The use of comparative larval morphology and drumming behavior in stonefly systematics is discussed. A tentative assignment of plesiobehavioric and apobehavioric states to drumming in Plecoptera is made, based upon the described behavior of 46 North American species, representing 8 families and 25 genera. Experiments are described which show that pairs of Perlinella drymo effectively transmit and receive signals at minimum distances of 8 m through a continuous wooden rod, 5-9 mm in diameter. Communication was achieved for shorter distances of 10-200 cm by male and female P. drymo drumming in manilla paper boxes resting on foam rubber pads. Pairs of P. drymo were unable to communicate at distances of 25 cm on a 4.2 kg rock, nor were Pteronarcella badia (Hagen) at a distance of 25 cm, when male and female were on separate, dried aspen limbs.

A set of 21 ponds was sampled three times for odonate larvae during spring 2002. At the same time 17 environmental variableswere recorded including area, wet phase duration, total nitrogen, total phosphorus, aquatic macrophytes and land use. Atotalof 16 odonate species belonging to Lestidae, Coenagrionidae, Aeshnidae and Libellulidae were recorded, and the total numberof species per pond varied from zero to six. The relationships between species richness, assemblages and environmental variableswere studied by simple and multiple correlation and by Canonical Correspondence Analysis (CCA). The results showed thatpermanent ponds were larger, deeper, had more macrophyte species, had more extensive macrophytes cover and lower concentrationsof nitrogen and phosphorus than temporary ponds. Multiple regression analysis showed that the number of odonate specieswas positively affected firstly by the number of macrophyte species, and then by pond depth. However, pond depth appearedto be interchangeable with several others variables, such as pond area and water duration and negatively correlated withnitrogen concentration, variables which are all linked with the permanent or temporary status of the ponds. CCA analysis indicatedthat odonate species presence was linked with a few environmental variables, showing a tendency of Odonata to avoidponds with higher nitrogen concentrations, with the exception of Lestes barbarus, a species typical of temporary water in centralItaly. At the same time, the majority of species were linked with longer water phase duration and with greater macrophytespecies richness. Acomparison with previous studies, and in particular with those carried out in central Italy, confirmed the positiveinfluence of macrophytes, water duration, and also the negative effect of nutrient load. However, several other variables,in particular land use, shade, presence of fish, which were influential in other studies, were not significant in this study.

We investigated the abundance, diversity and community structure of mayflies (Ephemeroptera), stoneflies (Plecoptera) andblackflies (Diptera : Simuliidae) in the Sébaou basin (Algeria). Fifty-five species were collected (i.e. 22 mayflies, 14 stonefliesand 19 blackflies species) in 18 sampling sites located in both main streams and tributaries of the Sébaou river (Great Kabylie,North Algeria). Analysis of species diversity of the three considered taxa showed an altitudinal gradient with maximal diversityin the piedmont and low altitude mountain areas (from 200 to 500 m), which provided the most heterogeneous habitats to thebenthic fauna. In contrast, the low diversity of the lowland sites was due to high water temperatures, reduced summer dischargeand anthropogenic disturbances. In the same way, the low diversity of the high mountain areas can be attributed either to lowwater temperatures or high fluctuation in daily temperature. Three species assemblage groups are revealed, the first two are relatedto an upstream-downstream gradient, with headwater sites characterised by stoneflies species and middle stream sites by ahigh mayfly and blackfy diversity and abundance. The third group was identified as spring sites characterised by a low abundanceand occurrence of stonefly species.Both altitudinal species diversity gradient and species assemblage of the Sébaou wadi were different from European and temperateareas, revealing that the accentuated North African Mediterranean climate could induce changes to both species and communitystructure. These results provide insights to the influence of some environmental features on aquatic insect species distributionand community structure in North African streams.

