Habitat fragmentation in freshwater ecosystems alters dispersal pathways, creating conditions where stochastic processes can dominate the community assembly. We used a controlled indoor microcosm experiment to investigate how phytoplankton metacommunities assemble when dispersal is reduced under environmentally homogeneous conditions. A single inoculum from a Pampean stream was acclimated and distributed into six microcosms, maintained for 11 weeks under identical abiotic conditions. We tested three hypotheses: (H1) if deterministic processes dominated, communities would converge in taxonomic composition and functional attributes despite isolation; (H2) if stochastic processes dominated, communities would diverge in both taxonomic and functional trajectories under identical conditions; and (H3) the relationship between taxonomic and functional dissimilarity would depend on the degree of functional redundancy, with convergence in functional space when redundancy was high, or tighter taxonomic-functional coupling otherwise. Despite identical starting conditions, communities diverged in both richness and abundance trajectories, with relatively high and sustained beta-diversity throughout the experiment. Functional composition showed lower dispersion than taxonomic composition, but taxonomic and functional dissimilarity were significantly correlated, indicating partial coupling between community structure and function rather than full functional convergence. Our results support the view that fragmentation itself does not directly cause divergence. By reducing dispersal, fragmentation allows stochastic processes such as drift and priority effects to operate independently across fragments. These experimental insights highlight the potential for stochastic dynamics to drive community divergence in fragmented freshwater systems, and stress the importance of integrating taxonomic and trait-based functional dimensions when evaluating ecosystem resilience.
Thermal springs create strong temperature and geochemical gradients that can act as environmental filters for aquatic biota. We assessed seasonal patterns of benthic macroinvertebrates and their relationships with water physicochemistry at four sites influenced by thermal and cold limnocrene springs in the Tuzla region (& Ccedil;anakkale, NW T & uuml;rkiye) during 2023. The system was highly saline (50.97-62.53 ppt), and the thermal pool reached 73.3 degrees C, where no macroinvertebrates were detected. Across the remaining three sites (S1-S3), Diptera dominated and Ephydridae accounted for 61 % of all individuals. Physicochemical conditions showed seasonal varia-tion, with significant differences in dissolved oxygen (F = 5.837, p = 0.0206) and total dissolved solids (F = 45.45, p = 2.27e-05), while salinity showed only weak evidence of variation (p = 0.0923). PERMANOVA indicated no significant overall differences in macroinvertebrate community composition among stations and seasons (R2 = 0.435, F = 0.616, p = 0.935), consistent with the overlap observed in ordination space. Separate regression models showed that Simpson's diversity index declined significantly with increasing total dissolved solids (p = 0.0212). Constrained ordination further suggested positive associations of Chironomidae with dissolved oxygen and pH, and of Ceratopogonidae with water temperature. Overall, the extreme thermal-salinity regime acted as a strong envi-ronmental filter, providing a baseline for biomonitoring and future comparative work in geothermal spring systems.
Anguillicola crassus (Kuwahara, Niimi, & Itagaki, 1974) is a common nematode parasite of the European eel (Anguilla anguilla Linnaeus, 1758), which is critically endangered. This two-year study investigated the prevalence, abundance and intensity of A. crassus infections in 1,265 wild eels sampled from three lakes (Bafa, Kocag & ouml;l, K & ouml;yce & gbreve;iz) and one estuary (G & uuml;ll & uuml;k Lagoon) in southwestern T & uuml;rkiye. Eel infections were evaluated and compared by sampling year, season, location, eel phase (yellow or silver) and eel length. In addition, infected swim bladders and mature parasites containing eggs and larvae were examined histologically. Results showed seasonal variation in prevalence. Prevalence was not significantly influenced by site, eel phase or length. Abundance and intensity differed with eel length. Parasite abundance varied significantly with sampling season, location and fish length, but was not influenced by eel phase. Overall, Bafa had the highest abundance. Although mean intensity was highest in summer, the differences between seasons were not statistically significant. Sampling year, location and fish length significantly influenced parasite intensity. Macroscopic and histological analyses confirmed swim bladder damage, including epithelial erosion, haemorrhagic reactions and parasite-induced structural changes.
