Victorian Populations Research Articles

Population genomics of decline and local extinction in the endangered Australian Pookila

Modern sequencing approaches, especially museum genomics, have unlocked the potential to integrate genome-scale data from across decades of collections to reconstruct population decline and extinction. Understanding species declines, both pre- and post-anthropogenic impact, is critical for data-driven approaches to conservation and genetic management of endangered species worldwide. This is especially important in Australia, where the ecological consequences of European invasion have resulted in the highest rate of mammal extinction in the world. Using historical museum specimens, cryopreserved cell cultures, and field tissue collections, we generate genomic data (1298 nuclear exons and whole mitogenomes) from extinct and surviving populations of the endangered Australian Pookila (Pseudomys novaehollandiae), a species that has suffered severe declines since European invasion in 1788. Our results reveal 23.2–35.3 % of unique genetic diversity has been lost to local extinction in Victoria in the past 50 years, with ongoing population decline and inbreeding exacerbated by natural barriers to dispersal. We show that small, isolated remnant populations are especially vulnerable to extinction, reinforced by the extinction of seven out of 12 historically recorded populations in Victoria. Future extinction of any one of three Victorian populations examined here will result in the loss of 15–46 % of remaining unique alleles. We recommend genetic rescue within Victoria as a critical management intervention, in combination with the continuation of population monitoring and adaptive habitat management, to save P. novaehollandiae from extinction. Broadly, we demonstrate how integrating historical and contemporary collections can provide crucial guidance for genetic management and conservation of threatened species.

Monitoring the population status of a secretive lizard, the threatened heath skinkLiopholis multiscutata, in south‐eastern Australia using surrogate metrics: An update

AbstractOur recent study compared monitoring data collected using surrogate metrics during 2014–2018 inclusive with baseline data from 2007 to evaluate the trajectory of the population status of the threatened heath skinkLiopholis multiscutatain Victoria. The heath skink is a secretive burrowing species that is a habitat specialist and exists in north‐western Victoria as a few small and highly disjunct populations on large dunes in semi‐arid heathland or mallee. We re‐assessed the trajectories of the Victorian populations with additional monitoring data collected in 2021 and found continuing decline across all four Victorian heath skink populations. Urgent management intervention is required to arrest this decline, likely due to predation, reduced availability of habitat and life history and demographic traits that make this species susceptible to decline.

Phylogenetic placement of a recently discovered population of the threatened alpine she-oak skink Cyclodomorphus praealtus (Squamata: Scincidae) in Victoria

The alpine she-oak skink Cyclodomorphus praealtus is a threatened alpine endemic lizard from the mainland of Australia. The species is previously known from disjunct populations in Kosciuszko National Park in New South Wales and three isolated localities in the Victorian Alps. The New South Wales and Victorian populations represent separate evolutionarily significant units. In 2011, a fourth Victorian population was discovered. We conducted a phylogenetic analysis and determined that the newly discovered population is discrete and may have been separated from other populations since the end of the last glacial maxima. This population requires separate management.

An endangered flightless grasshopper with strong genetic structure maintains population genetic variation despite extensive habitat loss.

Conservation research is dominated by vertebrate examples but the shorter generation times and high local population sizes of invertebrates may lead to very different management strategies, particularly for species with low movement rates. Here we investigate the genetic structure of an endangered flightless grasshopper, Keyacris scurra, which was used in classical evolutionary studies in the 1960s. It had a wide distribution across New South Wales (NSW) and Victoria in pre‐European times but has now become threatened because of land clearing for agriculture and other activities. We revisited remnant sites of K. scurra, with populations now restricted to only one area in Victoria and a few small patches in NSW and the Australian Capital Territory (ACT). Using DArtseq to generate SNP markers as well as mtDNA sequence data, we show that the remaining Victorian populations in an isolated valley are genetically distinct from the NSW populations and that all populations tend to be genetically unique, with large F ST values up to 0.8 being detected for the SNP datasets. We also find that, with one notable exception, the NSW/ACT populations separate genetically into previously described chromosomal races (2n = 15 vs. 2n = 17). Isolation by distance was detected across both the SNP and mtDNA datasets, and there was substantial differentiation within chromosomal races. Genetic diversity as measured by heterozygosity was not correlated with the size of remaining habitat where the populations were found, with high variation present in some remnant cemetery sites. However, inbreeding correlated negatively with estimated habitat size at 25–500 m patch radius. These findings emphasize the importance of small habitat areas in conserving genetic variation in such species with low mobility, and they highlight populations suitable for future translocation efforts.