Une étude de la stabilité des peuplements interstitiels dans les niveaux supérieurs de la nappe alluviale du Rhône à l'est de Lyon, a été réalisée en relation avec la stabilité physique des milieux et l'action d'une perturbation. Deux stations ont été choisies sur le Haut-Rhône : l'une est sujette aux remontées de nappe et aux crues de l'Ain (station 8) ; la seconde, alimentée par voie phréatique, ne subit aucune turbulence hydrologique (station 10).La station la plus exposée à des mouvements hydrologiques présente une biocénose qualitativement et quantitativement très structurée dans un plan vertical, avec une variabilité temporelle négligeable.La seconde station, plus "calme", abrite une biocénose moins stratifiée et moins structurée dans l'espace, caractérisée par une importante variabilité temporelle.Une modification identique des conditions de milieu :

- ne produit pas de variations notables de la biocénose de la St. 8

- constitue une perturbation à laquelle la faune réagit de manière différente suivant son adaptation au domaine souterrain, dans la St. 10.

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

In the present paper Candonopsis murchisoni n. sp., C. dani n. sp., C. williami n. sp., C. kimberleyi n. sp., and C. westaustraliensisn. sp., are described, while C. tenuis (Brady, 1886) is redescribed. All species have been collected in the subterraneanwaters of Western Australia. The new species are easily distinguishable from the existing world species in details of the carapace,walking leg, cleaning leg, furca and hemipenis. Because of new features found, revised diagnosis and a key to the worldspecies are provided. Some species, previously described in the genus Candonopsis Vavra, 1891, are considered as incertaesedis, while others are removed from this genus, which now contains 25 species. Finally, the authors propose the elevation ofthe subgenera Caribecandona Broodbakker, 1983 and Cubacandona Broodbakker, 1983 to the generic level.

Nous avons analysé la distribution régionale de 147 espèces appartenant aux 4 ordres d'insectes aquatiques les mieux connusdans le Sud-Ouest de la France - Ephéméroptères, Plécoptères, Trichoptères, Coléoptères Elmidae et Hydraeniidae -, afin d'établirune classification des cours d'eau basée sur des associations spécifiques au sein du réseau hydrographique Adour-Garonne(116 000 km2). La distribution spatiale des espèces a été précisée par des Analyses Factorielles des Correspondances (AFC), etles noyaux d'affinité entre espèces et/ou stations ont été recherchés par la Méthode des Nuées Dynamiques. Six zones ont étédéfinies, ainsi que leurs peuplements théoriques. Un intérêt majeur de telles classifications est que la stabilité spatio-temporelledes associations spécifiques peut être utilisée pour définir des sites ou des stations de référence, pour une surveillance biologiquedes rivières au sein d'une région ou d'une section longitudinale identifiée par un peuplement référentiel.

Cypridopsis vidua (O.F.M.) lives within dense stands of Chara fragilis Desv. in Mondsee. The species develops fast and is very voracious, feeding on the "Aufwuchs" of the Chara stems. Under experimental conditions, C. vidua actively explores the interstitial of a fine gravel sediment. The ostracodes are also able to find their way out of the interstitial labyrinth.The limited colonisation of deep groundwater habitats by C. vidua (e.g. in the Danube and the Rhône valleys the species lives in superficial alluvial sediments located near the bottom of surface waters) is presumably due to its high energetic requirements.C. vidua recognises the chemical alarm signals of predators such as the fish Abramis brama (L.) ; the ostracods react by drecreasing their motility in both the surface and the interstitial habitat.

This work represents a concerted effort aimed at understanding the microbiological and chemical evolution of a small boreal lake during the diurnal cycle of photosynthesis. We studied diurnal variation of ∼40 dissolved macro- and trace elements, organic carbon and bacterial population dynamics in the surface and bottom water layer of the shallow Vilno Lake in the White Sea basin. Four-days continuous measurements with 6 h sampling steps both at the surface (0.5 m) and on the bottom (4.0 m depth) during no-bloom periods revealed constant concentrations (within ±20–30%) of all major elements (Na, Mg, Si, K, Ca), organic and inorganic carbon and most trace elements (B, V, Cr, Fe, Cu, Ga, As, Rb, Sr, Y, Zr, Sb, Cs, Ba, all REEs, Hf, Pb, Th, U). At the same time, the concentration of some biologically important trace metals (Mo, Mn, Co, Cd) was subjected to variations partially reflecting the change of bacterioplankton concentration. This work enables two types of element behavior to be distinguished during photosynthesis in the water column – constant concentration and sinusoidal variations – depending on their speciation in solution and their affinity to aquatic microorganisms.