The decline of submerged plants in shallow lakes is a global concern due to their critical roles in maintaining water quality and ecosystem stability. Propagules of these plants can survive long in sediment, making the propagule bank crucial for restoration. We aimed to determine the long-term dynamics of the aquatic plant community and its propagule bank in Changhu Lake, a typical large shallow lake in the middle and lower reaches of the Yangtze River, China, identify factors influencing plant changes, and propose restoration measures. We combined literature data with in situ investigations on the plant community and propagule bank, and analyzed long-term fluctuations in water quality, land use changes, and water level variations. The study revealed a severe decrease of the aquatic plant community, with coverage plummeting from nearly 100 % in the 1950s to less than 1 % by 2018. The propagule bank has also been nearly depleted, with significant declines in species richness and density from 2008 to 2023. Increased total phosphorus led to eutrophication, and frequent extreme climatic events occurred in recent decades. These stressors caused a shift from a clear-water state to a turbid-water state. Our findings highlight the importance of the propagule bank in restoration strategies. Successful restoration of Changhu Lake requires reducing external nutrient inputs, managing water levels, and supplementing the propagule bank to re-establish a resilient submerged plant community.
The introduction of native and alien trout into naturally fishless alpine lakes has long been associated with significant ecological consequences. This study focuses on an unforeseen effect: the accidental introduction and spread of bait fish, particularly minnows (Phoxinus sp.) and stone loach (Barbatula barbatula), in alpine lakes within Retezat National Park, Romania. Fish stocking, initiated in the 1960s and 1970s for recreational purposes, had potential cascading effects on aquatic biodiversity by facilitating the colonization of bait fish. Between 2022 and 2024, 25 alpine lakes were inventoried for fish presence. We used visual surveys and umbrella-traps in the littoral areas for smaller lakes, and additionally aerial and aquatic drone surveys for larger lakes. We observed a decline in trout populations in lakes that had been stocked in the past. In addition, bait fish were found in 12 lakes, all of which had either native fish present or had previously been stocked. The findings suggest that bait fish introductions are associated with fishing activities, with their successful establishment attributed to their ecological plasticity and high reproductive potential. This study highlights the unintended ecological consequences of fish stocking and the challenges in managing introduced species in alpine ecosystems.
The hyporheic zone represents an important habitat for aquatic invertebrates. However, the study of this biological component remains methodologically complex, particularly due to the difficulties associated with sampling interstitial fauna. This study aimed to examine the composition of the invertebrate communities in the hyporheic zone on a local scale of a semi-arid river and to assess the efficiency of two sampling techniques: Bou-Rouch technique, which removed organisms from sediment, and Artificial Substrates, which create new biotopes. Hyporheic fauna were sampled using the Bou-Rouch pump and artificial substrates in both pool and riffle habitats, at sediment depths of 30 and 50 cm, during the high water period (May to October) and the low water period (November to April). Analysis of the hyporheic fauna composition revealed a total of 31 invertebrate taxa and 2600 specimens collected across both sampling techniques. The majority of taxa (30 taxa) were recovered using the Bou-Rouch technique, while the Artificial Substrate method yielded 19 taxa. Only 55 % of the recorded taxa were common to both methods, with Cyclopidae being the dominant invertebrate taxon. PERMANOVA analysis revealed a significant difference between the two techniques in assemblage composition with a significant interaction between techniques and depths. Our results suggested that the Bou-Rouch technique provide a more effective and representative means of assessing hyporheic invertebrate communities, particularly in terms of taxonomic richness and abundance. In contrast, the Artificial Substrate method appears to offer a more limited and less accurate depiction of the community structure, highlighting the importance of selecting appropriate sampling methods for ecological studies in hyporheic environments.
