Two new genera of Baetidae are described from East Kalimantan (Borneo): Asiobaetodes n.gen. and Acerobiella n.gen. Both genera are monospecific and only known from a very restricted area. They are highly adapted to fast flow and are closely related to Oriental genera Liebebiella Waltz & McCafferty, 1987 and Platybaetis Müller-Liebenau, 1980. Asiobaetodes is characterized by five pairs of ventrally orientated gills and tubular accessory gills at the bases of mouthparts and forelegs; these characters are also present in the Panamerican genus Baetodes Needham and Murphy, 1924 and the African genus Afrobaetodes Demoulin, 1970. The study of the mouthparts clearly indicates that the similarities must be considered as homoplasies. Acerobiella is characterised by its dorsal armature, especially the spike tubercles turned upwards on tergum II, which constitutes a unique character among the Baetidae.

To understand ostracod distribution and ecology at high altitudes (1659–2889 m a.s.l.), 78 different aquatic sites located in the city of Van were sampled during summer of 2009. A total of 29 ostracod species were recorded in 57 sites. Among the species, Trajancypris laevis (G.W. Müller 1900), is a new report for the Turkish ostracod fauna. First axis of Canonical Correspondence Analysis (CCA) explained about 68% of the relationships between the 13 most abundant species and environmental variables. Four variables (redox potential, habitat type, pH and electrical conductivity) had the greatest effect on species composition (P<0.01). Twenty-six species encountered from 38 stations were restricted between 1659 and 1750 m a.s.l. Above 1750 m a.s.l., the numbers of species were not significantly affected by altitude (P>0.05). Three species (Heterocypris incongruens (Ramdohr, 1808), Ilyocypris bradyi Sars, 1890 and Potamocypris villosa (Jurine, 1820)) occurred extensively from 1650 to 2350 m a.s.l. Spearman rank correlation revealed a negative relationship between Limnocythere inopinata (Baird, 1843) and altitude (r=−0.894, P=0.05), while two species (I. bradyi and Prionocypris zenkeri (Chyzer and Toth, 1858)) had a positive correlation to dissolved oxygen (P=0.05). There was a significantly negative relationship between Ilyocypris inermis Kaufmann, 1900 and electrical conductivity, and H. incongruens showed a significant correlation to station type. Five groups of species were determined by UPGMA analysis. Species in each cluster were grouped according to ecological conditions suitable for them. Results revealed that species ecological tolerances and optimum levels can be species-specific but species with cosmopolitan distributions tend to have high tolerance ranges to different variables, including altitudinal changes.

Knowledge on ecological impacts of forestry practices on aquatic ecosystems relies almost exclusively on data from large-scale forest harvesting, often involving clearfelling of whole stream catchments. To determine effects associated with less intensive and widespread forest management, we examined the responses of headwater streams to small-scale forest harvesting, including riparian zones adjacent to study reaches but corresponding to less than 5% of the catchment areas. Stream reaches running through recently (2–4 years) harvested forest patches were paired with and compared with adjacent reaches bordered by mature broadleaf forest. We determined abiotic stream characteristics, invertebrate community structures and abundances, trout size and population densities, and leaf litter breakdown rates in each of these pairs. Harvested reaches were found to have different channel cross-section morphology and greater invertebrate abundances in leaf packs than mature forest reaches. Shifts in the abundance of common invertebrate predators were also attributed to riparian forest harvesting. Litter breakdown rates and brown trout densities did not show any significant difference between harvested and mature forest reaches across the four site pairs, possibly because of nonlinear responses to post-harvest riparian canopy openness. Managers must be aware that small-scale forest harvesting in stream riparian areas is not without consequences for aquatic ecosystems. Whether natural riparian forest openings, such as caused by tree death and blow-down, have similar effects on stream ecosystems is an important question to address if we are to confirm the usefulness of small-scale forestry and improve forest and stream management schemes.

Headwater woodland streams are primarily heterotrophic: they receive substantial inputs of organic matter from the riparian vegetation, while autochthonous primary production is generally low. A substantial part of leaf litter entering running waters may be buried in the streambed because of flooding and sediment movement. Although the general significance of the hyporheic zone for stream metabolism has been reported early, organic matter storage within the sediment of streams has received less attention, with most studies only quantifying accumulations at the streambed surface and ignoring other stream compartments. In the present study, the amounts of three fractions of coarse particulate organic matter (CPOM; >16, 4–16 and 1–4 mm) were determined in late autumn and early spring in the interstitial and benthic zones of three headwater streams of the Montagne Noire (South-Western France) differing in their substratum grain size. Our findings demonstrated that the total CPOM content in the interstitial zone can be much (up to one order of magnitude) higher than at the sediment surface. The sandy bottomed stream exhibited a higher amount of CPOM (whatever the size fraction) than the two other streams, suggesting that the sediment particle size may be a major determinant of CPOM storage. Given the large amount of organic matter stored in the interstitial zone, this compartment may play an important role for the carbon turnover and associated trophic dynamics in the stream ecosystem.