The aim of our paper was to study the space and time variations of phosphorus contents in the sediment, water and tissue of aquatic plants. Tissue Total Phosphorus of six aquatic plants (Callitriche platycarpa, C. hamulata, C. obtusangula, Elodea nuttallii, E. canadensis and Ranunculus peltatus) was analysed alongside the sediment Total Phosphorus (TP) and Soluble Reactive Phosphorus concentrations (SRP) in water, at the same site. Twelve sites were selected, and, samples were collected to test the seasonal and the annual patterns of phosphorus variation in 3 compartments. Streams ranged from oligotrophic to eutrophic waters. The sediments varied from mesotrophic to eutrophic states. A highly significant site effect was shown for water and for sediment. Water SRP varied with time (season, year), whereas no significant time effect was established for the sediment TP. Tissue TP varied according to year and season in Callitriche platycarpa, C. hamulata and E. nuttallii. The tissue phosphorus storage depended on the trophic level of sediment and water and varied according to species. The rank order of tissue TP content was C. obtusangula > R. peltatus ≥ E. nuttallii ≥ E. canadensis > C. platycarpa > C. hamulata. Removal of aquatic plants biomass with its accumulated phosphorus could be an alternative technique to other eutrophication control strategies. Further work is needed to improve our knowledge to estimate the ecological risk of harvesting on biodiversity and on ecosystem function.

Animal populations have a certain synchronization between their fluctuations and the environmental factors which have adirect influence on density, sex ratio and recruitment. Trichodactylus borellianus is a common freshwater crab of theTrichodactylidae family, originary from South America. This crab is omnivorous and grazes upon the littoral communities. Thepresent study is the first analysis of the natural distribution and population dynamics of freshwater crabs in La Plata Basin(Argentina) and their relationship with certain abiotic and biotic parameters. It was carried out in three environments (riverinezone of streams and river) of the Paraná River floodplain. Crab populations were sampled monthly from August 2001 to October2002. The mean crab abundance among the study sites was significantly different, being lower in samples from the environmentsurrounding the principal channel of the Paraná River. Crab density showed two peaks: the highest occurred during late winterand early spring, and the lowest during late summer. Males were only more abundant in late winter and spring. In spring, summerand autumn, the population showed a contagious distribution. The population displayed a regular arrangement in winter.From mid-spring to mid-autumn juveniles were very frequent whereas adults predominated the rest of the year. Total crab numberin the stream nearest to the main channel varied according to the level and temperature of the river. In the other sites, locatedfurther from the main channel of the Paraná River, crab numbers and vegetation biomass showed a more similar arrangementwith a higher correlation.

1. Les cycles de développement de 17 espèces d'Ephéméroptères d'un ruisseau à truites des Pyrénées (le Lissuraga) sont étudiés en utilisant les critères suivants déterminés après l'analyse des prélèvements mensuels échelonnés sur trois ans : nombre et mensuration des larves et des subimagos, durée du développement embryonnaire.

2. Une espèce est semivoltine : Ephemera danica.

3. Six espèces sont univoltines avec la période de sortie des subimagos commençant à la fin de l'hiver (Rhithrogena semicolorata et Habroleptoides modesta), au printemps (Paraleptophlebia submarginata, Torleya belgica et Caenis rivulorum) et en été (Habrophlebia lauta).

4. Dix espèces sont polyvoltines : quatre espèces d'Heptageniidae (Epeorus torrentium, Rhithrogena picleti picleti, Ecdyonurus venosus et E. angelieri) et une espèce d'Ephemerellidae (Ephemerella ignita) présentent une seconde génération partielle. Deux espèces semblent posséder deux générations par an (Baetis scambus et Caenis macrura) ; trois espèces de Baetidae (Baetis muticus, B. rhodani et B. gemellus) semblent présenter une troisième génération, vraisemblablement partielle.

