Ephemeroptera Communities Research Articles

Reservoir longitudinal gradient promotes ordered losses on diversity and density of Ephemeroptera community.

Reservoir operations alter, eliminate or restrain the natural hydrologic cycles. Biotic community has become subject to these non-cyclic events, responding by reducing the species diversity. Ephemeroptera species present distinct responses to environmental deterioration such that poses this assemblage between the most useful groups in biomonitoring programs. We hypothesized an alteration in beta diversity at the longitudinal species gradient, which will be influenced mainly by species losses between zones. Changes in temporal beta diversity is also expected, but the main drivers of such alterations will be the species turnover between the sampling period. Ephemeroptera community was monitored in nine sampling points from Itaipu Reservoir, where were installed three sets of substrates composed by a float and 2 wooden substrates. We took biological samples in triplicates monthly, from June-01 to August-02. Our initial hypothesis was partially supported and with significant variations only for spatial approach, between the Reservoir zones. The generated ordering from Non-Metric Dimensional Scale - NMDS - corroborated with spatial analyzes, with the formation of two groups along the gradient zonation of the reservoir. The temporal ordination showed no clear pattern. As expected, the contribution to beta diversity was different for our two approaches, such that the loss of species was more important along the spatial gradient and despite of no significant result, the species replacement was more important among months. The spatial results lead us to infer that differences in limnological characteristics between zones are important for determining differences in Ephemeroptera composition and can reflect the dependency degree of the species in relation to the lentic and sometimes-lotic conditions, mainly in the riverine zone of reservoirs. On the other hand, the absence of a temporal pattern can be result of chaotic variations in the physical and chemical attributes imposed by the reservoir operation, disrupting continuity of the biota and natural succession processes.

New records of Ephemeroptera from the Colombian Orinoco river basin of the Meta department

There is extensive research of the Ephemeroptera communities taxonomy and ecology in the Andean region of Colombia. However, other regions such as the Orinoquia have been insufficiently studied. From this region, in the Meta department, four species have been registered: Varipes lasiobrachius Lugo-Ortiz & McCafferty, Coryphorus aquilus Peters, Miroculis (Atroari) colombiensis Savage & Peters and Tricorythopsis rondoniensis (Dias, Cruz & Ferreira). The main objective of this study is to report for the first time for this region the species: Mayobaetis ellenae (Mayo), Hydrosmylodon primanus (Eaton), Haplohyphes baritu Domínguez, Camelobaetidus edmundsi Dominique, Mathuriau & Thomas and Nanomis galera Lugo-Ortiz & McCafferty.

Biotope Determinants of EPT Assamblages Structure – Târnava Watershed (Transylvania, Romania) Case Study

Abstract This study aims to analyze the biotopic factors affecting the EPT assemblage diversity in the rivers of the Târnava Watershed. Our research revealed that the high diversity of the Plecoptera communities is associated with river reaches with boulder and cobble lithological substrate, accentuated slope and natural bank dynamics, and also it is directly correlated with dissolved oxygen and inversely correlated with chemical and biochemical oxygen demand, total hardness, nitrates and total nitrogen in the water. The high diversity of the Trichoptera communities is associated with water which presents moderate quantities of nutrients (total phosphorus, phosphates) and with river reaches with heterogeneous structures (where runs and bends were present). The diversity of the Ephemeroptera communities is positively correlated with the multiannual average flow and riverbed width.

Determining the Reference Ephemeroptera Communities in the Eastern Part of the Black Sea Region for the Implementation of the Water Framework Directive in Turkey

Abstract In this study, we aimed to determine the reference sites and their reference Ephemeroptera communities according to the Water Framework Directive methods in the Eastern Part of the Black Sea Region of Turkey between 2008-2011. From the area, twentyfour collecting sites were chosen. There were thirty Ephemeroptera species identified, belonging to seven families and eleven genres. Cluster analysis based on Bray-Curtis similarities was applied. Reference habitat conditions of the studied sites and their reference Ephemeroptera communities were determined by combining both ecological and statistical results. As a result, sixteen sites had reference habitat conditions and their reference Ephemeroptera species were identified.