Evolutionary history and genetic connectivity across highly fragmented populations of an endangered daisy

Conservation management can be aided by knowledge of genetic diversity and evolutionary history, so that ecological and evolutionary processes can be preserved. The Button Wrinklewort daisy (Rutidosis leptorrhynchoides) was a common component of grassy ecosystems in south-eastern Australia. It is now endangered due to extensive habitat loss and the impacts of livestock grazing, and is currently restricted to a few small populations in two regions >500 km apart, one in Victoria, the other in the Australian Capital Territory and nearby New South Wales (ACT/NSW). Using a genome-wide SNP dataset, we assessed patterns of genetic structure and genetic differentiation of 12 natural diploid populations. We estimated intrapopulation genetic diversity to scope sources for genetic management. Bayesian clustering and principal coordinate analyses showed strong population genetic differentiation between the two regions, and substantial substructure within ACT/NSW. A coalescent tree-building approach implemented in SNAPP indicated evolutionary divergence between the two distant regions. Among the populations screened, the last two known remaining Victorian populations had the highest genetic diversity, despite having among the lowest recent census sizes. A maximum likelihood population tree method implemented in TreeMix suggested little or no recent gene flow except potentially between very close neighbours. Populations that were more genetically distinctive had lower genetic diversity, suggesting that drift in isolation is likely driving population differentiation though loss of diversity, hence re-establishing gene flow among them is desirable. These results provide background knowledge for evidence-based conservation and support genetic rescue within and between regions to elevate genetic diversity and alleviate inbreeding.

Identifying a surrogate metric for monitoring the population status of a secretive habitat specialist, the heath skinkLiopholis multiscutata,in south‐eastern Australia

AbstractThreatened species that exist in small isolated populations are vulnerable to extinction processes, so effectively monitoring the trajectory of such populations will help determine the most appropriate management actions to combat extinction threats. In this study, we aimed to track the population status of the fossorial heath skinkLiopholis multiscutatathat is listed as threatened in Victoria, south‐eastern Australia, and exists there as a few small and highly disjunct populations, by using an appropriate surrogate population monitoring metric. This secretive lizard is a habitat specialist, is highly localised in Victoria and lives in warrens in semi‐arid heathland or mallee on large dunes. Survey data, which included every warren and their constituent burrows, as well as an assessment of whether each burrow was ‘active’, were collected for the four known Victorian populations in 2007 and annually during 2014–2018 inclusive. We compared five population indices per monitoring site: number of active warrens (NAW), number of active burrows (NAB), population area for 80% of active warrens (PA80), percentage of warrens that were active (PAW) and average number of active burrows per active warren. The heath skink currently occurs in small populations (8–46 active warrens) and these populations have typically declined over recent years. NAW was the most robust metric; NAB and PA80 did not reveal strong temporal trends. PAW indicated that inactive warrens and burrows persist less than a year and hence may provide information about recent (within months) population changes. It is imperative to establish a material link between the effective monitoring of small, vulnerable populations and the implementation of management actions that benefit such populations. Here, NAW could be used as a long‐term monitoring tool to provide an estimate of the minimum population size of the heath skink at a site. Its use would also ensure continuity in monitoring approaches for the Victorian populations.

Molecular Assessment of the Introduction and Spread of Potato Cyst Nematode, Globodera rostochiensis, in Victoria, Australia.