Two species of North American branchiobdellidans, Cambarincola gracilis Robinson, 1954 and Cambarincola okadai Yamaguchi, 1933, have been reported in Europe for the first time. These branchiobdellidans together with Xirogoniton victoriensis Gelder and Hall, 1990 were found on signal crayfish, Pacifastacus leniusculus (Dana, 1852), collected from the Lot and Tarn River drainages in southern France. Specimens of X. victoriensis were also reported on the same host in the Mayenne River drainage in northeastern France. Brief morphological descriptions of the three alien branchiobdellidan species are given. These introductions are briefly discussed and compared with similar alien ectosymbiotic associations found in Japan.

Based on collections in three coast Brazilian states, Hydrosmilodon plagatus sp. nov. and Needhamella mazama sp. nov. are described based on nymphs and adults. Besides the description of these species, new geographic records of the Hermanella complex are presented. The species included are: Hermanella maculipennis (Ulmer, 1920); Hermanella froehlichi Ferreira and Domínguez (1992); Hydrosmilodon gilliesae Thomas & Péru (2004); Hylister plaummani Domínguez and Flowers (1989); Leentvaaria palpalis Demoulin (1966); and Needhamella ehrhadti (Ulmer, 1920). In addition, in this work Leentvaaria palpalis is recorded from Brazil for the first time.

The aim of this study was to examine morphometric differentiation of gudgeon (Romanogobio and Gobio) species inhabiting the Carpathian Basin, Hungary, with special regard to two recently described species classified into the Gobio genus. For statistical analyses, 23 morphometric and 8 meristic characters were measured on each of the 733 preserved specimens originating from museum collections. The analyses of the standardized morphometric traits revealed low intraspecific variability in all studied species, but varying degrees of interspecific differences. The strongest morphometric differentiation was found in Romanogobio uranoscopus (Agassiz, 1828), which can be characterized by the most special environmental needs. The two allopatric Gobio species showed the weakest morphometric difference. The meristic characters showed high variability in the Romanogobio spp., but did not show significant differences in the two Gobio species. The results show that the morphometric and meristic similarity of the studied Gobio species is definitely high, which preclude reliable identification based on phenotypic characters if only some specimens are available. It seems that the most usable discriminating feature for these species is the localization of the collection site.

Podonomus Philippi was recently found in Brazilian inselbergs. In this study, we used sequences from the barcode region of cytochrome c oxidase I (COI) to assess Podonomus molecular diversity from mountains in Southeastern Brazil. Our results revealed the adult female and the larvae of Podonomus pepinellii Roque and Trivinho-Strixino, 2004 and extended the known geographical distribution of the species. Moreover, we found high molecular divergence in two populations located in the Serra da Mantiqueira and Serra do Espinhaço mountain range when compared with the only species recorded to Brazil, indicating the possibility of two more species to be described.

The testate amoeba, ciliate and rotifera communities living in interstitial waters in peatbog in eastern Poland were studied. Sampling was done on a monthly basis from April to November 2007–2008. Microbial communities were examined in a transect including three sites: (1) pine forest (site located 5 m from the lagg/forest contact zone), (2) lagg, (3) open peatbog (the centre of the peatbog). At each of the sites, interstitial water was sampled by means of piezometric wells placed to a depth of 1 m. The species richness and abundance of protozoa and rotifers significantly differed between the studied stations, with the lowest numbers in the pine forest and the highest in the lagg. These differences between macro-habitats may be due to differences in environmental conditions. The distribution of samples in ordination space led to conclude that studied habitats are distributed along the falling gradient of pH and rising gradient of total organic carbon, water table depth and nitrate nitrogen. Assemblages of all three groups showed a strong compositional gradient correlated with water-table depth, conductivity and total phosphorus. However, species composition of ciliates and rotifers was explained by nitrate nitrogen and/or phosphates concentrations. The results suggest that lagg zone of a raised bog can fulfil the function of an ecotone zone, distinguished by a significant increase in biodiversity, abundance and species specificity of micro-organisms. It can also be a place of very efficient matter and energy flow in a peat bog ecosystem.

