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Occurrence of neurotoxic chemicals in the aquatic environment is on the rise posing a potential threat to aquatic biota including fish. In teleosts, zebrafish has become a popular model organism for toxicological studies and testing strategies. However, over the decade, siluriformes (catfish) are also finding ever increasing application being robust as well as their adaptability to adverse ecological conditions, surgical interventions, and tolerant models for toxicity studies and manipulations. Such information can infer potential effects occurring to other species exposed to neurotoxins in their aquatic environment and predicting potential risks of a chemical for the aquatic ecosystem. The aim of this review is to compare and interpret recent results published concerning neurobehavioral and morphological disturbances caused by toxicants/pollutants providing a holistic view of potential neurotoxic outcomes in catfish. Overall, this review summarizes various effects of toxicants/pollutants in terms of neurotoxicity and neurodegeneration associated with behavioral phenotypes. [ABSTRACT FROM AUTHOR]

Animals rely on olfaction to detect and process invaluable chemical information about their environment. For olfaction to function, chemicals must first be detected, which leads to the activation of signal-transduction pathways at the peripheral olfactory organ. As the olfactory system is in direct contact with the environment, the system is constantly vulnerable to damage by contaminants entering the atmosphere or hydrosphere. Contaminants may have a variety of effects, including disrupting olfactory signals generated during chemical detection, or altering numerous targets along the signal transduction pathway. With any impairment of chemical detection, animals may be unable to rely on olfaction to make correct decisions about their environment and thus their fitness. While other reviews have focussed on olfactory toxicology in general, here we specifically explore how contaminants may affect the signal-transduction pathways at various points and link those changes to olfactory functionality across vertebrates with a focus on fishes. [ABSTRACT FROM AUTHOR]

Several types of contaminants are anthropogenically introduced into natural aquatic ecosystems and interact with other chemicals and/or with living organisms. Although metal toxicity alone has been relatively well studied, the toxic metal ion effects in the mixture have been thoroughly studied only during the last decades. This review focuses on the published reciprocal effects of different metals on different species of algae, together with describing their toxic effects on studied parameters. Phytoplankton as a bioindicator can help to estimate the reciprocal metal risk factor. Many methodologies have been developed and explored, such as the biotic ligand model (BLM), concentration addition (CA), independent action (IA), sensitivity distribution of EC50 species sensitivity distribution (SSD curves), and others, to study reciprocal metal toxicity and provide promising results, which are briefly mentioned too. From our review, we can commonly conclude the following: Zn acted antagonistically with most heavy metals (Al, Cu, Cd, and Ni). The Cu interaction with Cd, Fe, and Pb was mostly antagonistic. Cd showed synergistic behaviour with Hg, Cu, Zn, and Pb and antagonistic behaviour with Co and Fe in many cases. Methods and techniques need to be developed and optimised to determine reciprocal metal toxicity so that the ecotoxicological predictions made by using phytoplankton can be more accurate and related to real-time toxic metals risks to the aquatic ecosystem. This is the main objective of ecotoxicological tests for risk assessment. Understanding how metals enter algal cells and organelles can help to solve this challenge and was one of the main parts of the review. [ABSTRACT FROM AUTHOR]

Lakes host a high level of biodiversity, especially in their littoral zone, and provide various ecological and socio‐economic services. Lake ecosystems are impacted by a combination of pressures from different human activities (industry, hydroelectricity, agriculture, recreational activities, domestic and urban uses). Anthropic pressures can lead to alterations and dysfunctions in lakes, particularly in the littoral zone.The 2000 EU Water Framework Directive led to considerable efforts to improve the ecological status of European water bodies. However, in France, measures implemented by lake managers to counteract, limit or suppress anthropogenic impacts are still poorly identified. Moreover, their effects on hydromorphology, physico‐chemistry and biotic communities are often only partially reported (the monitoring being incomplete or heterogeneous, if not missing).This paper proposes a framework to harmonize the monitoring of habitat improvement actions conducted in the littoral zone of lakes. The monitoring method is presented as well as the sampling protocols and techniques set out to survey both the restored and control zones at the European French territory scale.Long‐term monitoring of hydromorphological, biological and physicochemical features is expected to improve our understanding of recolonization mechanisms following restoration. The proposed approach will therefore guide practitioners to identify the best restoration options and ultimately contribute to the conservation of recipient populations and communities. [ABSTRACT FROM AUTHOR]

The expansion of scientific image data holds great promise to quantify individuals, size distributions and traits. Computer vision tools are especially powerful to automate data mining of images and thus have been applied widely across studies in aquatic and terrestrial ecology. Yet marine benthic communities, especially infauna, remain understudied despite their dominance of marine biomass, biodiversity and playing critical roles in ecosystem functioning.Here, we disaggregated infauna from sediment cores taken throughout the spring transition (April–June) from a near‐natural mesocosm setup under experimental warming (Ambient, +1.5°C, +3.0°C). Numerically abundant mudsnails were imaged in batches under stereomicroscopy, from which we automatically counted and sized individuals using a superpixel‐based segmentation algorithm. Our segmentation approach was based on clustering superpixels, which naturally partition images by low‐level properties (e.g., colour, shape and edges) and allow instance‐based segmentation to extract all individuals from each image.We demonstrate high accuracy and precision for counting and sizing individuals, through a procedure that is robust to the number of individuals per image (5–65) and to size ranges spanning an order of magnitude (<750 μm to 7.4 mm). The segmentation routine provided at least a fivefold increase in efficiency compared with manual measurements. Scaling this approach to a larger dataset tallied >40k individuals and revealed overall growth in response to springtime warming.We illustrate that image processing and segmentation workflows can be built upon existing open‐access R packages, underlining the potential for wider adoption of computer vision tools among ecologists. The image‐based approach also generated reproducible data products that, alongside our scripts, we have made freely available. This work reinforces the need for next‐generation monitoring of benthic communities, especially infauna, which can display differential responses to average warming. [ABSTRACT FROM AUTHOR]

High-frequency water quality measurements in streams and rivers have expanded in scope and sophistication during the last two decades. Existing technology allows in situ automated measurements of water quality constituents, including both solutes and particulates, at unprecedented frequencies from seconds to subdaily sampling intervals. This detailed chemical information can be combined with measurements of hydrological and biogeochemical processes, bringing new insights into the sources, transport pathways, and transformation processes of solutes and particulates in complex catchments and along the aquatic continuum. Here, we summarize established and emerging high-frequency water quality technologies, outline key high-frequency hydrochemical data sets, and review scientific advances in key focus areas enabled by the rapid development of high-frequency water quality measurements in streams and rivers. Finally, we discuss future directions and challenges for using high-frequency water quality measurements to bridge scientific and management gaps by promoting a holistic understanding of freshwater systems and catchment status, health, and function.

