Search

The increasing environmental concerns of conventional antifouling coatings have led to the exploration of novel and sustainable solutions to address the biofouling caused by Limnoperna fortunei. As a rapidly expanding invasive species, the fouling process of Limnoperna fortunei is closely associated with microbial fouling, posing significant threats to the integrity of aquatic infrastructure and biodiversity. This review discusses recent progress in the development of non-toxic, eco-friendly antifouling coatings that are designed to effectively resist biofouling without using toxic chemicals. Recent research has focused on developing novel non-toxic coatings that integrate natural bioactive components with advanced material technologies. These formulations not only meet current environmental standards and exhibit minimal ecological impact, but also possess significant potential in preventing the attachment, growth, and reproduction of Limnoperna fortunei. This review aims to provide scientific guidance by proposing effective and sustainable solutions to address the ecological challenges presented by Limnoperna fortunei. The insights gained from current research not only reveal novel antifouling methods, but also identify key areas for further investigation aimed at enhancing performance and environmental compatibility. [ABSTRACT FROM AUTHOR]

The introduction of invasive species has become an increasing environmental problem in freshwater ecosystems due to the high economic and ecological impacts it has generated. This systematic review covers publications from 2010 to 2020, focusing on non‐native invasive freshwater bivalves, a particularly relevant and widespread introduced taxonomic group in fresh waters. We collected information on the most studied species, the main objectives of the studies, their geographical location, study duration, and type of research. Furthermore, we focused on assessing the levels of ecological evidence presented, the type of interactions of non‐native bivalves with other organisms and the classification of their impacts. A total of 397 publications were retrieved. The studies addressed a total of 17 species of non‐native freshwater bivalves; however, most publications focused on the species Corbicula fluminea and Dreissena polymorpha, which are recognised for their widespread distribution and extensive negative impacts. Many other non‐native invasive bivalve species have been poorly studied. A high geographical bias was also present, with a considerable lack of studies in developing countries. The most frequent studies had shorter temporal periods, smaller spatial extents, and more observational data, were field‐based, and usually evaluated possible ecological impacts at the individual and population levels. There were 94 publications documenting discernible impacts according to the Environmental Impact Classification for Alien Taxa (EICAT). However, 41 of these publications did not provide sufficient data to determine an impact. The most common effects of invasive bivalves on ecosystems were structural alterations, and chemical and physical changes, which are anticipated due to their role as ecosystem engineers. Despite a considerable number of studies in the field and advances in our understanding of some species over the past decade, long‐term data and large‐scale studies are still needed to understand better the impacts, particularly at the community and ecosystem levels and in less‐studied geographic regions. The widespread distribution of several non‐native freshwater bivalves, their ongoing introductions, and high ecological and economic impacts demand continued research. Systematic reviews such as this are essential for identifying knowledge gaps and guiding future research to enable a more complete understanding of the ecological implications of invasive bivalves, and the development of effective management strategies. [ABSTRACT FROM AUTHOR]

Limnoperna fortunei (L. fortunei) (Dunker, 1857), the golden mussel, is an invasive species possessing exceptional environmental adaptability and a destructive impact on water systems and artificial structures. To better conservation of freshwater ecosystems by controlling this mussel, it is essential to study its distribution, potential for invasion, environmental tolerance and biological traits.This paper outlines the distribution of L. fortunei in Asia and South America, as well as its potential for future invasion in freshwater habitats, along with the research methods employed.We find that the mussel had a temperature tolerance range of 8–35 °C and a pH range was 5–10, with some individuals surviving in extreme conditions for extended periods.We find that temperature was a decisive factor for success at reproductive stages, larval development and adult growth.The biological traits of L. fortunei are discussed, focusing on feeding habits, attachment characteristics and locomotion, with an emphasis on byssus structure, foot proteins and adhesion mechanisms. The study elucidates the impact of flow velocity, light exposure and substrate material on their attachment, with the optimal attachment being identified at a flow velocity of 0.3–0.9 m/s. Additionally, the mussel exhibits strong light avoidance performances and a preference for rough surfaces.Extensively‐researched control strategies are classified and summarized, primarily categorized into physical, chemical and biological control, with an outline of their respective strengths and limitations. [ABSTRACT FROM AUTHOR]

The intrusion of freshwater mussel Limnoperna fortunei into water conveyance projects could cause bio-fouling that affects structural safety, and the commonly used chemicals for fouling control still need to be further investigated, so the analysis of the mussels to the toxicological effects of fouling-control agents, such as NaClO and KMnO4, is particularly important. In this paper, through analyzing the mussels' responses to the stress by NaClO and KMnO4 in terms of enzyme activity and lipid peroxide, the integrated biomarker response (IBR), were used to evaluate the toxicological effects of NaClO and KMnO4 on L. fortunei. In addition, LC-MS non-targeted metabolomics was used to analyze the metabolic changes in the gill tissues of the mussels after being exposed to NaClO and KMnO4 for 72 hours in order to investigate the toxicological and metabolic regulation mechanisms of NaClO and KMnO4 from a molecular biology point of view, thus laying a basis for accurately determining an effective dosage. The results of the study are briefly concluded as follows: (1)The activities of antioxidant enzymes (superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx)) in the gill tissues decreased with an increase of NaClO concentration; the activities of the antioxidant enzymes first increased, then decreased when mussels were exposed to KMnO4 in solution, i.e., the maximum activity appeared when KMnO4 concentration being 2.0 mg/L, but decreased as the increase of the KMnO4 concentration; and lipid peroxide level which was used to characterize the tissue damage, went up with the increase of the agents concentration; (2)The results of evaluation using IBR, and the analysis of the mortality suggested that with regard to the in-activation effectiveness, NaClO was better than KMnO4 as NaClO concentrations <4.0 mg/L, while KMnOi was better than NaClO as KMnO4 concentration being 8.0 mg/L; and (3) Metabolomics analysis showed that the amino-acid metabolism pathways were present in all of the treatment groups, and only as the KMnO4 concentration was 8.0 mg/L, purine metabolism and ether lipid metabolism pathways were not found; when the concentration was <4.0 mg/L, the ether lipid metabolism was the main pathway, but when the NaClO concentration was >4.0 mg/L, purine metabolism turned to be the main pathway; and when the KMnO4 concentration was 8.0 mg/L the pathways were dominated by amino acid metabolism. In conclusion, for the purpose of better controlling L. fortunei bio-fouling in the long-distance water conveyance systems, the achievement of this study could provide basic data about the optimal dose concentrations of fouling-control agents such as NaClO and KMnO4. [ABSTRACT FROM AUTHOR]

The Sr/Ca and 87Sr/86Sr ratios are used as natural indicators (geomarkers) in fish to reveal migratory patterns, due to significant relationships between these ratios measured in the water and in the fish calcified structures (otoliths, bones). The aim of this study was to assess the potential use of the Limnoperna fortunei shell as a proxy for monitoring the spatial and temporal variability of Sr/Ca and 87Sr/86Sr in water. These ratios were compared in water samples and bivalve shells proceeding from eight sites of four hydrogeological regions of the La Plata Basin (Argentina and Uruguay), collected in two hydrological periods (winter and summer) in order to depict the pattern of geographical and temporal variability and to evaluate the relationship between both matrices. Significant positive linear relationships were found between shell edge and water for 87Sr/86Sr (R2 = 0.96–0.97, p < 0.005) and Sr/Ca (R2 = 0.83–0.86, p < 0.05) in summer and winter. Slopes did not differ significantly from 1 (p > 0.05) for 87Sr/86Sr, while they differed from 1 for Sr/Ca in both seasons (p < 0.05), indicating that the elemental ratio would be influenced by endogenous/exogenous factors. No significant seasonal differences were found for both natural tags (p > 0.05), except for the lower Uruguay River (87Sr/86Sr) and outer estuary (Sr/Ca). These results indicate that the L. fortunei shell could be a valuable tool for monitoring spatio-temporal variations in water 87Sr/86Sr. Shell Sr/Ca shows high potential utility as a geomarker in freshwater, but additional assessments are needed to understand the impact of temperature and growth on this ratio. [ABSTRACT FROM AUTHOR]

