Native Biota Research Articles

How to coexist with the ‘killer shrimp’ Dikerogammarus villosus? Lessons from other invasive Ponto‐Caspian peracarids

Abstract Studying interactions among co‐evolved invaders might help us in understanding, predicting, and perhaps mitigating the impact of the invading species on the native biota. The factors of spatial niche differentiation were investigated among invasive Ponto‐Caspian peracarids with the aim of revealing how co‐evolved species can coexist with the ‘killer shrimp’ Dikerogammarus villosus, an invasive gammarid replacing non‐Ponto‐Caspian species throughout Europe. Multi‐habitat samples from the third Joint Danube Survey were analysed by partitioning the variation in species density data between environmental and spatial explanatory variable sets. Relevant predictors were identified by forward selection and their role was interpreted based on the redundancy analysis (RDA) triplot. The effect of substrate types was further analysed in certain species using generalized linear models. The analysis revealed characteristic differences in habitat preference (i.e. spatial niche differentiation) among the species, allowing coexistence with D. villosus at different spatial scales. The relatively small and lean body of Chaetogammarus ischnus and Jaera sarsi might allow the avoidance of interference with large Dikerogammarus specimens by using narrow interstices among pebbles and stones (microhabitat‐scale differentiation). The remaining Ponto‐Caspian species included in the analysis showed an affinity for substrate types (Obesogammarus obesus) or current velocity intervals (Dikerogammarus bispinosus) that differed from those preferred by D. villosus (mesohabitat‐scale differentiation), presumably in connection with feeding preferences in some cases (Dikerogammarus haemobaphes and Trichogammarus trichiatus). These results provide a framework for a preliminary risk assessment concerning the continuing high potential for range expansion of D. villosus: i.e. the identification of the most vulnerable species in those regions of the world not invaded at present but potentially colonizable, based on their habitat preference and morphology. The lessons learned from Ponto‐Caspian peracarids can be applied to the whole macroinvertebrate fauna, as the same principles (i.e. the avoidance of interference) can be expected to determine their coexistence with D. villosus.

Transmission of parasites from introduced tilapias: a new threat to endemic Malagasy ichthyofauna

Invasive species are a major threat to biodiversity. In Madagascar, one quarter of freshwater fish fauna consist of introduced species. The introduction of non-native species affects native biota by means of direct interactions but also through indirect interactions including those mediated by parasites, as parasites are usually co-introduced with their hosts. Almost nothing is known about the parasites co-introduced with their fish hosts into Madagascar and their potential impact on native endemic fish fauna. We studied the metazoan parasites of native and introduced cichlid fishes (and some non-cichlids) in the northern part of Madagascar. Using parasite data we evaluated the effect of fish introduced from mainland Africa on native Malagasy cichlid fauna. We documented the co-introduction into Madagascar of parasite species from mainland Africa and also probably from Eurasia. Malagasy cichlids and some other species living in sympatry with non-native cichlids acted as competent hosts for generalist parasites and also for host-specific parasites of African mainland cichlids. However, African mainland cichlids were not susceptible to infection by parasites specific to Malagasy cichlids. The different compositions of parasite communities and infection parameters in endemic and non-native cichlids in the regions investigated may be potentially explained by the different sources and timings of fish introductions. In addition, native endemic parasite fauna even seem to be outcompeted by introduced parasites, which cross the barriers of host specificity. The transmission of non-native parasites associated with the introduction of non-native freshwater fishes may represent a serious risk to endemic freshwater fish and parasite fauna in Madagascar.

Behavioral responses to, and fitness consequences from, an invasive species are life-stage dependent in a threatened native fish

Native wildlife are impacted by invasive species in numerous ways and will be more vulnerable if they cannot recognize the threat posed by an invader. Impacts, however, are generally assessed for a single life stage and without consideration of behavioral responses. This limits knowledge of the mechanisms underpinning the threats of invaders and the responses that could help or hinder native animals to mitigate this threat.We conducted a series of experiments to examine if the threat of an invader and behavioral responses by a native animal are life-stage dependent. Our focal species were a widespread invasive (Gambusia holbrooki) and a threatened native Australian freshwater fish (Galaxiella pusilla). We show that the threat of, and behavioral responses to, the invader vary across life-cycle stages. Gambusia holbrooki had different effects on G. pusilla: inhibiting reproduction and consuming larvae but not eating eggs or reducing adult growth and survival. Although larval G. pusilla avoided visual cues from G. holbrooki, native predators and conspecific adults, they did not avoid olfactory cues from G. holbrooki, which is maladaptive considering the predation risk. In addition, adult G. pusilla did not avoid any G. holbrooki cues, providing further evidence of maladaptive behavior.Our study is one of the first comprehensive evaluations of how the threats of an invader to a native species, as well as the responses to this threat, are life-stage dependent. We use our empirical results to develop a general framework for understanding the mechanisms by which invasives threaten native biota, and highlight how this can be used to help assess and mitigate the threat of invaders.