The flood pulse regime and the hydrological connectivity determine the lateral bidirectional exchanges of water, chemical compounds, and biota between the river and the floodplain habitats. The primary goal of the present research was to analyze the effect of water flow on macroinvertebrates in two water levels in a lateral connectivity gradient, from the main channel through a connection channel to a permanently connected lake. We tested the hypothesis that the water flow from the main channel to the floodplain habitats during high water level causes a decrease in beta diversity between the sites, increasing similarity in the system. To test this hypothesis, we sampled a river–floodplain–lake system of the Middle Paraná River during two water levels, and analyzed the spatial and temporal turnover of species between sites and habitats. Local physical characteristics, such as depth, benthic particulate organic matter, and grain size of bottom sediments influenced assemblage composition. Taxa richness, density, and Shannon diversity differed among habitats within the river–lake system, but did not show significant differences between water levels. Richness, density, and diversity were higher in the lake and the connection channel than in the Paraná River bank. Beta diversity was significantly higher during high water period. During low water period, benthic assemblage composition was homogenized, as reflected by the lower values of species turnover between the sites situated in the main channel–lake corridor during this phase. The lateral bidirectional exchanges among the habitats are essential for maintaining the specific invertebrate diversity of large river corridors.

Invasive species are a global problem, which costs the world economy billions of dollars and world ecosystems millions of tons of herbicides, pesticides and other cides. Anthropogenic translocation of freshwater copepods associated with early shipping activities was postulated for some time, but was never tested with molecular tools. Here, we examine global molecular diversity of one cyclopoid species, test if the current cosmopolitan distribution is a result of anthropogenic translocation or natural dispersal, and investigate a possibility of cryptic speciation. We use patterns of haplotype frequency of DNA and RNA sequences of four genes (12S, 16S, 18S and cytB) and 11 populations (from England, Scotland, France, Germany, USA, New Zealand and Australia) to test inter- and intrapopulation variability, and three different methods (neighbour joining (NJ), maximum likelihood (ML) and maximum parsimony (MP)) for reconstructing their phylogenetic relationships. They were then tested against two competing hypotheses, and complemented by comparative morphology of microcharacters. Reconstructed phylogenies present strong evidence for anthropogenic translocation, with the same haplotype found in highly disjunct populations in Western Australia, Germany and the USA. Four different clades were revealed with the 12S, 16S and cytB genes, probably representing four cryptic species. Morphological examination of females of two clades contributed a set of microcharacters that can be used in the future taxonomic revision of this species complex. We prove for the first time that cuticular pores and sensilla are homologous structures. This research provides evidence for both homogenization of world freshwater fauna and our inadequate methods of identifying some of its most common species.

The larvae of three species of the Rhyacophila tristis group: Rhyacophila aquitanica, Rhyacophila pubescens and Rhyacophila tristis are described. A key is given. Revised data on their distribution in France are presented.

Mediterranean temporary ponds (MTPs) are crucial breeding sites for local amphibians, a faunal group in decline in the Mediterranean mainly due to wetland destruction. Although the disappearance of lentic habitats in other regions of the world has been ameliorated by the creation and restoration of wetlands, these tactics remain untested in Mediterranean wetlands. To evaluate the amphibian colonization dynamics of artificial MTPs in the north-eastern Iberian Peninsula, we monitored two artificial MTPs (one in a high-diversity area and the other in a low-diversity area) over 2 years. We selected reference wetlands at each area, and amphibian communities of man-made MTPs were compared to those of reference wetlands. We found that, beginning in the first year, artificial MTPs were a valuable habitat for regional amphibian fauna. Posteriorly, we focused on the reproductive success of the natterjack toad, Bufo calamita. Using a drift fence equipped with pit-fall traps, we measured the abundance of both reproductive adults entering the pond and post-metamorphic individuals exiting the pond. Using mark-recapture methods, we analyzed the time and energy costs associated with reproduction in the artificial MTPs. We observed a highly variable colonization dynamics between sites, between hydroperiods, and within hydroperiods, and these dynamics often depended on meteorological factors. Our results suggest that even at a short timescale, native amphibian species such as B. calamita can benefit from wetland creation in the Mediterranean region.