This study aims to assess the quality of lagoon water used as a dumping ground for shrimp farming waste. The research uses the descriptive method. The research was conducted at the Shrimp Cultivation Site in the Banaran Kulon Progo Village, Special Region of Yogyakarta, Indonesia. The research focuses on physicochemical parameters, including temperature, pH, total suspended solid ( TSS), dissolved oxygen ( DO), ammonium (NH 4-N), nitrate (NO 3-N), and phosphate. The sampling technique is based on SNI 6989.57:2008. Sampling was carried out 48 times in 3 lagoons during rainy and dry seasons. Dialysis data was descriptively classified with the help of Storage and Retrieval of Water Quality Data System (STORET) and water quality was generally classified as C (moderately polluted) and D (heavily polluted) categories in dry and rainy seasons. The results showed that in the rainy season the highest pH, nitrate and phosphate levels of 8.3, and 6.1 and 20.8 mg∙dm –3, were up to 15% less than in the dry season in the same point. Thus, it can be concluded that these values from the STORET in the dry season are larger than those in the rainy season. The study results are expected to become a basis for the evaluation of the quality of shrimp farming wastewater so that environmental health can be controlled and the risk of waste pollution reduced.

Morphometry is the process that deals with mathematical analysis and calculations of the various land surface dimensions. In this study, morphometry analysis and changes in riverbeds due to anthropogenic activities have been studied using geospatial techniques for a stretch of the Yamuna river in Delhi. The parametric values related to morphometry, such as low permeability and high surface run-off were determined through Remote Sensing, which is helpful to understand the characteristics of the area. The study reveals that morphometric parameters and land surface properties are closely interrelated and are dependent on each other. Analysis has lightened up that over the year river span has been reduced from 5.15 to 4.23 sq. km and there is a trend of reduction and alteration of the channel in upcoming days. The morphometric conditions also indicate a concern of flood during monsoon. This study also focuses on the adverse effects of anthropogenic activities on the Yamuna riverbed morphology. There is a need for restriction on haphazard human activities, effective planning and management for sustainable development of the Yamuna riverbed in Delhi. The study suggests further research on aquatic ecology, water quality, and life expectancy of the river due to immense anthropogenic pressure. [ABSTRACT FROM AUTHOR]

Springs are crucial as primary water sources for various human needs, including in Batu City, East Java, Indonesia. Preserving the integrity of these springs is essential to protect them from contamination, including emerging pollutants such as microplastics, which have been reported in aquatic ecosystems. Therefore, it is vital to analyze the presence of microplastics in springs to mitigate pollution. However, there is a lack of studies reporting the content of microplastics in springs, particularly in Batu City. This study aims to analyze microplastics in multiple springs within Batu City using a descriptive research method. The research materials encompass the abundance and characteristics of microplastics and various water quality parameters such as dissolved oxygen, pH, temperature, turbidity, color, total dissolved solids, taste, odor, and current velocity. Sampling was conducted at six springs in Batu City: Sumber Ngesong, Sumber Banyuning, Sumber Gemulo, Sumber Torong Belok, Sumber Kasinan, and Sumber Dari. The findings of this study indicate that the water quality in the springs of Batu City complies with established standards. However, microplastics were detected in all the sampled springs, with concentrations ranging from 208 to 354 particles/m³. The identified microplastics primarily included fibers, films, and fragments. MP polymers obtained in this study were Nylon, Low-Density Polyethylene (LDPE), Polyethylene terephthalate (PETE), and Polyvinyl chloride (PVC). Based on the study results, while the water in the spring area of Batu City meets water quality standards, it is necessary to implement mitigation measures to address the emerging pollutant pollution, such as microplastics, to safeguard the springs as a vital water source for human life. To the best of our knowledge, this study is the first to report the characteristics of microplastics in the springs of Batu City.

Macrophytes not only integrate environmental conditions but also reflect the trophic state of the aquatic environment through several metrics. The lack of knowledge on the biology and ecology of aquatic plants in Moroccan rivers makes it very difficult to establish a comprehensive and effective national metric for assessing the trophic state of rivers. Indeed, the use of one of the European methods, which have been the subject of geographical intercalibration projects across different countries, particularly those in the Mediterranean region, proves necessary. Given Morocco's geographic location within the Mediterranean Basin, Macrophyte Biological Index for Rivers (IBMR) was chosen as a method to assess Moroccan running waters. Furthermore, it allowed answering a number of questions about the usage of biological metrics based on macrophytic communities throughout Morocco. The obtained results showed that the IBMR can provide an indication of the overall trophic state of the watercourse, but with well-defined conditions, namely stable hydrological conditions with a significant richness in contributing pollution-sensitive species. Although this macrophyte index showed correlations with the parameters responsible for eutrophication phenomena, it remained less effective in the face of the downgrading parameter. Thus, the particular context of Moroccan watercourses, namely the watercourses of the Upper Oum Er-rbia basin, and the major pitfall that still lies in the knowledge of the ecology of plant groups in Moroccan running waters, can pose a problem in the application of the IBMR index, especially with regard to ubiquitous species that dominate the downstream sites of the studied rivers. [ABSTRACT FROM AUTHOR]