The increasing environmental concerns of conventional antifouling coatings have led to the exploration of novel and sustainable solutions to address the biofouling caused by Limnoperna fortunei. As a rapidly expanding invasive species, the fouling process of Limnoperna fortunei is closely associated with microbial fouling, posing significant threats to the integrity of aquatic infrastructure and biodiversity. This review discusses recent progress in the development of non-toxic, eco-friendly antifouling coatings that are designed to effectively resist biofouling without using toxic chemicals. Recent research has focused on developing novel non-toxic coatings that integrate natural bioactive components with advanced material technologies. These formulations not only meet current environmental standards and exhibit minimal ecological impact, but also possess significant potential in preventing the attachment, growth, and reproduction of Limnoperna fortunei. This review aims to provide scientific guidance by proposing effective and sustainable solutions to address the ecological challenges presented by Limnoperna fortunei. The insights gained from current research not only reveal novel antifouling methods, but also identify key areas for further investigation aimed at enhancing performance and environmental compatibility.

Copyright of Ecological Applications is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Magnetite (Fe3O4) nanoparticles were extracted from the shells of freshwater Limnoperna fortunei (Dunker 1857) and marine Perna perna (Linnaeus 1758) mussels, followed by full physical and chemical characterization using ICP-OES, UV–Vis, EDX, Raman, and XRD spectroscopy, VSM magnetometry, and SEM and TEM techniques. Considering their spatial distribution, the ferrimagnetic particles in the shells had low concentration and presented superparamagnetic behavior characteristics of materials of nanometric size. Transmission electron microscopy (TEM, especially HRTEM) indicated round magnetic particles around 100 nm in size, which were found to be aggregates of nanoparticles about 5 nm in size. The TEM data indicated no iron oxide particles at the periostracum layer. Nevertheless, roughly round iron (hydr)oxide nanoparticle aggregates were found in the nacre, namely, the aragonite layer. As the aragonite layer is responsible for more than 97% of the shell of L. fortunei and considering the estimated size of the magnetic nanoparticles, we infer that these particles may be distributed homogeneously throughout the shell.

Simple Summary: Limnoperna fortunei, known as the golden mussel, is an invasive bivalve in South America responsible for economic damages in hydroelectric plants due to its ability to attach and grow on the walls of water pipes and tubes. Chemical compounds are often used to control golden mussel infestations in water systems. Here, we investigated the effects of two biocides—MXD-100 ™ and sodium dichloroisocyanurate (NaDCC)—through the assessment of morphological and gene-expression alterations in the gills. Both biocides were able to modulate the expression of defensive genes and morphological changes. Yet, it seems that NaDCC needs continuous exposure to control golden mussel infestation, whereas MXD-100™ can inflict severe damage to the mussels in as little as 24 h. Our results can be used to enhance control strategies for managing mussel growth in water systems, simultaneously reducing the environmental impact associated with costly and harmful chemical releases. Limnoperna fortunei, the golden mussel, is a bivalve mollusk considered an invader in South America. This species is responsible for ecological and economic damages due to its voluminous fouling capability. Chemical biocides such as MXD-100™ and sodium dichloroisocyanurate (NaDCC) are often used to control L. fortunei infestations in hydraulic systems. Thus, we proposed to investigate the effects of different periods (24, 48 and 72 h) of exposure to MXD-100™ (0.56 mg L−1) and NaDCC (1.5 mg L−1) on the gills of L. fortunei through morphological and molecular analyses. NaDCC promoted progressive morphological changes during the analyzed periods and only an upregulation of SOD and HSP70 expression during the first 24 h of exposure. MXD-100™ led to severe morphological changes from the first period of exposure, in addition to an upregulation of SOD, CAT, HSP70 and CYP expression during the first 24 h. In contrast, MXD-100™ led to a downregulation of CAT transcription between 24 and 48 h. In static conditions, NaDCC causes lethal damage after 72 h of exposure, and that exposure needs to be continuous to achieve the control of the species. Meanwhile, the MXD-100™ treatment presented several effects during the first 24 h, showing acute toxicity in a shorter period of time. [ABSTRACT FROM AUTHOR]

Magnetite (Fe3O4) nanoparticles were extracted from the shells of freshwater Limnoperna fortunei (Dunker 1857) and marine Perna perna (Linnaeus 1758) mussels, followed by full physical and chemical characterization using ICP-OES, UV–Vis, EDX, Raman, and XRD spectroscopy, VSM magnetometry, and SEM and TEM techniques. Considering their spatial distribution, the ferrimagnetic particles in the shells had low concentration and presented superparamagnetic behavior characteristics of materials of nanometric size. Transmission electron microscopy (TEM, especially HRTEM) indicated round magnetic particles around 100 nm in size, which were found to be aggregates of nanoparticles about 5 nm in size. The TEM data indicated no iron oxide particles at the periostracum layer. Nevertheless, roughly round iron (hydr)oxide nanoparticle aggregates were found in the nacre, namely, the aragonite layer. As the aragonite layer is responsible for more than 97% of the shell of L. fortunei and considering the estimated size of the magnetic nanoparticles, we infer that these particles may be distributed homogeneously throughout the shell. [ABSTRACT FROM AUTHOR]

Golden mussel is an invasive species in South America that causes environmental and economic damage due to the formation of large colonies without natural predators. This study aimed to test the agricultural use of golden mussel shell as a limestone substitute, as the shell is rich in calcium carbonate. The experiment was carried out in pots, with eight treatments (sandy soil; clay soil; sandy soil + 1.0 Mg ha-1 of limestone; clay soil + 1.0 Mg ha-1 of limestone; sandy soil + 1.0 Mg ha-1 of fresh shell; clay soil + 1.0 Mg ha-1 of fresh shell; sandy soil + 1.0 Mg ha-1 of calcined shell; clay soil + 1.0 Mg ha-1 of calcined shell), in addition to the application of the following fresh and calcined shell doses: 0, 1.0, 1.5 and 2.0 Mg ha-1. Rice was cultivated in all treatments, and the soil fertility and rice shoot and root dry masses were evaluated. The shell provided good chemical conditions to the soils and raised their pH and phosphorus and calcium contents. The agricultural use of golden mussel shell showed to be efficient for soil correction and can be considered an alternative to limestone.