The impact of Elodea canadensis on aquatic macrophyte biodiversity in (Lake) Steinsfjord has been studied through extensive lake-wide surveys and photographic sampling. E. canadensis greatly expanded in Steinsfjord since its appearance in 1978 and still dominated the macrophyte community in 2004. The areal distribution of E. canadensis peaked within 6 years from invasion and has remained relatively stable since; however, stands no longer reach the water surface. E. canadensis significantly increased its depth range, but the cover-weighted mean depth remained unchanged, suggesting that 3–4 m is its optimal depth in Steinsfjord. Species richness has not changed significantly since the earliest survey in 1936–38. However, species composition has changed remarkably, from isoetid dominance in 1936–38 to a diverse community dominated by Najas flexilis in 1979–80 to a less diverse community dominated by E. canadensis in 2004, with Potamogeton berchtoldii and Myriophyllum alterniflorum as lake-wide subdominants. Regardless of their abundance at the onset of the E. canadensis invasion, taxa whose cover-weighted mean depth overlapped with E. canadensis's in 1979–80 greatly reduced their abundance in 2004, shifted to deeper or shallow water or disappeared from sampling stations. Our survey indicates that E. canadensis may be the reason for the decrease of N. flexilis, likely through depletion of CO2 in the water column and reduced nutrients in sediments. The abilities to survive and grow in periodically exposed shallow areas, combined with minor herbivory by waterfowl, are likely important factors for the increase of M. alterniflorum in Steinsfjord's shallow waters.

The effects of cyanobacterial toxins on herbivorous zooplankton depend on cyanobacterial strains, zooplankton species and environmental conditions. To explore the relationship between zooplankton and cyanobacteria, we investigated the effects of Planktothrix agardhii extracts on Daphnia magna population dynamics. We designed an experiment where individuals were grown in the presence of extracts of two P. agardhii strains. We monitored daily life-history parameters of D. magna individuals subjected to microcystin-RR (MC-RR), intracellular and extracellular extracts of a microcystin-producing strain (MC-strain, PMC 75.02) and a microcystin-free strain (MC-free strain, PMC 87.02) of P. agardhii. Measured life-history parameters of D. magna were used to build population dynamics models and compute expected population growth rate, replacement rate, generation time and proportion of adult and juveniles at demographic equilibrium. Results show that MC-RR tends to slow the life history (reduced growth rate and larger proportion of adults). In contrast, intracellular extracts of the two strains tend to accelerate the life history (increased growth rate, decreased generation time and lower proportion of adults). Extracellular extracts produce the same trends as the intracellular extracts but to a lesser extent. However, the MC-strain has stronger effects than the MC-free strain. Interestingly, extracellular extracts of the MC-free strain may have effects comparable to pure MC-RR. Moreover, in the presence of MC-RR and both cyanobacterial extracts, the daily fecundities present a cyclic pattern. These results suggest that MC-RR and unknown metabolites of cyanobacterial extracts have negative effects on D. magna reproduction processes such as those observed with endocrine-disruptive molecules.

Exposure to water movement has been observed to alter various processes in the plants including growth, hormone concentration and nutrient uptake. In the current study, Chara fibrosa was exposed to three different turbulence conditions and compared with a control. Turbulence was generated in the laboratory by using a vertically oscillating grid setup. Exposure to turbulence caused a reduction in shoot length and nutrient uptake in C. fibrosa. Variation of stable isotope composition was measured as a surrogate variable that is able to integrate variations of many physiological processes. It was initially hypothesized that the reduction of diffusion boundary layer around the plant will increase isotopic discrimination against 13C and 15N, when exposed to increasing turbulence. Although the results generally agree with the hypothesis, a trend of increment was observed in δ13C in the plants exposed to turbulent velocities from 0.46 to 1.93 cm s−1, against the hypothesis. Mechanical stress induced reduction of carbon uptake and lipid peroxidation due to the development of oxidative stress may be the reasons behind the above-mentioned trend. The study exhibits that the net effect of physical and physiochemical changes of the plants was displayed in δ13C signatures and it is important to consider physical conditions of the local environment, in using stable isotope signatures for ecosystem studies.

Phragmites australis is a stand forming emergent macrophyte that displays large phenotypic variation within Lake Balaton. The present study assesses morphological variations of P. australis within three transects of different reed stands of Lake Balaton which differ with respect to bathymetry, reed quality and geographic position in order to achieve a morphological typization. On average the southern stable stand produced the largest and thickest plants (295±9 cm and 7.5±0.2 mm), while plants of the northern die-back stand were approximately half this size (141±2 cm and 3.5±0.1 mm). The slow growth and development of Phragmites characterizing the northern die-back stand was the result of fewer and shorter internodes, which also resulted in the low number of green leaves. The most influential factor shaping the phenotypic properties of the plants was determined to be the reed quality (general condition), although site-specific differences, shore-specific differences, water depth and spatial position within reed stand transects were also found to be significant. Despite the differences in the studied stands and almost certain genetic dissimilarities, three morphological ecotypes of Phragmites were distinguished on the basis of stem height to basal diameter ratio, stem density and phenotypic plasticity of plants. These ecotypes were primarily correlated to water depth at their position within the reed stand. The similarity of the spatial distribution of stem heights to basal diameter ratios and phenotypic plasticity of plants along all studied reed stands suggests that morphological typization should be considered to provide additional information on ecological zonation of stands.