This document contains abstracts from research papers on microphytobenthos, specifically focusing on biofilms and diatoms. The abstracts cover various topics such as the ecological function and adaptability of microphytobenthic biofilms, the response of microphytobenthos to multiple stressors, and the metabolites of light and their role in adaptation. They also discuss the phototobiology of benthic diatoms, the variability in microphytobenthos biomass and production, the motility of epipelic diatoms, and the effect of heat stress on phototrophic biofilm photosynthesis. These abstracts provide insight into current research in this field and emphasize the importance of microphytobenthos in coastal ecosystems. Additionally, the document mentions the invasive seaweed Rugulopteryx okamurae, which has spread to various locations in Spain, Morocco, Portugal, the Azores, Madeira, and the Canary Islands. This species has had significant environmental and socioeconomic impacts, displacing native species and affecting fishing and tourism industries. Research is being conducted to understand the biology, ecology, and impact of R. okamurae, and efforts are underway to monitor and mitigate its spread in affected regions. [Extracted from the article]

Traditionally, trophic ecology research on aquatic ecosystems has focused more on the quantity of dietary energy flow within food webs rather than food quality and its effects on organisms at various trophic levels. Recent studies emphasize that food quality is central to consumer growth and reproduction, and the importance of food quality for aquatic ecosystems has become increasingly well recognized. It is timely to synthesise these findings and identify potential future research directions. We conducted a systematic review of omega‐3 polyunsaturated fatty acids (ω3‐PUFAs) as a crucial component of high‐quality food sources in freshwater ecosystems to evaluate their impact on a variety of consumers, and explore the effects of global change on these high‐quality food sources and their transfer to higher trophic consumers within and across ecosystems. In freshwater ecosystems, algae rich in ω3 long‐chain PUFAs, such as diatoms, dinoflagellates and cryptophytes, represent important high‐quality food sources for consumers, whereas cyanobacteria, green algae, terrestrial vascular plants and macrophytes low in ω3 long‐chain PUFAs are low‐quality food sources. High‐quality ω3‐PUFA‐containing food sources usually lead to increased growth and reproduction of aquatic consumers, e.g. benthic invertebrates, zooplankton and fish, and also provide ω3 long‐chain PUFAs to riparian terrestrial consumers via emergent aquatic insects. Consumers feeding on high‐quality ω3‐PUFA‐containing foods in turn represent high‐quality food for their own predators. However, the ω3‐PUFA content of food sources is sensitive to global environmental changes. Warming, eutrophication, increased light intensity (e.g. from loss of riparian shading), and pollutants potentially inhibit the synthesis of algal ω3‐PUFAs while at the same time promoting the growth of lower‐quality foods, such as cyanobacteria and green algae. These factors combined could lead to a significant reduction in the availability of ω3‐PUFAs for consumers and constrain their overall fitness. Although the effect of individual environmental factors on high‐quality ω3‐PUFA‐containing food sources has been investigated, multiple environmental factors (e.g. climate change, human activities, pollution) will act in combination and any synergistic effects on aquatic food webs remain unclear. Identifying the sources and fate of ω3‐PUFAs within and across ecosystems could represent an important approach to understand the impact of multiple environmental factors on trophic relationships and the implications for populations of freshwater and riparian consumers. Maintaining the availability of high‐quality ω3‐PUFA‐containing food sources may also be key to mitigating freshwater biodiversity loss due to global change. [ABSTRACT FROM AUTHOR]

Body mass underpins many ecological processes at the level of individuals, populations, and communities. Often estimated in arthropods from linear morphological traits such as body length or head width, these relationships can vary even between closely related taxa. Length–mass relationships of mosquito (Diptera: Culicidae) larvae are poorly known despite the importance of this family to disease and aquatic ecology. To fill this gap, we measured ontogenetic changes in linear traits (body length, head width, and thorax width) and dry and wet masses and estimated length- and width–mass relationships in larvae of 3 culicid species inhabiting different niches: the tropical Aedes albopictus (Skuse, 1894), the temperate Culex pipiens (Linnaeus, 1758), and the snowmelt Ochlerotatus punctor (Kirby, 1837). We compared our results with published length–mass allometries of other aquatic dipteran larvae. We showed that thorax width and body length, but not head width, reliably predicted body mass for our 3 species. The length–mass allometry slopes in aquatic dipterans varied considerably between and within families but were independent of phylogeny, specimen handling, preservation techniques, and data fitting methods. Slope estimates became less precise with decreasing sample size and size range. To obtain reliable estimates of the allometric slopes, we have thus recommended using data on all larval stages for intraspecific allometries and a wide range of species for interspecific allometries. We also cautioned against the indiscriminate use of length–mass allometries obtained for other taxa or collected at lower taxonomic resolutions, e.g. when using length–mass relationships to estimate biomass production at a given site. [ABSTRACT FROM AUTHOR]

Filamentous algae blooms (FABs) have been increasing globally in recent years, and their presence can have both harmful and beneficial effects on aquatic ecosystems. As one of the most common FABs, Cladophora blooms have been reported in the lakes of the Qinghai-Tibet Plateau during the past few years. However, there have been few studies focused on how FABs impact other aquatic organisms, especially in alpine lakes since these are at the forefront of responding to global climate change. In this study, the phytoplankton communities in different regions of Qinghai Lake were profiled in different seasons using meta-barcode sequencing. The phytoplankton assemblages in areas with Cladophora blooms were compared to those without Cladophora. The phytoplankton community structure correlated with physicochemical properties including water temperature, electrical conductivity, nitrate, and the presence or absence of Cladophora blooms. The relative abundance of Bacillariophytes was found to be higher in zones with Cladophora blooms than in other regions. Significant seasonal changes in phytoplankton biomass and β diversity were observed in zones with Cladophora blooms. Growth and microbial degradation of Cladophora can change the pH, dissolved oxygen, secchi depth, and nitrate. Together with seasonal temperature and electrical conductivity changes, Cladophora growth can significantly impact the phytoplankton biomass, community dissimilarity and assembly process. These results showed that Cladophora plays a key role in littoral aquatic ecosystem ecology. [ABSTRACT FROM AUTHOR]

