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North African streams and rivers face multiple anthropogenic stressors, and their aquatic fauna is rapidly dwindling before comprehensive knowledge of their distribution and ecology has been attained. We investigated the distribution and life cycle of the Maghrebian endemic Ecdyonurus rothschildi Navas, 1929 in northeastern Algeria. The species was recorded both from permanent and intermittent freshwater habitats with stony substrate. It exhibited pronounced sexual dimorphism, with F-0 females being significantly larger than F-0 males. Three generations were completed during an annual multivoltine cycle. The first generation extended from October to February/March, the second spanned the months of March to June, and the third stretched from June to the end of September/October. We argue that monitoring of E. rothschildi could prove useful for assessing the rapid changes affecting North African hydrosystems, which are in need of adequate management.

Ecdyonurus aurasiussp. nov., a micro-endemic species reported from several streams within the Aurès Mountains (north-eastern Algeria), is described and illustrated at nymphal, subimaginal and imaginal stages of both sexes. Critical morphological diagnostic characters distinguishing the new species are presented, together with molecular affinities as well as notes on the biology and distribution of the species.

Several Alpine streams are currently changing from perennial to intermittent systems with expected detrimental consequences on benthic invertebrates, through the alteration of hydrological conditions, substrate composition, and trophic resources. We examined the ecological niche of three phylogenetically-related scraper macroinvertebrates, namely Ecdyonurus, Epeorus, and Rhithrogena (Ephemeroptera, Heptageniidae) experiencing recurrent summer dewatering events in perennial and intermittent stretches in 13 Alpine streams. We evaluated the overlap among the ecological niches of the three examined taxa in terms of hydraulic stress, substrate coarseness, and total primary production and we investigated their ecological preferences in perennial and intermittent sites. Our results showed a broad overlap of their ecological niches, suggesting exploitative competition among the examined taxa. Their ecological niches were smaller in intermittent than perennial sites, pointing out a reduction of available microhabitats. All groups were favored by substrate coarseness and total primary production in reach types, while the hydraulic stress showed an opposite effect in perennial (negative) and intermittent (positive) sites. Overall, our results emphasize how stream physical parameters play a key role in determining the ecological niche of Heptageniidae and underline how benthic communities in intermittent sections of previously perennial Alpine streams are currently under pressure.

Paper description: Molecular biomarkers of oxidative stress are the most apropriate parameters for detecting early influence of pollutants. The effects of trout farms on aquatic insects at the molecular level have been scantily investigated. We examined the influence of trout farm effluents on the molecular biomarkers of oxidative stress in larvae of Ecdyonurus venosus as a very sensitive bioindicator of water quality. Changes in components of antioxidative defense in E. venosus proved to be reliable and sensitive biochemical biomarkers of environmental stress caused by trout farm effluents, making this species an excellent bioindicator of freshwater pollution. Abstract: The aim of the present study was to establish the extent to which the outlet waters of trout farms affect the ecosystems of the Crnica and Skrapež rivers in Serbia. We monitored selected biomarkers of oxidative stress: superoxide dismutase (SOD), glutathione peroxidase (GPx) and total glutathione (GSH) in larvae of the species Ecdyonurus venosus , and simultaneously analyzed the changes in the physical and chemical parameters. The investigations were carried out in spring at four localities along the Skrapež and Crnica rivers: one upstream (the control localities), and three downstream from the fish farm outlets. On the Skrapež River, the fish farm was clearly visible and was markedly changed by the chemical parameters of the water, manifested as a decreased concentration of dissolved oxygen, increased concentrations of nitrates, nitrites, ammonium ions, total phosphorus and total organic carbon, and increased SOD and GPx activities and decreased GSH concentration in larvae from the first downstream locality as compared to the control locality. On the Crnica River, due to the high values of water flow (around 3 m 3 /s), effluents from the fish farm had no effect on the chemical parameters of the water or on the tested biomarkers. https://doi.org/10.2298/ABS181220004R Received: December 20, 2018; Revised: January 29, 2019; Accepted: January 30, 2019; Published online: February 1, 2019 How to cite this article: Radojevic A, Mircic D, Živic M, Peric-Mataruga V, Božanic M, Stojanovic K, Lukicic J, Živic I. Influence of trout farm effluents on selected oxidative stress biomarkers in larvae of Ecdyonurus venosus (Ephemeroptera, Heptageniidae). Arch Biol Sci. 2019;71(2):225-33.

Ecdyonurus (Helvetoraeticus) picteti (Meyer-Dür, 1864) Baetis sp.? Picteti Meyer-Dür, 1864: 221. Heptagenia Picteti. – Eaton, 1871: (transfer). Ecdyonurus picteti. – Puthz, 1975: 321 (transfer). Ecdyonurus (Helvetoraeticus) picteti . – Bauernfeind & Soldán, 2012: 279 (transfer to new subgenus). Locus typicus: „… Muraglbach bei Pontresina, im Rosegthal, am Chalchagn und am Bernina bis 6700’ ü.M…“. Type material: MHNG; lectotype, ♀ subimago; 620 Engadin 48 Alpes coll. Pictet / val Muragl 25 (6) / Baetis Picteti Meyer Engadin / Ecdyonurus picteti (Meyer-Dür) ♀ Lektotypus Puthz 1973 (Fig. 7). Remarks: Puthz (1975) was the first to rediscover specimens of this species in F.-J. Pictet’s collection. Besides the lectotype, there is another female subimago with the following labels: 620 Pontresina 48 Alpes coll. Pictet / Pontresina 5/6 selten / Ecdyonurus picteti (Meyer-Dür) ♀ Paralektotypus Puthz 1973. Furthermore, there is a third one, also a female subimago, which does not belong to this species: 620 Bernina 48 6700’ Alpes coll. Pictet / Bernina bis 6700’ 4/6 / Syntypus von Baetis picteti Meyer-Dür = cf. Ecdyonurus venosus (F.) Puthz 1973., Published as part of Sartori, Michel & Bauernfeind, Ernst, 2020, Mayfly types and additional material (Insecta: Ephemeroptera) examined by F. - J. Pictet and A. - E. Pictet, housed in the Museums of Natural History of Geneva and Vienna, pp. 315-339 in Revue suisse de Zoologie 127 (2) on page 331, DOI: 10.35929/RSZ.0022, http://zenodo.org/record/5743794, {"references":["Meyer-Dur L. R. 1864. Beobachtungen auf einer entomologischen Reise wahrend des Sommers 1863 durch das Seegebiet von Tessin und Oberengadin. Mitteilungen der Schweizerischen Entomologischen Gesellschaft 1 (7): 219 - 225.","Eaton A. E. 1871. A monograph of the Ephemeridae. Transactions of the Entomological Society of London 1871: 1 - 164.","Puthz V. 1975. Uber einige europaische Heptageniiden (Insecta, Ephemeroptera). Sur les Ephemeropteres du Museum d'histoire naturelle de Geneve. IV. Revue suisse de Zoologie 82 (2): 321 - 333.","Bauernfeind E., Soldan T. 2012. The Mayflies of Europe. Apollo Books, Ollerup [now: Brill Publ., Leiden], 781 pp."]}

Here we revise the entire Ephemeroptera collection of F.-J. Pictet deposited in the Natural History Museum of Geneva (MHNG) and voucher specimens housed in the Natural History Museum of Vienna (NMW). Due to several unforeseen turns of events, the MHNG collection was already in bad condition at the end of the 19th century. However, the specimens sent by V. Kollar to F.-J. Pictet, and used by the latter for his monograph (1843-1845), have been well curated after their return to the NMW and allow an important nomenclatural change. The species Baetis forcipulaF.-J. Pictet, 1843 is now considered a junior subjective synonym of Ephemera venosaFabricius, 1775, currently Ecdyonurus (Ecdyonurus) venosus (Fabricius, 1775). The specimens described by Thomas in 1968b from southwestern France under the name Ecdyonurus forcipula (F.-J. Pictet, 1843) belong to a new species, Ecdyonurus alaini Bauernfeind sp. nov., which is described herein. Mayfly specimens described by F.-J. Pictet's son, A.-E. Pictet, are also reviewed. Furthermore, information is provided on some other valuable specimens housed in the MHNG and NMW, such as Ametropus fragilisAlbarda, 1878 which was already collected in Italy in the 19th century, or Rhithrogena cinctaNavas, 1921 from the Spanish Pyrenees, which is the second specimen currently known of this species.

Knowledge of the basic life history traits of an aquatic organism such as voltinism and growth patterns is a fundamental step in understanding its potential use as indicator taxon and how it adapts to its complex environment. The distribution and life cycle of the Maghrebian endemic Choroterpes atlas Soldan & Thomas, 1983 was studied over a two year period. Random forest classification indicated that the species occupied both permanent and intermittent streams with high water depth, large river bed width and strong water flow. Density-based clustering of body measurements allowed the identification of last-instar nymphs which exhibited a significant sexual dimorphism: F-0 females were significantly larger than corresponding males. In addition, size-frequency plots and generalized additive models indicated that C. atlas exhibited a multivoltine annual cycle with three overlapping generations. Nymphal growth of the first generation happened in winter and spring with emergence occurring in June/July. The second generation grew from June/July to September whereas the third generation was completed from August/September to November. GAMs also indicated that body size varied significantly between years. The large regional distribution, habitat requirement, and phenology of C. atlas may ideally complement the potential use of Ecdyonurus rothschildi as a useful environmental indicator for North African streams and rivers.

This study investigates the potential for physical damage caused by suspended fine sediment on gills of three macroinvertebrate species, Hydropsyche siltalai, Ephemera danica and Ecdyonurus venosus. Macroinvertebrate cadavers were exposed to three suspended sediment concentrations (control 3.5, low 83.7 and high 404.0 mg l−1) at two velocities (low 0.19 m s−1 and high 0.37 m s−1), for 6 h in a recirculating flume. Tracheal gill surfaces were subsequently examined for evidence of physical damage using scanning electron microscopy (SEM) images. Physical damage predominantly consisted of fine sediment coverage of gill surfaces, appearing as a deposited layer of sediment obscuring and potentially clogging the gill. For E. venosus, suspended sediment concentration influenced gill cover, but velocity had no significant effect. Coverage of H. siltalai gill surfaces increased significantly between low and high sediment concentrations but only at the higher flow velocity. Gill coverage of E. danica did not differ across any sediment concentration. The results were consistent with reported species sensitivities to fine sediment, despite the use of cadavers. However, we found limited evidence of physical abrasion as a direct physical effect of fine sediment under the experimental conditions used.

According to the River Continuum Concept, headwater streams are richer in allochthonous (e.g. terrestrial leaves) than autochthonous (e.g. algae) sources of organic matter for consumers. However, compared to algae, leaf litter is of lower food quality, particularly omega-3 polyunsaturated fatty acids (n-3 PUFA), and would constrain the somatic growth, maintenance, and reproduction of stream invertebrates. It may be thus assumed that shredders, such as Gammarus, receive lower quality diets than grazers, e.g. Ecdyonurus, that typically feed on algae., The objective of this study was to assess the provision of dietary PUFA from leaf litter and algae to the shredder Gammarus and the grazer Ecdyonurus. Three different diets (algae, terrestrial leaves, and an algae-leaf litter mix) were supplied to these macroinvertebrates in a flume experiment for 2 weeks. To differentiate how diet sources were retained in these consumers, algae were isotopically labelled with C-13., Both consumers became enriched with C-13 in all treatments, demonstrating that both assimilated algae. For Gammarus, n-3 PUFA increased, whereas n-6 PUFA stayed constant. By contrast, the n-3 PUFA content of Ecdyonurus decreased as a consequence of declining algal supply., Results from compound-specific stable isotope analysis provided evidence that the long-chain n-3 PUFA eicosapentaenoic acid (EPA) in both consumers was more enriched in C-13 than the short-chain n-3 PUFA alpha-linolenic acid, suggesting that EPA was taken up directly from algae and not from heterotrophic biofilms on leaf litter. Both consumers depended on algae as their carbon and EPA source and retained their EPA from high-quality algae.

