Abstract Dormancy is an essential component of the life cycle for populations that disappear from the plankton during winter. The hatching of resting eggs is the main mechanism for restoring active population components. Here, we analyzed the hatching dynamics of zooplankton from sediments of a shallow lake as affected by temperature. Sediment samples collected every other month were incubated at in

Abstract Allometry, a growth pattern in which different parts of an organism grow at defined rates, is a common feature of fish and can be influenced by environmental factors. The rare minnow Gobiocypris rarus Ye et Fu, 1983 undergoes allometric growth, and this study investigated its allometry patterns and assessed whether the culture environment affects them by comparing growth patterns in conventional

Abstract Introduction of alien species leading to unfavorable economic impacts and ecosystem collapse is a well-known threat. The aim was to define if high salinity may be a limiting factor for the survival and spread of the invasive crayfish Procambarus clarkii. Both sexes were exposed to increasing salt concentrations reaching 35.3‰ after 65 days to simulate the natural transition from freshwater

Abstract Land-use practices in Mongolia can lead to environmental degradation and consequently affect the structure and function of biological communities. The main aim of this study was to determine land-use effects on freshwater macroinvertebrate communities based on their response to grazing and mining, using a trait-based approach (TBA). The functional structure of macroinvertebrate communities

Abstract Ommastrephid squid produce some of the smallest cephalopod hatchlings, whose feeding behavior has not been observed. The present study aimed at indirectly filling this knowledge gap by describing ontogenetic changes in beak morphology and morphometry and integrating these results with published datasets on Illex argentinus arm crown morphology and gut contents. Individuals [0.7–15 mm mantle

Abstract The Local Ecological Knowledge of shellfish harvesters in a Northern Brazil estuary was recorded to provide socio-ecological information for the development of a co-management system. The research was carried out in the community of Acaú, Paraiba state, from January to October 2015, and involved 120 shellfish harvesters (average age 44 years). Participant observations, interviews, questionnaires

Abstract Conservation of the endangered freshwater pearl mussel (FPM) includes artificially rearing juveniles, but the pulsed flow-through (PFT) method, enabling the continuous renewal of water and food in culture containers, has not been applied to FPM. This study tested the PFT method in culture of FPM juveniles, and the effect of water source (tap vs well water) and food concentration (mixture of

Abstract The relative importance of allochthonous and autochthonous resources in fueling tropical headwater streams remains an open topic. We combined estimates of secondary production and assessment of its trophic basis to determine which resources were responsible for animal production. We studied benthic insect assemblages in two streams in the Luquillo Experimental Forest, Puerto Rico. Habitat-weighted

Abstract Seagrass meadows are productive ecosystems that contribute to climate change mitigation by accumulating ‘Blue Carbon’ in their plant biomass and sediments. However, there is wide variation in reported sediment carbon stocks (Cstocks) across different global regions and between meadows composed of different seagrass species. Therefore, understanding the drivers for sediment Cstocks variation

Abstract Despite the importance of shredders in organic matter processing in streams, information about the habitat specificities of different taxa is scarce. Herein, we evaluated the habitat preferences of invertebrate shredders in tropical forest streams. A total of 72 leaf patches were sampled in three Atlantic Forest streams (SE Brazil). For each sample, 20 environmental variables were measured

Abstract Laboratory behavioral experiments are an important tool in ecology and evolution, but whether these behaviors reflect the field function of organisms is not always clear. Directly connecting laboratory behaviors to field interactions would increase understanding of a variety of organisms. A recent study proposed using stable isotopes to link laboratory behaviors to field function of individuals

Abstract Artificial light at night (ALAN) has been recently recognized as a threat for aquatic systems, but a comprehensive knowledge of its effects is still lacking. A fundamental question is whether and how ALAN might affect temporal variability of communities, thus undermining the stability of mature assemblages or influencing the colonization process. Here we investigated the role of ALAN on temporal

Abstract The potential role of positive interactions among co-invaders is at the core of the invasional meltdown hypothesis. The interaction of non-native species could result in an exacerbation of each other’s effects. Thus, the resulting effect of multiple non-native species on ecosystems can be greater than the sum of their individual effects. We designed an analytical framework and a set of mesocosm

Abstract Natural water bodies contain physically interconnected habitats suitable for microbes, such as different water layers and substrates for biofilms. Yet, little is known on the extent to which microbial communities are shared between such habitats and whether differences and similarities are consistent between sites. Here we explicitly tested hypotheses on similarities between aquatic bacterial

Abstract The present study aims to describe the ontogenetic changes in the skull of the loggerhead turtle, Caretta caretta by focusing on the stages of development in the western South Atlantic Ocean. Our hypothesis is based on the premise that changes in feeding habits will reflect changes in the shape and/or size of the skull. The existence of changes in skull of the loggerhead turtle were analyzed