Groundwater is a vital ecosystem of the global water cycle, hosting unique biodiversity and providing essential services to societies. Despite being the largest unfrozen freshwater resource, in a period of depletion by extraction and pollution, groundwater environments have been repeatedly overlooked in global biodiversity conservation agendas. Disregarding the importance of groundwater as an ecosystem ignores its critical role in preserving surface biomes. To foster timely global conservation of groundwater, we propose elevating the concept of keystone species into the realm of ecosystems, claiming groundwater as a keystone ecosystem that influences the integrity of many dependent ecosystems. Our global analysis shows that over half of land surface areas (52.6%) has a medium‐to‐high interaction with groundwater, reaching up to 74.9% when deserts and high mountains are excluded. We postulate that the intrinsic transboundary features of groundwater are critical for shifting perspectives towards more holistic approaches in aquatic ecology and beyond. Furthermore, we propose eight key themes to develop a science‐policy integrated groundwater conservation agenda. Given ecosystems above and below the ground intersect at many levels, considering groundwater as an essential component of planetary health is pivotal to reduce biodiversity loss and buffer against climate change. [ABSTRACT FROM AUTHOR]

This document is a summary of a special issue on "Taxonomy, Biodiversity, and Ecology of Parasites of Aquatic Organisms." The special issue focuses on the challenges faced by parasitologists in assessing the biodiversity of parasite species and understanding their distribution and ecological roles. The issue includes seven research articles that use integrative approaches, combining morphological, ecological, and molecular evidence, to address taxonomic and evolutionary questions related to parasitic organisms in aquatic environments. The articles cover a range of parasites, including apicomplexan parasites, acanthocephalans, monogeneans, nematodes, trematodes, and platyhelminthes. The research highlights the importance of integrative taxonomy in advancing our understanding of parasite diversity and its implications for fields such as biogeography, evolution, and ecology. [Extracted from the article]

Water is essential in our daily lives, and conserving and monitoring its quality is crucial. Biological assessment is one of the methods for evaluating water quality. This study aimed at predicting the average score per taxon (ASPT), a biological assessment of the water quality index, for 109 Japanese rivers, mainly by machine learning using extreme gradient boosting and random forest. To this end, we extracted and utilized freshwater macroinvertebrate distribution data collected during 1991–2017 under the "National Census on River Environments" (NCRE) by the Ministry of Land, Infrastructure, and Transport. Five factors (average temperature, biochemical oxygen demand, elevation, slope, and human impact index) were addressed as environmental data affecting the macroinvertebrate distribution. Based on the biological data and five factors, predictive models were developed for 71 taxa used for ASPT. To confirm the accuracy of the prediction model, we compared the ASPT values that were predicted to the actual values. The actual values were within the range of the predicted values at elevations below 200 m, and the actual and predicted values diverged at elevations above 200 m, probably because 91% of the biological data used in the model were gathered at elevations lower than 200 m. Thus, the model is applicable at elevations below 200 m. This study is the first to show that it is possible to predict ASPT values for Japanese sites that have not been surveyed. These results suggest that accumulating biological data, such as NCRE data, will enable the preliminary screening of ecological predictions in freshwater areas. [ABSTRACT FROM AUTHOR]

Warming has broad and often nonlinear impacts on organismal physiology and traits, allowing it to impact species interactions like predation through a variety of pathways that may be difficult to predict. Predictions are commonly based on short‐term experiments and models, and these studies often yield conflicting results depending on the environmental context, spatiotemporal scale, and the predator and prey species considered. Thus, the accuracy of predicted changes in interaction strength, and their importance to the broader ecosystems they take place in, remain unclear. Here, we attempted to link one such set of predictions generated using theory, modeling, and controlled experiments to patterns in the natural abundance of prey across a broad thermal gradient. To do so, we first predicted how warming would impact a stage‐structured predator–prey interaction in riverine rock pools between Pantala spp. dragonfly nymph predators and Aedes atropalpus mosquito larval prey. We then described temperature variation across a set of hundreds of riverine rock pools (n = 775) and leveraged this natural gradient to look for evidence for or against our model's predictions. Our model's predictions suggested that warming should weaken predator control of mosquito larval prey by accelerating their development and shrinking the window of time during which aquatic dragonfly nymphs could consume them. This was consistent with data collected in rock pool ecosystems, where the negative effects of dragonfly nymph predators on mosquito larval abundance were weaker in warmer pools. Our findings provide additional evidence to substantiate our model‐derived predictions while emphasizing the importance of assessing similar predictions using natural gradients of temperature whenever possible. [ABSTRACT FROM AUTHOR]

Analysis of the qualitative signature of fatty acids in tissues of organisms is an increasingly utilized tool in studies of trophic ecology in aquatic and terrestrial ecosystems. Here, we studied a colonial waterbird, the black-headed gull Chroicocephalus ridibundus, nesting in three colonies. We aimed to investigate whether fatty acid composition of its eggs is affected by the location of the colony (reflecting the spatial variation in habitat composition and, in turn, female diet at the time of egg formation), and the egg laying sequence (reflecting the temporal variation in female diet). We found that the composition of fatty acids in eggs of black-headed gulls differed among colonies, but not among subsequent eggs within the clutch. We interpret these results in the context of spatial differences in the diet of females breeding in different colonies and a lack of temporal variation in the diet of individual females. The pattern of the ratio of omega-3 to omega-6 fatty acids reflected the contribution of aquatic/terrestrial prey to their diet, and was consistent with the area of water courses around the colonies. High levels of omega-6:omega-3 can promote inflammation and thus lead to increased susceptibility to antigens. Further studies with prey sampling are required to reconstruct the diet composition of females during egg formation in more detail. [ABSTRACT FROM AUTHOR]