O grande impacto do Clostridium perfringens na avicultura

Clostridium perfringens type A is a Gram-positive anaerobic bacterium that inhabits the intestinal native biota of the intestine of birds. The objective of this review is to analyze different factors that predispose their pathogenicity and bacterial growth, leading to necrotic enteritis, a enterotoxemic disease characterized by hemorrhagic necrosis of the intestinal mucosa, affecting mainly broilers between 4 to 8 weeks of age or older, especially in poultry farms intensified, being a problem for morbidity and mortality hurting performance, weight, food, and due to its presence along the production of broilers, conversion it can be transmitted to humans through the consumption of contaminated poultry products. Its importance in the poultry field has led us to investigate alternatives to prevent and control the disease produced by Clostridium perfringens in poultry, and also reduce the proliferation and economic losses.

DNA Barcoding Reveals Identity of Mugilids (Teleostei: Mugiliformes) from the East China Sea along the Coast of Zhejiang, China

Dramatically intensified economic development in the coastal areas of Zhejiang, China, has posed unprecedented challenges and pressures on the native coastal marine biota. Mugilids (Teleostei: Mugiliformes) are widely distributed across marine, brackish, and freshwater habitats in tropical, subtropical, and temperate regions of the world. In this study, DNA sequences of a consensus length of 611 nucleotides in mitochondrial Cytochrome c Oxidase subunit I (COI ) were used to identify 144 mugilid samples collected from various intertidal waters along the coast of Zhejiang in the East China Sea. A total of 35 distinctive COI haplotypes was scored. Results of neighbor-joining ( NJ) clustering clearly support classification of seven species, in agreement with morphological diagnosis: Planiliza affinis, Planiliza haematocheila, Planiliza sp. H, Planiliza subviridis, Crenimugil sp. A, Osteomugil cunnesius, and Mugil sp. C. Planiliza affinis was found to be the dominant mugilid in the coastal waters. This research provides critical scientific data for understanding the identity and abundance of mugilids and managing their fishery resources and habitats along the coast of Zhejiang.

Recent Trends of Demersal Marine Fish and Invertebrate Production in Southeast Asia – A Hypothesis-based Analysis

Demersal marine fish and invertebrate production data for Southeast Asia (1996–2007) obtained from the Southeast Asian Fisheries Development Center (SEAFDEC) statistical bulletin indicated a reduced production by Thailand largely due to over-exploitation and altered coastal ecosystems. In contrast, increased production by Philippines, Indonesia and Malaysia was due to an increase in mechanised fishing fleets. Moreover, marginal increases in the ecosystem indicators were attributed to increased exploitation of high and mid trophic level organisms suggesting the development of “top-down” cascade effect in the future. In this bioregion, land use pattern affecting water quality coupled with altered monsoonal sequences and rising sea surface temperatures interfere with biological processes. The most apparent manifestations of these disturbances are recurrences of extensive algal blooms and coral bleaching events. Fish mortality as a result of these events threatens to weaken the native biota and facilitate invasions that would modify the trophic dynamics of the coastal habitats.

Inundation of a floodplain lake woodlands system: nutritional profiling and benefit to mature Eucalyptus largiflorens (Black Box) trees