Abstract Light, temperature, and discharge control stream metabolism, but the response of gross primary production (GPP) and ecosystem respiration (ER) to seasonal variation in these physical drivers may differ in accordance with the types of human activities present in the catchment. Our study examined three mid-order streams in southern Ontario, Canada that differed in anthropogenic nutrient sources

Abstract Coffee farming is an important practice in the tropics, but studies addressing its effect on streams, especially at high elevations in high productivity regions, are limited. We evaluated streams draining the high-elevation coffee farming region of Tarrazú, Costa Rica, in terms of water quality and benthic macroinvertebrates over the course of a year. We compared our observations to regulatory

Abstract In shark populations, variation in sexual size dimorphism (SSD) appears to be related with the reproductive mode. Here, we aimed to investigate the reproductive biology of the narrowmouth catshark Schroederichthys bivius, an oviparous shark with size and secondary sexual dimorphism. For this purpose, specimens were collected during research surveys covering almost their entire distribution

Abstract The amazing morphological diversity of phytoplankton has to be considered an evolutionarily driven compendium of strategies to cope with the strong variability and unpredictability of the pelagic environment. Phytoplankton collects unicellular and colonial photosynthetic organisms adapted to live in apparent suspension in turbulent water masses. Turbulence represents a key driver of phytoplankton

Abstract Chlorophyll measurements are commonly used to estimate phytoplankton biomass. However, phytoplankton readily acclimate to variations in light through a range of phenotypic responses, including major adjustments in chlorophyll pigmentation at the cellular level. The ratio of pigment chlorophyll to carbon concentration (Chl:C) is a commonly used metric in the oceanographic community to explore

Abstract Water level fluctuations (WLFs) affect phytoplankton dynamics, water quality, and fish populations in lakes and reservoirs around the world. However, such effects are system-specific and vary due to interactions with other external factors such as solar radiation, air temperature, wind, and external phosphorus loading. Utilizing data from a long-term monitoring program (1990–2016), we developed

Abstract Non-native species can simultaneously affect ecological structures, functions, and services of the invaded ecosystem. In this paper, we report that the study of non-native species impacts on ecosystem function is an emerging topic in aquatic ecology, though studies measuring functions remain relatively uncommon. We hypothesized that study of ecosystem function can reveal emergent effects of

Abstract Otter diet in reservoirs is known to experience seasonal changes. We selected a reservoir with a large population of exclusively wintering great cormorants and seasonal changes in stored water volume to test the relative influence of abiotic and biotic factors on otter foraging ecology. DNA metabarcoding of otter spraints revealed a dietary change from autumn to winter. Otters had a diet dominated

Abstract Aquatic ecosystem community dynamics are affected by anthropogenic pressures and subsequent environmental change. This study investigated the influence of land use in the Richmond River Catchment (New South Wales, Australia) on dietary sources for the freshwater Atyid shrimp Paratya australiensis. Carbon and nitrogen stable isotopes and Bayesian modelling determined the contribution to shrimp

Abstract Diversion of river waters to adjacent estuaries may occur during wetland restoration, navigation channel development, or storms. We proposed that diversions of nitrogen- and phosphorus-enriched waters from the river to estuarine waters would result in increased phytoplankton biomass and shifts to noxious or harmful algal blooms. We tested this hypothesis by conducting four seasonal microcosm

Abstract Owning to dissimilarity with native macrophytes, invasive macrophytes may negatively affect the diet and foraging efficiency of fishes. We evaluated the invertebrate availability, diet composition, and foraging efficiency of four fish species that use macrophytes as habitat in a native and a highly invasive macrophyte. The samples were taken in a reservoir in Brazil (22° 33′ S, 52°54′ W).

Abstract Swimming is a fundamental trait of many protists and optimizes growth and survival. We present an easy to use set-up for filming algal cells using Apocalathium aciculiferum and Borghiella dodgei as case studies; both dinoflagellates are model organisms of psychrophilic dinoflagellates. We filmed at low temperature (4.5°C) using a digital camera directly connected to a microscope and used open-source

Abstract Animals and plants engineer their physical environment by building structures that create or modify habitat. Biotic effects on physical habitats can influence community composition, trophic dynamics, and ecosystem processes; however, the scales and mechanisms regulating the importance of biotic engineering effects are not well documented. We used a laboratory experiment with common and abundant

Abstract A growing interest in the importance of simuliids in health and animal welfare in certain areas in Europe, such as around the Mediterranean basin, together with the fact that there is fragmentary ecological information on the pre-imaginal stages of these dipterans has led to the need to carry out further research. We studied the abundance and distribution of pre-imaginal stages—mainly the