5. Une étude comparative des cycles de développement déterminés chez les mêmes espèces, dans différentes régions d'Europe (Iles Britanniques et Europe centrale surtout) et dans le Lissuraga, conduit aux remarques suivantes pour le Lissuraga :

- précocité dans la période de sortie des subimagos variant de un à trois mois, chez toutes les espèces qui peuvent être comparées sauf chez H. lauta et E. danica ; on observe chez ces deux espèces un maintien de la période de première sortie des subimagos ainsi qu'un retard de la dernière sortie des subimagos (un mois et demi environ). Chez E. danica, la possibilité d'une modification de cycle pour une petite partie de la population du Lissuraga (semivoltin en univoltin) est envisagée ;

- allongement de la période de sortie des subimagos de toutes les espèces polyvoltines du Lissuraga ; les subimagos sont présents sur ce ruisseau 8 (E. ignita) à 12 mois (B. rhodani) par an.

6. Le développement larvaire des Ephéméroptères univoltins du Lissuraga s'échelonne de 10 à 11 mois pour la plupart des espèces. La durée de vie larvaire atteint 22 à 23 mois ou 13 à 14 mois chez Ephemera danica seule espèce semivoltine, selon le type de développement.

7. Le développement larvaire des Ephéméroptères polyvoltins du Lissuraga est relativement rapide : en période estivale, il peut être de trois à cinq mois pour les Baetidae et de cinq à six mois pour les individus d'Heptageniidae et d'E. ignita de la seconde génération partielle ; en période hivernale il peut varier de sept (Baetidae) à huit ou dix mois (Heptageniidae et E. ignita).

8. Le développement larvaire des Ephéméroptères du Lissuraga présente une périodicité saisonnière marquée ; le rôle des facteurs périodiques primaires (températures et photopériode) et secondaires (nourriture) est discuté.

L'étude a été réalisée début mai et fin juin 1994 dans 19 stations : 12 au long du cours principal et 7 au niveau de sources ou d'importants affluents. Les richesses taxonomique et spécifique (principalement Mollusques, Ephéméroptères, Plécoptères, Coléoptères et Trichoptères) montrent une évolution semblable avec un maximum à l'aval. L'analyse biotypologique par A.F.C. sur 68 espèces distingue 4 zones : le haut cours incluant les sources et les affluents montagnards, une zone de transition, une section moyenne très homogène avec les bas cours des principaux affluents malgré des perturbations polluantes et un bas cours à l'aval de deux barrages-retenues. Trois assemblages faunistiques majeurs se dégagent : un d'espèces du crénon-rhithron, un d'espèces plutôt eurytopes et thermophiles, et un d'espèces potamo-limnophiles. La zone de transition se définit alors par les deux assemblages entre lesquels elle se situe. Sur cette base typologique, la prise en compte des groupes trophiques montre que, seule, la basse Moulouya ne s'inscrit pas dans le schéma fonctionnel du 'R.C.C.'. La discontinuité observée à l'aval est probablement due aux effets des barrages (réduction du débit et de la largeur du lit), mais aussi au fait que cette section du fleuve retrouve un caractère plus naturel (ripisylve moins dégradée).

The aquatic larvae of the Diptera are often the most abundant and most diverse group of the benthic macroinvertebrate fauna.They are able to survive in and colonise practically all freshwater habitats, and some species can tolerate harsh environmentalconditions. They are therefore both a qualitatively and quantitatively important group of biological indicators for assessing freshwatersystems. On the other hand their determination at the species level is very difficult. This is in part due to a lack of taxonomicwork in the group, but also the absence of comprehensive determination keys, that meet the needs of water managers. Asa result, the aquatic larvae of the Diptera often play a subordinate role in water management. In light of the EU Water FrameworkDirective the present work is a first step in improving the integration of the important group of the Diptera in water managementpractice: a comprehensive determination key, which is geared at water managers. The key includes 60 taxa, largely at the familyand genus level. In contrast to already existing keys the present work tries to differentiate the taxa on the basis of simple anduser-friendly characters. Numerous figures allow for easy checking of determination results. The key is applicable in Germany,Scandinavia, Great Britain and the Benelux states. Mainly taxa from running water systems are considered, but the key can alsobe used at the family level to determine taxa from standing water bodies.