A simple environmental DNA (eDNA) filtration and extraction method that can be implemented on-site from water sampling to analysis was developed. In suspended glass fiber (SGF) method, 10 mg of the SGF was added to 1 L of environmental water to adsorb eDNA. The glass fiber was then collected using gravity filtration only, and eDNA was extracted using a simple reagent. eDNA was extracted from 85 samples of aquarium water, agricultural water, and river water using the SGF and standard methods. Under the laboratory condition, the SGF method was able to recover more DNA in the water containing lambda DNA than in the standard eDNA filtration and extraction method using adsorption columns. The invasive aquatic bivalve Limnoperna fortunei was used as a target species for detection using qPCR analysis or loop-mediated isothermal amplification (LAMP) analysis, which is less sensitive to DNA amplification inhibitors. The results showed that the positivity rate of the SGF-extracted DNA in qPCR and LAMP analysis was comparable or higher than that of the standard method extraction-qPCR analysis. In particular, as LAMP analysis is less time consuming than qPCR analysis and the presence or absence of DNA amplification can be determined visually, it is considered suitable as a rapid, on-site eDNA analysis method. The SGF method combined with the LAMP analysis has the potential to be applied to eDNA surveys of various species. [ABSTRACT FROM AUTHOR]

Background The golden mussel (Limnoperna fortunei) is a highly invasive species that causes environmental and socioeconomic losses in invaded areas. Reference genomes have proven to be a valuable resource for studying the biology of invasive species. While the current golden mussel genome has been useful for identifying new genes, its high fragmentation hinders some applications. Findings In this study, we provide the first chromosome-level reference genome for the golden mussel. The genome was built using PacBio HiFi, 10X, and Hi-C sequencing data. The final assembly contains 99.4% of its total length assembled to the 15 chromosomes of the species and a scaffold N50 of 97.05 Mb. A total of 34,862 protein-coding genes were predicted, of which 84.7% were functionally annotated. A significant (6.48%) proportion of the genome was found to be in a hemizygous state. Using the new genome, we have performed a genome-wide characterization of the Doublesex and Mab-3 related transcription factor gene family, which has been proposed as a target for population control strategies in other species. Conclusions From the applied research perspective, a higher-quality genome will support genome editing with the aim of developing biotechnology-based solutions to control invasion. From the basic research perspective, the new genome is a high-quality reference for molecular evolutionary studies of Mytilida and other Lophotrochozoa, and it may be used as a reference for future resequencing studies to assess genomic variation among different golden mussel populations, unveiling potential routes of dispersion and helping to establish better control policies. [ABSTRACT FROM AUTHOR]

Copyright of Agricultural Research in the Tropics / Pesquisa Agropecuária Tropical is the property of Pesquisa Agropecuaria Tropical and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Limnoperna fortunei, the golden mussel, is a bivalve mollusk considered an invader in South America. This species is responsible for ecological and economic damages due to its voluminous fouling capability. Chemical biocides such as MXD-100™ and sodium dichloroisocyanurate (NaDCC) are often used to control L. fortunei infestations in hydraulic systems. Thus, we proposed to investigate the effects of different periods (24, 48 and 72 h) of exposure to MXD-100™ (0.56 mg L−1) and NaDCC (1.5 mg L−1) on the gills of L. fortunei through morphological and molecular analyses. NaDCC promoted progressive morphological changes during the analyzed periods and only an upregulation of SOD and HSP70 expression during the first 24 h of exposure. MXD-100™ led to severe morphological changes from the first period of exposure, in addition to an upregulation of SOD, CAT, HSP70 and CYP expression during the first 24 h. In contrast, MXD-100™ led to a downregulation of CAT transcription between 24 and 48 h. In static conditions, NaDCC causes lethal damage after 72 h of exposure, and that exposure needs to be continuous to achieve the control of the species. Meanwhile, the MXD-100™ treatment presented several effects during the first 24 h, showing acute toxicity in a shorter period of time.

Abstract The study was conducted to compare the distribution and composition of the Molluscs community in 4 ecosystems (4 sites) in southern of Iraq, namely: (Site 1)- in Euphrates River at Al-Madinah city, (Site 2)- in Shatt Al-Arab at Al-Sharsh area, (Site 3)- in the Garmat Ali River at Al-Mashib area and Site 4- in the Al-seba area. Samples were collected from study sites during a period of January to August 2019. (11) species from the class Gastropoda and (4) species from the class Bivalves, species were predominated in most of the study months which are species: Melenodies nodosa, Bellamya bengalensis and Melanopsis turbculata from Gastropoda and two of the species are bivalve: Corbicula fluminalis and Limnoperna fortunei (Dunker, 1857), and the last species, L. fortunei, was recorded in the current study for the first time in freshwater of Iraq. The total biodiversity values of Molluscs at the Euphrates River at Al-Madinah area (Site. 1), Al-Sharsh area (Site 2), Al-Mashib area (Site 3) and Al-seba area (Site 4) were 3.1, 2.9, 2.4, 1.8, respectively, and It was noted that the highest seasonal densities of the species in the current study were recorded in the winter season, reaching 1013, 905, 762 and 639 individuals / m2 in four sites, respectively.

Mussel colonization can affect the water quality through restructuring nearby bacterial communities. In this study, we conducted an experiment to detect the bacterial alteration associated with live and dead golden mussel colonies, and used a high-throughput sequencing method based on 16S rRNA genes to reveal the changes in bacterial communities. It is revealed that these bacterial assemblages consumed nutrients and/or tissues of the mussels and produced metabolites, resulting in poor water quality and low bacterial alpha-diversities, particularly in dead mussel groups. The dissimilarity of bacterial community among the live and dead mussel groups was more significant than that among the different initial water qualities, indicating that mussel colonization and living status dominates the bacterial community. Co-occurrence network analysis revealed that the bacterial community associated with live mussel colonies exhibited more intensive interactions compared to that associated with dead ones. Furthermore, phenotype prediction indicated that mussel colonies, especially the dead mussel colonies, promoted the growth of pathogenic bacteria. Amino acid metabolism and carbohydrate metabolism were dominant pathways relevant to metabolism, leading to off-odors and the production of toxic compounds. The effect of these processes on water quality suggests that mussels that might be killed in water diversion projects should be removed promptly to avoid impacts on water quality.

The presence of competing mussel species in the green mussel of Banyuurip Village, Ujungpangkah District, Gresik Regency, namely the Golden mussel (Limnoperna fortunei) is urgently important to take attention. This mussel is known to have the ability to adapt and co-exist with green mussels and other shellfish. This form of interaction might be negative and potentially affects the productivity of green mussels. Length and weight are several parameters applied for an overview of the health and environmental suitability of population. Analysis of the length-weight relationship is intended to measure variations in certain lengths and weights of individual species or groups of individuals as an indicator of obesity, health and gonadal development. The relationship between the two shellfish (Perna viridis and Limnoperna fortune) in Banyuurib waters has a negative allometric pattern, meaning that the growth in length is faster than the growth in weight. Furthermore, the relative condition factor (Perna viridis and L fortunei) is that environmental conditions are equally supportive for the growth of both types of shellfish which have a competitive interaction pattern so that the presence of L. fortunei in the waters of Ujungpangkah, Gresik has the potential to interfere with the growth of Perna viridis green mussels. [ABSTRACT FROM AUTHOR]