Abstract Predicting the potential distribution of invaders is informative for pre-emptive policy or management decisions and identifying suitable areas for establishment of new populations. Temporal projection of potential distributions is complicated by the magnitude and pace of changing climate, which could alter suitability under future conditions. The wetland invader, Butomus umbellatus is widespread

Abstract There is practically no stream or river without non-native beaver impact, past or current, in Tierra del Fuego (TDF), Argentina. In this study, we evaluated the effect of beaver activity on water quality and algal composition in forested streams and rivers from TDF. We sampled five streams and rivers with current beaver activity during the austral summers of 2016 and 2017. Also, three streams

Abstract The aim of present research is to study the patterns of phyto- and zooplankton fluctuations in endorheic soda lakes (Uldz Gol-Torey Basin, southeastern Transbaikalia, Russia) under arid conditions because studied area is becoming increasingly arid. Plankton samples were collected in summer during time intervals with different lake water levels using standard hydrobiological methods. We detected

Abstract Invasive species may affect the equilibrium of natural communities, competing for resources and occupying niches of the native biota. Dendrocephalus brasiliensis (DEN) has potential to aquaculture, although its use is concerning, since DEN is allochthone in some regions of Brazil. Here, we aimed to study the possible effects of DEN on three cladocerans Moina micrura (MOI), Macrothrix flabelligera

Abstract The aim of this study was to test the effects of agricultural land use on benthic insect population body-mass and community biomass size spectrum. Agricultural land use effects were assessed by conducting a reciprocal transfer experiment between two stream reaches exposed to differing intensities of row crop and livestock agricultural activity representing best attainable and highly developed

Abstract Our experimental study was designed to assess the effects of temperature on food isotopic integrity and trophic fractionations (of carbon and nitrogen stable isotopes: Δ13C and Δ15N) in chironomid larvae. A laboratory experiment was run using Chironomus riparius larvae at 15, 18 and 23°C, and under three pulverized food resources. There were significant changes in the stable isotopic composition

Abstract We evaluated the structural responses of marine sponge assemblages to different substrates as well as their positioning around Ilha Grande, a local hotspot of marine biodiversity sheltered in a bay area off Southeast Brazil. Sampling sites were distributed between sides of the island facing the continent (North) and ocean (South) across two depth-dependent substrates. As proved by ordination

Abstract Looking at taxa that could dominate Anthropocene reefs, the fire corals, Millepora spp., represent compelling alternative because of their similar role than scleractinian corals. However, species identification has been the subject of much debate over the past 150 years. As they may turn as among the last refuges for reef biodiversity, it is critical to accurately delimit their species boundaries

Abstract Between-habitat distributions of prey shared by multiple predators depend on habitat use by the predators, whose own distributions may interact. We used a large-scale, whole-system natural experiment to examine distributions of anuran tadpoles and insect predators between pond microhabitats with contrasting complexity (open water vs emergent littoral vegetation) in drainable ponds that were

Abstract Non-native tilapia species were repeatedly introduced to Asian and South American countries because of their adaptiveness to new environments and new environmental conditions. Such founder populations rapidly adapted by evolving outstanding ecological and physiological features, making them highly successful invaders throughout the tropical and subtropical regions. In Japan, nine tilapia species

Abstract The byproducts of anaerobic biogeochemical processes, many mediated at the sediment–water interface, can degrade water quality in the bottom of reservoirs. Using both experimental sediment–water chambers and field monitoring, this study assessed nutrient and metals cycling in the profundal zone of hypereutrophic Hodges Reservoir, San Diego (maximum depth = 29.1 m; maximum surface area = 6

Abstract South-western Australia is isolated from other forested regions of Australia by desert and bounded on southern and western sides by the Southern and Indian Oceans, respectively, with Westralunio carteri (Iredale, 1934) as the sole endemic freshwater mussel. Its conservation status is vulnerable. This species has a history of nomenclatural change and its systematic placement and population

Abstract The metacommunity concept incorporates spatial dynamics into community ecology, shedding light on how local and regional processes interact in structuring ecological communities, and to which measure they are deterministic or stochastic. We reviewed metacommunity studies on freshwater meiobenthos published since 2004, when the main principles of metacommunity theory were conceptualized. The

Abstract The Water Framework Directive requires European states to monitor the ecological quality of their lakes. Detailed information on the composition and abundance of biological groups such as aquatic plants (macrophytes) and phytoplankton (including chlorophyll a) must be expressed as an ecological quality ratio (EQR), ranging from 1 (close to reference status) to 0 (bad status). Effort is often

Abstract Dissolved organic matter (DOM) input is a key factor for freshwater ecology, since it regulates many aspects of aquatic ecosystem metabolism. Aquatic and terrestrial animals that inhabit or frequent aquatic environments also influence the DOM inputs via their faeces, supplying nutrients such as carbon (C), nitrogen (N), and phosphorus (P). Here, we analyse the response of a bacterial community

