For the first time, a faunistic list of the Chironomidae fauna of Greece is presented along with its ecological distribution. Chironomidae larvae and pupal exuviae were collected from 61 locations in mainland Greece during 2006–2008. 76 taxa (genera to species) were recorded. The genera Potthastia, Brillia, Euorthocladius, Synorthocladius, Tvetenia and Xenochironomus are recorded for the first time from Greece. Furthermore, 12 species are new for Greece and five are new for mainland Greece. Chironomidae collected from running waters were analysed with ordination techniques. The results revealed that Chironomidae assemblages were distinguished into three ecoregions with distinct climatic, geological and hydrochemical features. Running waters in Northwestern Greece were generally dominated by species tolerant to water acidification. Chironomids typical of eastern uplands preferred relatively slow current and soft bottom sediments. Assemblages of the southern Peloponnese Peninsula were represented by species of relatively fast flowing, warm streams. However, these are only preliminary results and many more data are needed to justify this ecological distinction of Chironomidae assemblages. This is the first study contributing to the knowledge of a rather neglected insect group of the Greek fauna. It is expected that more species remain to be identified and recorded and future works will contribute to this initial faunal list.

The diversity of chironomid larvae in relation to flooding and drought phases in a marginal fluvial wetland of the Middle ParanáRiver floodplain was analyzed. Four sampling stations in the right bank of the Tiradero Viejo River towards the interior of themarginal wetland were established: one at the riverside, and three more at 10, 30 and 40 m from the river. Bottom sedimentsamples were extracted during the hydrosedimentological cycle of 2001. A total of 25 taxa of Chironomidae were recorded. Thevalues of taxonomic richness, density and diversity were higher in the marginal fluvial wetland than in the riverside, increasingwhen the wetland is disconnecting from the river. Polypedilum (Tripodura) spp., Polypedilum (Polypedilum) spp., Ablabesmyia(Karelia) spp., Coelotanypus sp., Monopelopia cf. boliekae, Goeldichironomus holoprasinus and Chironomus gr. decorus spp.were dominant in marginal wetlands. The results indicate that the variations in the hydrosedimentological regime, the degree ofdisconnection with the river and the progressive desiccation at each one of the stations of the marginal fluvial wetland arelimitant factors in the distribution and abundance of aquatic chironomids. The different assemblages of Chironomidae werestrongly conditioned by temporal changes related to the gradient of inundation-drought and to the hydroperiod dynamics.

The epiphytic diatom communities living on two macroalgae, Chara vulgaris L. and Cladophora glomerata Kütz.) and oneangiosperm Potamogeton densus L., were collected in the Mediterranean river Durance. Each macrophyte species was studied on the basis of three plant replicates, each of which cut into three segments. Although considerable heterogeneity was observed in density of the epiphytic populations between the plant species studied as regards, the composition of these algal populations showed a conspicuous degree of homogeneity within each macrophytic species. These observations were corroborated by the coefficients of variation calculated on the main diatoms and by the non parametric Friedman tests.The qualitative homogeneity of epiphyton on Potamogeton densus foliage made it possible to map the spatial repartition of the main groups of diatoms growing on the upper side of leaves.These data support the hypothesis that the epiphytic algae occupy specific microhabitat niches on their host plants according to a non stochastic pattern of distribution.

The responses of 32 Hydraenidae and Elmidae species to six chemical parameters - alkalinity, Cl-, SO4 --, COD, NO3 - and total P have been analysed in the Orbigo river basin. The study of the distribution in relation to these factors by means of elaborating their ecological profiles pointed out the indicator species for each one of these parameters, according to their reciprocal species-factor information.