Limnoperna fortunei is an invasive mussel species that is continuously expanding through South American. It has five larval stages, which usually differ in tolerance to environmental factors. How different abiotic filters affect L. fortunei larval stages has not been studied in depth. We employed a detailed database describing five floodplain environments to investigate the distribution of L. fortunei larval stages within and among these environments and determine which local abiotic filters affect the density of each larval stage. We found that the two youngest larval stages accounted for up to 83% of the larval density in four of the five environments studied, confirming an expanding population pyramid of L. fortunei in these environments. We also found positive and negative relationships among abiotic filters, and these relationships affected, directly and indirectly, the density of the youngest larval stages. Turbidity, water level, and suspended inorganic matter directly decreased the density of the two youngest larval stages. Conversely, temperature and pH directly increased the density of D-shaped and umbonated stages, respectively. Additionally, water level indirectly increased the density of the youngest larval stages mediated by declines in turbidity and suspended inorganic matter. Our findings suggest a likely expansion of L. fortunei in the Upper Paraná Floodplain. However, local abiotic filters, such as turbidity, water level, and suspended inorganic matter, decrease the density of the youngest larval stages. This finding illustrates that the establishment of L. fortunei can be prevented mainly if the youngest larval stages are controlled. [ABSTRACT FROM AUTHOR]

Nanoparticles such as zinc oxide nanoparticles (ZnO-NP) that are incorporated in consumer and industrial products have caused concern about their potential ecotoxicological impact when released into the environment. Bivalve mollusks are susceptible targets for nanoparticle toxicity since nanomaterials can enter the cells by endocytosis mechanisms. The aim of this study was to evaluate the influence of ZnO-NP on the redox metabolism in Limnoperna fortunei and the DNA damage after exposure to ZnO-NP. Adult bivalves were incubated with 1-, 10-, and 50-μg mL−1 ZnO-NP for 2, 4, and 24 h. Ionic Zn release, enzymatic and non-enzymatic antioxidant activity, oxidative damage, and DNA damage were evaluated. Oxidative damage to proteins and lipids were observed after 4-h exposure and returned to baseline levels after 24 h. Superoxide dismutase levels decreased after 4-h exposure and increased after 24 h. No significant alteration was observed in the catalase activity or even DNA double-strand cleavage. The dissociation of ZnO may occur after 24 h, releasing ionic zinc (Zn2+) by hydrolysis, which was confirmed by the increase in the ionic Zn concentration following 24-h exposure. In conclusion, ZnO-NP were able to induce oxidative stress in exposed golden mussels. The golden mussel can modulate its own antioxidant defenses in response to oxidative stress and seems to be able to hydrolyze the nanoparticles and consequently, release Zn2+ into the cellular compartment. [ABSTRACT FROM AUTHOR]

It is of great significance for air pollution control and personnel safety guarantee to master the release characteristics of harmful gases in the process of Limnoperna fortunei corruption. In view of the lack of research on the environmental pollution caused by the corruption of Limnoperna fortunei, a model experiment was designed to study the three harmful gases of NH3, H2S, and CH4 in the putrid process of Limnoperna fortunei by considering the density of Limnoperna fortunei and the time of leaving water. The results show that: (1) The recognition and processing of outliers based on wavelet decomposition and K-means algorithm can effectively reduce the standard deviation and coefficient of variation of the data set and improve the accuracy of the data set. (2) The variation of NH3 and H2S gas concentrations with the time of water separation satisfies polynomial linear regression (R2 > 99%). (3) At a density of 0.5–7.0 × 104 mussels/m2, the highest concentration of NH3 reached 47.9777–307.9454 mg/m3 with the increase in the density of Limnoperna fortunei and the extension of the time away from water, far exceeding the occupational exposure limit of NH3 of 30 mg/m3, potentially threatening human health and safety. The highest detection value of H2S concentration is 0.1909–5.0946 mg/m3, and the highest detection concentration of CH4 is 0.02%, both of which can be ignored. [ABSTRACT FROM AUTHOR]

Aim: Golden mussel Limnoperna fortunei is an invasive bivalve in many freshwater ecosystems in Asia and South America. Cold winter temperatures are expected to restrict its spread to high‐latitude areas. Cold tolerance and potential distribution of this species remain largely unstudied because the most extensively studied populations occur in tropical and sub‐tropical areas. We sought to investigate cold tolerance of golden mussels and to model their potential distribution at higher latitudes. Location: China, Global. Methods: We investigated overwintering survival of caged golden mussels in a reservoir located at the northern invasion front in north China. We then determined the lowest water temperature at which mussel filtering occurred in laboratory. Finally, we modelled relative environmental suitability globally based on Maximum Entropy using the species' most updated occurrence records. Results: Golden mussels in a northern invasion front reservoir could survive over a course of 6 days at <1°C, or 41 days at <2°C, or 108 days at <5°C, with 27% survival overall. Caged mussels were inaccessible to local predators and reproduced, with the subsequent population size increasing in early summer by ~280%, representing a potential source population. Laboratory tests demonstrated that the lowest water temperature at which mussels could filter water was 5.5°C, and 50% of individuals became active when temperature rose to 7.5–8.0°C. Species distribution modelling illustrated a potential distribution of golden mussels at higher latitude than presently found. Models that considered updated high‐latitude occurrence records predicted a significantly larger suitable area than currently exists, including near the lower Laurentian Great Lakes. Main conclusions: Our findings suggest enhanced cold tolerance of golden mussels and wider potential distribution than currently exists. We emphasize the importance of examining samples from invasion fronts when developing distribution predictions for spreading invasive species. [ABSTRACT FROM AUTHOR]

Copyright of Innotec is the property of Laboratorio Tecnologico del Uruguay and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Biological invasions and climate change are important drivers of biodiversity loss. In freshwater ecosystems, golden and zebra mussels are two highly aggressive invasive species that have caused ecological and economic damages in South and North America, respectively. Here, we used ecological niche models (ENMs) to investigate the invasive potential of golden and zebra mussels in present and future scenarios of global warming in the New World. We found two main patterns in the distribution of suitable areas for golden and zebra mussels. First, the distribution of potentially suitable areas, both in present and future scenarios, is different between mussel species: zebra mussel has areas that are more suitable in temperate regions, while suitable areas for golden mussel are concentrated in tropical and subtropical regions. Second, suitable habitats for golden mussel will increase more in future global warming scenarios compared to suitable habitats for zebra mussel. Indeed, there are experimental indications that zebra mussel has a lower tolerance to high temperatures compared to golden mussel, which is in agreement with our findings. We recommend that the future monitoring of both golden and zebra mussels in the New World should consider areas of highest thermic suitability for current and future scenarios. [ABSTRACT FROM AUTHOR]

The golden mussel Limnoperna fortunei (Dunker, 1857) is an invasive freshwater bivalve species that exerts harmful effects on the environment, as well as man-made structures, such as water-treatment systems. By using conventional sampling methods, it is difficult to detect mussels under low-density conditions; however, environmental DNA (eDNA) analysis may be a rapid and efficient method for monitoring this aquatic organism. In this study, we conducted surveys based on the eDNA analysis of L. fortunei in 15 farm ponds in Japan and compared the results with those of two conventional survey methods, visual census and plankton larval survey, to clarify the effectiveness of eDNA analysis for field surveys of L. fortunei. Primers and a probe specific to L. fortunei were developed, and a method for analysis was established. In the laboratory experiments, the species eDNA was detected in all water tanks containing the mussels, and the concentration of eDNA was high in the experimental tank that had high density of L. fortunei. In the field survey, L. fortunei eDNA was detected in all ponds where the mussels were found by conventional survey, and low concentrations of eDNA were also detected in several ponds where no L. fortunei were found by traditional methods. These results suggest that eDNA analysis has greater sensitivity for the detection of L. fortunei in farm ponds than that of conventional methods. Environmental DNA surveys have little impact on water management and are suitable for surveys at water facilities that have not yet been damaged by the mussels. [ABSTRACT FROM AUTHOR]