River management continues to challenge riparian systems worldwide, with climate change impacts and anthropogenic extractions escalating. The Murray–Darling basin (MDB) in Australia is critical to agricultural production and habitat provision to maintain biodiversity. Concern for the condition of native trees and biota in the MDB has led to substantial research investment to increase ecosystem function understanding and improve floodplain and wetland management. This field study offers new insights into tree nutrition and physiology as interpreted against the plant-soil-environment dynamics of recent flooding. Black Box (Eucalyptus largiflorens (Myrtaceae) is the only key native riverine MDB tree restricted to that region; and appears stressed at the far reaches of certain significant floodplain ecosystems. Here, nutritional and ecophysiological comparisons were made between Black Box trees that had just been inundated, and those nearby that had not. Leaf stomatal conductance, transpiration, total soil aluminium (Al) concentration, soil pH, and soil conductivity were different between inundated and dry sites. Soil moisture increased due to inundation, thus reducing tree water stress across the three study locations. Changes in leaf chemistry were not detected at the very early stages of flooding examined in this study. An increase in soil acidity due to inundation may also enhance bioavailability of nutrients to trees. New insight into immediate plant benefits gained from this study suggests further investigation is warranted to elucidate the influence of flood and drought on nutrient balance and how future wetland management can benefit from a more holistic understanding of plant-soil-environment dynamics.

Using Natural Disturbance and Portfolio Concepts to Guide Aquatic–Riparian Ecosystem Management

The U.S. Forest Service and other federal land managers are responsible for maintaining the productivity of aquatic–riparian ecosystems, the associated native biota, and the ecosystem services they provide. These public lands are important sources of water, recreation opportunities, and habitat for a suite of animals and plants, including many that are protected under the Endangered Species Act. To meet these challenges and responsibilities, recent science suggests modifying practices to provide a broader array of habitat, biological conditions, and ecosystem functions than are associated with traditional management approaches. We suggest that by linking approaches based on natural disturbance and portfolio concepts, managers can achieve a robust strategy and desired outcomes more reliably and cost effectively. Locally complex habitat conditions created by natural disturbances provide the template for biological diversity to play out if provided enough time. Accordingly, natural disturbance regimes play an important role in creating and sustaining habitat and biological complexities on the landscape, suggesting that, to the extent possible, management actions should emulate natural disturbance processes at appropriate spatial and temporal scales. In concert with this approach, the portfolio effect (i.e., diversity that mitigates risk) provides justification for promoting connected heterogeneous habitats that reduce the risk of synchronous large‐scale population and ecosystem collapse. In this article, we describe how disturbance and portfolio concepts fit into a broader strategy of conserving ecosystem integrity and dynamism and provide examples of how these concepts can be used to address a wide range of management concerns. Ultimately, the outcome for populations, habitats, and landscapes depends on how well environmental change is understood, the degree to which change is appropriately addressed by natural resource managers, and solutions that allow populations and ecosystems to persist in the presence of and be resilient to a growing scope of human influences.

Clonal crayfish as biological model: a review on marbled crayfish

Since the mid-twentieth century, numerous vertebrates and invertebrates have been used as model organisms and become indispensable tools for exploring a broad range of biological and ecological processes. Crayfish seem to be adequate models which resulted in their involvement in research. In the two decades since its discovery, ongoing research has confirmed that the marbled crayfish (Procambarus virginalis Lyko, 2017) is an ideal taxon in this regard, especially due to its almost continuous asexual reproduction providing a source of genetically identical offspring. This review provides an overview of the occurrence, biology, ecology, ethology, and human exploitation of marbled crayfish with primary focus on its use as a laboratory model organism as well as potential risks to native biota in case of its introduction. Genetic uniformity, ease of culture, and a broad behaviour repertoire fosters the use of marbled crayfish in epigenetics and developmental biology, as well as physiological, ecotoxicological, and ethological research. Marbled crayfish could be further exploited for basic and applied fields of science such as evolutionary biology and clonal tumour evolution. However, due to its high invasive potential in freshwater environments security measures must be taken to prevent its escape into the wild.

Lentification in Alpine rivers: patterns of diatom assemblages and functional traits

Hydrological alterations in Alpine rivers have been largely increasing due to the combined effects of global climate change and local impacts. Water flow intermittency starts with a process called lentification, which leads to the transformation of the aquatic ecosystem with severe consequences on biotic communities. These consequences have a greater impact in Alpine headwater streams, which are considered important and fragile hotspots of biodiversity and a source of threatened species; the new regime creates conditions to which native biota are poorly adapted. The main aim of our work was to evaluate taxonomical, functional and structural changes of diatom communities in Alpine rivers during the lentification process that precedes a supra-seasonal drought. Contrary to what was expected, communities exposed to river shrinking showed a level of homogeneity comparable to those collected in permanent sections. We therefore hypothesized that lentification created an intermediate disturbance that favoured heterogeneity of assemblages. Conversely, ecological guilds, growth forms and eco-morphological groups varied along temporal and spatial gradients driven by the lentification process. Small, motile and medium-sized low profile species were more abundant during summer, as well as adnate and stalked ones. Lentification limited the presence of high profile guilds and mucous-forming colonies. Droughts in Alpine streams are fairly recent processes, and the dynamics of aquatic communities facing water scarcity are largely unknown. The results we obtained provide important insights towards a more refined functional classification of diatoms for evaluating hydrological alterations.

