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The Santa Cruz River is the last free-flowing river in Argentinean Patagonia. Two dams are projected, and no comprehensive pre-impoundment study has been undertaken. The present study investigated macroinvertebrate communities along three different hydrological periods and at three river sections located upstream and downstream of future dams. Fifty-three macroinvertebrate taxa were identified, with the most abundant orders being Ephemeroptera, Plecoptera, Coleoptera, and Crustacea (particularly amphipods). Ordination methods (CCA) and generalized linear models (GLM) were applied. According to the CCA, the main environmental variables related to macroinvertebrate density were temperature, suspended solids, depth, and substrate size. For the GLM, the main factors associated with macroinvertebrate abundance were location and hydrological period, and variables with the highest influences were temperature, substrate size, current speed, and depth. We anticipate that dam construction will modify in-stream habitat conditions, leading to changes in (i) macroinvertebrate community structure and (ii) local fish abundance due to loss of key prey taxa. [ABSTRACT FROM AUTHOR]

Macroinvertebrate colonization of restored rivers is a function of dispersal into the restored reach and its suitability for population establishment. To maximize potential for colonization success, spatial considerations such as distance to colonizer source pools and dispersal pathways must be included in restoration planning. Unfortunately, the dispersal abilities of macroinvertebrates and ecological importance of different dispersal modes for colonization are still poorly understood. We used a field experiment that controlled colonization by passive drift and allowed distinction between active upstream aquatic and active/passive aerial dispersal, thus testing their differential importance during colonization of experimentally restored stream reaches. Two agricultural streams emanating below culverts were longitudinally separated along the first 30 m and one stream side each was covered with a fine-mesh net to limit aerial dispersal. Colonization of manually disturbed background and experimentally introduced cobble substrate was investigated over 6 months. We found that upstream in-stream dispersal, especially in these agricultural streams, can be rapid (days) and play an important role in the short-term colonization of restored streams. We conclude that a landscape perspective, in addition to in-stream measures, must be considered when attempting to restore streams dominated by agricultural and urban land use that constrains available species pools and limits dispersal pathways. [ABSTRACT FROM AUTHOR]

Copyright of Iheringia. Série Zoologia is the property of Fundacao Zoobotanica do Rio Grande do Sul and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Iheringia. Série Zoologia is the property of Fundacao Zoobotanica do Rio Grande do Sul and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Iheringia. Série Zoologia is the property of Fundacao Zoobotanica do Rio Grande do Sul and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Biological assemblages are affected by both environmental and spatial processes. Spatial autocorrelation can be specially marked in discrete ecosystems patchily distributed over a large region ( e.g. , lakes arranged in districts). Lake typologies are exclusively based on environmental features, but we hardly know to what extent spatial patterns can hinder their implementation. We analysed the role of environmental factors and spatial autocorrelation in shaping littoral macroinvertebrate communities of 51 mountain lakes from a large Spanish region in order to test: 1) the suitability of the variables currently used to construct typologies; 2) the influence of spatial patterns on typology implementation. Biologically meaningful types of lakes were created and described by means of cluster analysis (Jaccard index) and multiple discriminant analysis. Water permanence, substrate type and vegetation were the main drivers of the assemblage composition. The cluster analysis and Mantel tests showed that spatial patterns did not generally hamper recognizing lake types. Only in the district with lakes closest to each other (Sanabria Natural Park), spatial autocorrelation was strong enough to overcome the effects of some factors (substrate type), but not others (water permanence). [ABSTRACT FROM AUTHOR]

A study of the impact of developmental activities on the distribution and biodiversity of aquatic macroinvertebrates of Kano River was conducted between June 2014 to May 2016. Six sampling sites from the upstream receiving point to downstream were selected along the river. Result indicated that the species richness were 2271 and 2844 in first twelve months and preceding respectively, grouped into 19 families and classified into five functional feeding groups. Chironomidae was found to be the dominant family in the study accounting for 24% abundance and 18% abundance in wet and dry seasons of 2014-2015 and 2015-2016 respectively. Communities were most diverse at Site C (0.94) in 2014-2015. Site A was the least evenly distributed in the first Twelve month as indicated by the lowest index (0.50). However high evenness was observed in Site C (0.99). Sites species composition in degrees of association using Pearson Product Moment Correlation (PPMC) revealed site A and F showed high correlation of (.968) while the lowest value was between site F and D (.622). However, in 2015-2016 site E and F showed high correlation of (.995) while moderate correlation was between Site E and A (.611). Results were discussed, concluded and recommendations were made. [ABSTRACT FROM AUTHOR]

While anthropogenic biodiversity loss in fresh waters is among the most rapid of all ecosystems, impacts on the conservation of associated riparian zones are less well documented. Riverine ecotones are particularly vulnerable to the combined 'squeeze' between land-use encroachment, discharge regulation and climate change. Over a 3-year period of persistent low discharge in a regulated, temperate river system (River Usk, Wales, UK; 2009-2011), specialist carabid beetles on exposed riverine sediments (ERS) were used as model organisms to test the hypotheses that catchment-scale flow modification affects riparian zone invertebrates more than local habitat character, and that this modification is accompanied by associated succession among the Carabidae. Annual summer discharge during the study period was among the lowest of the preceding 12 years, affecting carabid assemblages. The richness of specialist ERS carabids declined, while generalist carabid species' populations either increased in abundance or remained stable. Community composition also changed, as three ( Bembidion prasinum, B. decorum and B. punctulatum) of the four dominant carabids typical of ERS increased in abundance while B. atrocaeruleum decreased. Despite significant inter-annual variation in habitat quality and the encroachment of ground vegetation, beetle assemblages more closely tracked reach-scale variations between sites or catchment-scale variations through time. These data from multiple sites and years illustrate how ERS Carabidae respond to broad-scale discharge variations more than local habitat character. This implies that the maintenance of naturally variable flow regimes is at least as important to the conservation of ERS and their dependent assemblages as are site-scale measures. [ABSTRACT FROM AUTHOR]