Freshwaters are particularly vulnerable to pesticide contamination from adjacent agriculture and forestry. Cypermethrin is a commonly used pyrethroid insecticide, but information on its toxicity to non-target freshwater invertebrates is limited to a small number of taxa. We assessed cypermethrin toxicity to nymphs of the common European mayflies Baetis rhodani and Ecdyonurus venosus, and the stonefly Isoperla grammatica in 96 h static bioassays. The 96 h median lethal concentrations (LC50) we recorded for the three species were 0.08 μg/L, 0.15 μg/L, and 0.13 μg/L, respectively. The effective concentration (EC50), quantified as lack of escape response (implying inability to avoid drift, predation or abiotic stress), was usually 32 % of the LC50. All 96 h LC50 values were lower than the maximum concentrations detected in streams in UK and continental Europe. Alarmingly, the 96 h LC50 for B. rhodani was below the currently applied single-pesticide EU safe drinking water standard of 0.1 μg/L. Contrasts among species were most evident at 24 h LC50, when B. rhodani was approximately ten times more sensitive than the other two taxa. B. rhodani is a key algal grazer, ubiquitous in European streams, and its decline could exacerbate algal blooms. The order of taxa sensitivity to cypermethrin in our study contrasts with their sensitivity to organic pollution in the same region, which suggests a tolerance trade-off, and thus a compounding effect of simultaneous stressors. Mayflies and stoneflies are important prey for instream and riparian predators, and key components of most eutrophication indices globally, all of which could be compromised in presence of cypermethrin.

Streams in the Mongolian Altai Mountains are mostly fed from glaciers and are extreme conditions for mayflies because of high elevation, low temperatures and low annual precipitation. Previous information about mayflies of Western Mongolia is scarce, but with this study a total of 38 species belonging to 26 genera and subgenera and 8 families of mayflies has been recorded in the Mongolian Altai region. Study material was entirely imagos and collected from 78 sites during expeditions led by the Mongolian Aquatic Insect Survey in 2008, 2009 and 2010. Raptobaetopus tenellus, Caenis luctuosa and Caenis rivulorum are recorded as new to the fauna of Mongolia, and there are new distribution records for Ameletus montanus, Baetis (Acentrella) lapponica, Baetis sibiricus, Baetis (Labiobaetis) attrebatinus, Centroptilum luteolum, Procloeon pennulatum, Ephemerella aurivillii, Serratella setigera, Ephemera sachalinensis, Ecdyonurus (Afronurus) abracadabrus, Cinygmula kurenzovi, Ecdyonurus (Afghanurus) vicinus and Epeorus (Belovius) pellucidus from the Mongolian Altai region. Baetis vernus and Ephemerella aurivillii are the most frequently encountered species in this region.

The distribution characteristics of functional feeding groups and biological evaluation of water quality with benthic macroinvertebrates were investigated from 2013 to 2014 in the mountain streams of Jirisan National Park. Both quantitative and qualitative collection had been performed six times during study periods in twelve sites located at upstream, midstream and downstream of four valleys, Chilsungol, Baemsagol, Daesunggol and Piagol of freshwater ecosystem in Jirisan National Park. As results, the total collected benthic macroinvertebrates were 3 phyla, 4 classes, 11 orders, 37 families, 107 species and 4,028 individuals. In 2013, 3 phyla, 4 classes, 10 orders, 32 families, 89 species and 1,829 individuals were collected. And in 2014, 3 phyla, 4 classes, 9 orders, 31 families, 80 species and 2,199 individuals were identified. The total dominant species was Ecdyonurus kibumensis, and EPT groups occupied 80.39% of total species number. Biotic indices were also compared to site and to season. The dominant index (DI) was highest at the downstream of Baemsagol in the spring of 2013, and the evenness index (J') was highest at the downstream of Daesunggol in the summer of 2013. Both diversity index (H') and richness index (RI) were highest at the upstream of Baemsagol in the summer of 2014. The correlation between altitude above sea level and functional feeding groups of benthic macroinvertebrates was also researched in this study. As a result, the species number of shredders and predators have significantly increased according to the increase of the altitude of their habitat. On the other hand, individuals of gathering collectors have increased according to the increase of altitude. The biological water quality was evaluated and compared with several methods in this study, and we suggest that ESB and GPI are more appropriate than KSI and BMI to evaluate biological water quality of mountain stream water.

We described the life cycles of 17 riffle-dwelling mayfly species in a central Japanese stream. Both species of Baetidae (Alainites yoshinensis Gose and Baetis thermicus Ueno) and two of nine species of Heptageniidae (Ecdyonurus scalaris Kluge and Epeorus latifolium Ueno/l-nigrus Matsumura) in this stream were multivoltine (more than one generation per year). Seven other heptageniid species (two unidentified species of Cinygmula, Epeorus aesculus Imanishi, E. curvatulus Matsumura, E. ikanonis Takahashi, E. napaeus Imanishi, and Rhithrogena japonica Ueno) and all six species of Ephemerellidae [Cincticostella elongatula (McLachlan), C. nigra (Ueno), Drunella basalis (Imanishi), D. ishiyamana Matsumura, D. sachalinensis (Matsumura), and D. trispina (Ueno)] were essentially univoltine.

Ecdyonurus (Ecdyonurus) eurycephalus Hrivniak & Godunko, sp. nov. (Figs 2–45) Type material (numbers in parentheses correspond to localities on Fig. 1 and Appendix 1). Holotype: male imago: ARMENIA, Shirak province, NE of Musayelyan village; small steppe river, tributary of Akhurian River; 41°00'13.15" N, 43°57'24.87"E; 2195 m a.s.l.; 02/09/2015, (36). Paratypes: 2 male imagoes (genitalia and wings of 1 individual mounted on slide), 9 female (1 mounted on slide) and 6 male larvae (4 mounted on slide), same data as holotype (36); 10 female (2 mounted on slide) and 8 male larvae (1 mounted on slide): ARMENIA, Shirak province, NE of Musayleyan village; steppe stream, tributary of Akhurian River; 41°00'20.12"N, 43°59'14.04"E; 2286 m a.s.l.; 02/09/2015, (35); 3 female and 1 male larvae: ARMENIA, Shirak province, N of Amasia village, steppe stream, tributary of Akhurian River; 40°58'20.49"N, 43°46'06.88"E; 1987 m a.s.l.; 02/09/2015, (38); 1 female larva: ARMENIA, Shirak province, E of Aghvorik village, steppe stream, tributary of Akhurian River; 41°04'21.19"N, 43°44'44.83"E; 2052 m a.s.l.; 03/09/2015, (39); 3 female (1 mounted on slide) and 5 male larvae (l mounted on slide): ARMENIA, Shirak province, E of Torosgyugh village, small steppe river, tributary of the Akhurian river; 40°55'54.99"N, 43°52'45.26"E; 1885 m a.s.l.; 03/09/2015, (40). Other material studied (not type): 3 female and 1 male larvae, (36); 1 female larva: ARMENIA, Lori province, W of Katnarat, steppe stream, tributary of the Dzoraget River; 41°03'59.85"N, 44°05'44.24"E; 1949 m a.s.l.; 02/09/ 2015, (33); 2 female and 1 male larvae, (35); 1 female larva, (40). All types and other studied material were collected by P. Manko, J. Oboňa and Ľ. Hrivniak. Material is deposited in the collection of the Czech Academy of Sciences, Biology Centre, Institute of Entomology, České Budějovice, Czech Republic.

Ecdyonurus (Ecdyonurus) eurycephalus Hrivniak & Godunko, sp. nov. (Figs 2���45) Type material (numbers in parentheses correspond to localities on Fig. 1 and Appendix 1). Holotype: male imago: ARMENIA, Shirak province, NE of Musayelyan village; small steppe river, tributary of Akhurian River; 41��00'13.15" N, 43��57'24.87"E; 2195 m a.s.l.; 02/09/2015, (36). Paratypes: 2 male imagoes (genitalia and wings of 1 individual mounted on slide), 9 female (1 mounted on slide) and 6 male larvae (4 mounted on slide), same data as holotype (36); 10 female (2 mounted on slide) and 8 male larvae (1 mounted on slide): ARMENIA, Shirak province, NE of Musayleyan village; steppe stream, tributary of Akhurian River; 41��00'20.12"N, 43��59'14.04"E; 2286 m a.s.l.; 02/09/2015, (35); 3 female and 1 male larvae: ARMENIA, Shirak province, N of Amasia village, steppe stream, tributary of Akhurian River; 40��58'20.49"N, 43��46'06.88"E; 1987 m a.s.l.; 02/09/2015, (38); 1 female larva: ARMENIA, Shirak province, E of Aghvorik village, steppe stream, tributary of Akhurian River; 41��04'21.19"N, 43��44'44.83"E; 2052 m a.s.l.; 03/09/2015, (39); 3 female (1 mounted on slide) and 5 male larvae (l mounted on slide): ARMENIA, Shirak province, E of Torosgyugh village, small steppe river, tributary of the Akhurian river; 40��55'54.99"N, 43��52'45.26"E; 1885 m a.s.l.; 03/09/2015, (40). Other material studied (not type): 3 female and 1 male larvae, (36); 1 female larva: ARMENIA, Lori province, W of Katnarat, steppe stream, tributary of the Dzoraget River; 41��03'59.85"N, 44��05'44.24"E; 1949 m a.s.l.; 02/09/ 2015, (33); 2 female and 1 male larvae, (35); 1 female larva, (40). All types and other studied material were collected by P. Manko, J. Oboňa and Ľ. Hrivniak. Material is deposited in the collection of the Czech Academy of Sciences, Biology Centre, Institute of Entomology, Česk�� Budějovice, Czech Republic., Published as part of Hrivniak, ��ubo��, Sroka, Pavel, Godunko, Roman J., Palatov, Dmitry, Pol����ek, Marek, Manko, Peter & Obo��a, Jozef, 2018, Diversity of Armenian mayflies (Ephemeroptera) with the description of a new species of the genus Ecdyonurus (Heptageniidae), pp. 195-221 in Zootaxa 4500 (2) on page 198, DOI: 10.11646/zootaxa.4500.2.3, http://zenodo.org/record/5297537

We provide the first commented checklist of Armenian mayflies, based on all relevant literature and recent extensive sampling of 72 localities throughout Armenia during 2011, 2014, and 2015. Altogether 46 species are listed, eight of them reported from Armenia for the first time. One new species, Ecdyonurus (Ecdyonurus) eurycephalus sp. nov. is described (larva and male imago) based on morphological and molecular (COI) data. The species is characterized by a unique head shape in male imago and by the presence of tracheal filaments on gill plate VII in the larval stage.

We have studied characteristics of community structure on the benthic macro-invertebrates at twelve selected sites in upstream, midstream and downstream of Paemsagol, Piagol, Chilseongol and Daeseonggol, major streams of Jirisan Mountain, for three years from April 2008 to September 2010. As a result, 2 phyla, 3 classes, 11 orders, 41 families, 119 species and 4,449 individuals of benthic macro-invertebrates have been collected and classified in this study. Among them EPT group (Ephemeroptera, Plecoptera, Trichoptera), commonly appearing taxa in clean stream ecosystem, was found most frequently. The highest species number of benthic macro-invertebrates were collected in 2008, the year with lower climatic influence including heavy rain. In almost all of survey sites 80% or over of EPT group were counted, and St. 1 scored highest rate of EPT group at 92.59%. Most dominant species was Ecdyonurus kibumensis at 12.83% of dominance index, and subdominant species was Goerodes KUb at 6.81% of dominance index. The investigation of the feeding function group indicated that gathering-collectors were dominant with 26 species and 1,334 individuals, while the number of filtering-collectors was lowest with 11 species and 230 individuals. This result represents that the feeding function group of Jirisan Mountain is mountainous stream-specific one. Both diversity index and richness index were lowest at the midstream of Chilseongol (St. 5), while the midstreams of Daeseonggol (St. 11) and Piagol (St. 8) were highest in diversity and richness indices respectively. The analyses of linear regression and correlation were performed in order to investigate and to predict the appearance aspect of EPT group by altitude. The results showed that the ratio of Plecopteran species number has increased by the elevation of the altitude at 0.05 significance level. Cluster analysis was also carried out for evaluating environmental similarities among survey sites. As a result, upper regions of Paemsagol (St. 1) and Piagol have clustered as most similar sites each other, while the midstream of Piagol (St. 8) has separated with lower similarity value than other sites in species composition.