Amazon basin pasture soils reveal susceptibility to phytopathogens and lower fungal community dissimilarity than forest

The advance of livestock towards the hydrographic basin of Mutum-Paraná River, in the state of Rondônia contributes to the conversion of the amazon forest to pasture. This process can decrease the plant diversity, contributing to loss of endemic microorganisms and natural enemies leading to the replacement of native biota by non-native and generalist species. Thereby, we hypothesized that this conversion changes fungal composition, reduce fungal alpha diversity and community dissimilarity and increase the incidence of potential phytopathogenic genera at pasture soils compared to forest. Soil of 10 sampling points from forest and 10 from pasture were collected at the Mutum-Paraná River basin. Via ITS amplicon sequencing of the total soil DNA, differences in composition and in the taxonomic diversity between the two environments were addressed. The phylum Ascomycota predominated in both forest and pasture. Basidiomycota presented lower percent in both, but was higher in pastures. Zygomycota and Glomeromycota presented opposite tendencies, the first being predominately present in forest and the second only present in pasture with low incidence. The fungal diversity was higher in pasture soils, contrasting our hypothesis. There were also significant correlations between soil physicochemical properties and fungal community. The reduction of the dissimilarity in pasture was confirmed and this signalized for a biotic homogenization. In addition, higher incidence of potential phytopathogenic fungi was observed in pasture. These results contribute to a better understanding of how fungal communities are driven by forest-to-pasture conversion.

Fate of Enrofloxacin in Lake Sediment: Biodegradation, Transformation Product Identification, and Ecotoxicological Implications

ABSTRACTVarious pharmaceutical drugs are being detected in different environmental compartments such as surface waters, groundwater, and sediment; a major concern since they are biologically active substances which can interfere with biological systems affecting the native biota. Among these drugs, antimicrobials are especially worrisome mainly due to the development of bacterial resistance. The aims of this study were to investigate if enrofloxacin, an emergent antibiotic pollutant, could be biodegraded in lake sediment, identify its break down products and to determine if these products have antimicrobial properties or are toxic. Three biodegradation products were identified and the antibiotic susceptibility assay proved that the products formed did not display antibiotic effects. Ecotoxicity testing with green algae suggested that the degradation products do not cause adverse effects statistically. However, it is suggested that further investigations are needed to identify the mechanism of degradation and the microbes involved.

Host specificity and risk assessment of Archanara geminipuncta and Archanara neurica, two potential biocontrol agents for invasive Phragmites australis in North America

Invasive Phragmites australis is widespread in North America and despite decades of management and large annual expenditures (>5 million US$) using physical and chemical means, local populations and the species range are expanding. Allowing continued expansion does not only threaten native wetland biota but also an endemic North American subspecies Phragmites australis americanus. We used extensive multi-pronged investigations in Europe and North America to evaluate host specificity and impact of two European stem mining noctuid moths, Archanara geminipuncta and A. neurica. Both moth species are specific to the genus Phragmites and both show a very strong, but not absolute, preference for invasive P. australis over endemic P. australis americanus. No-choice tests or tests in small cages provided inconsistent results, but both moths showed consistently high preferences for introduced P. australis. Open field multiple-choice oviposition tests affirmed this; moths laid 6.5% of their eggs on native P. australis americanus. The native subspecies is further safeguarded by increased mortality of eggs and larvae when laid on, or developing in P. australis americanus. Phragmites populations in the southern US, particularly along the Gulf of Mexico, occur outside the climate range of these two temperate moth species. We consider potential threats to P. australis americanus demography due to A. geminipuncta and A. neurica attack to be far smaller than allowing expansion of invasive P. australis to continue. We therefore recommend release of these two biocontrol agents in North America.