The North River, one of the tributaries of the Pearl River in southern China, is a main source of water supply for the cities of Shaoguan, Qingyuan, Zhaoqing and Foshan (Guangdong Province). The North River is also largely impacted by the construction of dams. Filamentous diatoms, formed by spiny or protruding structures connected between neighboring cells, are dominant taxa in river phytoplankton communities and crucial to riverine ecosystems. We conducted environmental surveys of the North River in April, August and November 2019 to investigate the species diversity and morphological characteristics of filamentous diatoms in a fragmented river. A total of 17 filamentous diatoms (including varieties) were identified, including 14 species of Aulacoseira and 3 species of Melosira. The highest biomass contribution of Aulacoseira was made by Aulacoseira granulata, followed by Aulacoseira ambigua f. japonica, while Melosira varians had the highest occurrence among Melosira, followed by Melosira juergensii var. bothnica. Spatiotemporal characterization of filamentous diatom biomass and filament length showed that biomass was greater in April than in August and November, mainly related to temperature, runoff, pH and competition with other algae. In general, the biomass and filament length of Aulacoseira were larger than those of Melosira. Spatially, the maximum or minimum biomass often appeared at stations closest to the dams in April. However, this pattern was not observed in August and November. In the three periods of investigation, spatial distribution was characterized by different filament lengths at different dams. At the most downstream dam, there was a tendency for the mean filament length to gradually increase with downstream distance from the dam. This might be related to the long filament lengths of the filamentous diatoms, with longer filament lengths having a greater specific surface area, as a larger specific surface area was more likely to follow the flow in turbulent downstream. Additionally, there was also an increasing trend in the biomass of filamentous diatoms after the last dam. However, unlike the continuous increase in filament length, the biomass showed a discontinuous surge, which might result from the restoration of river connectivity.
Historically, regular mixing occurred predictably in Lake Bosumtwi in August. However, recent reports indicate a shift towards prolonged stratification, reduced seasonal mixing depth, and a decline in fish productivity, consistent with the effects of climate warming. This study aimed to investigate the perceived changes in the mixing and stratification regime by comparing historical (2004-2006) and current data to determine the magnitude of climate warming on the lake's hydrodynamic properties. From 2018 to 2020, daily measurements of meteorological variables, including temperature, wind speed, and rainfall within the crater, were recorded at an onshore weather station. Monthly data on water column temperature, dissolved oxygen, and electrical conductivity were collected, and Schmidt stability was calculated. Time series analyses suggest alterations in the stratification and mixing patterns of the lake induced by air temperature and wind speed forcing. The air temperature increased from 26.56 degrees C (SD = 3.13) to 27.28 degrees C (SD = 3.32) resulting in a 0.30 degrees C rise in the water column, greater thermal stability and a decline in dissolved oxygen concentration with depth. There appears to be a notable shift in the timing and intensity of the mixing period, transitioning from August to September, attributed to diminished convective cooling processes. Evidence indicates a transition from a holomictic state to meromictic. This transformation in the lake's hydrodynamics will affect nutrient renewal rates and primary productivity, with implications for water quality, fisheries, ecotourism, and livelihood activities vital to the lake communities.
Surface waters receive megatons of plastic waste annually that degrade into microplastics in a variety of shapes including spheres, fragments, and fibers. Microplastic fibers (MFs) ranging in length from < 100 m to 5 mm are most common, generated by synthetic textile laundering and aquatic equipment degradation. Zooplankton encountering MFs frequently mistake the foreign particles for food and/or become entangled. The current study investigated whether fiber length influences zooplankton MF ingestion and mortality. Daphnia magna were exposed to one of four polyethylene terephthalate (PET) MF treatments: 0 (control), 45, 70, or 100 mu m lengths at a concentration of 50,000 MFs L-1 for 7 days in the laboratory. Mortality was assessed daily while the concentration of ingested MFs was measured only at the conclusion of the experiment. The proportion of zooplankton ingesting fibers was similar across treatments. However, length influenced the level of MF accumulation in zooplankton; accumulation of 70 mu m MFs was 2 and 4x higher than for 45 or 100 mu m lengths, respectively. There were no differences in mortality after 7 days across all treatments. This investigation demonstrated that zooplankton readily ingest MFs across a range of sizes and that fiber length influences the number of MFs consumed. However, no instances of entanglement were observed independent of fiber length, suggesting the primary mechanism through which zooplankton interact with MFs is via ingestion. Over longer time periods, it is possible that MF accumulation interferes with zooplankton feeding, which could elevate mortality and reduce food availability to higher trophic levels.