The first representative of the subgenus Helvetoraeticus Bauernfeind & Soldán, 2012, from the Caucasus Mountains, Ecdyonurus (Helvetoraeticus) adjaricus sp. nov., is described on the basis of larvae, female imago (reared from larva) and male imago from the Autonomous Republic of Adjara, Georgia. The male imago of the new species can be separated from other representatives of Helvetoraeticus by its conspicuous yellowish wings coloration (especially of hind wings) and the shape of the penis lobes. The larva has a distinctive broad and apically pointed lateral projection on the pronotum, pointed bristles on the ventral side of the posterior border of the femora and markedly long, sharp posterolateral expansions of abdominal sterna. This last character is unique within Helvetoraeticus. The new species is most closely related to E. krueperi (Stein, 1863).

Understanding the feeding habits of aquatic invertebrates under reference conditions can contribute to our understanding of community assemblages in fresh waters. Here, seasonal changes in the diet of three species of Ephemeroptera from Irish high status rivers were investigated. A fluorescent dye, 4'6 diamidino-2-phenylindole, was used to differentiate the various types of gut contents and to allow bacteria and biofilm matrix to be visualised. Through interpretation of gut contents and feeding strategy plots, Baetis rhodani was found to have a generalist diet with detritus, algae and biofilm the main food types. Two congeneric species, Ecdyonurus venosus and E. insignis, were found to be detritus specialists. Seasonal sampling indicated that biofilm can provide a valuable food source to E. venosus at times of high flow when detritus is not readily available. There was evidence of niche separation in summer when E. insignis and E. venosus co-existed. E. insignis fed on coccoid algae while E. venosus consumed no coccoid algae. B. rhodani consistently ingested a similar broad diet throughout the year. A detritus-based diet is likely nutrient poor leading to lower growth rates. These findings are discussed in the context of the behaviour of these species and sensitivity to nutrient enrichment.

This study evaluates the impact of anthropogenic activities on the Shahrood River using water physico-chemical variables and macroinvertebrates data sets obtained over a period of 12 months between February 2012 and February 2013 at 8 sampling sites. Biotic indices i.e. FBI and BMWP based on macroinvertebrates and physico-chemical indices (MPI, HPI and NSF-WQI) were employed to evaluate the water quality status in connection with natural- and human-induced pressures. Based on physico-chemical indices, water quality was categorized as low polluted level and it is suitable for drinking purposes. The water quality based on biotic indices was related to the anthropic activities; a clear deterioration of the water quality was observed from upstream to downstream sites. The water quality along the river changed from very good (class I; reference sites) to good (class II; midstream sites) and turned into moderate (class III) and poor (class IV) quality (downstream sites). These findings indicate that biotic indices are more powerful indicators in assessing water quality than physico-chemical indices. Allocapnia, Glossosoma and Hesperoperla were exclusively related to least disturbed sites, and Naididae, Orthocladiinae and Ecdyonurus were found in sites showing notable degradation. Our results recommended that the use of macroinvertebrates could be employed as a cost-effective tool for biomonitoring and controlling of polluted riverine ecosystems in the Middle East. Finally, the results from this study may be useful not only for developing countries, but also for any organization struggling to use macroinvertebrate based indices with restricted financial resources and knowledge.

The purpose of this application, under Articles 75.6 and 81 of the Code, is to conserve the prevailing usage of the generic name Ecdyonurus Eaton, 1868 and the specific name Ecdyonurus venosus (Fabricius, 1775), by setting aside the existing name-bearing type of Ecdyonurus venosus and designating a neotype. The existing name-bearing type of E. venosus, type species of Ecdyonurus Eaton, 1868, is not in accord with the current use of the name Ecdyonurus venosus sensu auct.

The life histories and the secondary production of 9 mayflies (Ephemeroptera) species were studied at two sites in a submountain stream (West Carpathians, Slovakia). The disturbed site has a deforested and converted to meadows and pastures catchment and the undisturbed one is a well-preserved submountain stream with 60% of the catchment covered by spruce forests. Differences in the forest cover and in the thermal regime of both streams were reflected in the structural as well as the functional measures. At the undisturbed site, the total secondary production of mayfly community was more than two times higher (3568 mg DW m–2 y–1) than at the disturbed site (1446 mg DW m–2 y–1). Species could be divided according to their affinity to particular disturbance level. Ecdyonurus picteti, Rhithrogena carpatoalpina, Habrophlebia lauta and Habroleptoides confusa appeared to prefer undisturbed conditions. On the contrary, Ecdyonurus aurantiacus and Habrophlebia fusca occurred only at the disturbed site. The dominant species Baetis rhodani and Electrogena samalorum did not show any clear preference regarding the catchment disturbance. However, nymphs of Electrogena samalorum seem to be more successful at the disturbed site, where they reached bigger body sizes (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Fine sediment in streams and rivers is one of the most globally widespread of all freshwater pollutants. However, the ecological implications are still poorly quantified, and field experiments to assess likely functional and structural effects are scarce. We assessed the response of stream invertebrates to fine sediment (i.e. inert sand) added to trays (n = 65) containing otherwise natural substrata over a three-week period in three replicate streams in the Usk catchment, Wales. Sediment addition to 0.6–18 kg m−2 affected both the structure and functional composition of invertebrate assemblages while also reducing overall abundance and in some common species (Baetis rhodani, Ecdyonurus sp. and Leuctra geniculata). Sediment also reduced richness and overall trait diversity (TD), while different life-history traits were either favoured (polivoltinism, tegumental respiration and burrowing behaviour) or disfavoured (swimmers, attached taxa, gill respiration). Moreover, sediments appeared to promote a nested subset pattern in species composition, with generalists favoured at the expense of specialists either through exclusion or impaired colonization. Effects were due largely to the loss of five taxa that contributed to the significant nestedness across the sand gradient: B. rhodani, Ecdyonurus sp., Leuctra geniculata, Simuliidae and Ephemerella ignita. This short-term experiment supports recent surveys in indicating how sedimentation can change the structural and functional composition of stream invertebrate assemblages even at low to moderate rates of deposition. In revealing direct effects on trait adversity, trait representation and nestedness, the data are also consistent with survey data in indicating that sediments have potentially important ramifications for conservation by removing organisms systematically according to life-history features.

Summary 1. The hydraulic and geomorphic characteristics of stream patches are often associated with distinctive assemblages or densities of stream invertebrates, and it is routinely presumed that these patterns reflect primarily species-specific habitat requirements. An alternative hypothesis is that such patterns may be influenced by constraints on movement, such as the results of departure and settlement processes. We describe a manipulative experiment that examined how the hydraulic environments created by topographic bedforms influenced the drift behaviour and potential settlement sites for two species of mayfly (Baetis rhodani and Ecdyonurus torrentis). These species are common in the drift and often co-occur in streams, but differ in their small-scale distribution patterns, body shape and movement behaviour. 2. Flume experiments were carried out to determine how the hydraulic environments conditioned by a step bedform influence the behaviour of mayflies in the drift (swimming, posturing, tumbling), and the consequences of those behaviours (drift distance and time), compared to drift over a plane bed. The ramped step in the flume mimicked step bedforms that are common in coarse-grained, high-gradient streams. In contrast to the plane bed, a zone of recirculating flow was created downstream of the step, above which flow was faster and more turbulent. Uniform flows are used in most flume studies of drift; our approach is novel in recreating a complex hydraulic environment characteristic of stream channels. 3. Both species had some behavioural control over drift, and drift distances and times were shorter for live larvae than for dead larvae over the plane bed. The step had no impact on drift time or distance for live Baetis, but dead larvae were trapped in the flow separation eddy and drift time increased accordingly. Some Ecdyonurus also became trapped in the eddy, but live larvae drifted farther than dead larvae, and farther over the step than the plane bed. 4. Whilst in the drift, larvae altered their behaviour according to the ambient hydraulic environment, but in a species-specific manner. Over the plane bed, Baetis had occasional swimming bursts, but primarily postured (maintained a stable body orientation), whereas Ecdyonurus spent roughly equal time posturing and swimming. In the more turbulent flows generated by the step, Baetis spent proportionately more time swimming, whereas Ecdyonurus spent more time posturing and often tumbling as body orientation became unstable. 5. In a high-gradient stream, Baetis was more abundant close to steps than in plane bed patches with less complex flow, whereas the opposite pattern held for Ecdyonurus. Thus, the small-scale distribution patterns of these species within streams correspond to their drift behaviours and ability to access various hydraulic patch types in our flume. These results are consistent with the hypothesis that constraints on movement and settlement may be important driver of distribution patterns within streams.

We manipulated hydraulic conditions over patches of sands and fine gravels in an upland, gravel-bed river using a portable flume and assessed changes in the drift rates of three mayflies (Baetis, Ecdyonurus and Caenis). On average, manipulations doubled water velocity in experimental locations and resulted in shear stresses that exceeded the critical threshold for entrainment of patch sediments. Bedload transport rates were used as an indicator of bed disturbance during the manipulations. Partial Least Squares Regression (PLSR) indicated that between 59 and 81% of the variation in the drift rates of the three taxa could be accounted for by the combined effects of shear stress and bed disturbance. Shear stress was more important than bed disturbance as a cause of drift in Ecdyonurus and Baetis, while for Caenis the two variables were equally important. Drift rates fell markedly (10-fold) after only 5 mins of increased shear stress and bed disturbance. The experiments indicate that (a) dramatic loss of mayflies can occur rapidly from patches of fine and relatively unstable sediment during periods of increased discharge and (b) for some taxa, losses may cause a depletion of the benthic source-pool and hence result in the exhaustion of supply. Copyright © 2009 John Wiley & Sons, Ltd.

Summary 1. The delivery, entrainment and deposition of inert fine sediments are among the most significant contributors to stream and river impairment worldwide. Associated ecological effects have been observed frequently, but specific experiments to identify sensitivity and avoidance behaviour in stream organisms are few, particularly in headwaters. 2. In a field-experiment, we added fine sand at low levels (c. 4–5 kg m−2) to 10 m reaches of two replicate headwater streams in the Usk catchment (Wales, U.K.) over two periods (autumn and summer). Upstream reaches were used as control in a classic before-after-control-impact design. Invertebrate drift and benthic composition were measured for 2 days before and 1 day after sediment impact. 3. Sediment addition significantly increased overall drift density (by 45%) and propensity (by 200%), with effects largest on the night following addition rather than immediately (i.e. within 9 h). The mayflies Baetis rhodani, B. muticus and Ecdyonurus spp., simuliid and chironomid dipterans, and helodid beetles were the strongest contributors. 4. There were no marked effects on benthic composition, but density declined in treated reaches by 30–60%, particularly in B. rhodani, Ecdyonurus spp. and Leuctra hippopus + L. moselyi. 5. All effects were consistent between both seasons and streams. 6. These data show how even low-level, short-term, increases in fine sediment loading to upland, stony streams can reduce overall benthic density through increased drift. We suggest that the likely cause of the delayed drift response was a change in habitat quality which prompted avoidance behaviour. Longer-term experiments are required to assess whether these effects reduce fitness or explain the losses of some types of organisms observed recently in sediment-impaired reaches of this and other catchments.

The neotype of Ecdyonurus nigrescens (Klapalek, 1908) has been designated, basing on male imago reared from larva, collected in the Chornohora Range (the Ukrainian Carpathians). The male imago of this species is redescribed; male subimago, female imago and subimago, larvae and the structure of egg chorion are described and illustrated for the first time. Critical diagnostic characters distinguishing this species from other representatives of the Ecdyonurus helveticus species-group are discussed. The type locality is defined in accordance with the Article 76.3 and Recommendation 76A of ICZN as follows Ukraine: Zakarpattia Region, Carpathian Biosphere Reserve, the Chornohora Range, Polonyna Brebeneska district, mountain valley between SW slope of Gutyn Tomnatek Mt. and NW slope of Brebeneskul Mt., upper section of the Brebeneskul stream (left-bank tributary of the Hoverla stream, Tysa river-basin), 1450 m. a.s.l. The data on the original syntype series and type locality are discussed in detail. Al...