Using several clonal lineages of Simocephalus vetulus (Cladocera, Daphniidae) as a random sample, we investigated the genetic component of the halotolerance of one brackish and two freshwater populations of this littoral filter feeder. We hypothesized that genotypes from the brackish population were more tolerant than freshwater ones, via adaptation to local environmental conditions. Clonal identity was established by a cost-effective molecular fingerprinting technique (microsatellite-primed polymerase chain reaction (MSP-PCR)). Two distinct methodologies were used to assess cladoceran sensitivity to synthetic-grade sodium chloride (NaCl): (i) standard 48-h acute assays and (ii) 12-h survival time (ST) trials. No correlation was found between acute EC50 and ST values. The sensitivity of brackish and freshwater clones was comparable in terms of acute EC50 (varied from 2.28 to 3.83 g.L−1). On the contrary, genetically determined differential tolerance to NaCl among populations was found for ST: all brackish genotypes, except one, were more resilient (ST>120 min) than freshwater clones (ST<120 min). Bearing in mind that these results were obtained with isolates from the extant population, it is surprising that the range of acute sensitivity of the freshwater and brackish genotypes was similar, and that the only difference between them was the ability of brackish clones to survive longer under high salinity stress (6 g.L−1, in ST trials). We must conclude that the effect of salinity (original environment context) on the selection of genotypes was weaker than we had expected and than other authors have shown for other stressors.

The winter of 2009/2010 was particularly severe in Northern Portugal resulting in higher river flow levels. A study was undertaken to assess the impact of this situation on several populations of freshwater bivalves (e.g., Anodonta anatina, Corbicula fluminea, Margaritifera margaritifera, Potomida littoralis and Unio delphinus) in the catchments of the Rivers Minho, Douro, Tâmega, Tua and Sabor. Massive die-offs occurred for all species in all rivers, resulting in the removal of great numbers and biomass from the riverbed to the adjacent riverbanks, reaching maximum values of 2280 individuals.m−2 and 10 225 g wet weight.m−2, respectively. The invasive Asian clam C. fluminea had both highest density and biomass (however, this invasive bivalve is not dominant in several surveyed sites, and some rivers are still not colonized by this species). Results show that the quantitative and qualitative importance of this carrion transfer to the riverbank should be incorporated in future studies on the assessment of ecosystem function, contributing to a better understanding of the role of freshwater bivalves as resource pulses in adjacent terrestrial habitats. Some of the affected species have conservational importance and these extreme climatic events are predicted to increase in the future. These massive die-off events should be incorporated into management plans and selected restoration measures such as rapid relocation of endangered native mussels back to the riverbed can be easily applied to lessen possible impacts.

Two consecutive earthquakes temporary changed a zooplankton community in a high-mountain Lake Krn (altitude 1383 m a.s.l.). It was dominated by the eurytherm copepod, Cyclops vicinus, until 1998, when the first earthquake hit the lake (EMS=5.6). After the earthquake, the population of C. vicinus collapsed and the thermophilic cladoceran, Ceriodaphnia quadrangula, took over. After the second earthquake in 2004 (EMS=4.0), C. vicinus became untraceable. In 2008, few copepods reappeared and by 2010 they became the sole dominant again. Only Secchi-disc depth showed a statistically significant increase over time, while Ntot, Ptot and temperature showed an increasing trend, yet the relationship was insignificant. To compare multi-parameter properties of the water column, the studied period was divided into Period 1 (before the first earthquake), Period 2 (between earthquakes) and Period 3 (after the second earthquake). A Hotteling T2 test confirmed a statistically significant difference between Periods 1 and 2 & 3 (P<0.01), but not between Periods 2 and 3 (P>0.1). During simple laboratory experiment, specimens of C. vicinus were covered with a thin layer of sediment, to mimic the earthquake's effect on their survival. A hypothesis was that the timing of both earthquakes had been crucial for decimation of C. vicinus population as they re-suspended sediment with hibernating copepodites. As these became subsequently buried they were deprived of a re-activation signal and exposed prolonged anoxic conditions there. C. quadrangula temporary filled the void left by the copepod, which needed 6 years to regain its dominance.