Toxic contaminants, including pesticides, microplastics, and heavy metals, have a significant impact on aquatic life and other aquatic species. These pollutants come from anthropogenic sources such as crop growing, industrial operations, effluent, residential wastewater, and leaching, as well as environmental events like storms, floods, and seismic processes. Pesticides, particularly pesticides, have been shown to have detrimental effects on aquatic ecology, causing decreased growth, restricted larvae and embryo development, and dysfunction in primary organs like the gill, liver, kidney, and gonad. Genotoxicity from pesticide exposure raises safety concerns, as prolonged exposure can lead to oxidative stress, mutagenicity, and cellular apoptosis. Pesticide exposure can lead to elevated levels, even without measurable concentrations in biological matrices. The toxicity of pesticides directly affects aquatic life, leading to high mortality rates or the complete elimination of species that serve as their food source.To maintain the well-being of aquatic organisms, particularly fish, and protect aquatic ecosystems, it is crucial to investigate safe, acceptable, and efficient alternatives to pesticides. In this study, we focuses on the hematological, biochemical, and histopathological changes induced by pesticide exposure and highlights strategies for mitigating the adverse impacts of pesticides on fish. Further investigation is needed to determine species suitability for toxicity detection, an essential aspect of monitoring aquatic environments for agricultural pesticides. [ABSTRACT FROM AUTHOR]

Recent arachnid phylogenies support an Arachnopulmonata clade including scorpions, pseudoscorpions and the tetrapulmonate arachnids (i.e. spiders and their closest relatives). The position of the other arachnids is less certain, with molecular data suggesting that Arachnida may be paraphyletic with respect to horseshoe crabs. Here we explore the potential role fossil data can play in this debate. We outline the beneficial aspects of including fossils in phylogenies -- fossils calibrate trees to time -- as well as the challenges integrating these data. We tabulate the oldest occurrences of all major groups and superimpose these on recent phylogenetic hypotheses. Given that a key question is when (and how often) arachnids moved from water onto land, we review the early plant fossil record as a framework for when arthropod life on land may have been viable. In light of the aquatic ecology of horseshoe crabs, we then discuss the implications of placing this group within the arachnids, especially since some extinct lineages differ substantially from living species. In this context we re-assess what a horseshoe crab is from a palaeontological perspective, and speculate that some traditional Xiphosura fossils may actually lie on other parts of the euchelicerate tree. The oldest unequivocal horseshoe crabs are Ordovician in age (ca. 480 Ma), and probably predate complex terrestrial ecosystems. We conclude that recent phylogenetic results are best reconciled with fossils by inferring multiple terrestrialization events, possibly involving quite different approaches to breathing air. The lung-bearing (arachnopulmonate) branch of the tree is well resolved. Future work should focus on the apulmonate arachnids, and integrate the various early horseshoe-crab-like fossils into chelicerate phylogeny. [ABSTRACT FROM AUTHOR]

The Indus River dolphin (Platanista minor) is a severely threatened species of freshwater dolphin that occurs only in the lower Indus River system of Pakistan and India. The dolphin's range has declined by 80% since the 1870s, and total species abundance is estimated as approximately 2000 individuals.In 2007, a remnant population of Indus dolphins was discovered above Harike Barrage, in the Beas River in India, 600 km away from all other individuals of its species. This paper provides an overview of the conservation status of Indus dolphins in the Beas River, details the threats they face, and suggests priorities for their conservation and management.Between 2011 and 2022, 40 dolphin direct count surveys were conducted. Indus dolphins occur only in the lower third of the Beas River and reported counts have been from one to eight individuals. The data do not indicate an increase in abundance, and instead suggest a potential decrease; however, sightings of calves continue to be reported annually indicating reproduction is still taking place.Threats to the Beas River dolphin population include accidental entanglement in fishing gear, pollution, escapement downstream of Harike barrage, altered and depleted river flow regimes' and the effects of a very small population size. Urgent conservation measures are essential if this small, but important satellite population is to persist.Recommended management actions include the complete removal of fishing nets from dolphin habitat, reducing pollution, ensuring adequate river discharge to sustain aquatic ecology including dolphins, evaluating and monitoring dolphin movement through Harike barrage and into canals, and engaging riverside communities to protect dolphins. In addition, the possibility of conservation translocations to supplement this population with individuals from larger healthy populations elsewhere in the range of the species should be explored. [ABSTRACT FROM AUTHOR]

Background: Freshwater zooplankton is an important component of the ecological communities of inland water bodies. It acts as an important part of the food web and participates in the selfpurification processes of aquatic ecosystems. To study the abundance and distribution of species, a sampling event dataset was compiled and then published through GBIF. The aim of the work was to describe the current zooplankton fauna (Rotifera, Cladocera and Copepoda) and its abundance, based on a recently published dataset. The research was conducted from 2015 to 2022. Zooplankton samples were collected by vertical towing a plankton net (70 µm mesh) from the bottom to the water surface or by filtering through a net, the water being collected with a measuring bucket. The samples were concentrated to 100 ml and fixed with a final concentration of 4% formalin solution. For each sampling event, the coordinates of the location, number of individuals and date were recorded. New information: The dataset contains information on 259 tax?, including 257 species and subspecies of zooplankton from 36 families found in the tributaries of the Cheboksary Reservoir. The families Chydoridae (35 species), Brachionidae (31) and Cyclopidae (27) were the most species-rich. Four invasive species were found: Kellicottia bostoniensis (Rousselet, 1908), Acanthocyclops americanus (Marsh, 1893), Ilyocryptus spinifer Herrick, 1882 and Thermocyclops taihokuensis Harada, 1931. [ABSTRACT FROM AUTHOR]

Copyright of World Water Policy 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.)