The duration and timing of egg development is crucial to the survival of invertebrates in glacier-fed rivers. The relationship between egg development and environmental conditions was investigated in 3 mayfly species, Baetis alpinus, Rhithrogena nivata, and Ecdyonurus picteti, in an alpine glacier-fed alluvial system. Field-collected eggs were reared in the laboratory at temperatures representing field conditions (1.5, 3, 5, and 7°C). Egg-incubation period and degree-days demand (DD) were determined, and hatching in the field was predicted from field temperature records. Egg development and temperature relationships for B. alpinus and R. nivata were documented for the first time. Baetis alpinus had synchronous egg development and high hatching success. Faster development in warmer habitats enabled it to hatch during favorable autumnal conditions. Ecdyonurus picteti had a very long development time that decreased slightly at higher temperatures. However, the variation in DD was considerable. The ob...

Summary 1. Although mean pH is increasing in acidified streams throughout Europe, benthic invertebrates are recovering only slowly. One developing hypothesis is that acid episodes continue to restrict recolonisation and recovery. Here, we used intra-annual sampling in replicate circumneutral, acid and episodic streams at the Llyn Brianne experimental catchments to assess possible mayfly exposure to episodic effects quantified from a risk index based on long-term discharge. Episodic effects were then tested using short-term transplantations of animals in enclosures. 2. No mayflies occurred in acid streams while Baetis rhodani occurred in episodic streams but declined to zero density following low pH in autumn. Ephemerella ignita, Baetis vernus, B. muticus, Rhithrogena semicolorata, Ecdyonurus spp. and Heptagenia lateralis occurred only in the circumneutral streams. The first two species were present as nymphs only during July and August so that episodic exposure risk was minimal, but the remaining species occurred as nymphs in all months. 3. Baetis rhodani transplanted during base-flow (September 2003) and high-flow (April 2004) were exposed to either; (i) continual (chronic) exposure in the acid streams over 16 days or (ii) repeated short-term (episodic) exposure to acid conditions for 2 × 4 day periods interspersed with 4-day recovery periods in the circumneutral streams. Baetis survival in the circumneutral streams (always pH > 5.7) remained high during both low- and high-flow. By comparison, mortality increased (P 80%) > episodic (>40%) >circumneutral (

Invertebrate diversity patterns were examined in six rheocrene springs and six nearby, runoff-fed streams in Cantabria, Northern Spain. Periphyton biomass, organic matter and biomass of moss were always higher in springs than streams. Species densities (number of species/area) and rarified species richness (number of species/number of individuals) were lower and invertebrate densities greater in spring habitats. Of 22 variables chlorophyll-a was the best predictor of species richness, whereas total organic matter was the best predictor of invertebrate density, although neither relationship was strong. Spring habitats had invertebrate communities dominated by non-insect taxa (e. g., Echinogammarus, and Hydrobiidae and Neritidae snails), in contrast to the insect dominated communities in runoff-fed streams (e. g., Baetis, Ecdyonurus, Elmis, Prosimulium, Scirtes and Chironomidae). Echinogammarus had the highest densities in springs; an order of magnitude greater than any other taxa. The effects of biotic processes, such as predation from Echinogammarus on community structure may be more marked in springs because predated individuals cannot be as readily replaced by drifting animals from upstream reaches. The reduced diversity in springs compared to streams could be a result of several factors including increased predation from animals such as Echinogammarus or the unusually constant thermal characteristics.

As a result of studies of material of Ecdyonurus from Spain, nymphs and adults of two new species, E. baeticus sp. n. and E. olgae sp. n., are described. Three species described by Navas must be considered as nomina dubia (E. diversus Navas, 1923, E. excelsus Navas, 1927 and E. fluminum var. speciosus Navas, 1915). Variability in adults of E. venosus is figured and discussed.

The ultrastructure of the globular papillae located along the inner side of the forceps of the two flying stages, imago and subimago, of male mayflies belonging to Ecdyonurus venosus (F.) is described. The external shape of the globular papillae varies with their position on the forceps’ segments and the stage. In longitudinal section, the globular papillae of the imago and subimago have a single dendrite ending in a tubular body, a feature consistent with their function as mechanosensory sensilla. During mating, the mechanical pressure on the forceps may be sensed by the cuticular surface of the papillae and transmitted to the tubular body. In the subimago, the globular papillae have a pointed apex and are less numerous. Another kind of sensillum, hairs having the typical organization of mechanoreceptive bristles, are scattered on the forceps of both imago and subimago.

Intra- and interspecific niche overlap for two mayfly species with similar life cycle timing, Rhithrogena semicolorata and Ecdyonurus sp. gr. venosus, were investigated. The nymphs were classified into 5 classes according to size and spatial overlaps are measured along a substratum roughness gradient. Substratum roughness selection was investigated by defining utilisation curves, optimum and tolerance values of the nymphs in relation to larval growth. Differences between species and size classes within each species were observed. Ecdyonurus sp. gr. venosus dominated on rough substrates, whereas R. semicolorata was most abundant on smooth substrates. An intermediate value of total interspecific substratum roughness overlap (0.49) was found. Higher intraspecific than interspecific overlap values suggested a spatial niche segregation between the two species. The results suggested that the spatial niches measured, were closer to the `fundamental niches' than could be expected if competition was acting on the two studied populations.

The ability of microcystins (MCs), the main group of cyanotoxins, to affect the physiological processes and tissues of insects has received little attention. Fresh water dissolved MCs represent one of the main sources of cyanotoxins. In the experiment described herein, captured wild mayfly E. angelieri Thomas, 1968 larvae were exposed to 5 ppb of two distinct microcystins, MC-LR and MC-LW, in separate assays. Evidence of induced mortality, MCs bioaccumulation and severe histological damage affecting fat body and alterations in the tracheal system were evident. Our results reveal the acute sensitivity of the mayfly E. angelieri to MCS, which may serve as early indicators or cyanotoxins production and the quality of freshwater streams., This work was funded by Ministerio de Educación y Ciencia del Gobierno de España means the research project RETROCALMED (CGL-2006-11339/161 BOS) and GRACCIE (CSD2007-00067/Programa Consolider).

Total lipid content of freshwater macroinvertebrates from different orders and with different life histories was investigated. Lipids were determined as HIP-extractable lipids (HIP = hexane: isopropanol). Macroinvertebrate taxa were assigned to different feeding guilds, and life histories for insect taxa: Gammarus pulex (Amphipoda/shredder), Ecdyonurus sp. (Ephemeroptera/hemimetabolous/grazer), Perla sp. (Plecoptera/hemimetabolous/predator), Hydrophsyche sp. (Trichoptera/holometabolous/ suspension feeder), and Atherix ibis (Diptera/holometabolous/predator). Animals were collected in two streams in Switzerland bimonthly between October 1994 and October 1995. Lipids, expressed as percent dry mass (dm), were estimated using two techniques: (1) as total lipid content, determined by the sulphophosphovanilline method; (2) as total fatty acids (= sum of fatty acids), determined by gas chromatography. The annual average total lipid contents for G. pulex, Ecdyonurus and Perla were 6.1 %, 7.0 % and 6.0 % dm, respectively. The two holometabolous insects, Hydropsyche (8.0 %) and A. ibis (9.3 %), exhibited the highest total lipid content. Total fatty acids as a percentage of total lipids was lowest in G. pulex (62 %), followed by Ecdyonurus (64 %), Perla (73 %), Hydropsyche (80 %), and A. ibis (85 %), The dry mass of holometabolous insects (Hydropsyche and A. ibis) related positively with lipids, indicating an increase in body concentration during larval growth. No or only a weak positive relationship with dry mass was found for the hemimetabolous Ecdyonurus and Perla. Gammarus pulex, in contrast, showed a negative relationship. Male G. pulex attained a larger size and contained less fat than juveniles and adult females. Seasonal changes in total lipid content were recognisable only as weak trends because of high variation among individuals. Gammarus pulex had higher total lipid content in spring, while Perla and Hydropsyche maxima occurred in summer. No seasonal trends in total lipid content could be observed in Ecdyonurus and A. ibis.

The effects of herbivory and light on epilithic periphyton from Minor Creek (2,200 m above sea level), a Swiss alpine stream, were examined by manipulating light intensity and the densities of two abundant grazers in streamside channels. We hypothesized that the high light intensities in Minor Creek (exceeding 2,000 mmol m 22 s 21 on the stream bed) would cause photoinhibiton and thus regulate algal composition and biomass accrual. After 18 d, full sunlight had negative effects on all measures of periphytic abundance in streamside channels. A five-level light gradient experiment in Minor Creek corroborated these findings: full sunlight suppressed periphytic accumulation. To test the interactive effects of grazing and light, we used two herbivorous insects with distinctly different feeding structures. Ecdyonurus sp. (Heptageniidae) possesses brushing mouthparts; Drusus lateralis (Limnephilidae) has scraping mandibles. In accordance with a conceptual model that predicts algal physiognomy and herbivore feeding mode regulate algal susceptibility to grazing, we hypothesized that Ecdyonurus would primarily reduce physiognomies composing the periphytic overstory (e.g., stalked and filamentous algae), whereas Drusus would have greater access to understory physiognomies (e.g., prostrate forms). In addition, we hypothesized that tall physiognomies would be less abundant under full sunlight due to the exposure of the periphytic mat to photoinhibiting irradiance. Thus, we expected Ecdyonurus to have a smaller effect on periphyton at high light intensities. Light in channels did not directly modify grazing effects; however, the data suggest light intensity altered periphytic susceptibility to grazing. Channels receiving full sunlight had less periphyton, yet grazer weights did not differ between light treatments despite the fact that weight gain for each grazer was negatively correlated with conspecific biomass, implicating competition for limited periphytic food. Algal responses were most pronounced under grazing by Ecdyonurus, which was associated with decreases in the abundance of six of the seven algal physiognomies. Contrary to model predictions, Ecdyonurus reduced low-lying as well as overstory physiognomies. Drusus, by contrast, was associated with reductions in only four physiognomies. Results from this study suggest that understanding periphytic community responses to grazing will require more sophisticated models of periphytic structure.

The anatomy of the gut and the fine structure of the foregut and midgut of the nymphal, subimaginal and imaginal stages of C. dipterum are described. A new description is given of the nymphal foregut‐midgut junction and its relationship to peritrophic membrane formation. Although the mouthparts are lost at the end of the nymphal stage, and the structure of the gut undergoes extensive and often degenerative changes both during and after each of the moults to subimago and imago, the structure of the subimaginal and imaginal gut nevertheless suggests that the gut is still performing some active function during both adult stages. This is also suggested by the persistence in subimagos and imagos of rhythmical waves of midgut contraction, an energetically expensive process for an animal which has ceased to feed. Although a very occasional uptake of fluids by imagos has been observed, it has been shown, by the use of a fluorescent stain, that fluid which disappears from the mouth region is most frequently being spread as a very thin film over the body surface rather than entering the gut. Frequency of midgut contraction has been measured in resting subimagos and imagos of C. dipterum and C. simile, in imagos of C. dipterum during and after being held in a dry atmosphere, in ovipositing imagos of C. dipterum, in ejaculating male imagos of C. simile and Ecdyonurus venosus, and after successive bouts of flying by E. venosus. Previous claims that the midgut contractions either control or affect oviposition and sperm ejaculation have not been substantiated. The possibility of a key relationship between the midgut contractions and the need for rapid transport of metabolities is discussed.