Methane (CH4) is a potent greenhouse gas, mainly produced in anoxic environments through the degradation of organic matter. Measurements of dissolved CH4 concentrations and environmental variables were made in the two largest tributaries of the Amazon, the Negro and Solim & otilde;es river, between 2005 and 2011, including years of exceptional high and low water levels. Diffusive CH4 emissions were estimated from CH4 concentrations. These rivers have distinct chemical and physical properties and are of unique economic and cultural significance to their riverine populations. Both rivers were consistently over-saturated with CH4 in relation to the atmosphere, with the Negro River generally presenting higher concentrations (between 0.004 mu M and 0.223 mu M) than the Solim & otilde;es River (between 0.005 mu M and 0.037 mu M). Diffusive fluxes were also found to be larger for the Negro River (0.09 to 8.6 mmol m- 2 d-1) than for the Solim & otilde;es River (0.04 to 1.07 mmol m- 2 d-1). A clear seasonal pattern was observed for both rivers with respect to dissolved CH4 concentrations and diffusive fluxes: the highest concentrations and diffusive fluxes of CH4 were found during LW, while the lowest concentrations and fluxes were found during HW. This seasonal trend was more pronounced in years of severe or atypical flood or drought events. Regression models indicated that water depth and temperature can explain the variation in the dissolved CH4 concentration in the Negro (70 %) and Solim & otilde;es River (58 %). This study shows the potentially strong effects of interannual hydrological variation on river CH4 concentrations and the subsequent river CH4 outgassing.
The impact of Stratiotes aloides on the abundance and composition of phytoplankton and zooplankton, as well as its potential application in the fight against harmful cyanobacterial blooms, was examined in the model ecosystems (microcosms). There was a decrease in the abundance of phytoplankton in general and cyanobacteria in particular in the microcosms with S. aloides. The concentration of microcystins both in water and in phytoplankton biomass decreased significantly. The effect of S. aloides on the intensity of microcystins production by cyanobacteria has not been found. The concentration of toxins per unit of cyanobacterial biomass did not differ significantly throughout the experiment. In the microcosms with S. aloides, the diversity and abundance of zooplankton increased. Crustaceans, such as filter feeders Ceriodaphnia quadrangula and Diaphanosoma brachyurum, and detritivores from the family Chydoridae, as well as rotifers, prevailed in zooplankton. A complex of factors, such as the known allelopathic potential, changes in the concentration of nutrients and ionic composition, shading, as well as a certain zooplankton community associated with S. aloides stands, caused the inhibitory effect of plants on cyanobacteria. The results of the experiment demonstrate the potential of using S. aloides in "green" technologies to control cyanobacterial bloom.
The allelopathic properties of cyanobacteria were investigated, and their effects on microalgae were screened. Among the studied cyanobacterial cultures, Oscillatoria SS-8 exhibited the ability to suppress the growth of Chlorella vulgaris SP and Chlamydomonas reinhardtii CC-124, with inhibitions at levels of 48 % and 46 % respectively (p < 0.05). The cyanobacterial culture Synechococcus SS-3 demonstrated a stimulating effect on the growth of Chlamydomonas reinhardtii CC-124. The growth dynamics of microalgae were comparable to the control group at the end of the experiment, despite the initial reduction in cell numbers induced by the cell-free filtrates of Anabaena SS-6 and Phormidium SS-7. Chemical analysis of the cell-free filtrate of Oscillatoria SS-8 revealed the presence of various organic compounds, including hexadecanoic acid, 1,2-benzenedicarboxylic acid, and dibutyl phthalate. These compounds are widely distributed in nature and are known for their involvement in antibacterial and antioxidant processes. The results underscore the importance of studying the chemical compounds produced by cyanobacteria and their impact on aquatic ecosystem communities, as well as the interactions between different trophic levels within these ecosystems.
Microalgae play a fundamental role in the functioning of aquatic ecosystems. The diversity and structure of the microalgae community are always influenced by the availability of nutrients in the environment, which is one of the causes of water eutrophication. Microalgae are the best biological indicators of pollution and eutrophication in aquatic environments. In this study, the diversity and structure of microalgae were determined and indicator species of eutrophic water were identified in the water of the Loumbila reservoir, a drinking water source in Burkina Faso. Algae and water samples for physico-chemical analyses were collected monthly from January 2014 to June 2015 in three sampling points. Phytoplankton species were observed under a light microscope and identified using standard methods. The results showed that pH, dissolved oxygen, water transparency, conductivity, nitrates and orthophosphates levels showed distinct spatial and seasonal variations at p <= 0.05. The determination of the specific composition and density of microalgae allowed the inventory of 205 species composed of 5 phyla with a higher specific diversity of Chlorophyta (48.30 %) and a higher density of Cyanobacteria (43.71 %). Analysis of microalgae diversity showed a Shannon-Wiener index varying from 3.11 to 3.60 between sampling points and from 1.70 to 3.73 between seasons. Microcystis aeruginosa, Pediastrum duplex, Pediastrum simplex and Aulacoseira granulata were identified as indicator species for eutrophic water. This study provides basic information on the diversity and structure of microalgae in water reservoirs. It also provides elements for a future assessment of the water quality of drinking water sources using indicator algal species to prevent or reduce eutrophication phenomena.