It is of great significance for air pollution control and personnel safety guarantee to master the release characteristics of harmful gases in the process of Limnoperna fortunei corruption. In view of the lack of research on the environmental pollution caused by the corruption of Limnoperna fortunei, a model experiment was designed to study the three harmful gases of NH3, H2S, and CH4 in the putrid process of Limnoperna fortunei by considering the density of Limnoperna fortunei and the time of leaving water. The results show that: (1) The recognition and processing of outliers based on wavelet decomposition and K-means algorithm can effectively reduce the standard deviation and coefficient of variation of the data set and improve the accuracy of the data set. (2) The variation of NH3 and H2S gas concentrations with the time of water separation satisfies polynomial linear regression (R2 > 99%). (3) At a density of 0.5–7.0 × 104 mussels/m2, the highest concentration of NH3 reached 47.9777–307.9454 mg/m3 with the increase in the density of Limnoperna fortunei and the extension of the time away from water, far exceeding the occupational exposure limit of NH3 of 30 mg/m3, potentially threatening human health and safety. The highest detection value of H2S concentration is 0.1909–5.0946 mg/m3, and the highest detection concentration of CH4 is 0.02%, both of which can be ignored.

Limnoperna fortunei, the golden mussel, is a bivalve mollusc native to Southeast Asia, which was introduced to South America via ballast water from commercial cargo ships from China and South Korea. In Brazil, the golden mussel is considered an invasive species, which has caused enormous economic and environmental damage. This is mainly due to the obstruction of pipes carrying water for the cooling systems within hydroelectric power plants. The presence of this invasive species also negatively impacts native fauna and flora. Early detection and rapid response during the early stages of infestation for this invasive species is essential to effectively control populations and prevent new infestations from forming. Techniques within molecular biology allow for more efficient detection of the golden mussel in all stages of development. In addition, the analysis of the genome, transcriptome and proteome of this species makes it possible to identify targets of biotechnological interest, which may be useful for the control of the golden mussel or for the generation of products of technological innovation. This review presents an overview of molecular studies involving this species and the perspectives on the prevention, control and combat of the golden mussel using these approaches. [ABSTRACT FROM AUTHOR]

In this study we test the sensitivity of three sizes of golden mussel (Limnoperna fortunei), an introduced species in Argentina, to a 96-h exposure to Cd 2 + , Cr 6 + , and Ni 2 + . We also analysed the relative sensitivity of L. fortunei compared to other freshwater bivalve equivalent sensitivity data. The ANOVA results showed that both factors, heavy metal and size, had significant effects (p = 0.0013 and p = 0.0091, respectively) on the mortality of the golden mussel. Tukey's test showed significant differences for Cr 6 + treatment and the smallest size class (7 mm ± 1 ). The relative sensitivity analysis showed that LC 50 values for the smallest size class of L. fortunei exposed to Ni 2 + and Cd 2 + were in the low range, with values of 11.40 mg/L and 12.65 mg/L, respectively. In the case of Cr 6 + (1.66 mg/L), its LC 50 was in the medium-low range of the freshwater bivalve sensitivity distribution. [ABSTRACT FROM AUTHOR]

The golden mussel is a species from China, which has spread to Asia and America, causing various economic impacts, as well as an ecological imbalance. Globally, the application of the invasive species has been investigated to mitigate the problems caused, and the present work evaluates the use of the golden mussel shells in the removal of methylene blue from contaminated waters. The material was characterized by the analysis of scanning electron microscopy, X-ray fluorescence, Fourier transform infrared spectroscopy and zeta potential, indicating favorable characteristics for the adsorption of pollutants. As for the adsorption studies, the adjustment of the pseudo-first-order model was verified, resulting in adsorption capacity of 26.4 mg g–1 at the equilibrium time of 300 min and 0.03 g of adsorbent. Henry’s model was applied at 25°C, 35°C, and 45°C indicating the favorable effect of temperature increase. Thus, it is observed the potential of using this material as adsorbent of water contaminants. [ABSTRACT FROM AUTHOR]

Brazilian poultry farming occupies a prominent position in the world scenario and there is a need for this production to occur in a sustainable way, so the nutrition of these animals must be carried out in a way that causes the least possible environmental impact. In front of it, the calcareous shells of the golden mussel, an invading mollusk that occupies a large part of the freshwater rivers of South America, arise and are responsible for generating large environmental impacts. The high content of calcium present in the golden mussel makes it a potential food with the capacity to replace calcitic limestone in broiler diets, but its feeding habit makes it possible to contain contents of toxic metals such as cadmium (Cd) and lead (Pb) that are contained inside the mussel can cause contamination of the chickens and consequently of the food products derived from them.

Limnoperna fortunei (L. fortunei) is one of the most abundant freshwater bivalves in southeast Asia, with wide-ranging direct and indirect impacts on ecosystems. To estimate material flows in the habitats of L. fortunei, a combination of stable-isotope and fatty-acid analyses were applied to assess the feeding spectrum of L. fortunei in southern China. Using the isotope-mixing model, the contribution proportions to the diet of L. fortunei were estimated as 19.8%–28.2% for plankton, 57.6%–65.2% for particulate organic matter (POM) and 10.2%–21.1% for sediment organic matter. We conclude that POM is the principal food source of L. fortunei. The δ13C enrichment of fixed carbon from POM to L. fortunei was 0.67%–2.41%. Based on the fatty acid data, it was estimated that L. fortunei consumed or selectively accumulated Chlorophyceae, Cryptophyceae, Dinophyceae, bacteria and terrestrial organic matter. The feeding spectrum of L. fortunei is similar to that of Dreissena polymorpha. We suggest that L. fortunei is able to differentiate suitable food items using chemical cues and the surface properties of particles.

The trophic state is usually defined by the concentrations of total phosphorous and chlorophyll a. Besides the input of nutrients from catchment, the internal process can modify the trophic state in reservoirs and lakes. Embalse Río Tercero is a multipurpose reservoir that has been object of a limnological study since 1996, as a requirement of the Nuclear Power Plant that uses the water for cooling. Invasive species have been reported in this reservoir: the mussel Limnoperna fortunei Dunker 1857, since 1996 and the dinoflagellate Ceratium hirundinella (O.F.Müller) Dujardin 1841, since 1999. As a result of their successful colonization, some characteristics of water quality and plankton composition have been modified. Despite this, during a long time period, the trophic state has not been modified. However, since 2013 noticeable increases in phosphorous and clorophyll a have been detected, and C. hirundinella reached exceptional abundances and became the dominant algae. Coincidentally, L. fortunei almost disappeared without any apparent reason. We intended to interpret the long-term tendencies of main trophic variables, and hypothesized some explanations for the population changes of C. hirundinella.