Species composition, distribution and biomass of benthic macrophyte communities have been studied in a high mountain, oligotrophic, softwater lake from the Central Pyrenees. Isoetids (Isoetes lacustris L., Isoetes setacea Lam., Subularia aquatica L. and Eleocharis acicularis (L.) Roemer & Schultes) are the dominant macrophytes in areas over 2-3 meters in depth. Natopotamids (Sparganium angustifolium Michx.) are restricted to shallow waters. Algae (Nitella gracilis (Smith) Agardh) only predominate in deep waters. Three main communities have been distinguished : the Sparganium angustifolium community (160 g dwt m-2), the Isoetes lacustris community (120-460 g dwt m-2) and the Nitella gracilis community (11 g dwt m-2). Biomass differences between shallow and deep water Isoetes populations have been attributed to ice-scour stress. Neither irradiance nor slope can explain the lower boundaries observed in the distribution of vascular plants ; sediment features may be responsible for them. Mean lake macrophyte biomass amounts to 140 g dwt m-2 (20 g C -2), a very high value if compared with boreal lakes with similar limnological characteristics.

Plant litter breakdown, an important process for energy and matter flows in freshwater ecosystems, has been extensively studied except in the karst (and calcite depositing) habitats. The aim of this paper was to answer three questions regarding the breakdown of leaf litter in calcite depositing environment: (i) Does leaf decomposition hinder calcite deposition and vice versa?; (ii) What role do other environmental factors play?; and (iii) How long does leaf litter persist in these habitats? Leaves of beech (Fagus sylvatica) and butterbur (Petasites hybridus) were exposed for 8 weeks in 8 microhabitats: 2 calcite deposition rates × 2 flow velocities × 2 seasons. A linear model was better at predicting leaf litter persistence but only for the period after the extreme loss of leaf mass occurring during the initial leaching of highly hydrosoluble compounds in the first week (11.6% of beech and 54.2% of butterbur regardless of the studied environmental factors). Higher flow velocity and calcite deposition rates stimulated the breakdown of both leaf species. During summer, breakdown was accelerated for butterbur leaves only. Since breakdown rates of both litter types were faster at high calcite depositing sites, it can be concluded that the breakdown process is not hindered by calcite deposition in general. The amount of deposited calcite per gram of leaf litter increased linearly over time (after the first week of exposure) on both leaf species. More calcite was deposited on the fast-decomposing butterbur leaves than on beech leaves.

Les auteurs présentent la première liste des Diptères Chironomidae signalés jusqu'en 1990 de France continentale et de Corse. Il a été tenu compte des synonymies anciennes et récentes. Des corrections et des additifs sont apportés aux listes régionales publiées antérieurement. La présentation choisie permet de faire le lien avec la partie consacrée aux Chironomidés dans la Limnofauna Europaea éditée par Illies (1978). Avec 598 espèces recensées, le territoire français s'avère être l'un des plus riches d'Europe en Diptères Chironomidés.

The chub, Leuciscus cephalus, colonizes the Durance river from its confluence with the Rhône river (alt. 13 m) up to the Serre Ponçon dam (alt. 780 m.). The Durance has been exposed to strong human pressure, notably dam construction, reduction of flow rate and perturbation of the natural zonation patterns. The linear growth of chub was studied by scale measurement at six stations in the Durance catchment area : two of which are located in its main tributaries, the Buech river and the Verdon. An analysis (ANOVA) of the mean size of fish from one to five years of age shows significant differences between the stations. Principal Component Analysis, in which the stations are characterized by eight mesological variables associated with the density of invertebratesand the number of degree-days above 12° and 22°C established a correlation between chub growth and species habitat, defined in terms of current flow rate, depth and substrate type and temperature. This correlation could be explained in two ways : 1- in slow-flowing homogenous riffle zone, the low water depth and absence of shelters limit the diversity of habitats and the biological richness; nevertheless the abundance of invertebrates does not seem to play an important role ; 2 - in zone of slow flowing riffles subjected to large daily and seasonal variations in water temperature, as in this mediterranean river, temperature might be quite high. Fish older than two years, therefore prefer zones of deep water, where the thermic inertia is stronger.

Se describe una nueva especie de Tubificidae, Phallodrilus riparius n. sp., capturada en el río Tambre (Galicia). La forma y el número de sedas peniales, la forma de las espermatecas y la presencia de tubo digestivo son los principales caracteres que, combinados, la distinguen de los demás representantes del género. Contrariamente a la inmensa mayoría de los Phallodrilus conocidos, P. riparius n. sp. es una especie de agua dulce.