Both in foraging groups and in a sequential prey encounter context, learning had a visible eVect on the pattern of selection for three live prey types (Ecdyonurus larvae, Hydropsyche larvae, and Gammarus) by juvenile Atlantic salmon Salmo salar. Compared to wild-caught fish, naive, hatchery-reared fish that had not been exposed to natural prey ate Hydropsyche larvae in a remarkably low proportion, and consumed a higher proportion of Gammarus. Ecdyonurus experienced a high and rather steady predation rate across the experience gradient, but after a short period of experience with live prey the consumption rate for Hydropsyche increased drastically, and that of Gammarus decreased, matching the selection pattern exhibited by wild fish. Individual fish oVered prey in a sequential encounter context increased consumption rates of all the prey types as they gained experience, but the improvement was higher for the prey that were less consumed initially. Fish became more selective as they approached satiation, conforming to the prediction of optimal foraging theory that higher predator’s energy requirements, as well as low food availability, result in reduced selectivity. The results also suggest that fish from distinct populations can diVer in the degree of diet selectivity according to their energetic requirements for growth. The fast learning response of Atlantic salmon parr towards novel prey probably allows fish to maintain a high foraging eYciency when faced with frequent changes in the availability of diVerent prey types. ? 1998 The Fisheries Society of the British Isles

1. A factorial experiment was conducted in artificial outdoor streams to quantify the effects of irradiance (two levels) and two mayfly grazers (four densities of each) on periphytic community structure. The mayflies were Ecdyonurus venosus (Heptageniidae), a grazer using brushing mouthparts, and Baetis spp. (Baetidae) a grazer which uses mandibles and maxilla to scrape and gather periphyton. The experiment ran for 16 days. 2. Grazer densities in channels approximated those existing in a shoreline habitat in the River Sihl, Switzerland. Light treatments were natural (daily mean = 810 μmol m–2 s–1) and shaded (daily mean = 286 μmol m–2 s–1). 3. Higher irradiance increased total algal abundance by a factor of 4. Algae most affected were prostrate/motile and erect diatoms, filamentous chlorophytes and Hydrurus foetidus. 4. Both species of mayfly reduced periphytic and algal biomass. Mayfly–mayfly interactions, however, were associated with statistical increases in algal biovolume and chlorophyll-a content, indicating that the two grazers may have interfered with one another as their densities increased. The mayfly–mayfly interaction did not influence periphytic ash-free dry mass (AFDM). Light modified the influence of Ecdyonurus such that this mayfly produced greater reductions in algal biovolume under high irradiance. 5. Despite efforts to exclude other grazers, chironomids colonized experimental channels. Chironomid biomass was approximately eight times less than mayflies across treatments and was positively correlated with all measures of periphytic abundance, suggesting that these grazers were responding to periphyton rather than controlling it. Chironomids were also associated with an increase in the abundance of diatoms having a prostrate/motile physiognomy. The only physiognomy to show a negative relationship with chironomid biomass was the thallus type, a form which comprised less than 1% of the algal biovolume across channels. 6. Ecdyonurus and Baetis had distinct influences on algal physiognomy. Ecdyonurus, for example, reduced adnate, stalked and Achnanthes-type physiognomies, but was associated with a significant increase in the abundance of filamentous chlorophytes (primarily Ulothrix sp.). Baetis reduced erect, Achnanthes-type and thallus physiognomies. Neither mayfly influenced the abundance of prostrate/motile diatoms; a physiognomy that comprised 21% of the algae in channels. 7. Light and mayfly interactions affected algal community structure. The interaction of Ecdyonurus with light had a negative effect on erect diatoms, filamentous chlorophytes and the thallus physiognomy, but a positive effect on stalked and Achnanthes-type physiognomies. Baetis interacting with light had a positive effect on adnate diatoms. 8. Although both mayfly taxa influenced periphytic community structure, physiognomy was not a good predictor of algal susceptibility to grazing. The type of substratum to which an alga is attached (detritus or algal filaments vs hard surfaces) and location within the periphytic matrix may be better indicators of vulnerability to grazing than physiognomy.