Ecological and statistical models were developed using freshwater algal assemblages to assess water quality and ecological health of a regulated river. These models were used to inform configuration of flows to maintain or improve environmental conditions of the waterway whilst meeting consumptive water supply commitments. The flow regime of the MacKenzie River, western Victoria, Australia, has been substantially modified since the construction of a water supply reservoir on its upper reach in 1887. Water is withdrawn at several locations downstream of the reservoir, creating a substantially modified flow regime, impacting key environmental values of the river. To assess the impact of the different flow regimes on river health and ecosystem function, ten sites were repeatedly sampled along the river between February 2012 and April 2014. Physical and chemical characteristics of water, including pH, temperature, turbidity, electrical conductivity, dissolved oxygen, total nitrogen, total phosphorous, cations, and anions, were measured. Biological properties of the algal periphyton communities, including dry mass, ash-free dry mass, chlorophyll-a concentration, and species composition, were also measured. Exploration of the algal assemblage and water chemistry data using the computationally unconstrained ordination technique such as principal component analysis principal component analysis (PCA), correspondence analysis (CA), detrended correspondence analysis (DCA), and canonical correspondence analysis (CCA) indicated two strong gradients in the data sets. Furthermore, the quantitative ecosystem response models have been developed as the prototype tool to assist in the future configuration of flows in this river. The empirical data and models showed the lower reaches of the river to be in poor condition under low flows, but this condition improved under flows of 35 ML/day, as indicated by the reduction in green algae and cyanobacteria and improvement. Finally, the results are presented to tailor discharge and duration of water volume by amalgamation of consumptive and environmental flows to improve the condition of the stream thereby supplementing the flows dedicated to environmental outcomes. [ABSTRACT FROM AUTHOR]

Copyright of Eurasian Journal of Ecology is the property of Al-Farabi Kazakh National University 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.)

The toxicity of linear alkylbenzene sulfonates (LABs) to Clarias gariepinus was investigated. For 30 days, the fish were exposed to LABs at 0.00, 0.50, 1.00, 1.50, and 2.00 mg/L. After each trial period, one fish from each plastic tub was chosen and its heart was punctured for blood samples. The blood samples were then collected and deposited in pre-designated bottles for analysis. Following blood collection, a fish was dissected and its organs were extracted. The organs were preserved in liquid nitrogen at -25oC until they were analyzed. A portable refractometer was used to quantify total serum protein content. A microplate reader was used to measure reduced glutathione (GSH). Albumin was quantified using the Bromocresol Green albumin assay kit, whereas alanine aminotransferase activity was assessed colorimetrically. Subtracting albumin from protein concentration yielded the globulin content. On days 23 and 30, protein content corresponds positively with exposure length and differs significantly (p < 0.05) between the control and treatment groups. The activity of GSH reduced slightly but not significantly (p > 0.05). Significant variations in albumin and globulin (p < 0.05) only on day 30. AAS activity differs significantly (p < 0.05) between treatments and the control. This study demonstrated that LAB exposure can be harmful to human health. Because anthropogenic sources are the primary source of LAB exposure, authorities must implement strict mitigation measures to limit this risk. [ABSTRACT FROM AUTHOR]

An investigation was carried out to evaluate ichthyofaunal diversity of in Lakhan Majra drains of Rohtak, Haryana and field data was collected from September-2021 to May-2022. The results of the investigation revealed the presence of a total of 45 fish species, which were classified into 28 genera, 12 families and 7 orders. As per IUCN status the majority of the species being categorized as "Least Concern" (35 species) is generally a positive sign, suggesting that they are not currently facing a significant risk of extinction. However, it's important to monitor and assess the status of species categorized as Vulnerable (5), Near Threatened (2), Endangered (1), and those that are Data Deficient (1) and Not Evaluated (1). Conservation efforts might need to be focused on these species to ensure their survival and the health of the ecosystem as a whole. The status of N. chitala and O. pabda are under Near threatened category. Various diversity indices were employed in aquatic ecology to elucidate relationships within ecosystems. The result of the study showed that the value of Margalef richness index (10.17), Shannon-Wiener index (3.637) and Simpson index (0.973) was observed to be highest during Sept. 2021 and in terms of seasons; the monsoon period exhibited the greatest abundance of individuals, and succeeded by the post-monsoon and premonsoon phases. In September 2021, the K-dominance curves displayed a gradual rise on the lower end, reflecting an increase in species richness. The calculation of Bray-Curtis similarity through hierarchical clustering in the comprehensive cluster analysis illustrated the similarity among various months. The concurrent findings indicated a decrease in diversity. Nonetheless, it is essential to implement suitable management strategies to ensure the sustainability and abundance of species diversity. [ABSTRACT FROM AUTHOR]

Although the planktonic eukaryotic community (PEC) is an important component of freshwater ecosystems and plays an important ecological role, the impact of artificial water ecological modification on PEC has not been fully evaluated. To analyze the impact of lotus planting on the structure of PEC in urban park ponds, in this study, we analyzed the differences in PECs in different regions (artificial fountain region, potted lotus region, and direct lotus planting region) of an urban pond in subtropical China before and after lotus planting in the short term (~10 d) and for more than a month. Our results indicated that more than a month after planting lotuses, there were evident differences in the compositions of PECs in the three regions. Although there was no significant difference in operational taxonomic unit number and Chao1 indices before and after planting lotuses, planting lotuses significantly increased the Shannon index of the PECs. Moreover, different planting modes of lotuses can alter the structure of PECs after more than a month of growth, and planting lotuses can continuously strengthen the interconnection of various organisms in the PECs. These results expand our understanding of the impacts of artificial ecological modifications on the structure of PECs in urban ponds. [ABSTRACT FROM AUTHOR]

Microplastics adsorb heavy metals and organic pollutants to produce combined pollution. Recently, the adsorption behavior of antibiotics on microplastics has received increasing attention. Exploring the sorption behavior of pollutants on microplastics is an important reference in understanding their ecological and environmental risk studies. In this paper, by reviewing the academic literature in recent years, we clarified the current status of research on the adsorption behavior of antibiotics on microplastics, discussed its potential hazards to ecological environment and human health, and summarized the influence of factors on the adsorption mechanisms. The results show that the adsorption behavior of antibiotics on microplastics is controlled by the physical and chemical properties of antibiotics, microplastics, and water environment. Antibiotics are adsorbed on microplastics through physical and chemical interactions, which include hydrophobic interaction, partitioning, electrostatic interaction, and other non-covalent interactions. Intensity of adsorption between them is mainly determined by their physicochemical properties. The basic physicochemical properties of the aqueous environment (e.g., pH, salinity, ionic strength, soluble organic matter content, and temperature) will affect the physicochemical properties of microplastics and antibiotics (e.g., particle size, state of dispersibility, and morphology), leading to differences in the type and strength of their interactions. This paper work is expected to provide a meaningful perspective for better understanding the potential impacts of antibiotic adsorption behavior of microplastics on aquatic ecology and human health. In the meantime, some indications for future related research are provided. [ABSTRACT FROM AUTHOR]