Se observa y estudia la variación con la edad del binomio sedas ventrales bífidas-sedas ventrales con punta simple en una población de Peloscolex velutinus (Grube) y se describen, finalmente, las sedas génitales de Rhyacodrilus subterraneus Hrabe y una forma original de Tubifícido (Tubificidae gen. sp.) que no hemos podido encontrar hasta la fecha en estado de madurez sexual.

Les faces dorsales et ventrales des capsules céphaliques larvaires de 8 espèces du genre Hydropsyche sont représentées et une clé est proposée pour la détermination des larves âgées. Des données biologiques et écologiques complètent cet essai de taxonomie pratique.

The changes in the dynamics of cladocerans in Lake Vela (Portugal), as well as the morphologic and life history traits of the small-bodied cladoceran Ceriodaphnia pulchella, were studied intensively during one month characterized by deep and fast changes in the phytoplankton community: the beginning of the cyanobacteria dominance. Lake Vela, located in the Mediterranean region, is a polymictic shallow lake exhibiting characteristics typical of an advanced trophic status, namely the permanently turbid water, the reduction in biodiversity and the occurrence of cyanobacteria blooms. The density and composition of the cladocerans populations varied considerably during the short-term period analyzed. Coincident with the increase of cyanobacteria, the density of Daphnia longispina decreased drastically, associated with an increase of Bosmina longirostris and Chydorus sp. The constant density of C. pulchella, even during the cyanobacteria dominance, and the strong relationship found between weight and size, suggests that the low quality of phytoplanktonic food in Lake Vela did not play an important role in its fitness. Besides the small size of C. pulchella, this fact could be also related to its diversified diet. Nevertheless, a closer examination of the life history parameters of C. pulchella revealed a reduction in the fecundity, size at first reproduction, mean size of ovigerous females and maximum size of the population, which suggest an increase of the fish pressure after the decline of Daphnia. C. pulchella showed also a short-life cycle and a fast turnover of individuals, which constitutes also an advantage, allowing a fast adaptive response of the population.

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

Recent publications suggest that in large watersheds a large proportion (20 to 70%) of the net nitrogen input to the aquaticenvironment may be removed during water’s downstream path towards the outlet. In small watersheds there are few to no evaluationsof the importance of in-stream processes in the overall nitrogen budget due in part to the lack of simple and robustmethods for measuring in-stream nitrate uptake. We propose a comparative study for laboratory and field measurements on openmesocosms, 30 cm in diameter. Nitrate uptake was evaluated from the kinetics of disappearance of nitrate in water overlyingundisturbed sediment cores, both in the laboratory and in-situ. Using both laboratory and in-situ mesocosms was an effort todetermine whether the methods were comparable and applicable on a routine basis. Nitrate disappearance kinetics in the laboratoryyielded expected results, which are that nitrate uptake rates are linearly correlated to nitrate concentration in the watercolumn. In such conditions, our results show that the potential for nitrate uptake in streams can be calculated from the mass transfercoefficient. Our comparative study shows that incubations conducted in the laboratory intrinsically limit hyporheic exchanges,associated with small water level fluctuations, which may in fact prevail in the field as the in-situ incubations have shown.In-situ experiments yielded unexpected results, such as the succession of disappearance and gain of nitrate in the mesocosmsthrough time. This was attributed to hyporheic exchanges, both natural and artificially induced by the design of the mesocosms.Both methods should be considered for future nitrate uptake studies as they yield complementary results, provided that somesimple changes are made in the design of in-situ mesocosms.