The literature indicates that exotic species have a greater tolerance to environmental stressors compared with native species. In recent decades, the introduction of contaminants into the environment has increased as a result of industrialization. The objective of this study was to verify the resistance of bivalve mollusks from freshwater native (Anodontites trapesialis) and exotic (Limnoperna fortunei) species to chemical contamination using an ex vivo/in vitro approach. Gill and muscle tissues were exposed to two different types of environmental stressors, copper (metal), and Roundup Transorb® (herbicide). The tissues were submitted to a cytotoxicity test in which the lysosomal integrity was assessed, from the adaptation of a method to isolated cells, and multixenobiotic resistance (MXR) test which evaluated cellular defense. In the exotic species, only copper at 9000 μg/L and Roundup Transorb® at 5000 μg/L were cytotoxic. In the native species, copper cytotoxicity at 900 and 9000 μg/L and Roundup Transorb® at 50 and 5000 μg/L were observed. Results were the same in both tissues. The MXR, responsible for the extrusion of contaminants (cell defense), was inhibited in both species when exposed to the contaminants, this cell defense system seems to be more inhibited in the native species, when exposed to both pollutants, indicating greater sensitivity. Therefore, cytotoxicity may be related to the lack of capacity of cellular defense. In relation to lysosomal integrity, the native species was more sensitive to cytotoxic pollutants, where a greater number of experimental conditions of metals and herbicide showed cytotoxicity, as well as more experimental situations inhibited its ability to defend itself. [ABSTRACT FROM AUTHOR]

Abstract Biofouling by the invasive mussel species Limnoperna fortunei has caused severe negative consequences in various freshwater ecosystems, but there is still a lack of effective antifouling strategies for this species, particularly in drinking water treatment systems where many existing strategies cannot be used. Chemical oxidants have been proposed to potentially control fouling mussels by influencing 3,4‑dihydroxyphenylalanine oxidation involved in byssus adhesion. To test this potential control strategy, L. fortunei adults were exposed to four oxidants: sodium hypochlorite (NaClO), potassium permanganate (KMnO 4), hydrogen peroxide (H 2 O 2) and chloramine T (CAT) at concentrations of 0.5, 1.0, 3.0 and 5.0 mg L−1 for one week. The results showed that low concentrations of KMnO 4 stimulated foot protein secretion, which was beneficial to byssus production (number and length). NaClO and H 2 O 2 , but not KMnO 4 and CAT, significantly inhibited byssus production and reduced breaking force, causing an increased byssus shedding rate. However, only NaClO dissolved byssus and altered the failure location from the byssal thread to adhesive plaque, even when exposed at low concentrations, showing its great impacts on byssus adhesion. Further analysis of polyphenoloxidase activities and gene expression profiles of LfBP-1 , LfFP-2 and LfBP-3 revealed that chemical oxidants affected byssus adhesion by altering Dopa oxidation and foot protein gene expressions. This study, therefore, suggests that a low concentration of NaClO can be used as an alternative and environmentally friendly chemical for controlling L. fortunei biofouling by weakening byssus adhesion. Graphical abstract Unlabelled Image Highlights • Effective strategies to control the fouling mussel Limnoperna fortunei are largely needed. • NaClO and H 2 O 2 , rather than KMnO 4 and chloramine T, inhibited byssus production. • NaClO reduced byssus performance and increased byssus shedding rate. • Only NaClO can dissolve byssus at even low concentrations. • NaClO can be used to control L. fortunei biofouling by weakening byssus adhesion. [ABSTRACT FROM AUTHOR]

The golden mussel, Limnoperna fortunei, is native to South China but has spread to Japanese freshwater environments as a nuisance invasive species. The golden mussel colonizes hard manmade substrates and its attachment can cause economic losses at water intake facilities. To evaluate the repellent effects of the high alkalinity (pH 12-13) of freshly prepared cement mortar on golden mussels, test pieces made of cement were immersed in a Japanese urban tidal river. Compared with coated mortar, and wood and limestone test pieces, the cement mortar did not show significant repellent effects on golden mussel attachment. Therefore, concrete constructions on riverbanks may be a preferred substrate for golden mussel colonization. A 4-year immersion experiment showed that copper substrate had a strong repellent effect on biofouling, while cement mortar, aluminum, and stainless steel did not have any adverse effects on golden mussel attachment. This experiment also revealed the settlement of invasive golden mussel in an urban tidal area where the salinity fluctuated up to 20.0‰. [ABSTRACT FROM AUTHOR]

The invasion of Limnoperna fortunei (L. fortunei) has been identified as one major biofouling in the operation of hydraulic engineering, which not only corrodes the concrete structures but also reduces the pipe diameter and increases the surface roughness, leading to the decrease of water conveyance capacity and the increase of the project operation cost. To better cope with this problem, an automated underwater inspection analysis scheme for the biofouling of L. fortune is provided in this study, which innovatively integrates the underwater remote operating rover (ROV) and computer vision techniques to inspect and evaluate the invasion of L. fortunei in water conveyance structure. This scheme first presents an image enhancement approach based on the fusion strategy to improve the quality of images extracted from underwater robot inspection videos. Then, the L. fortunei is segmented by U-Net in the enhanced underwater images, and the definition of adherent area ratio quantitatively assesses the biofouling severity. At last, the underwater inspection analysis scheme is implemented in a typical aqueduct, and the automatic analysis results are compared with the field investigation during the emptying maintenance of the aqueduct. In this study, the dataset of real ROV inspection video sequences was first used to evaluate the effectiveness of the proposed method for inspecting L. fortunei invasions in realistic scenarios, and then for the comparison with state-of-the-art methods. The results show that the proposed automated inspection scheme is capable of efficiently improving the underwater imaging quality and accurately detecting the L. fortunei. [ABSTRACT FROM AUTHOR]

Biofouling mediated by byssus adhesion in invasive bivalves has become a global environmental problem in aquatic ecosystems, resulting in negative ecological and economic consequences. Previous studies suggested that mechanisms responsible for byssus adhesion largely vary among bivalves, but it is poorly understood in freshwater species. Understanding of byssus structure and protein composition is the prerequisite for revealing these mechanisms. Here, we used multiple methods, including scanning electron microscope, liquid chromatography–tandem mass spectrometry, transcriptome sequencing, real-time quantitative PCR, inductively coupled plasma mass spectrometry, to investigate structure, and protein composition of byssus in the highly invasive freshwater mussel Limnoperna fortunei. The results indicated that the structure characteristics of adhesive plaque, proximal and distal threads were conducive to byssus adhesion, contributing to the high biofouling capacity of this species. The 3,4-dihydroxyphenyl-α-alanine (Dopa) is a major post-transnationally modification in L. fortunei byssus. We identified 16 representative foot proteins with typical repetitive motifs and conserved domains by integrating transcriptomic and proteomic approaches. In these proteins, Lfbp-1, Lffp-2, and Lfbp-3 were specially located in foot tissue and highly expressed in the rapid byssus formation period, suggesting the involvement of these foot proteins in byssus production and adhesion. Multiple metal irons, including Ca2+, Mg2+, Zn2+, Al3+, and Fe3+, were abundant in both foot tissue and byssal thread. The heavy metals in these irons may be directly accumulated by L. fortunei from surrounding environments. Nevertheless, some metal ions (e.g., Ca2+) corresponded well with amino acid preferences of L. fortunei foot proteins, suggesting functional roles of these metal ions by interacting with foot proteins in byssus adhesion. Overall, this study provides structural and molecular bases of adhesive mechanisms of byssus in L. fortunei, and findings here are expected to develop strategies against biofouling by freshwater organisms.