Excessive consumption of cleaning and disinfecting agents, which constitute a distinct group of emergent pollutants known as PPCPs ("Pharmaceutical and Personal Care Products"), results in their accumulation in aquatic environments. Conventional wastewater treatment plants are unable to effectively remove the emergent pollutants that are present, including personal care product residues. This article focuses on the determination of surfactant substances in model samples prepared from selected personal care products and their biodegradability under laboratory-created aquatic ecosystem conditions. The conducted biodegradation processes, based on the monitored indicator (surfactants) in the model samples, confirm that the utilization of aquatic vegetation and gravel substrates can efficiently eliminate the present contaminants. Insights gained from researching the biodegradability of PPCP group products are applicable, including experiences with plant compositions used in aquatic environments, particularly in the construction of root-zone wastewater treatment systems. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Water Resources Journal / Revue Canadienne des Ressources Hydriques is the property of Taylor & Francis Ltd 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.)

Conventional seafood production contributes to some of the most alarming global problems we face at present, such as the destabilization of aquatic ecosystems, human health risks, and serious concerns for the welfare of trillions of aquatic animals each year. The increasing global appetite for seafood necessitates the development of alternative production methods that meet consumer demand, while circumventing the aforementioned problems. Among such alternatives, cell-based seafood is a promising approach. For its production, cells are taken from live aquatic animals and are cultivated in growth media, thus making the rearing, catching, and slaughtering of a great number of animals redundant. In recent years, this alternative production method has transitioned from aspiration to reality, and several cell-based seafood start-ups are preparing to launch their products. Market success, however, has been reckoned to largely depend on consumer attitudes. So far, there has been little research exploring this within Asia, and none in Japan, which has one of the highest seafood consumption footprints per capita globally. The present study explores cell-based seafood-related knowledge, attitudes and behavioral intentions of Japanese consumers (n = 110) via a questionnaire-based, quantitative analysis. Although findings suggest low awareness of the concept of cell-based seafood, attitudes and intentions were positive overall, with about 70% of participants expressing an interest in tasting, and 60% expressing a general willingness to buy cell-based seafood. Younger age was significantly associated with more positive attitudes, while prior knowledge of cell-based seafood was strongly linked to willingness to pay a premium for cell-based products. While highlighting the need for information campaigns to educate Japanese consumers about cell-based seafood, this study's findings suggest the Japanese market to be moderately ready for the launch of such products. [ABSTRACT FROM AUTHOR]

At the sediment-water interfaces, filamentous cable bacteria transport electrons from sulfide oxidation along their filaments towards oxygen or nitrate as electron acceptors. These multicellular bacteria belonging to the family Desulfobulbaceae thus form a biogeobattery that mediates redox processes between multiple elements. Cable bacteria were first reported in 2012. In the past years, cable bacteria have been found to be widely distributed across the globe. Their potential in shaping the surface water environments has been extensively studied but is not fully elucidated. In this review, the biogeochemical characteristics, conduction mechanisms, and geographical distribution of cable bacteria, as well as their ecological effects, are systematically reviewed and discussed. Novel insights for understanding and applying the role of cable bacteria in aquatic ecology are summarized.

This editorial discusses the impact of climate change on aquatic organisms, focusing on their ecology, diversity, and migration patterns. The Intergovernmental Panel on Climate Change (IPCC) reports that climate change is a significant threat to global biodiversity, and aquatic species are expected to shift their habitats in response to climate changes. The rise in temperature negatively affects marine species' performance and survival, and climate change also has unpredictable impacts on freshwater resources. The editorial highlights the importance of understanding these impacts and provides insights into specific topics such as siphonophores, odour-producing microorganisms, and the vulnerability of coral reefs. The authors emphasize the need for further research and conservation efforts to mitigate the effects of climate change on aquatic ecosystems. [Extracted from the article]

Metals and metalloids are toxic, persistent, and non-biodegradable and can be biomagnified (e.g., Hg), and therefore pose a serious threat to the algal flora of aquatic ecosystems. This laboratory study tested the effects of metals (Zn, Fe, and Hg) and a metalloid (As) on the cell wall morphology and protoplasmic content of living cells of six widespread diatom genera over 28 days. Diatoms exposed to Zn and Fe had a higher frequency of deformed diatom frustules (> 1%) compared to the As, Hg, and control treatments (< 1%). Deformities in the valve outline and striae were found in all treatments, including the control, whereas deformed raphes and more than one type of deformity were more prevalent under Zn and Hg stress. The order of toxicity is as follows: Zn > Fe > Hg≈As. Deformities were more frequent in Achnanthes and Diploneis (adnate forms) than in the motile genera of Nitzschia and Navicula. The correlation between the % healthy diatoms and % deformities in all six genera showed a negative relationship with the integrity of protoplasmic content (i.e., greater alteration in protoplasmic content was associated with greater frustule deformation). We conclude that diatom deformities can be a good indicator of metal and metalloid stress in waterbodies and are very useful in the rapid biomonitoring of aquatic ecosystems. [ABSTRACT FROM AUTHOR]