Impact of riparian land-use patterns on Ephemeroptera community structure in river basins of the southern Western Ghats, India

Key-words: Ephemeroptera, riparian land use, bioindicators, KMTR, Western Ghats This study analysed the impact of riparian land use in structuring the larval ephemeropteran communities from 25 sites in streams and rivers of Kalakad-Mundanthurai Tiger Reserve (KMTR) of the southern end of the Western Ghats, India. A total of twenty-eight species belonging to twentyfour genera of six families were collected across all the sites. Baetidae and Leptophlebiidae were the most numerous and ubiquitous families, comprising eight genera in each family and eleven and nine species, respectively. The physico-chemical parameters and species richness and abundance of mayflies varied across streams and rivers with different riparian land-use types. Species distribution was influenced by the environmental gradients. Canonical Correspondence Analysis revealed a clear separation of the mayfly assemblages along water quality and riparian landuse gradients. The results of this study suggest that Ephemeroptera taxa can be potentially used as sensitive indicators of riparian land use in lotic ecosystems.

Environmental and spatial processes determining Ephemeroptera (Insecta) structures in tropical streams

Community diversity is expected to reflect variations in local conditions but, recently, ecologists have started to realize that local diversity is also under pressure from global processes. As a result, the traditional view of community structure based on local interspecific interactions was replaced by the idea that community structure is a result of multiple processes acting in different spatial scales. This study is aimed at quantifying the relative importance of spatial, environmental and spatially structured processes on Ephemeroptera community in Cerrado streams in Brazil. Thirty-four rivers and streams in the Brazilian state Mato Grosso were sampled. Ephemeroptera species composition, based on abundance and presence data, was evaluated in relation to niche and neutral predictors by using a partial redundancy analysis (pRDA). Results obtained through the pRDA indicated that both environmental and spatial processes influenced Ephemeroptera abundance. On the other hand, only environmental processes showed effects on community patterns when using species presence data from preserved, altered and large streams and also when looking only at the preserved sites. When streams larger than 20 m were excluded from analysis, both environmental and spatially processes showed influence on Ephemeroptera composition. Adjusted R2 values were higher for environmental than for spatial processes in all analyses. The relatively high influence of both environmental processes and stream width in the analyses highlights the sensitivity of mayflies assemblies to environmental variation, and emphasizes the importance of local processes, as predicted by niche theory, while neutral processes act to a lesser extent on the structure of the studied communities.

Longitudinal Distribution of Ephemeroptera Communities for the Sasar River and its

The Sasar River basin is located in the Baia Mare Depression; it covers an area of 311 sq km and it is located in NW Romania. Due to urbanization and industrialization, and to a lesser extent agriculture, Sasar Basin shows a simplification of the biocenosis, more or less brutal, the intensity of pollution.This paper summarizes the results of sampling campaigns that were carried out between 2003-2008, when a total of 10 stations of the investigated basin were identified and analyzed, according to the Normalized Global Biological Index (IBGN) methodology. Subsequent to the systematical study, 20 species belonging to 6 Ephemeroptera families ( Leptophlebiidae, Ephemeridae, Ephemerelllidae, Caenidae, Heptageniidae, Bäetidae  ) were identified. Ephemeroptera is a group of demanding environmental conditions; high specific abundance was recorded in the stations located in areas with minimal and moderate anthropogenic impact (upstream Blidari-10 species; Valley Măriuţii- 10 species, upastream Baia Sprie - 9 species). The number of species is drastically reduced for the stations located downstream of the Baia Sprie and Baia Mare industrial centers (downstream Baia Sprie-3 species, downstream Baia Mare -1 species). Within the communities of Ephemeroptera high frequencies were performed by Bäetis rhodani (90%), considered in terms of the ecological valence, average tolerance to pollution. Pollution-sensitive species had low frequencies: Rhithrogena semicolorata  (40%), Bäetis alpinus (40%).

The relationship between Ephemeroptera and presence of the white-clawed crayfish (Austropotamobius pallipes). Case study in the Poitou-Charentes region (France)