The aim of this study was to analyze the biochemical alterations in the golden mussel Limnoperna fortune i under dietary glyphosate exposure. Mussels were fed during 4 weeks with the green algae Scenedesmus vacuolatus previously exposed to a commercial formulation of glyphosate (6 mg L −1 active principle) with the addition of alkyl aryl polyglycol ether surfactant. After 1, 7, 14, 21 and 28 days of dietary exposure, glutathione-S-transferase (GST), catalase (CAT), superoxide dismutase (SOD), acetylcholinesterase (AChE), carboxylesterases (CES) and alkaline phosphatase (ALP) activities, glutathione (GSH) content and damage to lipids and proteins levels were analyzed. A significant increase (72%) in the GST activity and a significant decrease (26%) in the CES activity in the mussels fed on glyphosate exposed algae for 28 days were observed. The ALP activity was significantly increased at 21 and 28 days of dietary exposure (48% and 72%, respectively). GSH content and CAT, SOD and AchE activities did not show any differences between the exposed and non exposed bivalves. No oxidative damage to lipids and proteins, measured as TBARS and carbonyl content respectively, was observed in response to glyphosate dietary exposure. The decrease in the CES activity and the increases in GST and ALP activities observed in L . fortunei indicate that dietary exposure to glyphosate provokes metabolic alterations, related with detoxification mechanisms. [ABSTRACT FROM AUTHOR]

The invasive golden mussel Limnoperna fortunei is known to strongly affect benthic communities in South American freshwaters, but the evolution of these effects after the early invasion stages is poorly understood. Using predator exclusion (covered with 15- and 40-mm meshes) and inclusion (unprotected) substrates, we investigated the interaction between golden mussels and benthic invertebrate communities at different levels of exposure to predators in the Paraná River delta. Colonization of the substrates was largely dominated by the mussels. Oligochaeta, Nematoda, and Hirudinea were the most abundant accompanying groups, while Rotifera, Tardigrada, Copepoda, Cladocera, Chironomidae, Gastropoda, Hydracarina, Amphipoda, and nauplii appeared sporadically. Regardless of their different trophic modes and functional attributes, the numbers and biomass of associated invertebrates were not only enhanced by protection against predators, but also by the presence of mussel colonies. Enhancement of invertebrate densities associated with mussel colonies was higher on unprotected than protected substrates, suggesting that invertebrate facilitation increases with increasing predation pressure. Comparisons with a similar study carried out a decade earlier suggest that, after two decades of invasion, the reproductive potential of the mussel, the predation pressure on its colonies, and its facilitation effects on other invertebrates have increased in the Paraná River delta. [ABSTRACT FROM AUTHOR]

The study was conducted to identify the effect of different types of tube traps on the sampling efficacy and accuracy for invasive golden mussels, Limnoperna fortunei (Dunker, 1857), at four sites in Japan. The traps consisted of PVC tubes (diameter: 5.5 cm; length: 20 cm) inside which a PVC plate was fixed horizontally as settlement substrate, and we examined two trap characteristics: mesh covering at the tube ends (present or not) and substrate texture (even or uneven). Mesh covering had a negative effect (P<0.001) and uneven substrate had a marginally positive effect (P=0.08) on mussel settlement density. A positive relationship was found between larval and settlement density in traps without mesh. These results imply that the most effective type of tube trap had no mesh covering and used uneven substrate. The settlement density of the mussels was also examined on several surfaces of the tube trap and the rope used to suspend the trap. The mussel density on the rope was higher than that on the PVC plates and tubes. The best correlation between settlement density and larval density occurred on the outside of the PVC tubes. [ABSTRACT FROM AUTHOR]

Copyright of InterfacEHS is the property of Revista InterfacEHS and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: Since its introduction into South America around 1990, the freshwater bivalve Limnoperna fortunei (the golden mussel) has spread rapidly and is now a dominant component of the benthic and periphytic fauna in many rivers, lakes, and reservoirs. Sizable impacts of this nonindigenous species on nutrient recycling, plankton abundance and composition, and trophic relationships with fishes have been reported, but its effects on the sediments have received little attention. In this work, we use eighteen 20‐L flow‐through experimental units with and without mussels where changes in the mass and characteristics of the sediments accumulated throughout a yearly cycle in monthly, biannual, and annual intervals are analyzed. Experimental units with mussels yielded almost 2 times more sediments than units without mussels and contained significantly higher loads of organic matter and total N. Total P was not affected by the presence of mussels. Sediments accumulated in the biannual and annual experimental units agreed well with the yields of the monthly units, but the vertical stratification of organic matter, N, and P was unpatterned. Seasonal changes in the volume of total sediments, biodeposits, and their organic matter and N contents were positively associated with ambient water temperature and with intermediate (~150–250 NTU, nephelometric turbidity units) turbidity. Our results suggest that ecosystem‐wide modifications in the living conditions of the benthic epifaunal and infaunal organisms in waterbodies invaded by the mussel are likely significant, although variable locally, regionally, and across taxa. [ABSTRACT FROM AUTHOR]

Hydropower dams are widespread sources of anthropogenic alteration on lotic ecosystems, found in most hydrological basins system in the world. Our objective was to assess how such a run-of-river dam influences benthic macroinvertebrate assemblages in a neotropical river under a deactivated run of river dam. For that we tested four hypotheses: (1) a run-of-river dam diminishes the local diversity of the benthic macroinvertebrate assemblages; (2) the presence of the dam results in a more propitious habitat to the establishment of invasive species; (3) the presence of the dam results in a lower complexity of local benthic macroinvertebrate assemblages; (4) the ecological impacts are restricted to the sites directly affected by the dam. While the presence of the dam lowers the benthic macroinvertebrate assemblages’ diversity in its reservoir, the diversity downstream next to the dam actually increases. The habitats directly affected by the dam also supported much higher biomass proportion of invasive species. By using eco-exergy and specific eco-exergy indicators, we were able to assess the complexity of benthic macroinvertebrate assemblages and the assemblages in the reservoir appeared to be enhanced by the presence of invasive species. These results illustrate that deactivated run-of-river dams still alter significantly the structure of lotic benthic macroinvertebrate assemblagesand that is advisable a management intervention for decommissioning of the dam. Finally, our results show that exergy based indicators may improve our comprehension of ecological systems’ functioning in regards of ecological impacts of small dams, supporting environmental sustainable practices. [ABSTRACT FROM AUTHOR]

Biofouling mediated by byssus adhesion in invasive bivalves has become a global environmental problem in aquatic ecosystems, resulting in negative ecological and economic consequences. Previous studies suggested that mechanisms responsible for byssus adhesion largely vary among bivalves, but it is poorly understood in freshwater species. Understanding of byssus structure and protein composition is the prerequisite for revealing these mechanisms. Here, we used multiple methods, including scanning electron microscope, liquid chromatography--tandem mass spectrometry, transcriptome sequencing, real-time quantitative PCR, inductively coupled plasma mass spectrometry, to investigate structure, and protein composition of byssus in the highly invasive freshwater mussel Limnoperna fortunei. The results indicated that the structure characteristics of adhesive plaque, proximal and distal threads were conducive to byssus adhesion, contributing to the high biofouling capacity of this species. The 3,4-dihydroxyphenyl-α-alanine (Dopa) is a major post-transnationally modification in L. fortunei byssus. We identified 16 representative foot proteins with typical repetitive motifs and conserved domains by integrating transcriptomic and proteomic approaches. In these proteins, Lfbp-1, Lffp-2, and Lfbp-3 were specially located in foot tissue and highly expressed in the rapid byssus formation period, suggesting the involvement of these foot proteins in byssus production and adhesion. Multiple metal irons, including Ca2+, Mg2+, Zn2+, Al3+, and Fe3+, were abundant in both foot tissue and byssal thread. The heavy metals in these irons may be directly accumulated by L. fortunei from surrounding environments. Nevertheless, some metal ions (e.g., Ca2+) corresponded well with amino acid preferences of L. fortunei foot proteins, suggesting functional roles of these metal ions by interacting with foot proteins in byssus adhesion. Overall, this study provides structural and molecular bases of adhesive mechanisms of byssus in L. fortunei, and findings here are expected to develop strategies against biofouling by freshwater organisms. [ABSTRACT FROM AUTHOR]