• The diversity and composition of algal community exhibited temporal pattern. • Network elucidated the complex interactions among algae in different lakes. • Keystone algal-species played an integral role in maintaining ecological stable. • Structural equation model was built between water quality and algal community. • The responses of algal communities to water quality parameters were distinct. Urban lakes were critical in aquatic ecology environments, but how environmental factors affected the distribution and change characteristics of algal communities in urban lakes of Xi'an city was not clearly. Here, we investigated the algal community structure of six urban lakes in Xi'an and evaluated the effects of water quality parameters on algae. The results indicated that the significant differences on physicochemical parameters existed in different urban lakes. The maximum concentration of total phosphorus in urban lakes was (0.18 ± 0.01) mg/L and there was a phenomenon of phosphorus limitation. In addition, 51 genera of algae were identified and Chlorella sp. was the dominant algal species, which was affiliated with Chlorophyta. Network analysis elucidated that each lake had a unique algal community network and the positive correlation was dominant in the interaction between algae species, illustrating that mature microbial communities existed or occupied similar niches. Redundancy analysis illustrated that environmental factors explained 47.35% variance of algal species-water quality correlation collectively, indicating that water quality conditions had a significant influence on the temporal variations of algae. Structural equation model further verified that algal community structure was directly or indirectly regulated by different water quality conditions. Our study shows that temporal patterns of algal communities can reveal the dynamics and interactions of different urban ecosystem types, providing a theoretical basis for assessing eutrophication levels and for water quality management. [Display omitted]. [ABSTRACT FROM AUTHOR]

Macroinvertebrate assemblage assessments act as useful analysis tools for assessing aquatic ecosystems health. These animals also serve as a base trophic level, acting as a source of food for many other aquatic organisms including fish and salamanders. Obtaining baseline data for monitoring aquatic insects and subsequent river health is vital to understand food chains and river ecological interactions. We sampled macroinvertebrate communities in two streams in the Oconaluftee River basin, in the Cherokee Qualla, North Carolina. Over 600 macroinvertebrates were collected and identified to the lowest taxonomic level possible, providing a macroinvertebrate profile of both riffle and run habitats. We identified over 35 genera and report on functional feeding groups, with biotic indices of water quality. Ephemeroptera, Plecoptera, and Trichoptera values varied, 21% and 65.43% for Raven's Fork and 22% and 79.06% for the Oconaluftee rivers. This macroinvertebrate community suggests healthy stream aquatic insects and above average water quality, in spite of the urban land use found in the riparian zones of the sample sites. This research can be used as a baseline for future monitoring of aquatic streams in the area of the Cherokee Qualla. [ABSTRACT FROM AUTHOR]

Eurasian perch Perca fluviatilis has been a popular model species for decades in the fields of aquatic ecology, community dynamics, behaviour, physiology and ecotoxicology. Yet, despite extensive research, the progress of integrating genomic perspective into existing ecological knowledge in perch has been relatively modest. Meanwhile, the emergence of high‐throughput sequencing technologies has completely changed the methods for genetic variation assessment and conducting biodiversity and evolutionary research. During the last 5 years, three genome assemblies of P. fluviatilis have been generated, allowing substantial advancement of our understanding of the interactions between ecological and evolutionary processes at the whole‐genome level. We review the past progress, current status and potential future impact of the genomic resources and tools for ecological research in Eurasian perch focusing on the utility of recent whole‐genome assemblies. Furthermore, we demonstrate the power of genome‐wide approaches and newly developed tools and outline recent cases where genomics have contributed to new ecological and evolutionary knowledge. We explore how the availability of reference assembly enables the efficient application of various statistical tools, and how genomic approaches can provide novel insights into resource polymorphism, host–parasite interactions and to genetic and phenotypic changes associated with climate change and harvesting‐induced evolution. In summary, we call for increased integration of genomic tools into ecological research for perch, as well as for other fish species, which is likely to yield novel insights into processes linking the adaptation and plasticity to ecosystem functioning and environmental change. [ABSTRACT FROM AUTHOR]

Urocordylids represent a group of the late Carboniferous–early Permian basal tetrapods, with short limbs, extremely elongated bodies and a deep and distinctive tail and vertebral architecture, which is indicative of an aquatic habitat. However, the important morphological structures that would indicate their ecological preferences unambiguously (e.g. hyobranchial apparatus, lateral line sulci) remain unknown. Moreover, the high degree of skeletal ossification present in urocordylids contrasts with the common pattern seen in most other basal tetrapods known to inhabit aquatic environments. Here, we describe an exceptionally well-preserved skull, with an associated mandible and a partial postcranial skeleton, of Sauropleura scalaris from the locality of Nýřany, Czech Republic, based on high-resolution micro-computed tomography. The labial surface of the mandible shows the first evidence of the lateral line system in Urocordylidae, which consists of both small pits and elongated grooves, and unambiguously supports the aquatic ecology of the group. The juvenile stage of the specimen provides new information on ontogeny of sauropleurines. The partly ossified opisthotic bone indicates that, unlike development in most other early tetrapods, the otic capsules were among the first neurocranial elements to ossify in nectrideans. Finally, an almost complete caudal region suggests that tails were much longer in sauropleurines than previously assumed. [ABSTRACT FROM AUTHOR]

Understanding microbial community structure and the underlying control mechanisms are fundamental purposes of aquatic ecology. However, little is known about the seasonality and how trophic conditions regulate plankton community in subtropical reservoirs. In this study, we study the prokaryotic and picoeukaryotic communities and their interactions during wet and dry seasons in two subtropical reservoirs: one at oligotrophic state and another at mesotrophic state. Distinct microbial community compositions (prokaryotes and picoeukaryotes) and seasonal variation pattern were detected in the oligotrophic and mesotrophic reservoirs. The interactions between prokaryotic and picoeukaryotic communities were more prevalent in the oligotrophic reservoir, suggesting enhanced top-down control of small eukaryotic grazers on the prokaryotic communities. On the other hand, the microbial community in the mesotrophic reservoir was more influenced by physico-chemical parameters and showed a stronger seasonal variation, which may be the result of distinct nutrient levels in wet and dry seasons, indicating the importance of bottom-up control. Our study contributes to new understandings of the environmental and biological processes that shape the structure and dynamics of the planktonic microbial communities in reservoirs of different trophic states. [ABSTRACT FROM AUTHOR]