Potato cyst nematodes (PCN) are damaging soilborne quarantine pests of potato in many parts of the world. There are two recognized species, Globodera pallida and G. rostochiensis, with only the latter species-the golden cyst nematode-present in Australia. PCN was first discovered in Australia in 1986 in Western Australia, where it was subsequently eradicated and area freedom for market access was reinstated. In Victoria, PCN was first detected in 1991 east of Melbourne. Since then, it has been found in a small number of localized regions to the south and east. Strict quarantine controls have been in place since each new detection. It has previously been speculated that there were multiple separate introductions of PCN into Victoria. Our study utilized a historic (years 2001 to 2014) PCN cyst reference collection to examine genetic variability of Victorian PCN populations to investigate potential historical origins and subsequent changes in the populations that might inform patterns of spread. DNA was extracted from single larvae dissected from eggs within cysts and screened using nine previously described polymorphic microsatellite markers in two multiplex polymerase chain reaction assays. Sequence variation of the internal transcribed spacer region of the DNA was also assessed and compared with previously published data. A hierarchical sampling strategy was used, comparing variability of larvae within cysts, within paddocks, and between local regions. This sampling revealed very little differentiation between Victorian populations, which share the same microsatellite allelic variation, with differences between local regions probably reflecting changes in allele frequencies over time. Our molecular assessment supports a probable single localized introduction into Victoria followed by limited spread to nearby areas. The Australian PCN examined appear genetically distinct from populations previously sampled worldwide; thus, any new exotic incursions, potentially bringing in additional PCN pathotypes, should be easily differentiated from existing established local PCN populations.

Thermal Injury Deaths of Community-dwelling Older People With Dementia.

Although people with dementia are prone to the risk of fire and burn injuries, the relationship between fatal thermal injuries and dementia has not been investigated. We examined coronial files in the state of Victoria, Australia between July 1, 2000 and December 31, 2014, for unintentional thermal injury causing deaths of community dwelling people, aged 65 years and older to identify those with dementia. Mortality for Victorian populations with and without dementia was calculated using direct age standardization. In total, 105 deaths were identified of which 18 (17%) had dementia. Mortality was more than 3-fold greater for people with dementia (3.0 vs. 0.8 per 100,000 person-years) and they more often lived with others when the injury occurred (56%, n=10 vs. 29% n=25, P=0.028). Our results suggest that older people with dementia are at greater risk of death through thermal injury. Further research should consider investigating a larger population through combining databases across multiple jurisdictions.

Genetic structure and diversity of the koala population in South Gippsland, Victoria: a remnant population of high conservation significance

In the Australian state of Victoria, the history of koalas and their management has resulted in the homogenisation and reduction of genetic diversity in many contemporary populations. Decreased genetic diversity may reduce a species’ ability to adapt to future environmental pressures such as climate change or disease. The South Gippsland koala population is considered to be unique in Victoria, as it is believed to be a remnant population, not originating from managed populations that have low genetic variation. This study investigated genetic structure and diversity of koalas in South Gippsland, with comparison to other populations in Victoria (French Island/Cape Otway, FI and Raymond Island, RI), New South Wales and south east Queensland. Population analyses were undertaken using both microsatellite genotype and mitochondrial DNA sequence data. Non-invasive sampling of koala scats was used to source koala DNA, allowing 222 South Gippsland koalas to be genotyped. Using nuclear data the South Gippsland koala population was found to be significantly differentiated (Djost 95% CI SG–RI = 0.03–0.06 and SG–FI = 0.08–012) and more diverse (AR 95% CI SG = 4.7–5.6, RI = 3.1–3.3, FI = 3.0–3.3; p = 0.001) than other Victorian koala populations, supporting the premise that koalas in the South Gippsland region are part of a remnant population, not derived from translocated island stock. These results were also supported by mitochondrial data where eight haplotypes (Pc4, Pc17, Pc26, Pc27, and Pc56–Pc59) were identified in South Gippsland while a single haplotype (Pc27) was found in all island koalas tested. Compared to other Victorian koala populations, greater genetic diversity found in South Gippsland koalas, may provide this population with a greater chance of survival in the face of future environmental pressures. The South Gippsland koala population is, therefore, of high conservation significance, warranting the implementation of strategies to conserve this population and its diversity into the future.

Using non-invasive sampling methods to determine the prevalence and distribution of Chlamydia pecorum and koala retrovirus in a remnant koala population with conservation importance