Although contamination and invasive species are two of the most relevant anthropogenic drivers affecting ecosystems, their joint impact on the environment has been poorly investigated. Glyphosate, directly or indirectly, contaminates freshwater systems which in turn may be invaded by the golden mussel Limnoperna fortunei . Under laboratory conditions, we studied the combined effect of technical-grade glyphosate, Roundup Max ® and Glifosato Atanor ® , in scenarios with and without L. fortunei, on phytoplankton from Salto Grande Reservoir (Uruguay River, Argentina). We expected that the effects of the interaction on phytoplankton and water quality would vary with the form of herbicide applied. The assay was conducted for 14 days (Tf) using 3-L bottles as experimental units. Eight treatments were performed in triplicate: C: Control; M: mussel; G: technical-grade glyphosate acid; R: Roundup Max ® ; A: Glifosato Atanor ® ; MG: mussel + technical-grade glyphosate acid, MA: mussel + Glifosato Atanor ® and MR: mussel + Roundup Max ® . The active ingredient was applied at 6 ppm. The dissipation of glyphosate in water was 1.5–2.6 times higher in presence of mussels. Treatments G and A showed an increase in phytoplankton abundance, mainly the cyanobacteria Microcystis spp. wich rised to 289% and 639% at Tf, respectively, relative to their values at Ti. Roundup Max ® limited the growth of Microcystis spp., as its abundance decreased 59% relative to Ti. L. fortunei reduced phytoplankton abundances at Tf. Evenness increased significantly in M, MG, MR and MA, while it decreased in G, R and A relative to C. The interaction of factors produced a significant synergistic increase in periphyton; periphytic chlorophyll a concentration was 0.81 ± 0.02 μg cm −2 for MR; 0.09 ± 0.02 μg cm −2 for MA and 0.02 ± 0.01 μg cm −2 for MG. Limnoperna fortunei appeared as the driving force in the interaction. The assay described here allows for the rapid assessment of the impact of these types of agents on freshwater. [ABSTRACT FROM AUTHOR]

Golden mussels ( Limnoperna fortunei ), an invasive species of Mytilidae, settle on the inside surfaces of water pipelines with high density, often resulting in heavy biofouling and pipe clogging. The species invades pipelines during its planktonic veliger stage, which is apt to be killed by high frequency turbulence produced by turbulence-generating materials (TGMs), such as pore plates, which can be installed inside the pipelines. However, little is known about the influence of different types of TGMs on the pipeline hydraulics and veliger-killing mechanism. An experimental study was conducted to investigate the veliger-killing mechanism and pick out the most efficient TGM for veliger killing and prevention of golden mussel invasion in pipelines. Four types of TGMs, plates with hole diameters of 3 mm (PP3) and 6 mm (PP6) and wires with mesh spacings of 3 mm (WM3) and 2 mm (WM2), were installed in a 12.6 m-long experimental pipeline with sparse (space between two PP or WM = 50 cm) and intensive (space = 25 cm) layouts. The flow field downstream of the TGMs was measured by an Acoustic Doppler Velocimeter (ADV). The experimental results revealed that the TGMs caused a short disturbance both transversely and longitudinally downstream. The disturbance was significant for PP6 and weakened for the intensive layout. The WMs exhibited little influence on the discharge capacity of the pipe and enhanced the downstream flow velocity within a short distance for the intensive layout. The distribution of the downstream turbulence intensity of the TGMs presented a uniform transverse pattern except for WM2. The TGMs enlarged the frequency of the dissipation range in the energy spectra for turbulence and consequently reduced the length scale of the dissipative eddies, i.e. the Kolmogorov length scale. A positive relation was identified between the downstream ( d * ) max (the maximum ratio of the veliger body length to the Kolmogorov length) and the killing rate (increase of the veliger mortality rate after treated by the turbulence generated in the experimental pipeline). The test results indicated that the veliger community would be heavily damaged when the dissipation range (the Kolmogorov scale) had a similar or smaller length scale than the veliger body length. Therefore, ( d * ) max was considered to be a representative indicator for the evaluation of the killing effect of TGMs. The TGM could be considered to have high and steady killing capacity if ( d * ) max > 1. PP6 with a sparse layout is recommended for the control of golden mussel veligers considering both the killing efficiency and economic efficiency. [ABSTRACT FROM AUTHOR]

Applying the theories of Materials Science and Engineering to describe the composition and hierarchy of microstructures that comprise biological systems could help the search for new materials and results in a deeper insight into evolutionary processes. The layered microstructure that makes up the freshwater bivalve Limnoperna fortunei shell, an invasive specie in Brazil, was investigated utilizing SEM and AFM for the determination of the morphology and organization of the layers; and XRD was used to determine the crystalline phases of the calcium carbonate (CaCO3) present in the shell. The presence of the polymorphs calcite and aragonite were confirmed and the calcite is present only on the external side of the shell. The shell of L. fortunei is composed of two layers of aragonite with distinct microstructures (the aragonite prismatic layer and the aragonite sheet nacreous layer) and the periostracum (a protein layer that covers and protects the ceramic part of the shell). A new morphology of the calcite layer was found, below the periostracum, without defined form, albeit crystalline.

While invasion success is usually associated with the biological fitness of the invader and environmental similarity between the area of origin and the invaded range, some of the most notorious aquatic invasions involve species with traits that for millions of years were a burden, rather than an advantage, for their survival. These odd characteristics became major assets after man started reshaping the surface of the earth, facilitating their spread. Invasion risk-assessment models, chiefly based on environmental match parameters, are unlikely to predict the dispersion of these (and probably many other) species, whose invasive nature involves subtle and intricate mechanisms that operate at levels normally ignored by (and often unknown to) the models. Much of the literature on introduced species is focused on demonstrating their negative impacts on the ecosystems invaded. While the fact that invasive organisms can, and very often do, have enormous negative impacts, is beyond doubt, and all efforts possible for keeping biological invasions at bay should be made, once the introduction happens and the eradication of the invader is unfeasible, research efforts should be centered on objective analyses of how the invader interacts with the new ecosystem, untainted by efforts to forcibly demonstrate its negative impact. [ABSTRACT FROM AUTHOR]

Similar as biofouling of Dreissena species (zebra mussels and quagga mussels) on infrastructure concrete prevalent in the USA and Europe, the freshwater mollusk Limnoperna fortunei has also caused biofouling and exhibits chemical and physical deterioration on concrete structures. Given that numerous inter-basin water diversion projects containing enormous concrete structures have been constructed in L. fortunei colonized regions, it is critical to study the concrete deterioration caused by the mussel fouling such that effective prevention strategies can be proposed. This study analysed the characteristics of concrete deterioration associated with the fouling. Analysis of the affected concrete structures indicated that the pores of different sizes increased, resulting in increased water absorption and carbonation depth, while the compressive strength of the concrete decreased as a consequence of the mussel colonization. Concentrations of aluminum, manganese and iron increased while calcium decreased in the mussel-colonized concrete. These changes are due to the physiological requirements of mussel growth and adhesion activities. L. fortunei adhesion removes the calcium from the surface of the concrete and accelerates the concrete deterioration. [ABSTRACT FROM AUTHOR]