Dams and reservoirs are a common and globally widespread anthropogenic disturbance with documented negative effects on riverine and riparian habitats. The two most well-known impacts of river damming are longitudinal fragmentation of surface running waters and a shift from lotic habitats towards habitats with lentic characteristics that affect the benthic and pelagic communities. However, there is very little empirical evidence about the effects of damming on the aquatic fauna inhabiting interstitial habitats extending in and alongside the river-bed (i.e., hyporheic zone). In this study, we investigated the patterns in the interstitial community composition upstream, downstream and within the reservoir that was formed 80 years ago, when the river was dammed for the hydropower production. We used the rare opportunity to directly access the bottom of the reservoir drained due to dam maintenance in January 2018, to compare physical, chemical and faunistic data from the reservoir area, with those from downstream and upstream reaches of the two gravel bed rivers that are flowing into the reservoir. We sampled the interstitial invertebrate communities at seven locations, using a Bou-Rouch pump at two depths (30 - 60 cm and 60 - 90 cm within the river bed) and at three sampling points within each location. At the same sampling points we measured also physical and chemical parameters (temperature, conductivity, oxygen and pH). The interstitial water from the deepest point of the drained reservoir had substantially lower oxygen concentration, lower pH, and higher conductivity than water from the other sampling localities. This was also the site where taxa richness was lowest, and only one obligate groundwater species (i.e. stygobiont) was found. Most probably, the changes in morphology of the river channel and speed of water flow due to damming, which increased sedimentation rate and clogging of interstitial habitat, resulted in such large differences in environmental conditions and invertebrate community composition. This study provides rare empirical evidence of the effects of damming on the river interstitial habitats and fauna within the reservoir area. We recommend that environmental impact assessments conducted prior dam constructions should include also assessment of the effect of river damming on the interstitial communities. These organisms are playing important role in driving important ecosystem processes, such as organic matter degradation on one hand, and on the other hand, are composed of many rare and endangered species that need to be protected.
Eutrophication and phytoplanktonic primary productivity are intensifying in continental aquatic ecosystems as a result of climate and land-use changes. Therefore, the proliferation of potentially toxic cyanobacteria is increasing in frequency, magnitude and duration, representing an ecological risk to ecosystems and human health. Our objective was to evaluate the water quality of ten subtropical reservoirs (Jaguari, Jacarei, Atibainha, Paiva Castro, Rio Grande, Guarapiranga, Barra Bonita, Bariri, Broa and Salto Grande), of the S & atilde;o Paulo region (Brazil), with an emphasis on cyanobacteria and cyanotoxins. From October 2021 to February 2022, we collected surface water samples to determine turbidity, chlorophyll-a, phycocyanin, microcystin and saxitoxin concentrations and phytoplankton biovolume. Water turbidity, chlorophyll-a and phycocyanin concentrations ranged from 2.0 to 24.6 NTU, 3.2 to 105.1 mu g l(-1), 12.4 to 445.1 mu g l(-1), respectively across reservoirs. Cyanobacteria was the most representative class in terms of biovolume, ranging from 0.086 +/- 0.072 to 47.9 +/- 5.3 mm3 l(-1). Saxitoxins and microcystins were found in most reservoirs, with concentrations ranging from 0.016 mu g(-1) to 0.308 mu g l(-1), and from 0.107 to 200 mu g l(-1), respectively. According to the World Health Organization (WHO 2020) and the Brazilian legislation (Ordinance GM/MS n degrees. 888 of 2021), in the 10 reservoirs, saxitoxin concentrations are within the maximum permitted limits (3 mu g l(-1)). However, total microcystin concentrations are above the maximum allowed value (1 mu g l(-1)) according to the Brazilian legislation for most reservoirs. Considering all the information analyzed in relation to water quality and the community of cyanobacteria in the reservoirs, we can suggest that most of these environments present low water quality, which could present a risk to public health.