Context Pathogenic infections are an important consideration for the conservation of native species, but obtaining such data from wild populations can be expensive and difficult. Two pathogens have been implicated in the decline of some koala (Phascolarctos cinereus) populations: urogenital infection with Chlamydia pecorum and koala retrovirus subgroup A (KoRV-A). Pathogen data for a wild koala population of conservation importance in South Gippsland, Victoria are essentially absent. Aims This study uses non-invasive sampling of koala scats to provide prevalence and genotype data for C. pecorum and KoRV-A in the South Gippsland koala population, and compares pathogen prevalence between wild koalas and koalas in rescue shelters. Methods C. pecorum and KoRV-A provirus were detected by PCR of DNA isolated from scats collected in the field. Pathogen genetic variation was investigated using DNA sequencing of the C. pecorum ompA and KoRV-A env genes. Key results C. pecorum and KoRV-A were detected in 61% and 27% of wild South Gippsland individuals tested, respectively. KoRV-A infection tended to be higher in shelter koalas compared with wild koalas. In contrast with other Victorian koala populations sampled, greater pathogen diversity was present in South Gippsland. Conclusions In the South Gippsland koala population, C. pecorum is widespread and common whereas KoRV appears less prevalent than previously thought. Further work exploring the dynamics of these pathogens in South Gippsland koalas is warranted and may help inform future conservation strategies for this important population. Implications Non-invasive genetic sampling from scats is a powerful method for obtaining data regarding pathogen prevalence and diversity in wildlife. The use of non-invasive methods for the study of pathogens may help fill research gaps in a way that would be difficult or expensive to achieve using traditional methods.

Whistle characteristics of newly defined species, the Burrunan dolphin (Tursiops australis), in coastal Victorian waters in Australia

A newly defined species, the Burrunan dolphin (Tursiops australis), was described in 2011 by Charlton-Robb et al., and is endemic to southern and south-eastern Australian coastal waters. This species' distribution is characterized by small, isolated, and genetically distinct populations. With only two known populations in Victoria, the species is now listed as “Threatened” under the Victorian Flora and Fauna Guarantee Act. Describing and quantifying the vocal repertoire of a species is critical for subsequent analysis of signal functionality, geographic variation, social relevance, and identifying threats associated with anthropogenic noise. Here, we present the first quantitative analysis of whistle characteristics for the species, undertaken on these endemic Victorian populations. Vocalizations of T. australis were recorded during population based surveys in 2007 and 2014 across the Gippsland Lakes and Port Phillip Bay, Victoria. Acoustic parameters of whistles were measured including minimum frequency ...

Genetic differentiation in spite of high gene flow in the dominant rainforest tree of southeastern Australia, Nothofagus cunninghamii.

Nothofagus cunninghamii is a long-lived, wind-pollinated tree species that dominates the cool temperate rainforests of southeastern Australia. The species' distribution is more or less continuous in western Tasmania but is fragmented elsewhere. However, it is unknown whether this fragmentation has affected the species' genetic architecture. Thus, we examined N. cunninghamii using 12 nuclear microsatellites and 633 individuals from 18 populations spanning the species' natural range. Typical of wind-pollinated trees, there was low range-wide genetic structure (FST=0.04) consistent with significant gene flow across most of the species' range. However, gene flow was not high enough to overcome the effects of drift across some disjunctions. Victorian populations (separated from Tasmania by the 240 km wide Bass Strait) formed a genetic group distinct from Tasmanian populations, had lower diversity (mean allelic richness (Ar)=5.4 in Victoria versus 6.9 in Tasmania) and were significantly more differentiated from one another than those in Tasmania (FST=0.045 in Victoria versus 0.012 in Tasmania). Evidence for bottlenecking was found in small populations that were at least 20 km from other populations. Interestingly, we found little divergence in microsatellite markers between the extremes of genetically based morphological and physiological altitudinal clines suggesting adaptive differentiation is strongly driven by selection because it is likely to be occurring in the presence of gene flow. Even though the cool temperate rainforests of Australia are highly relictual, the species is relatively robust to population fragmentation due to high levels of genetic diversity and gene flow, especially in Tasmania.

The prevalence and clinical significance of Chlamydia infection in island and mainland populations of Victorian koalas (Phascolarctos cinereus).