Soil Microbial-Community Alteration in Response to Heterotheca subaxillaris – an Invasive Alien Plant

Plant invasions have become one of the biggest threats to natural ecosystems across the globe during the last decade, and there is growing interest in their effect on the native flora and biota in invaded areas. However, little is known about their effect on soil microbial communities, especially non-fungal communities, in harsh environments such as a sand-dune ecosystem. The objective of this study, conducted in the northern Sharon sand-dune area of Israel, was to investigate the influence of the invasive alien plant Heterotheca subaxillaris on a sand-dune microbial community. Soil samples were collected under the canopies of the invasive plant, a native plant (Artemisia monosperma), and from bare areas at two sites, at different distances from the seashore going inland during the wet and dry seasons. MicroRespTM system methodology provided data on microbial biomass, basal respiration, and the community-level physiological profile (CLPP) at the community level, in addition to abiotic components, e.g., soil moisture, organic matter, conductivity, and pH. The microbial community in the soil samples found under the canopy of H. subaxillaris was less active and exhibited significantly lower CLPP, microbial biomass, and basal respiration than in the A. monosperma (native plant) samples. Soil abiotic variables were strongly affected by seasonality, sites, and were related to plant cover and the ecophysiological adaptation of each one. This study emphasizes the threat to soil microbial communities induced by plant invasion, especially in unique and harsh sand-dune ecosystems. This threat might also affect other organisms living in this fragile environment.

Global Island Monitoring Scheme (GIMS): a proposal for the long-term coordinated survey and monitoring of native island forest biota

Islands harbour evolutionary and ecologically unique biota, which are currently disproportionately threatened by a multitude of anthropogenic factors, including habitat loss, invasive species and climate change. Native forests on oceanic islands are important refugia for endemic species, many of which are rare and highly threatened. Long-term monitoring schemes for those biota and ecosystems are urgently needed: (i) to provide quantitative baselines for detecting changes within island ecosystems, (ii) to evaluate the effectiveness of conservation and management actions, and (iii) to identify general ecological patterns and processes using multiple island systems as repeated ‘natural experiments’. In this contribution, we call for a Global Island Monitoring Scheme (GIMS) for monitoring the remaining native island forests, using bryophytes, vascular plants, selected groups of arthropods and vertebrates as model taxa. As a basis for the GIMS, we also present new, optimized monitoring protocols for bryophytes and arthropods that were developed based on former standardized inventory protocols. Effective inventorying and monitoring of native island forests will require: (i) permanent plots covering diverse ecological gradients (e.g. elevation, age of terrain, anthropogenic disturbance); (ii) a multiple-taxa approach that is based on standardized and replicable protocols; (iii) a common set of indicator taxa and community properties that are indicative of native island forests’ welfare, building on, and harmonized with existing sampling and monitoring efforts; (iv) capacity building and training of local researchers, collaboration and continuous dialogue with local stakeholders; and (v) long-term commitment by funding agencies to maintain a global network of native island forest monitoring plots.

Native crustacean species as a bioindicator of freshwater ecosystem pollution: A multivariate and integrative study of multi-biomarker response in active river monitoring

The aim of this study was to evaluate the ability of Palaemonetes argentinus to evidence the environmental degradation due to pollutants mixture in a freshwater aquatic ecosystem. For this purpose, an active monitoring (96 h exposure) was carried out in seven sites along the Ctalamochita River basin (Córdoba, Argentina), as a case of study.Our results evidenced sewage discharges impact in the water quality index, as well as metal pollution in water (Ag, Al, B, Pb, Hg) and sediments (Hg) with a potential effect on aquatic biota. The accumulation of total metals measured in exposed P. argentinus showed significant correlation with metals in water. Also, metallothioneins in cephalothorax showed significant changes along the basin, correlating with soluble concentrations of Cr, Zn, Cd, Hg, and V measured in shrimp tissues, which would be reflecting their bioavailability in the environment. In addition, the increase in antioxidant and detoxifying enzymes suggests the occurrence of oxidative stress in exposed shrimps. The integrative biomarker response index (IBR) pointed out the effect of metals on P. argentinus but also the occurrence of others pollutants.Finally, a high consensus was observed for water, sediments, and shrimps through the multivariate analysis (90%), indicating that P. argentinus can reflect changes in the abiotic matrixes. Moreover, studied sites were grouped according to their environmental quality.The use of active biomonitoring and the integration of biological responses through an IBR confirm that native biota could be a useful monitoring tool for bioavailable pollutants in aquatic ecosystems constituting a highly valuable approach.

Nest-site competition and killing by invasive parakeets cause the decline of a threatened bat population.