Ecdyonurus dispar gratificus ssp. nov. Figures 1–55 Ecdyonurus sp. nov.: Martynov 2012: 132; Martynov 2013: 15–16, fig. 5 Description. Male imago (main part of adults were reared from larvae) (Figs. 1, 4, 6, 9– 13). Size: body length 9.7 – 11.0 mm, forewing length 10.5–11.4 mm, cerci length 20.0– 24.5 mm (approximately 1.9–2.2 times longer than body). General color of body pale, yellowish brown to light brown (Fig. 1). Head light brown to brown, with paler (dirty yellow to light brown) clypeal part. No stripes or bands on the head. Eyes divided by a narrow gap, narrower than central ocellus; unicolorous grayish-blue to grayish-black, sometimes with one whitish strip laterally. Ocelli black at the base, whitish apically. Antennae light brown, paler basally (Figs. 1, 6). Prothorax dirty brown, paler centrally (Fig. 1). Mesothorax light brown to brown dorsally; diffuse brownish spot around anterolateral scutal suture. Prelateroscutum and posterior arc of prealar bridge with elongated dark brown spots. Scutellum dark brown. Metathorax brown to dark brown. Laterally thorax pale; mesothorax yellowish-brown, with brown to black spots on katepimeron and katepisternum; ventrally intensively brown. Forelegs generally darker than middle and hind ones (Fig. 1). Forefemora brown proximally, distinctly darker distally (approximately 1 / 2 to 2 / 3 of femora length dark brown). Foretibia and tarsi darker than distal part of femur or slightly paler. Middle and hind legs yellow to yellowish-brown; tibia darker proximally; tarsal segment V darker than other ones. All tarsal claws brown. Wings hyaline, transparent, with yellowish-brown to brown venation; no dark maculation around transversal veins; costal and subcostal field distally yellowish-milk colored in pterostigmatic area; pterostigma with several, mainly simple, cross veins (only 3–4 transversal veins are forked). Wings with typical Heptageniidae venation. Abdominal terga yellow to yellowish-brown; tergum I unicolorous brown, distinctly darker than others; terga II–VIII with broad diffuse brownish spot centrally, pair of small elongated pale spots situated centrally (passing occasionally on pale tine strokes, at least on terga II–VII); tergum IX unicolorous brown; tergum X unicolorous yellowish-brown. Terga II–VIII laterally yellowish-brown, with distinct brown oblique stripes connected dorsally in posterior margin of segment (Fig. 4). Sterna yellowish to dirty-yellowish, with two unclear brownish spots. Reddish to violet nerve ganglia visible on the sterna II–VIII. Cerci dark brown to yellow, distinctly paler apically. Joints of segments blackish. Genitalia. Styliger yellowish with distinctly brown forceps, with two small, not curved, symmetrical and rounded protuberances near forceps segment I; segment II with small hump at inner margin basally (Figs. 9–10). Penis lobes yellowish-brown, moderately expanded, not stretched laterally, with rounded outline distally, broadly trapezoidal. Basal sclerite massive, well separated from lateral sclerite with 1–3 small teeth (Figs. 12 a). Lateral sclerite large, tapered proximally; the widest part of lateral sclerite situated at its distal end; the tip of lateral sclerite distinctly broad. Apical sclerite remarkably wide, straight; the tip distinctly projecting above the lobes; inner margin covered with small spines (Figs. 11–13). Titilators brown, wide. Female imago (Figs. 2 –3, 5, 7–8). Size: body length 9.7–12.4 mm, forewing length 10.6–13.5 mm, cerci length 14.8–21.8 mm (approximately 1.4–1.7 times longer than body). Head yellowish-brown with reddish maculation; eyes and basal part of ocelli unicolorous grayish-black (Fig. 7). Antennae yellow to brown, paler basally. Thorax dorsally and ventrally brown to dark brown, with spots situated similar to those in male imago. Lateral portions of thorax yellow to brown (Figs. 2, 7). Legs slightly more robust than in male imago. Forelegs brown to dark brown, distinctly darker than middle and hind ones. Middle and hind legs yellowish-brown; femora darker than tibia and tarsi. Wings hyaline, transparent, with well visible brown venation. Costal and subcostal field distally milky colored, with numerous cross veins in pterostigmatic area. Color pattern of abdomen similar to those in male imago (Figs. 3, 5), occasionally more distinct. Blackish neural ganglia visible on sterna I–VII. Abdominal terga yellowish-brown, with unclear reddish maculation. Subgenital and subanal plates as in Fig. 8; subgenital plate widely rounded, occasionally reaching articulation of segment IX; subanal plate distinctly bent, with smoothly rounded outline distally. Cerci dark brown basally (at least of 1 / 3 of the length), yellowish-brown to yellow distally. Male subimago (Figs. 14–15). Size: body length 9.9–10.4 mm, forewing length 10.5 –11.0 mm, cerci length 12.1–13.6 mm (approximately 1.2–1.3 times longer than body). Head yellow to yellowish-brown, with grayish maculation. Eyes grayish-black apically; two distinct blackish stripes laterally, one of them at its base (Fig. 14). Ocelli as in male imago. Antennae grayish-brown, paler basally. Prothorax yellowish-gray to brown, darker laterally. Mesothorax dorsally pale, yellow to yellowish-brown (especially in central part). Spots arrangement the same than in male imago. Lateral portions of mesothorax yellowish, with darker suturae. Metathorax yellowish-brown (Fig. 14). Ventral side of thorax yellowish-brown to brown. Forelegs darker than middle and hind ones. Forefemora yellowish-gray to yellow proximally; intensively brown distally. Middle and hind legs uniformly yellowish-gray to yellow, tarsi occasionally darker. Wings dull yellowish-gray to brownish, relatively transparent. Venation yellowish-gray to brown; in some specimens, transversal veins darker than longitudinal, brown to black. Color pattern of abdominal terga similar to those in male imago, occasionally slightly paler. Lateral part of terga I–VIII with distinct brown stripes connected distally in posterior part of segments (Fig. 15). Sterna slightly darker than terga. Styliger plate yellowish-gray to yellow, forceps and protuberances of styliger plate slightly or distinctly darker, yellowish-brown to dark brown. The typical shape of penis already well apparent. Cerci brown to dark brown, distinctly paler apically. Female subimago (Fig. 16). Size: body length 9.8–12.6 mm, forewing length 10.5–14.5 mm, cerci length 10.1– 12.1 mm (approximately 1.1–1.2 times longer than body). Head and antennae yellow to yellowish-brown. Dorsal side of prothorax yellow, whitish posteromedially. Mesothorax pale, whitish-yellow to yellow, with brownish spots around suturae. Metathorax yellowish-brown. Legs of the same arrangement and color pattern as in male subimago. Wings uniformly dull yellowish-gray to brownish, relatively transparent, with brown to dark brown venation. Abdominal color pattern the same as in male subimago. Cerci dark brown (Fig. 16). Mature larva (Figs. 17–51). Size: body length (slightly differs between males and females): in male 8.8–11.8 mm; cerci length 8.0– 9.5 mm, paracercus length 8.0– 9.1 mm; in female 10.0– 14.4 mm, cerci length 9.0– 12.3 mm, paracercus length 8.0– 10.5 mm. General body color yellowish-brown to brown (Figs. 17–20). Abdominal segments of mature larvae with well visible dark pattern on lateral sides of terga, similar to adults (Fig. 21). Head yellowish-brown to brown, with apparent light (yellow) pattern consisting of: two central spots near fore margin; one central and two elongated transversally spots near antennal bases; lateral margins with two further spots near eyes; one central and two lateral spots near posterior margin. Head rectangular with the widest part at the level of the eyes (Fig. 19). Antennae yellow to light brown. Mouthparts: Labrum not wide, only slightly stretched laterally; one row of 6–9 median bristles dorsally typical of the subgenus Ecdyonurus (cf. Belfiore & Buffagni 1994) (Figs. 31–32). Hypopharynx without specific features, generally with long hair on the outer margin and distal part, typical of the subgenus Ecdyonurus. Mandibles (n = 20) with 9–11 prosthecal bristles. Maxillae (n = 20) (characters listed by Haybach 1999): number of comb-shaped bristles (N_CBS) = 13–18 (mainly 15−18) (+ 1–3 pointed bristles); number of teeth on 5 th comb-shaped bristle (N_TCB 5) = 9–12 (mainly 9–10); number of hairs on dorsal upper side (N_DOR) = 1–11 (mainly 3–5); outer margin of maxillae without hairs (N_OUT) = 0; number of hairs on ventral basal part of maxillae (N_VEN) = 5–17 (mainly 5–8); number of hairs at the base of maxillary palps (N_PLBas) = 9–13; number of hairs at outer base of the first segment of maxillary palps (N_PLH) = 11–16; number of setae on the outer margin of the first segment of maxillary palps (N_PLS) = 33–40; number of setae on the inner side of the first segment of maxillary palps (N_PLP) = 35–75 (mainly 40–60). Labial palps with numerous hairs on the dorsal side of its first segment (N_LPH) = 15–24 (mainly 17–20) arranged in 1–2 (rarely 3) rows. Glossae slightly stretched laterally (Fig. 33). Pronotum yellowish-brown to brown; several pale spots situated centrally and laterally; lateral projection paler (Fig. 19). Pronotum extended laterally and rounded. Lateral projection relatively short, asymmetrical, sometimes slightly curved outwards at the apex (Figs. 42–45). Apex of lateral projection bluntly pointed or pointed; the width/ length ratio of semipronotum to caudal projection (cf. Bauernfeind & Humpesch 2001) is 3.2–3.8. Meso- and metathorax yellowish-brown to darker brown; longitudinal pale (yellowish) lines in middle and lateral sides (Fig. 19). Legs yellowish-brown to brown; yellow pattern dorsally similar to "broken" cross (four lateral spots on a dark field) (Fig. 34). The nymphs' forelegs slightly darker than other ones. Tibiae yellow, with distinct brownish smudge centrally; tarsi yellowish-brown, with light smudge centrally (two brownish rings basally and apically). The length/ width ratio of metafemora is 2.8–3.2. Bristles on dorsal surface of femora of various types (Figs. 35–40): pointed or bluntly pointed apically bristles, with strongly convergent margins (dominant type); bluntly pointed apically bristles, with slowly convergent margins or spatula-like elongated bristles, with sub-parallel margins. Outer margin of femora with row of long slender bristles and regular row of small pointed spines (Fig. 41) (in contrast to E. aurantiacus (Burmeister, 1839), cf. Haybach 1999: 128, fig. 4 f; Haybach & Thomas 2002: 87, fig. 34). Tarsal claw brown, with 2–3 teeth (rarely up to 4–5 teeth) (Figs. 46−49). Abdominal terga yellowish-brown to brown with contrast yellow pattern. Tergum I with broad light spot centrally; terga II and III with two spots centrally, and two spots laterally near posterior margin of segment. The variations of color pattern of the terga IV–X are shown in Figs. 17, 18, 20. The nymphs with distinct hypodermal markings on lateral sides of abdominal terga as in imago (dark oblique stripes) (Fig. 21). Posterior margin of terga with large pointed teeth alternating with small ones (Figs. 50–51). Numerous small submarginal spines arranged in 2–3 rows. Surface of terga with numerous fain hairs. Sterna yellowish-brown: sternum I unicolorous with unclear light spots centrally; sterna II–IV with brown elongated spots laterally near anterior margin of segment; sterna V and VI with color pattern resembling that of the previous segments, but including broader spots laterally, divided towards the posterior margin of segment; sterna VII and VIII with diffuse brown spots laterally along the sides of segment, and one small spot (mainly on sternum VIII) frontally; (in male) sternum IX with dark brown spot frontally, and two spots laterally along the sides of segment (these spots surround the segment); forceps anlagen yellow colored centrally, with broad brown spots near bases of each forceps; (in female) sternum IX unicolorous brown, slightly paler distally. Well visible violet nerve ganglia on the segments II–VII (Figs. 22–23). Gills yellowish to light brown with distinct dark tracheation, sometimes with a conspicuous pigmented zone extending over the central and proximal part. Gill I with a specific shape: distinctly broad and asymmetrical; relatively long with divergent proximally margins in basal part (at least throughout of 1 / 2 – 2 / 3 of gill plate length); apical part broadly rounded; the widest part situated in 2 / 3 to 3 / 4 of gill length (Figs. 24–25). Gill IV distinctly wide and asymmetrical, occasionally outer margin conspicuously convex (Figs. 26–28). Gill VII elongated and asymmetrical, without a tuft of tracheal filaments (Figs. 29–30). Larger specimens have more rounded outline of gills (Figs. 25, 28, 30). Cerci and paracercus yellowish-brown to brown, paler distally. Egg. Measurements: length 160–175 μm; width 135–150 μm. Egg slightly elongated (Fig. 52). Chorionic surface covered by numerous attachment structures (represented by knob-terminated coiled threads – KCTs) and small tubercles, typical of the Ecdyonurus eggs (cf. e.g. Gaino & Rebora 2003; Kłonowska-Olejnik et al. 2007); significant concentrations of relatively large KCTs attachment structures (diameter 4.0– 4.4 μm, distance between them 1.8 –7.0 μm) on the whole surface of the egg. Many small rounded tubercles (0.7–1.1 μm) spaced at a distance of 0.05–0.7 μm, and scattered on the chorionic surface between KCTs attachment structures (Figs. 53–54). The same concentration of KCTs attachment structures on both eggs poles. Three to six micropyles visible in subequatorial area. Sperm guide ovoidal or slightly elongated, 8.0–10.0 μm in length and 5.2 –7.0 μm in width. Micropylar rim absent; margins of micropyles covered by a few sparsely distributed tubercles (Fig. 55). Etymology. The new subspecies is named in honor of Dr. Vladimir V. Martynov, father and first scientific adviser of the first author (name originates from the Latin adjective gratificus, i.e. appreciative). Material examined. Types . HOLOTYPE: male imago, UKRAINE, Donetsk Ridge, Donetsk Region, Artemivs’kyi District, vicinity of Debaltsevo urban settlement, (border of Donetsk and Lugansk Regions), Bulavyna River in the forest, 48 º 18 ’ 55 ’’N 38 º 26 ’07’’E, 22.08. 2011, Martynov A.V. leg. PATARYPES: UKRAINE, 4 larvae (were mounted on slides with Liquide de Faure), Donetsk Ridge, Donetsk Region, Artemivs’kyi District, vicinity of Debaltsevo urban settlement, (border of Donetsk and Lugansk Regions), Bulavyna River in the forest, 48 º 18 ’ 55 ’’N 38 º 26 ’07’’E, 13.07. 2008, Martynov A.V. leg.; 1 larva, ibid, 3.05. 2010, Martynov A.V. leg.; 4 larvae, ibid, 16.05. 2010, Martynov A.V. leg.; 6 larvae (one mounted on slide with Canada balsam), ibid, 30.05. 2010, Martynov A.V. leg.; 24 larvae, ibid, 11.06. 2010, Martynov A.V. leg.; 41 larvae, ibid, 1.07. 2010, Martynov A.V. leg.; 1 female subimago, ibid, 17.07. 2010, Martynov A.V. leg.; 14 larvae, ibid, 18.07. 2010, Martynov A.V. leg.; 19 larvae, ibid, 1.08. 2010, Martynov A.V. leg.; 43 larvae (11 were mounted on slides with Canada balsam), 2 female subimagoes, ibid, 20.08. 2010, Martynov A.V. leg.; 7 larvae, 1 female subimago, ibid, 19.09. 2010, Martynov A.V. leg.; 2 larvae, ibid, 4.06. 2011, Sergeev M.E. leg.; 6 larvae, ibid, 18.06. 2011, Martynov A.V. leg.; 35 larvae, 3 female imagoes, ibid, 8.07. 2011, Martynov A.V. leg.; 36 larvae, 9 female subimagoes, 9 male subimagoes, 20 female imagoes, 10 male imagoes, ibid, 22 – 23.08.2011, Martynov A.V. leg.; 1 larva, ibid, 15 − 16.10.2011, Martynov A.V. leg.; 2 larvaе, Donetsk Ridge, Donetsk Region, Amvrosiiv’kyi District, vicinity of Blahodatne village (2 km N −W from the village), stream in the forest – left tributary of Krynka river, 47 º 53 ’ 41 ’’N 38 º 27 ’00’’E, 20.11. 2011, Martynov A.V. leg.; 6 larvaе, Donetsk Ridge, Lugansk Region, Antratsytivs’kyi District, vicinity of Fashchevka village, stream in the forest, 48 º 15 ’ 34 ’’N 38 º 35 ’ 53 ’’E, 13.07. 2008, Martynov A.V. leg.; 2 larvae (were mounted on slides with Canada balsam), ibid, 1.08. 2010, Martynov A.V. leg.; 1 larva (mounted on slide with Liquide de Faure), Lugansk Region, Antratsytivs’kyi District, vicinity of Bokovo-Platove village, Kripen’ka River in the forest, 48 º08’01’’N 39 º01’ 29 ’’E, 24.10. 2008, Martynov A.V. leg.; 1 larva (mounted on slide with Liquide de Faure) Donetsk Ridge, Luhansk Region, Antratcitivs’kyi District, vicinity of Faschevka village, head of the Mius River in the forest, 48 º 16 ’00’’N 38 º 34 ’ 29 ’’E, 13.07. 2008, Martynov A.V. leg. Further material examined (no types). 2 larvae, Donetsk Ridge, Donetsk Region, Artemivs’kyi District, vicinity of Debaltsevo urban settlement, (border of Donetsk and Lugansk Regions), Bulavyna River in the forest, 48 º 18 ’ 55 ’’N 38 º 26 ’07’’E, 17.04. 2010, Martynov A.V. leg.; 7 larvae, ibid, 2.05. 2010, Martynov A.V. leg.; 38 larvae, ibid, 30.05. 2010, Martynov A.V. leg.; 35 larvae, ibid, 11.06. 2010, Martynov A.V. leg.; 34 larvae, ibid, 1.07. 2010, Martynov A.V. leg.; 53 larvae, ibid, 18.07. 2010, Martynov A.V. leg.; 62 larvae, ibid, 1.08. 2010, Martynov A.V. leg.; 22 larvae, ibid, 20.08. 2010, Martynov A.V. leg.; 1 larva, ibid, 13.03. 2011, Martynov A.V. leg.; 8 larvae, ibid, 29.04. 2011, Martynov A.V. leg.; 10 larvae, ibid, 4.06. 2011, Sergeev M.E. leg.; 1 larva, ibid, 18.06. 2011, Martynov A.V. leg.; 183 larvae, ibid, 8.07. 2011, Martynov A.V. leg.; 12 larvae, ibid, 15 – 16.10.2011, Martynov A.V. leg.; 1 larva, Donetsk Ridge, Donetsk Region, Artemivs’kyi District, vicinity of Debaltsevo urban settlement, (border of Donetsk and Lugansk Regions), stream in the forest – right tributary of Bulavyna River in the forest, 48 º 18 ’ 46 ’’N 38 º 25 ’ 58 ’’E, 8.07. 2011, Martynov A.V. leg.; 1 larva, Donetsk Ridge, Donetsk Region, Amvrosiiv’kyi District, vicinity of Blahodatne village (2 km N −W from the village), stream in the forest – left tributary of Krynka river, 47 º 53 ’ 41 ’’N 38 º 27 ’00’’E, 20.11. 2011, Martynov A.V. leg.; 9 larvaе, Donetsk Ridge, Donetsk Region, Amvrosiiv’kyi District, vicinity of Blahodatne village, Krynka river, 47 º 53 ’ 37 ’’N 38 º 30 ’ 17 ’’E, 18.05. 2011, Sergeev M.E. leg.; 9 larvaе, Donetsk Ridge, Donetsk Region, Shakhtar