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

The ability of rapid range expansion is one of the key determinants of invasive species success. In order to investigate potential drivers behind the rapid spread of invasive species, we explored changes in population characteristics and structure along the invasion pathway of a successful invader in European freshwaters, the signal crayfish (Pacifastacus leniusculus). Diverse population parameters such as relative population abundance, size and sex structure, differences in morphometry and frequency of injuries were compared between signal crayfish population samples at three uniformly distributed segments (approximately 40 km apart) in the lower section of the Mura River, which differed in time since invasion. Examined signal crayfish populations exhibited notable differences, with more recently established populations toward invasion front characterized by lower abundance and male-biased sex ratios, which highlighted males as initial dispersers. We also recorded significant increase in the relative claw size, a competitively advantageous and allometric trait for males, in more recently established populations away from source population. The recorded differences in population structure and male morphometry along the invasion pathway could lead to important clues about dynamics of range expansion and population establishment, highlighting the traits that promote dispersal and better response to local conditions in new habitats. Established differences can also provide insights into the development of targeted management responses aimed at invasive species control.

Nymphs of the three perlid genera known from southeastern Brazil, Anacroneuria, Kempnyia and Macrogynoplax, aredistinguished morphogically and a key is provided for their determination.

Benthic macroinvertebrates are an essential component of freshwater environments. The ecotoxicological risk of benthic communities, estimated through the assay of biochemical markers, can be used as an early warning signal for environment alterations. In this work the activities of a number of enzymes, regarded as potential biomarker of exposure to pollutants (catalase, acetylcholinesterase, glutathione-S-transferase) was determined in homogenates of whole organisms. Specimens were collected in the rivers Taro and Ticino, northern Italy, in stony bottom reaches in five and three stations respectively. The orders of aquatic Insects Diptera, Plecoptera, Odonata, Ephemeroptera and Trichoptera, the Crustacea Amphipoda, and Annelida Oligochaeta were examined. Additional enzymes, such as NADP-dependent malate dehydrogenase, isocitric dehydrogenase, glucose-6phosphate dehydrogenase, alcohol dehydrogenase, and lactate dehydrogenase were considered in the study. Results emphasize significant differences among taxa concerning the specific activity of most enzymes.

Despite their ecological importance and ability to react to environmental changes, including pollution, monogonont rotifers have never been used in palaeolimnological studies because they do not leave subfossil remains. In this study, we tested the possibility of using rotifer resting eggs as a proxy for reconstruction of changes in biodiversity during chronic copper pollution and recovery of a deep sudalpine lake (Lake Orta, Italy). The lake was selected owing to a rich history of previous studies that explored species-specific responses to environmental stressors. Rotifer-based results were compared with those on ephippia and on previously investigated Cladocera subfossil remains. Responses of Rotifera resting eggs to environmental changes were clear and consistent with those previously observed on Cladocera. The abundance of resting eggs increased during pollution, and new morphotypes appeared in addition to those already present. However, overall diversity decreased sharply, as a few morphotypes became dominant. Resting eggs of Brachionus calyciflorus as old as ca. 100 years were still fully viable; viability was not affected by toxic conditions of the environment in which the eggs were produced. Over a period of ca. 80 years, all resting eggs of B. calyciflorus belonged to a single clone, the most widely distributed one in North America. Cladocera ephippia started to accumulate later and at a lower level of abundance than rotifer resting eggs. Overall, Cladocera ephippia were, however, less effective than rotifers in tracing lake historical changes. The results point out at the great potential of using rotifer resting eggs in palaeolimnological reconstructions.

Extirpation or even extinction of freshwater invertebrate species is a neglected conservation issue; declines in abundance and spatial distribution for freshwater invertebrates are far less documented than for vertebrate species. In the Minho River tidal freshwater wetlands (northwest of Iberian Peninsula), a rapid decline in density and biomass of the bivalve Pisidium amnicum was recorded at 16 different sites over seven years, from 2004 to 2010, without any sign of a potential recovery. Mean density values reached more than 80 ind.m−2 in 2004, but declined to less than 1 ind.m−2 in 2009 and 2010. An identical declining trend was observed for biomass. A significant reduction in the spatial distribution also occurred. The abiotic changes resulting from the 2005 heat wave and possibly the negative interactions imposed by the non-indigenous invasive bivalve Corbicula fluminea were the main factors responsible for the declining trends. Given the very low density, P. amnicum is facing a serious risk of extirpation in this ecosystem and conservational measures are urgently needed.