Though much is known about freshwater snail ecology, their circadian rhythms remain poorly investigated. Well-fed, stress-free, mid-size adults of six species common in central Italian lakes were exposed to natural sunlight and photoperiod, and their activity status was recorded at 3-h intervals during a 9-d indoor experiment. All species exhibited evident diurnal habits despite high individual variability, with midday-to-early-afternoon activity peaks. Activity was correlated with diel light conditions but not with short-term changes in albedo. The prosobranch Bithynia (=Codiella) leachii and the pulmonates Physa (=Physella) acuta and Planorbis planorbis were the most active species and exhibited the longest-lasting response to daytime food addition. The prosobranch Valvata piscinalis exhibited long periods retracted in its shell with the operculum shut, and the remaining taxa (the pulmonates Galba (=Lymnaea) truncatula and Radix (=Lymnaea) auricularia) exhibited an intermediate degree of activity. P. acuta was the most active species at night and exhibited the quicker response to nighttime food addition. Alertedness to (diurnal) predators may be highest for the highly active P. acuta and P. planorbis, whose antipredator defenses are mainly behavioral. Diel activity patterns and other ecological characteristics suggest that P. acuta may be favored in food-rich habitats, while V. piscinalis may not be able to fully exploit food resources, especially if in limiting quantities. All snail species – and P. acuta in particular – may stimulate periphyton metabolism while keeping its biomass low by grazing mainly during the time of maximum photosynthesis.

We studied the status of Crested newt (Triturus cristatus superspecies) ponds in the province of Salzburg during the years 2004and 2005. Historical and current distribution data were collected and compared. In the end of 2004, 51 ponds with Crested newtrecords of which 39 still existed were known in Salzburg. In 2005 we carried out a monitoring of these ponds using a combinationof three survey methods. Presence or absence of adult and larval Crested newts and the number of syntopic amphibian specieswere recorded. Detection probabilities and the effects of seven characteristic pond features on pond occupancy were calculatedfor adult and larval newts separately. We observed a strong decline of ponds occupied by Crested newts with presence of adultsin 22 and presence of larvae in 16 surveyed ponds, respectively. Detection probabilities imply that we detected all ponds occupiedby adults and larvae. Key habitat features for Crested newt presence are low degree of shading for adults and larvae as wellas a high density of submerged vegetation for larvae. Pond size and depth are not significant. Furthermore we recorded a significantlyhigher number of amphibian species in ponds occupied by Crested newts. Our results might aid in the implementationof sustainable measures for a conservation of these critically endangered species in the province of Salzburg.

Les vitesses d'assimilation du phosphore et de l'azote sont exprimées par une équation de type Michaelis-Menten, et pondérée par une fonction de contrôle exercée par les réserves cellulaires internes. Pour chacun des deux nutriments, ont été déterminés : vitesse maximale d'assimilation (Vm), constante de demi-saturation (Ks), les quotas cellulaires minimum et maximum. L'interaction de la température a été déterminée pour Vm et Ks.

The rotifer fauna of twenty five localities (mainly shallow lakes) from Corrientes, Argentina was studied. 136 taxa were identified, 20 ofwhich, from the genera Lecane, Lepadella, Ploesoma, Ptygura, Squatinella, Testudinella and Trichocerca are new to the Argentine fauna. Most of these are (sub)tropical in distribution, and 8 % are endemic to South America. Ploesoma africana Wulfert, Ptygura kostei n.sp., Testudinella brevicaudata Yamamoto and Trichocerca vernalis Hauer are recorded from the Neotropical region for the first time. The rotiferan species richness of this area, is remarkable. The highest diversity was recorded from vegetated lakes, with acid waters, where one locality yielded 56 species.

Dans une installation d'essai, l'écoulement a été observé en présence d'obstacles simples, pour des vitesses moyennes variant de 1 à 100 cm/s. La technique utilisée a été la chronophotographie de particules d'aluminium en suspension dans l'écoulement. Ce procédé de visualisation a permis d'établir le tracé des lignes de courant et de connaître les valeurs des vitesses en des points précis. La valeur des pressions et l'amplitude des variations de pression ont été mesurées sur le fond du canal d'essai.

1. - L'évolution de l'écoulement a été observée à l'amont et à l'aval des obstacles en fonction de l'accroissement de la vitesse moyenne. Aux vitesses moyennes faibles, on observe un petit rouleau stable en aval des obstacles. Le mouvement est plus lent qu'en pleine eau. Avec l'augmentation des vitesses moyennes, à ce mouvement moyen se superpose une agitation de plus en plus importante des particules. Cette agitation traduit l'existence d'une turbulence qui devient intense aux vitesses moyennes élevées. L'instabilité du point d'attachement du rouleau entraîne l'existence de battements. Un petit rouleau évolue de façon semblable à la face amont de certains obstacles.