The identification of effects of invasive species is challenging owing to their multifaceted impacts on native biota. Negative impacts are most often reflected in individual fitness rather than in population dynamics of native species and are less expected in low-biodiversity habitats, such as urban environments. We report the long-term effects of invasive rose-ringed parakeets on the largest known population of a threatened bat species, the greater noctule, located in an urban park. Both species share preferences for the same tree cavities for breeding. While the number of parakeet nests increased by a factor of 20 in 14 years, the number of trees occupied by noctules declined by 81%. Parakeets occupied most cavities previously used by noctules, and spatial analyses showed that noctules tried to avoid cavities close to parakeets. Parakeets were highly aggressive towards noctules, trying to occupy their cavities, often resulting in noctule death. This led to a dramatic population decline, but also an unusual aggregation of the occupied trees, probably disrupting the complex social behaviour of this bat species. These results indicate a strong impact through site displacement and killing of competitors, and highlight the need for long-term research to identify unexpected impacts that would otherwise be overlooked.

Efficiency of rapid field methods for detecting non-native fish in Eastern Brazilian lakes

Where biodiversity conservation and environmental preservation are significant concerns, rapid assessment and monitoring of the colonization and spread of non-native species are essential for timely decision-making and response. We developed and evaluated the adequacy of a rapid assessment protocol (RAP) for detecting non-native fish species in 74 Eastern Brazilian lakes. The RAP consists of a single field day employing two surveyors to conduct interviews with local sport fishers, visual surveys of fish, angling with lures, and gillnetting. We compared our results with those from separate, intense, large sampling effort (LSE) field surveys. Despite requiring less than 1/100th of the field effort, the RAP was able to detect the presence of most non-native fish species that were reported in the same lakes by LSE surveys. Information from local sport fishers was invaluable, particularly for detecting species that were in low abundance, but was not available for lakes within a forest preserve area. Non-native introductions commonly lead to rapid and widespread invasion and adverse effects on native biota. Our results strongly suggest that the RAP could function as a cost-effective tool for efficiently assessing the presence of non-native fishes in lakes and monitoring their colonization and spread over large geographic areas.

The distribution and trophic ecology of an introduced, insular population of red-necked wallabies (Notamacropus rufogriseus)

Introduced non-native mammals can have negative impacts on native biota and it is important that their ecologies are quantified so that potential impacts can be understood. Red-necked wallabies (Notamacropus rufogriseus (Desmarest, 1817)) became established on the Isle of Man (IOM), an island with UNESCO Biosphere status, following their escape from zoological collections in the mid-1900s. We estimated wallaby circadial activity and population densities using camera trap surveys and random encounter models. Their range in the IOM was derived from public sightings sourced via social media. Wallaby diet and niche breadth were quantified via microscopic examination of faecal material and compared with those of the European hare (Lepus europaeus Pallas, 1778). The mean (±SE) population density was 26.4 ± 6.9 wallabies/km2, the mean (±SE) population size was 1742 ± 455 individuals, and the species’ range was 282 km2, comprising 49% of the island. Wallaby diets were dominated by grasses, sedges, and rushes; niche breadth of wallabies and hares (0.55 and 0.59, respectively) and overlap (0.60) suggest some potential for interspecific competition and (or) synergistic impacts on rare or vulnerable plant species. The IOM wallaby population is understudied and additional research is required to further describe population parameters, potential impacts on species of conservation interest, and direct and indirect economic costs and benefits.

Invasion of a Holarctic planktonic cladoceran Daphnia galeata Sars (Crustacea: Cladocera) in the Lower Lakes of South Australia.

We found a Holarctic microcrustacean Daphnia galeata Sars, 1863 (Cladocera: Daphniidae) in the Lower Lakes of South Australia. This taxon was never detected in continental Australia before. Its identity was confirmed by the sequences of mitochondrial COI, 12S and 16S and nuclear 18S and 28S genes. A maximum likelihood tree from a dataset from combining 12S + 16S mitochondrial sequence and a split network of the COI haplotypes are provided, but resolution of both genes is not sufficient to reveal the exact region of the Holarctic from where D. galeata was introduced to Australia; the vector of its invasion also is unknown. We hypothesize that appearance of D. galeata in the Lower Lakes of the Murray River is related to a recent anthropogenic eutrophication of water bodies in this region, keeping in mind that examples of successful invasion of some European lakes by D. galeata after their eutrophication are well-known. We also hypothesize that establishment of this non-indigenous taxon populations in Australia might have a strong negative impact on native lake biota.