Nowadays, the distribution of the European native white-clawed crayfish (Austropotamobius pallipes) is restricted, fragmented and mainly located in headwater streams. To preserve this indigenous species, it is necessary to characterize its habitat preferences. Although this species is endangered, little was known about its ecological requirements until recently. Recent studies conducted throughout its distribution area indicate that water pollution is the main cause of its disappearance. In particular, A. pallipes seems very sensitive to organic pollution. However, no study has focused on the macroinvertebrate assemblages that co-occur with A. pallipes. In this study, seven streams located in the Deux-Sevres Departement (western France) containing wild populations of A. pallipes were qualitatively sampled in April 2004 and Ephemeroptera were identified to species level. These sites were also sampled according to the French biotic index during the summer of 2004. Several chemical parameters were also analyzed e.g. Dissolved Oxygen, pH, Ca, Turbidity, UV 254mm , Conductivity, Total Organic Carbon (TOC) and Total Suspended Solids (TSS) The objectives of this study were: 1) to analyze the benthic invertebrate assemblage by determining the IBGN index in both reference zone (presence of A. pallipes) and zone without crayfish, 2) to identify the Ephemeroptera community in both zones to find some match with the presence of A. pallipes. The applied issue of this study is to use both physico-chemical criteria and Ephemeroptera communities to select suitable streams for a crayfish relocation program in the Poitou-Charentes region of France. It was found that (i) the IBGN scores did not separate the sites with/without A. pallipes (ii) Ephemeroptera diversity is statistically higher in sites with crayfish than in sites without (iii) there was a strong correlation between A. pallipes, species of Ephemeroptera mainly of Leptophlebiidae family (Habrophlebia fusca, Habrophlebia lauta and Paraleptophlebia submarginata) and dissolved oxygen at the study sites.

Mayfly (Insecta: Ephemeroptera) community structure as an indicator of the ecological status of the Nišava river (Central Balkan Peninsula)

Mayfly taxa are widely accepted as bioindicators of water quality, due to the wide variety of substrates they live on and high chances of detecting the pollution impact by assessing their community structure. Ephemeroptera samples and physicochemical data were analysed for 12 sites along the 151 km long stretch of the Nišava River in southeastern Serbia during a one-year period. Twenty eight morphologically distinct taxa belonging to eight genera were identified. The dominant genera were Baetis (35.27%) and Ephemerella (29.44%). The Ephemeroptera community structure analysis of samples from the Nišava River has shown a clear dependence of the mayfly community on the habitat type, physical and chemical parameters, and the season. The lowest Shannon's diversity index was estimated for the localities with the lowest percentage of the solid substrate and the highest average content of phosphorus and nitrogen.

Community structure of Ephemeroptera in Siberian streams

AbstractIn recent decades, the relationships between environmental conditions and community structures of stream macroinvertebrates have been investigated in many parts of the world. However, knowledge about assemblages of mayflies and other stream macroinvertebrates in Siberia (northern Asia) and Asia is limited. In fact, the patterns in mayfly species richness and assemblage structure in relation to environmental parameters have not been previously examined in western Siberia. The aim of the present study was to examine the relationship between Ephemeroptera community structure and physical parameters along a river altitude/longitude gradient in Siberia. The results showed that maximum species richness was at relatively low altitudes, high water temperatures, slow current velocities, medium stream widths, medium‐small substrate particle size, and the presence of macrophytes. The mayfly assemblage was separated using TWINSPAN classification into eight distinct groups, which differed significantly with respect to at least one measured environmental factor. Multivariate ordination (detrended correspondence analysis) revealed that mayfly assemblages are structured by a single dominant gradient of altitude‐related environmental variables; altitude and water temperature were the best predictors. Ordination further revealed that mayfly assemblages are structured by altitude‐related environmental factors at high elevations, whereas in the lowlands these factors are less important.

Eutrophication: are mayflies (Ephemeroptera) good bioindicators for ponds?

Ephemeroptera larvae are recognized worldwide for their sensitivity to oxygen depletion in running waters, and are therefore commonly used as bioindicators in many monitoring programmes. Mayflies inhabiting lentic waters, like lakes and ponds, in contrary have been poorly prospected in biomonitoring. For this purpose, a better understanding of their distribution in lentic habitats and of the relations of species presence with environmental conditions are needed. Within this framework, 104 ponds were sampled in Switzerland. The Ephemeroptera are found to be an insect order particularly well represented in the ponds studied here (93% of the lowland ponds). Nevertheless, in terms of diversity, they are relatively poorly represented (mean species number = 1.9). Two species dominated: Cloeon dipterum (Baetidae) and Caenis horaria (Caenidae). The investigations contributed to the updating of the geographical distribution of the species in Switzerland, as many of the observations appear to be from new localities. The trophic state of ponds appears here to be important for Ephemeroptera communities. First, there is a negative relationship between total phosphorus (TP) concentrations and species richness. Second, the presence of Caenis horaria or Cloeon dipterum is dependent on the trophic state. Caenis horaria is most closely associated with low levels of TP concentrations, while Cloeon dipterum appears to be less sensitive, and is most frequently found in hypertrophic conditions. A probable consequence of these relations, is that Baetidae are always present when Caenidae are also present. Contrastingly, Baetidae is observed as the only mayflies family present in several ponds.