents the standard error of the coefficients. Bold numbers indicate significant P-values. *indicates trending <i>P</i>-values. Abbreviations for predictor variables are listed in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0142370#pone.0142370.s001" target="_blank">S1 Table</a>.</p

Southern South Australian groundwater microbe diversity

Groundwater is increasingly used globally for domestic, industrial and agricultural production. While many studies have focused on groundwater as a resource, the diverse ecosystems within are often ignored. Here, we assess 54 Southern South Australian groundwater microbial communities from the populated part of the state to assess their status and dynamics in isolated groundwater systems. We observed a strong site-to-site individuality in groundwater bacterial communities, likely due to the isolated nature of groundwater bodies leading to unique ecosystems. Rank abundance analysis indicates bacterial diversity is maintained even at low abundances and that the distribution fits classical ecological models for strong competition in resource-limited environments. Combined, our data indicates that despite overrepresentation of pollutant-associated bacterial orders in and around the Adelaide metropolitan area, microbial communities remain diverse and show little evidence of converging on a common pollutant-effected community