2. - En aval des obstacles, la longueur d'attachement du rouleau est très réduite pour des vitesses moyennes faibles. Cette longueur augmente ensuite très rapidement avec l'accroissement de la vitesse moyenne et le rouleau devient très long. L'attachement du rouleau se rapproche ensuite de l'obstacle et demeure relativement stable aux vitesses moyennes supérieures.

3. - Le rouleau aval est le plus stable pour des obstacles à arêtes vives et à face amont normale au courant. En présence d'obstacles mieux profilés, et surtout en présence d'une rampe, l'instabilité de l'écoulement est plus grande que pour les autres obstacles.

4. - Les échanges entre les rouleaux et l'écoulement général sont très réduits pour les vitesses moyennes faibles. Ils deviennent de plus en plus importants au fur et à mesure de l'augmentation des vitesses moyennes.

5. - Les variations de pression ont été enregistrées en plusieurs points du fond du canal. L'amplitude maximale des variations de pression correspond à la zone d'attachement du rouleau aval. A l'abri de l'obstacle, les oscillations sont les plus faibles sur la face aval. Sur la face amont, les variations de pression peuvent être différentes suivant la stabilité de l'écoulement au point de décollement et suivant le relief de l'obstacle.

6. - L'agitation qui règne dans les "eaux mortes" pour des vitesses moyennes élevées peut se traduire par les variations de pression. L'étude de ces variations de pression dans le temps devrait permettre une meilleure connaissance des conditions de vie au niveau même de la faune benthique.

1.1. - Le mâle de Pachyleuctra bertrandi diffère de celui de P. benl-lochi par la forme du specillum, du dixième tergite abdominal et des appendices tergaux du cinquième segment abdominal.

1.2. - La séparation des genres Pachyleuctra et Leuctra est postérieure à l'isolement du genre Tyrrhenoleuctra.

2.1. - Des larves âgées de Leuctra major ont été capturées en milieu interstitiel hyporhéique profond.

2.2. - La larve de L. major est allongée et possède des pattes peu développées. Sa pilosité et sa pigmentation sont réduites par rapport à celles des autres Leuctra.

2.3. - Chez l'imago, l'allongement du corps est encore net, les pattes sont de dimensions normales, la pilosité, par contre, est beaucoup plus développée que chez les autres Leuctra. L'activité réduite des cellules trichogènes lors des mues larvaires est compensée par une sécrétion plus abondante lors de la mue marginale.

2.4. - L'étude des relations phylogéniques de L. major permet de retracer les étapes de l'acquisition des adaptations morphologiques de la larve à la vie en milieu interstitiel.

3. - Les styles des paraproctes de L. fusca et L. hippopus ne pénètrent pas dans la cavité génitale de la femelle lors de l'accouplement.

4. - Leuctra maroccana, espèce nouvelle pour la France, ne peut être rangée dans le groupe inermis.

5. - Les populations de Leuctra kempnyi, endémique pyrénéenne, présentent d'est en ouest de fortes variations morphologiques.

Benthic macroinvertebrates collected at seven different streams displaying different pollution levels were used to investigatespecies abundance patterns in polluted streams. Community response to disturbances in streams was analysed using speciesabundance distribution (SAD) for benthic macroinvertebrates across different levels of pollution. The slopes of rank abundancewere characteristically steeper with decreasing species richness at the polluted sample sites, while the slopes were less steep withhigher species richness at the clean or slightly disturbed sample sites. The SADs were broadly fitted to the log normaldistribution in benthic macroinvertebrate communities across different levels of pollution. A geometric series was partly acceptedfor the communities at the severely polluted sites where new species could not be readily introduced. A power law was applied tothe SADs, and the parameters reflected the states pertaining to the sample sites. The SADs were also efficient in revealingecological state of communities where physico-chemical indicators could not be easily differentiated for stressful conditions instreams.