Abstract Due to the lack of empirical data, meiofauna are often underestimated as prey for freshwater animals and are commonly regarded as trophic dead ends. Here we present a synthesis of recent evidence showing that meiofauna are significant as prey, not only for many benthic macroinvertebrates (chironomids, shrimps, and flatworms) but also for juveniles of widespread freshwater bottom-feeding fish

Abstract 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

Abstract Fish respond to predation threat by size/cohort-dependent presence in particular habitats and this may contribute to sexual segregation between habitats in species with sexual size dimorphism (SSD). The present study examines the validity of the “predation risk hypothesis” and importance of SSD on habitat (pelagic/inshore) segregation and dietary differences between sexes in three cyprinids

Abstract Secondary salinization threatens fresh waters worldwide leading to deleterious ecological and economic consequences. The goal of the present study was to assess the potential response of catabolic functions (respiration rate, activities of acid phosphatase and β-glucosidase) of stream biofilms to salinization. Biofilm assemblages from five streams were incubated under controlled conditions

Abstract The global offtake of wild animals is valued at US$400 billion annually and supports the livelihoods of 15% of the global population. Wetlands are amongst the most important ecosystems globally, but offtake may represent a substantial pressure. This study assessed the availability of information and evaluated the offtake of wild animals from wetlands by focussing on fish and waterbirds. A

Abstract This work evaluates the tolerance of adult Limnoperna fortunei to aerial exposure at different temperatures. The aim was to contribute knowledge about factors, such as the mussel’s capacity for survival out of water over long periods, allowing the invasion of new environments after terrestrial transport. The analysis of the results revealed that the time of exposure to air influenced mortality

Abstract In tropical climates, free-floating aquatic plants may dominate shallow lakes and affect trophic interactions between zooplankton and their predators have been presented as an important subject to be investigated. The present study used mesocosms within a tropical lake in rural São Paulo-Brazil to test the hypothesis that free-floating macrophytes (FFM) reduce predation pressure on prey, as

Abstract Small lakes of the boreal zone are highly sensitive indicators of both global environmental change and local anthropogenic pressure. This work presents the results of multidisciplinary study of three small, seasonally stratified lakes of NW Russia, conducted since 2002 to the present time. These lakes were subjected to various degree of impact by rural population and agricultural activity

Abstract In dry areas, natural and artificial ponds experience frequent water level fluctuation, affecting conditions for some aquatic and amphibiotic taxa. Water beetles, bugs, and dragonflies make up much of pond diversity, and are responsive to changes in environmental conditions. Using a drought-prone pondscape within the Greater Cape Floristic Region biodiversity hotspot, we determine (1) the

Abstract Worldwide catches of cannonball jellyfish Stomolophus meleagris (Cnidaria: Scyphozoa) have increased during the last years; nevertheless, this species still lacks updated biological knowledge for its management. This research proposes that the individual growth pattern for jellyfish can be estimated in the absence of age readings through cohort follow-up over time and by multi-model inference

Abstract Freeze coring is a commonly used method for the investigation of the bed sediment fauna of rivers. It is considered to produce quantitative numbers of invertebrate abundance in different depth layers. Calculations of abundance use total volume of the freeze core sample as spatial reference. This definition of sample volume is incorrect. In the present, study freeze core samples are shown to

Abstract We assessed the diversity of zooplanktonic resting stages through different spatial scales in intermittent ponds along a forest–grassland transition in southern Brazil. We tested how the diversity (richness) of resting stages varied through the following spatial scales: cores (α), among sediment cores within a pond (β1), among ponds (β2), and between biomes (β3). We also assessed the diversity

Abstract Epilithic algal community structure and function are important indicators of stream ecosystem health and are sensitive to ambient environmental changes. In this study, we examined the impact of light and nutrients on epilithic algal community structure and function by an in situ nutrient addition and shaded canopy experiment in subtropical streams in China. Epilithic algae structure, dominated

Abstract The Eurasian perch (Perca fluviatilis) is an economically and environmentally important fish. Its distribution is changing because of many anthropogenic factors, including aquaculture and restocking. Careless dislocations enhance risk disrupt the established geographical genetic structure of this species. Set as a benchmark for future studies, this paper investigates the current perch status

Abstract High latitude freshwater systems are facing changes in catchment-mediated allochthonous input, as well as physical and chemical controls triggered by on-going climate change, which may alter their carbon processing and ecological characteristics. To explore changes in chironomid functional responses and carbon utilization in relation to long-term environmental change, we studied a sediment

Abstract In Japan, farm ponds retain water throughout the year while rice fields are continuously inundated for no more than 2 months, usually from spring to early summer. Although the zooplankton fauna in artificial water bodies would be expected to vary according to differences in inundation periods, scientific confirmation of this relation is largely lacking. Due to its ubiquity, the cladoceran