Daphnia and Microcystis aeruginosa interaction is a cosmopolitan focus of ecological research. Singlecell or small-colony M. aeruginosa can be ingested by Daphnia, , whereas large colonies cannot, causing mechanical interference. However, the mechanism of the effects of different morphological M. aeruginosa on population parameters of Daphnia under interspecific competition is still unclear. In this study, population of two Daphnia species (D. D. galeata and D. sinensis) ) fed single-cell and colonial M. aeruginosa were investigated under interspecific competition. Somatic growth rates, number of offspring at first reproduction, and population growth rates of two Daphnia species under single- or mixed-species culture were all significantly inhibited in the presence of unicellular M. aeruginosa at a high concentration. However, their responses showed different patterns under colonial M. aeruginosa. . In the presence of colonial M. aeruginosa, , the population growth rate of D. sinensis was significantly higher under mixed-species culture than under single-species culture and significantly lower for D. galeata except in the small-colony and high concentration treatment. However, the number of offspring at first reproduction of the two Daphnia species was higher under mixed-species culture than under single-species culture. Therefore, interspecific competition promoted early reproduction of the two Daphnia species after short-term exposure to colonial Microcystis. . In contrast, interspecific competition strongly restrained the population growth of small-bodied D. galeata and strengthened the population growth of large-bodied D. sinensis after long-term exposure to colonial Microcystis. . Our results further reveal the interactions between Daphnia and Microcystis during a cyanobacterial bloom in eutrophic lakes.
The major energy source in small streams in temperate deciduous forests is from allochthonous inputs of leaf litter. We examined the decomposition of leaves from American chestnut (Castanea dentata), American beech (Fagus grandifolia), and red maple (Acer rubrum) in a headwater stream within a beech-maple forest in the Northeastern U.S. Chestnut was a dominant species in the watershed prior to chestnut blight but has been functionally extinct since the 1930's. Currently, maple and beech are dominant trees, with maple predicted to increase and beech decrease from climate change. The objectives of the study were to compare mass loss rates, microbial activity (respiration rates), nutritional quality (carbon/nitrogen ratio), and toughness (penetration force) of leaves for the three species and to determine whether the differences among species provide insight into how the fates of litter processing may be influenced by changes in forest composition. Leaf packs of the species were placed in the stream and sampled over 103 days. The molar carbon/nitrogen ratio of leaves decreased over time and was highest for chestnut. Mean microbial respiration rates on leaves ranged from 2.7- 8.3 mg dissolved O2/m2/h, and were lowest on beech. Leaf toughness for the three species decreased, with chestnut leaves being tougher than beech or maple. Mass loss was greatest for maple with breakdown rates being 0.013, 0.013, and 0.023, d-1 for chestnut, beech, and maple, respectively. Overall, breakdown rates of beech and chestnut were less than maple because their leaves had less microbial activity and were tougher, respectively. The faster processing of maple leaves would favor rapid mineralization of organic nutrients by microbes, whereas slower processing of chestnut or beech would divert more nutrients within the microbial loop to macroconsumers in the detritivore web. This indicates that long term changes in the relative abundances of these tree species in this region have the potential to affect the fate of energy and nutrients derived from leaf litter. However, successional changes within a watershed affect litter decomposition by more than just changing leaf species diversity. Predicting how disease and climate change may alter the fate of litterfall in streams requires a holistic examination of how compositional changes in watershed vegetation interact with processing under different stream conditions.
We tested how functional diversity (FD) along with its three components are correlated to ecological traits of nonmarine ostracods at seven elevational ranges from 800 to 1500 m. 38 ostracod taxa were collected from 55 aquatic sites in Aksaray province (Turkey). 21 species were new reports for the province. Shannon-Wiener diver-sity index indicated four cosmopolitans with more than 90 % of contribution. Results of the Canonical Correspond-ence Analysis (CCA) explained 76.8 % of the correlation between species and environmental variables. Salinity was the most effective variable on species. The highest functional divergence and functional richness were found in the elevational ranges of 800 - 899 m and 1100 -1199 m, respectively. When the highest functional evenness was accounted for the 1400 -1499 m, the functional dispersion was found higher in the range of 1200 -1299 m. A medium length of the carapace, the left valve overlaps the right valve, long swimming setae on the second antenna, a well-developed uropod, and a smooth carapace surface are the common traits of the species used in FD. Sampling sites were clustered by the common species, which also showed correlation with four cations (Ca, Na, Mg, K). Results suggest that 'functional diversity' can be used to correlate ostracod traits with their functional ecology.