Ecdyonurus (Helvetoraeticus) adjaricus sp. nov. Figures 1���41 = Ecdyonurus /fg 2 sp. H 5: Kluge 2004: 176. Types. HOLOTYPE: male imago (dried pinned specimen; right fore and hind wings, forelegs, parts of middle and hind legs, and cerci on slide), GEORGIA, Autonomous Republic of Adjara, Kobuleti District, Kintrishi State Nature Reserve (KSNR), meadow near Zeraboseli farm, middle part of Kintrishi River, approximately 41 �� 43,592 ���N 41 �� 49,096 ���E, 480 m a.s.l., 28.vi. 1974, leg. A. Zaguliaev. PARATYPES: female imago (reared from larva, with larval and subimaginal skins preserved), same locality as holotype, 27���31.vii. 1997, leg. D. Apanaskevich; 3 mature larvae (1 female, 2 males), ibid, 27���31.vii. 1997, leg. D. Apanaskevich; 4 larvae, Autonomous Republic of Adjara, Kobuleti District, 3 km downstream of Zeraboseli farm, border of KSNR near bridge, 41 �� 45,739 ���N 41 �� 58,582 ���E, 325 m a.s.l., 18.viii. 2009, leg. R.J. Godunko, T. Sold��n and P. Sroka; 1 larva, Kobuleti District, Chakhati village (centre), Kintrishi River, 41 �� 48,120 ���N 41 �� 55,545 ���E, 140 m a.s.l., 18.viii. 2009, leg. R.J. Godunko, T. Sold��n and P. Sroka; 1 larva, Kobuleti District, Khala village, Kemerkobis stream (bridge 100 m upstream from mouth), 41 �� 42,226 ���N 41 �� 47,525 ���E, 67 m a.s.l., 18.viii. 2009, leg. P. Sroka; 3 larvae, Kobuleti District, Khala village, Chakvistskhali River (mouth of Kemerkobis stream), 41 �� 42,226 ���N 41 �� 47,455 ���E, 60 m a.s.l., 19.viii. 2009, leg. R.J. Godunko; 14 larvae (6 of them were mounted on slides), Kobuleti District, 3 km upstream at Chakhati village, Kintrishi River, 41 �� 46,266 ���N 41 �� 58,325 ���E, 275, m a.s.l., 31.vii. 2010, leg. R.J. Godunko and N.O. Godunko; 5 larvae, Autonomous Republic of Adjara, Khelvachauri District, Tskhemlara [Tamara���] bridge near Chikuneti village, Machakhlistskali River, 41 �� 30,424 ���N 41 �� 49,215 ���E, 195 m a.s.l., 20.viii. 2009, leg. P. Sroka; 11 larvae, Khelvachauri District, 200 m downstream at Tskhemlara [Tamara���] bridge near Chikuneti village, small stream (left side tributary of Machakhlistskali River), 41 �� 30,345 ��� N 41 49 ��02,42���E, 185 m a.s.l., 20.viii. 2009, leg. R.J. Godunko and P. Sroka. Male imago (dried pinned specimen). Size: body length: 15.5 mm; forewings length: 17.0 mm; cerci lost. General body color distinctly dark, reddish-brown; few whitish spots on lateral sides of mesonotum. Head dirty brown to reddish-brown. Antennae blackish-brown, slightly paler distally. Ocelli dirty yellow apically. Eyes grayish, contiguous dorsally, with relatively narrow dark band basally. Thorax dark brown to reddish-brown, slightly paler ventrally. Forewings hyaline with yellowish area in basal part of wing, in anal and cubital fields, and between C and RA; C and Sc dark brown, other veins brown; pterostigmatic area opaque, dirty yellow, with 6 simple and 7���8 branched veins. Hind wings entirely yellowish; venation brown, darker distally. Forelegs distinctly darker than middle and hind ones, brown to reddish-brown; forefemora only slightly darker than tibiae and tarsi. Middle and hind legs brown; tarsi slightly darker than femora and tibiae. No maculation on femora surface. Abdomen dark brown to reddish-brown, sterna slightly paler. Lateral sides of terga II ���VIII with roundish or triangular spots surrounded with an indistinct light L -shape marking typical for Helvetoraeticus species. Cerci dark brown. Penis lobes yellowish-brown to brown. In dorsal and ventral view outline of penis lobes broadly rounded, not expanded laterally; lobes contiguous nearly over entire length (Fig. 1). Apical sclerite relatively massive and short, slightly curved, only slightly expanded laterally and bluntly pointed at apex; lack of conspicuous denticulation at medio-internal portion; several small spines at external margin near tip of titillators; apex of sclerite not projecting above the lobes; only a slight projection at inner border. Lateral sclerite not broad, relatively straight, with subparallel anterior and posterior margins. Basal sclerite relatively massive, with 2���3 small spines only, without conspicuous teeth. Penis stem without a hump. Titillators brown. Styliger intensively brown, with two distinct, slightly curved protuberances near gonostyli bases; gonostyli slightly darker; segment II without any hump at inner margin basally (Fig. 2). Female imago. Size: body length: 15.0 mm; forewings length: 20.0 mm; cerci length: 13.0 mm. General color of body similar to that in male imago, slightly paler; thoraxal pleurae with whitish blotches. Eyes with relatively narrow dark band basally. Fore and hind wings hyaline and transparent, uncolored; venation brown, darker distally. Legs light brown to brown, forelegs slightly paler. Abdominal pleurae with an indistinct light L - shape pattern. Cerci brown. Subgenital plate relatively wide; posterior margin slightly rounded. Subanal plate bluntly pointed apically. Female subimago. Measurements and body color similar to those in female imago; thorax and abdomen slightly paler. Forewings relatively dark, with well visible pattern formed by transversal grayish bands (zigzag type). Male subimago. Unknown. Mature larva. Size: body length: 12.0���16.0 mm; cerci length: 9.0��� 12.5 mm. General body color yellowish-olive, brownish-olive to brown. Head yellowish-olive to yellowish-brown with apparent light pattern, consisting of three blotches near fore margin of ocelli, and pair of spots near antennal bases; two small blotches near anterior margin of head; further large diffuse light spots situated laterally along posterior margin of head (Figs. 3, 5, 6, 8). Head capsule rounded anteriorly. Antennae with brown scape and pedicel; flagellum yellowish-white. Eyes and ocelli black. Labrum relatively narrow with slightly curved and short lateral lobes; ratio of total labrum width to its width at base 2.3 / 1; 8���11 relatively slender bristles arranged in a single row on ventral side of labrum (Fig. 17), diverging laterally into two irregular rows. Maxillae (n = 12): number of comb-shaped bristles (N_CBS) = 24���27 (mainly 26���27); number of teeth on 5 th comb-shaped bristle (N_TCB 5) = 11���14 (mainly 11���12); number of setae on inner side of first segment of maxillary palps (N_PLP)> 10; number of setae on outer margin of first segment of maxillary palps (N_PLS) = 22���38; number of hairs on dorsal upper side of galea-lacinia (N_DOR)> 15. Glossae stretched laterally, relatively widely spaced; glossae and paraglossae massive (Fig. 16). Superlinguae with pilosity typical for Helvetoraeticus (only few setae at tip). Pronotum yellowish-olive to light brown with several light spots centrally and laterally; lateral projections yellow to yellowish-white (Figs. 5, 6). Pronotum slightly extended laterally. Lateral projection large and long, relatively straight, only slightly asymmetrical, oriented parallel to body axis (Figs. 3, 5, 6, 8, 13, 14), or slightly outwards (Fig. 32); apex of lateral projection bluntly pointed; width/length ratio of semipronotum to caudal portion of projection is 1.95���2.30; length of caudal portion of projection is approximately half of total projection length. Meso- and metanotum yellowish-olive to light brown; mesonotum with longitudinal light lines and spots laterally from median longitudinal suture, interrupted by pale areas near fore and hind margins. Legs yellowish-olive and light brown to brown. Trochanters with 2 (rarely 3) irregular rows of bluntly pointed and slender spatulate bristles (Figs. 24, 25). Femora long and relatively slender; length/width ratio of metafemora is 2.75���3.35 (mean 3.0, �� = 0.21; n = 8); widest part of metafemur at its midlength. Dorsally femora with large yellowish-olive to light brown spots on yellowish to yellowish-white background; uniformly yellowish-white to whitish ventrally (general color pattern of dorsal side of femora as illustrated by Godunko & Kłonowska-Olejnik 2004: 17, fig. 10; 2008: 812, fig. 33). Dense rows of sharply pointed bristles at inner margin of femora (Fig. 19); outer margin of femur with row of long whip-like setae and dense rows of sharply pointed bristles (Figs. 18, 26, 27); same type of sharply pointed bristles at dorsal surface of femora (centrally and distally), occasionally more blunt in proximal part (Figs. 20, 21, 26, 27); a row of short pointed bristles on ventral side of posterior border of femora (Fig. 27). Tibiae yellowish-brown, with well visible darker smudge in centrally; dorsal surface with row of spatulate bristles (Figs. 28, 29). Tarsi brownish, with paler smudge centrally, indistinctly darker apically; sparse row of slender spatulate bristles at dorsal surface (Fig. 30). Claw brown with 2 denticles (Fig. 31). Abdominal terga with pronounced yellowish-brown to dark brown pattern and yellowish background (Figs. 3, 4, 7, 8): tergum I relatively pale, with broad diffuse spot medially and a pair of spots laterally; terga II and III with a pair of spots medially, and a pair of spots laterally; terga IV and V with V- (or U-) shaped spot medially, and a pair of broad spots laterally (occasionally lateral spots fused with central spot at tergum V); tergum VI with U- (or V-) shaped spot medially (consisting of three more or less separated small spots); terga VII and VIII with broad Vshaped spot medially, turning into light strip stretching along posterior margin and lateral sides of segment; tergum IX with oval median spot, occasionally a pair of small spots laterally; tergum X generally unicolorous brown, occasionally with a pair of unclear longitudinal paler strokes medially. Abdominal sterna yellowish-white, distinct neural ganglion in segment VII (occasionally also in segments IV ���VI); brown pattern of sterna mainly absent at segments I ���V (occasionally VI); sterna VII ���IX with pair of triangular brown spots laterally (in male) and with transversal brown stripes (in female); larval protogonostyli darker than abdominal sterna, light brown (Figs. 9���12). Posterior margin of terga with dense row of stout spines pointed apically, alternating with smaller ones (Figs. 15, 22); surface of terga with numerous hairs. Posterolateral extensions of abdominal sterna well developed, distinctly long, sharpened apically and directed outwards at different angles to the body axis (except for expansions of sterna 7���8 directed parallely to the body axis) (Figs. 9���12). Tergalii whitish to yellowish-gray, with distinct dark tracheae; tergalius I tongue-shaped, relatively long, moderately tapered distally, with plate longer than filamentous part (Fig. 33); tergalius IV relatively slender, moderately asymmetrical, only with slightly conspicuously convex outer margin, distal margin not blunt, length/width ratio 2.25���2.60 (mean 2.41, �� = 0.19; n = 8) (Fig. 34); tergalius VII broad and asymmetrical (widest part in 2 / 3 of tergalius length), without a tuft of tracheal filaments (Fig. 35). Caudalii yellowish-brown, paler distally; each segment with sharply pointed bristles alternating with hairs (Fig. 23). Egg. Measurements: length 180���200 ��m; width 130���155 ��m. Egg oval, slightly elongated (Figs. 36, 37). Chorion covered with attachment structures ��� knob-terminated coiled threads (KCTs), numerous small rounded tubercles and delicate granules (granular ground matrix) (Figs. 39, 40). Significant concentration of KCTs attachment structures (diameter 3.6���4.2 ��m) at one egg pole, where distance between them is 0.3���2.4 ��m (Figs. 38, 39); other egg surface with rather sparsely KCTs attachment structures (distance between them 2.0��� 12.5 ��m) (Fig. 40). Small rounded tubercles (1.4 ���2.0 ��m in diameter) are regularly distributed over whole chorion (0.1 ���3.0 ��m distance between them) (Figs. 39, 40). Two to three micropyles (13.3 ���15.0 ��m in length; 8.5���10.2 ��m in width) are visible in subequatorial region; micropylar rim thin, with a few sparsely distributed tubercles (Fig. 41). Etymology. The species is named after Adjara (autonomous republic within Georgia). Affinities. Ecdyonurus adjaricus sp. nov. holds a clearly isolated position within Helvetoraeticus. The shape of the male imago penis lobes is typical for the subgenus; at the same time apical sclerites are expanded only slightly laterally (in contrast to other Helvetoraeticus species with markedly laterally stretched apical sclerites). The larva of E. adjaricus sp. nov. can be recognized within the subgenus by the presence a well developed, relatively long posterolateral expansions of abdominal sterna; such size and shape of expansions is characteristic only for a few species of Ecdyonurus s. str. (Haybach 1999, figs. 2, 11). Additionally, several other characters of the larval mouthparts should be noted, e.g.: the single row of bristles on ventral side of labrum; a relatively small number of setae on the inner side of the first segment of the maxillary palps and the number of comb-shaped bristles on the maxilla (see Haybach 1999: 121, 137, 139). The placement of E. adjaricus sp. nov. within the subgenus Helvetoraeticus can be confirmed by the absence of long and dense setae on the distal portions of the superlinguae of the hypopharynx of larva, and the general shape and structure of male imago genitalia. The new species is very similar to E. krueperi (Stein, 1863) in both the adult and larval stages. These two species can be easily separated from other representatives of Helvetoraeticus by conspicuous wing coloration, especially that of the hind wings: yellowish in E. adjaricus sp. nov.; golden-brown in E. krueperi. At the same time, the hind wings of the new species are colored only in male imago, while they are colored in both sexes of E. krueperi (Puthz 1980: 349; Hefti & Tomka 1988: 332; Bauernfeind & Sold��n 2012: 277). Other differences in male imagoes are the following: (1) penis lobes are broadly rounded and not expanded laterally, with apically touching lobes in E. adjaricus sp. nov. (outline of penis lobes are distinctly triangularly rounded, more or less separated apically in E. krueperi; cf. Puthz 1980: 350, fig. 2; Hefti & Tomka 1988: 331���332, fig. 3; Hefti et al. 1989: 334, 338, fig. 10 d; Bauernfeind & Sold��n 2012: 277, 589, fig. 163); (2) apical sclerite only slightly curved, without conspicuous denticulation at medio-internal portion in E. adjaricus sp. nov. (apical sclerite strongly curved, with conspicuous denticulation medio-internally in E. krueperi; cf. Puthz 1980: 350, figs. 4, 5; Bauernfeind & Sold��n 2012: 277); (3) lateral sclerite not broad, relatively straight, with subparallel anterior and posterior margins, evenly sclerotized throughout its length in E. adjaricus sp. nov. (lateral sclerite almost square distally, broad, visibly sclerotized only in its central and distal part in E. krueperi; cf. Bauernfeind & Sold��n 2012: 277; for this reason some inconsistencies in the descriptions and figure were published by Hefti & Tomka 1988: 331���332, fig. 3 and Hefti et al. 1989: 334). Larvae of E. adjaricus sp. nov. and E. krueperi possess a similar shape of the lateral projection of the pronotum (relatively straight, only slightly asymmetrical, bluntly pointed at the tip, oriented almost parallel to body axis), and similar shape of femoral bristles (sharply pointed in both species). Larva of E. adjaricus sp. nov. can be separated from E. krueperi by the following features: (i) row of bristles on ventral side of labrum medially singular (in contrast to double in E. krueperi); (ii) glossae stretched laterally and relatively widely spaced (in contrast to elongated-quadrangular glossae in E. krueperi; cf. Hefti & Tomka 1988: 330, fig. 1 b; Hefti et al. 1989: 333, 335 [Table 1], fig. 6 b); (iii) pointed bristles on ventral side of posterior border of femora (lack of this type of bristles in E. krueperi; cf. Hefti et al. 1989: 333, 335 [Table 1]); (iv) posterolateral extensions of abdominal sterna well developed and distinctly long (in contrast to relatively short sternal expansions of E. krueperi, typical for all other Helvetoraeticus representatives); (v) shape of tergalius I (tongue-shaped, moderately tapered distally) and tergalius IV (relatively slender, moderately asymmetrical) (in contrast to broadly-shaped tergalius I and distinctly asymmetrical tergalius IV in E. krueperi; cf. Jacob & Braasch 1984: 60, fig. 27; Hefti et al. 1989, 335 [Table 1]). Additional differences between E. adjaricus sp. nov. and E. krueperi are found in the color of thoracic and abdominal segments of adults and larvae, i.e. the new species is generally more darkly colored. Only a few species of Helvetoraeticus (together with E. adjaricus sp. nov.) are characterized by a significant concentration of KCTs attachment structures on one egg pole, namely E. epeorides Demoulin, 1955, E. krueperi, E. picteti (Meyer-D��r, 1864), E. silvaegabretae Sold��n & Godunko, 2006 and E. siveci Jacob & Braasch, 1984 (see summarized data in Bauernfeind & Sold��n 2012). We are confident that the male imago (holotype, not reared from larva) and larvae (as well as reared female imago) described here belong to the same species. This is strongly supported by the fact that all material was collected in the same region (distance between the outermost studied localities is 30���35 km; 2���5 km between localities where holotype and paratypes were collected) and during the same summer period. The male imago body color is similar to that of the female. However the hind wings are colored in male and colorless in female. Distribution and biology. The known distribution of E. adjaricus sp. nov. is restricted to several rivers of south-western spurs of Meskheti [Adjar-Imereti] Range and Shavsheti Range within Georgia. In Meskheti Range all investigated rivers are located on northern slopes; Kintrishi and Chakvistskhali rivers flow directly into the Black Sea. The localities within the Machakhlistskali river-basin (a part of Chorokh [��oruh] river-basin) are situated on south slopes near the Turkey border. All habitats are located in the lowest parts of this area within altitudes 60���480 m a.s.l. There is a high probability that the new species can be found in other tributaries of Chorokh [��oruh] river-basin within Turkey (at least in rivers of Turkish part of Shavsheti Range, as well as rivers within Ka��kar Mountains [Ka��kar Daġları]). Information about distribution of Helvetoraeticus in Turkey have been earlier published by Kazancı (2001: 29, 50) and Tanatmış (2004: 235), as records of Ecdyonurus helveticus Eaton, 1883 from, Published as part of Kluge, Nikita J., Godunko, Roman J. & Apanaskevich, Dmitry A., 2013, Mayflies of the Caucasus Mountains. II. Description of the first representative of the subgenus Helvetoraeticus Bauernfeind & Sold��n, 2012 (Heptageniidae: Ecdyonurus), pp. 51-66 in Zootaxa 3608 (1) on pages 52-65, DOI: 10.11646/zootaxa.3608.1.3, http://zenodo.org/record/283261