Chlamydia infection is known to impact the health of koalas (Phascolarctos cinereus) in New South Wales (NSW) and Queensland, but the clinical significance of Chlamydia infections in Victorian koalas is not well described. We examined the prevalence of Chlamydia infection and assessed associated health parameters in two Victorian koala populations known to be Chlamydia positive. The same testing regimen was applied to a third Victorian population in which Chlamydia had not been detected. We examined 288 koalas and collected samples from the urogenital sinus and conjunctival sacs. Detection and differentiation of Chlamydia species utilized real-time PCR and high-resolution melting curve analysis. Chlamydia pecorum was detected in two populations (prevalences: 25% and 41%, respectively) but only from urogenital sinus swabs. Chlamydia was not detected in the third population. Chlamydia pneumoniae was not detected. Chlamydia pecorum infection was positively associated with wet bottom (indicating chronic urinary tract disease) in one Chlamydia-positive population and with abnormal urogenital ultrasound findings in the other Chlamydia-positive population. The prevalence of wet bottom was similar in all populations (including the Chlamydia-free population), suggesting there is another significant cause (or causes) of wet bottom in Victorian koalas. Ocular disease was not observed. This is the largest study of Chlamydia infection in Victorian koalas, and the results suggest the potential for epidemiologic differences related to Chlamydia infections between Victorian koalas and koalas in Queensland and NSW and also between geographically distinct Victorian populations. Further studies to investigate the genotypes of C. pecorum present in Victorian koalas and to identify additional causes of wet bottom in koalas are indicated.

Genetic diversity and population structure of the threatened freshwater catfish, Tandanus tandanus, in Victoria, Australia

In Australia, many species of freshwater fish have rapidly declined following European settlement in the late eighteenth century. The freshwater catfish (Tandanus tandanus) is listed as threatened in Victoria and accordingly, broodstock management and a captive breeding program to facilitate the reintroduction of hatchery bred fish into depleted populations have been suggested. Little work has been conducted on Victorian populations of T. tandanus, despite its threatened status. This study assessed the genetic diversity and genetic structure of T. tandanus in Victoria, using mitochondrial and microsatellite markers. Genetic diversity of T. tandanus in Victoria varied greatly between sites, with the Mallee containing the highest diversity at both markers. Sites where T. tandanus had been introduced in the past typically contained lower measures of genetic diversity, with the exception of the Wimmera site for microsatellite markers. Populations could be assigned to one of four broodfish zones in Victoria, based on levels of genetic differentiation; (1) Mallee, Little Murray, Wimmera, Gum Lagoon and Safe Lagoon; (2) Loddon and Avoca; (3) Turners Lagoon and Phyland Lagoon; and (4) Goulburn. These results will assist managers with implementing broodstock management and a captive breeding program by identifying which sites should be sourced for broodstock and where to reintroduce their progeny, without compromising genetic variation or structure in T. tandanus populations in Victoria.

Population genetic structure of the ectomycorrhizal fungus Laccaria sp . A resembles that of its host tree Nothofagus cunninghamii

The ectomycorrhizal fungus Laccaria sp. A is restricted to temperate rainforest of southeast Australia, associated with its host tree Nothofagus cunninghamii. Eight mitochondrial microsatellite markers were used to investigate the population genetic structure of L. sp. A across its distribution in Tasmania and Victoria. The highest allelic diversity was found in Tasmania, which appeared to contain a panmictic population, whereas the more fragmented Victorian populations were characterized by low allelic diversity and differentiation between east and west. There is evidence of glacial refugia in the west and the northeast of Tasmania, and in Victoria in the Otway Ranges and Central Highlands, with postglacial migration into the Strzelecki Ranges. Narrow host-specificity may have contributed to the presence of population structure in this fungus. Allelic diversity patterns in L. sp. A are largely congruent with diversity patterns already established in populations of its host, N. cunninghamii.

Whole range and regional‐based ecological niche models predict differing exposure to 21st century climate change in the key cool temperate rainforest tree southern beech (Nothofagus cunninghamii)

AbstractThe warmer and drier climates projected for the mid‐ to late‐21st century may have particularly adverse impacts on the cool temperate rainforests of southeastern Australia. Southern beech (Nothofagus cunninghamii; Nothofagaceae), a dominant tree species in these forests, may be vulnerable to minor changes in its climate envelope, especially at the edge of the species range, with Holocene fossil evidence showing local extinction of populations in response to small climate changes. We modelled the stability of this species climate envelope using the maximum entropy algorithm implemented in Maxent and two thresholds of presence/absence by projecting the modern climate envelope onto four Global Circulation Models forecasted for two time periods (2050s and 2070s). The climate envelope, as estimated from the species present climatic range, is predicted to shrink by up to 49% by the 2050s and up to 64% by the 2070s. The greatest predicted reduction is in Victoria with 91–100% of its current range being climatically unsuitable by the 2070s. Climatically similar areas to the species present range are predicted to remain in mountainous areas of western Tasmania, the Northeast Highlands of Tasmania, and the Baw Baw Plateau in the Central Highlands of Victoria. However, region‐specific modelling approaches made very different predictions from the whole‐range based models, especially in the severity of the predicted decline for Victorian populations of N. cunninghamii which occur in much warmer climates than the rest of the species geographical range. This shows that, for widespread species that span a range of climate zones, the exposure of current populations to climate change may be better modelled using a regional based approach. How the species responds to climate change will depend on the species ability to respond to drier and warmer climates and the concomitant increase in fire intensity.

Defining conservation units in a complex of morphologically similar, sexually deceptive, highly endangered orchids

In plants, rapid speciation attributed to pollination strategy is unlikely to lead to obvious morphological traits for identification or large genetic differences among populations. The species-rich Australian orchid genus Caladenia contains numerous taxonomically difficult species complexes, including the reticulata complex comprising 37 species, many of which are highly endangered with narrow-range geographic distributions as a consequence of severe habitat loss. Here, we test morphological species delimitation in the reticulata complex with a multigene phylogenetic analysis, detailed population genetic analysis and comprehensive data on specific sexually deceived pollinators of species within the complex. Phylogenetic analysis revealed limited species-level resolution within the reticulata complex and no difference between species with different pollinators. Microsatellite data confirmed this result for Victorian populations of the reticulata complex but revealed significant isolation by distance between Victorian and South Australian populations. Pollinator preference tests indicated that 10 reticulata complex morphospecies all shared the thynnid wasp pollinator Phymatothynnus nitidus, yet the microsatellite analysis revealed only limited differentiation between those and three species within the reticulata complex shown to employ different pollinators. The combined molecular and ecological approach revealed that morphospecies that share the same pollinator are likely to be the same biological species. Conservation and taxonomic focus should shift from a ‘microspecies’ approach to capturing key populations across the geographic range of the Caladenia reticulata biological species which will greatly assist the allocation of limited conservation resources.

MHC class II diversity of koala (Phascolarctos cinereus) populations across their range.

Major histocompatibility complex class II (MHCII) genes code for proteins that bind and present antigenic peptides and trigger the adaptive immune response. We present a broad geographical study of MHCII DA β1 (DAB) and DB β1 (DBB) variants of the koala (Phascolarctos cinereus; n=191) from 12 populations across eastern Australia, with a total of 13 DAB and 7 DBB variants found. We identified greater MHCII variation and, possibly, additional gene copies in koala populations in the north (Queensland and New South Wales) relative to the south (Victoria), confirmed by STRUCTURE analyses and genetic differentiation using analysis of molecular variance. The higher MHCII diversity in the north relative to south could potentially be attributed to (i) significant founder effect in Victorian populations linked to historical translocation of bottlenecked koala populations and (ii) increased pathogen-driven balancing selection and/or local genetic drift in the north. Low MHCII genetic diversity in koalas from the south could reduce their potential response to disease, although the three DAB variants found in the south had substantial sequence divergence between variants. This study assessing MHCII diversity in the koala with historical translocations in some populations contributes to understanding the effects of population translocations on functional genetic diversity.

Studies of the distribution and taxonomy of Xanthorrhoea glauca subsp. angustifolia (Xanthorrhoeaceae) in Victoria

The Victorian distribution and taxonomy of Xanthorrhoea glauca subsp. angustifolia D.J.Bedford is confirmed and described. Current morphological ranges for taxonomic characters do not provide adequately for Victorian populations. A revised key for Xanthorrhoea in Victoria is provided to resolve this matter. In Victoria the taxon occurs in woodland and forest on impoverished, often auriferous, soils on inland hills and foothills of the Great Dividing Range. The morphologically similar X. australis R.Br. has a non-overlapping distribution mainly in current and former coastal landscapes. The importance of marine transgression of western Victoria in contributing to speciation in Xanthorrhoea is discussed.

Targeting Drug Resistance Mechanisms in Mycobacterium tuberculosis

century. But with the advent of antibiotics starting around 80 years ago, TB then became a curable disease. It had no longer the deadly effectiveness as it did for ancient Roman and Victorian populations. As an effect, Mycobacterium tuberculosis, the causative agent of TB discovered by Robert Koch in 1882, finally faded out of the limelight.