The fatty acid compositions of total neutral lipids and total polar lipids from eight species of freshwater insects were determined: stonefly nymphs (Plecoptera), beetle larvae (Coleoptera), Chironomidae (Diptera), water boatmen (Corixidae and Notonecta; Heteroptera) and mayfly nymphs (Ecdyonurus venosus, Caenis, Ephemerella; Ephemeroptera). In addition, the compositions of individual phosphoglycerides were deter- mined for four of the species (Plecoptera, Corixidae, Ecdyonurus venosus and Emphemerella). Saturated and monounsaturated fatty acids together represented up to 85% of the fatty acids of total neutral lipids with 16:0 (18-31%) being the most abundant saturated fatty acid and 16:ln-7 (10-28%), 18:ln-9 (6-12%) and 18: ln- 7 (3-12%) the most abundant monounsaturates. Polyunsaturated fatty acids (PUFA) accounted for between 16% and 33% of the total fatty acids of neutral lipids, with 20:5n-3 (4-12%), 18:3n-3 (3-30%) and 18:2n-6 (1-8%) all being major components. Arachidonic acid, 20:4n-6 (0.4-1.0%) and 22:6n-3 were, respectively, minor and insignificant components of total neutral lipids. PUFA were major fatty acids (34-56% of the total) in total polar lipids and in phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine and phosphati- dylinositol. The major PUFA present were 20:5n-3 (14-27%) and 18:3n-3 (6-23%). The most abundant n- 6 PUFA, especially in phosphoglycerides from Corixidae, was 18:2n-6 (3-11%). Arachidonic acid, 20:4n-6, was present in all phosphoglycerides accounting for 1-4% of the total fatty acids, except in the phosphatidylinosi- tol of Corixidae where it accounted for 12% of the total. 22:6(n-3) was not present in significant amounts in any phosphoglyceride in any species. 18:ln-9 (8-20%) and 18:ln-7 (2-14%) were the most abundant monoun- saturated fatty acids, especially in phosphatidylethanolamine. 16:0 was abundant in phosphatidylcholine (11- 21%), and 18:0 (17-23%) was abundant in phosphatidylserine. The results are discussed in relation to the functions and origins of PUFA in freshwater insects. COMP BIOCHEM PHYSIOL 114B, 161-170, 1996.

Southwestern France consists of 24 departments and covers an area of 128,000 km2. A list of 60 unquestionably valid spe­ cies of mayflies is provided for the region. The study area is the Terra typica of ten of the species : one described by Joly, two by Eaton, and seven by Thomas et al. Five species are endemic to the Pyrenees and are probably restricted to the north slope : Baetis catharus, B. nicolae, Rhithrogena kimminsi, R. strenua, and Habroleptoides berthelemyi. R. germanica, Ecdyonurus macani, and Ephemera vulgata are at risk because their hyporhithron and epipotamon habitats have been endangered by agri­ culture runoff, regulation, and diversion of the streams for irrigation, in particular when the water levels are already very low. For the same reasons, Isonychia ignota, Neoephemera maxima, Brachycercus harisella, and Ephemera glaucops have not been taken for over a century, and Prosopistoma foliaceum for more than 60 years, and all have presumably vanished from the re­ gion.

Feeding experiments were conducted in situ in flow through boxes to determine the vulnerability of different prey types (the mayfly larvae Baetis, Ephemerella and Ecdyonurus spp., the caddisfly larva Hydropsyche spp. and the crustacean Gammarus spp.) to the predaceous water bug Aphelocheirus aestivalis and to estimate the predation impact of Aphelocheirus on prey populations. Experiments with equal densities of mixed prey and experiments where each prey was tested individually revealed that Baetis and Ephemerella were most vulnerable to Aphelocheirus predation: Hydropsyche, Ecdyonurus and Gammarus were little/not preyed upon. The present results suggest that vulnerability of prey depends mainly upon prey mobility and microhabitat overlap between predator and prey and that feeding behaviour of Aphelocheirus resembles more that of megalopterans than of stoneflies. Experiments with different prey densities (120–720 prey m−2) showed that the predation rate of Aphelocheirus increased with increasing prey density. Experiments with different substrates documented that mortality rates of prey decreased with increasing substrate complexity. When substrate conditions were complex mortality rates in the control and in the experimental boxes were the same which suggest little importance of Aphelocheirus predation on mayflies in the study site.

Genetic variation in larvae and imagines of three species of Heptageniidae from central Italy, Ecdyonurus sp. (venosus group), Electrogena grandiae (Belfiore, 1981), and Electrogenn lateralis (Curtis, 1834) was studied by starch-gel electrophoresis. Thirteen enzyme systems were analysed for a total of 20 loci (Aat, Ada, Adk-1, Adk-2, Ck-1, Ck-2, Est-1, Est-2, alpha-Gpdh, Gpi, La-1, La-2, Mdh-1, Mdh-2, Me-1, Me-2, Mpi, Pap, Pgm-1, Pgm-2), 15 of which were expressed in adults and 16 in the larvae. Only 11 loci (Aat, Ada, Est-2, Gpi, La-2, Mdh-1, Me-2, Mpi, Pap, Pgm-1, Pgm-2) were shared by larvae and adults. Observed heterozygosities were always lower than expected values; higher values were observed in larvae than in adults. Fixation indices and genetic distances were higher in the adults; however, the two genera were better discriminated using the larval samples. In conclusion, comparisons using larvae and adults simultaneously should be avoided, and absolute values of genetic identities and genetic distances to assess systematic levels have to be considered with caution, since they can vary from one developmental stage to another.

SUMMARY 1. The spatial niche shifts of the nymphs of two mayfly species (Rhithrogena semicolorata and Ecdyonurus sp, gr. venosus) in relation to their growth were investigated in two lowland springs of northern Italy where they are dominant species. 2. Ordination of the different size classes of the two species revealed a canonical trend related to season and bottom roughness. 3. Larger nymphs of both species colonized rougher substrata. Differences between species in the roughness of areas colonized by small nymphs, which were very numerous, may have been due to competition for space.

Ten species of freshwater invertebrates that are natural food organisms available to Atlantic salmon parr were collected and their lipid composition determined: stonefly nymphs (Plecoptera), beetle larvae (Coleoptera), Chironomidae (Diptera), water boatmen (Corixidae and Notonecta; Heteroptera), mayfly nymphs ( Ecdyonurus venosus, Caenis, Ephemerella ; Ephemeroptera), gammerids (crustaceans), Oligochaeta (anelids). Neutral lipids represented 40–70% and polar lipids 26–55% of total lipids. Triacylglycerol was always more than 35% of total lipids. Phosphatidylcholine (PC) and phosphatidylethanolamine (PE) were the major components of phospholipids. Monoenoic fatty acids and polyunsaturated acids (PUFA) were the most abundant fatty acids in total lipids. Saturated fatty acids comprised only 20–30% of the total fatty acids. PUFAs were principally present as the n −3 series, especially 18:3 n −3 and 20:5 n −3, 22:6 n −3 was present only in small amounts. Fatty acids of the n −6 series were mostly represented by 18:2 n −6 and 20:4 n −6. The invertebrate organisms analysed contained higher levels of 18:2 n −6, 18:3 n −3, 20:4 n −6 and 20:5 n −3 but considerably less 22:6 n −3 than commercial diets used in smolt production. These results suggest that a dietary fatty acid composition more closely resembling the freshwater invertebrates might be beneficial for growth, development and the prevention of pathologies in salmon parr.