Linopherus beibuwanensis sp. n. is described based on six specimens deposited in the Marine Biological Museum of the Chinese Academy of Sciences, Qingdao, collected from the Beibu Gulf (Tokin Gulf ), South China Sea. The new species differs from all other Linopherus species by the shape of prostomium and caruncle. The posterior margin of prostomium is bilobed; the caruncle arises medially and confluently from the posterior margin of the prostomium, joining together with prostomium. A key to distinguish the known species of the genus is provided. [ABSTRACT FROM AUTHOR]

Paramuricea clavata (Cnidaria, Octocorallia) is an important ecosystem engineer of coralligenous assemblages increasingly threatened by anthropogenic activities and climate changes. As climate warming is predicted to continue in the coming years it is important to hypothesize future scenarios. Here we tested the influence of gorgonian colonies on sedimentation rates and vagile fauna trends, comparing sediments collected by traps inside and outside a gorgonian garden, in a coralligenous community of the Western Ligurian Sea, at 32 m depth, over a period of 1 year. The results indicated that sea fans created a sort of homeostatic effect on the surrounding habitat. We found evidence that where gorgonian colonies were present, the monthly fluctuations of sediments rate were lower than outside a garden. Gorgonian colonies also influenced the distribution of the associated vagile fauna; these organisms were generally more abundant inside than outside the garden. The data collected in this work appear to confirm the role of P. clavata as an ecosystem engineer, affecting biomass and variability of the surrounding habitat at both spatial and temporal scales. [ABSTRACT FROM AUTHOR]

The inter-tidal zone around sewage discharges in a Southwest Atlantic shore (Mar del Plata, Argentina) is currently colonized by extensive inter-tidal reefs of the invasive spionid Boccardia proboscidea. Understanding the links between both human and natural disturbances and the massive development of non-indigenous species will help prevent marine bioinvasions, which are already favoured by global oceanic trade. We present herein predictive models for variations in the density of B. proboscidea around sewage discharges of Mar del Plata, using environmental ( pH, turbidity, temperature, salinity and total organic matter content), weather (wind direction and storm records), spatial (sites) and temporal (season and year) variables. Density variations were modelled by generalized linear models, and model averaging (multimodel inference) was used to obtain predicted values. The highest predicted values of B. proboscidea density occurred at sites to the south of the sewage effluent in spring. These sites are more affected by urban effluent discharges and they showed increased B. proboscidea density when the north wind was predominant. In addition, B. proboscidea density values were higher in sites with 20-22 °C (seawater temperature), high total organic matter content in sediments and low salinity. The averaged model was only a good 'predictive model' for sites to the north of the outfall, but was useful as an 'explanatory model' in all sites. Such predictions may help to back up conservation and management policies and decisions. [ABSTRACT FROM AUTHOR]

Context Multiple stressors constitute a serious threat to aquatic ecosystems, particularly in the Mediterranean region where water scarcity is likely to interact with other anthropogenic stressors. Biological traits potentially allow the unravelling of the effects of multiple stressors. However, thus far, trait-based approaches have failed to fully deliver on their promise and still lack strong predictive power when multiple stressors are present. Goal We aimed to quantify specific community tolerances against six anthropogenic stressors and investigate the responses of the underlying macroinvertebrate biological traits and their combinations. Methods We built and calibrated boosted regression tree models to predict community tolerances using multiple biological traits with a priori hypotheses regarding their individual responses to specific stressors. We analysed the combinations of traits underlying community tolerance and the effect of trait association on this tolerance. Results Our results validated the following three hypotheses: (i) the community tolerance models efficiently and robustly related trait combinations to stressor intensities and, to a lesser extent, to stressors related to the presence of dams and insecticides; (ii) the effects of traits on community tolerance not only depended on trait identity but also on the trait associations emerging at the community level from the co-occurrence of different traits in species; and (iii) the community tolerances and the underlying trait combinations were specific to the different stressors. Conclusion This study takes a further step towards predictive tools in community ecology that consider combinations and associations of traits as the basis of stressor tolerance. Additionally, the community tolerance concept has potential application to help stream managers in the decision process regarding management options. [ABSTRACT FROM AUTHOR]

Mechanisms underpinning flexible life-history strategies have rarely been tested in hydrologically unpredictable ecosystems where generalists may have life-history trade-offs and developmental constraints that limit their distributions. We investigated in situ nymphal growth and developmental strategies of 2 generalists, Xanthocnemis zealandica and Sigara arguta, across a habitat-permanence gradient. In response to temporary pond drying, we anticipated a flexible generalist response with rapid growth and shorter development, resulting in smaller adult size. In comparison, we expected nymphs living in permanent lakes with predatory fish to extend growth and development in favor of larger adult size. Both species maximized growth rates in temporary ponds but had different developmental strategies that influenced their distribution. Xanthocnemis zealandica had longer development requirements (≥125 d), which limited their distribution in less predictable temporary ponds, whereas S. arguta were less constrained in development (≥56 d) and inhabited more temporary ponds. The longer development time of X. zealandica meant they benefited from flexible life-history traits: shorter development, limited desiccation tolerance in temporary ponds, and extended development and predator avoidance in permanent habitats. Sigara arguta had an opportunistic life-history strategy with a fixed, rapid developmental response across the permanence gradient and rapid colonization of refilled temporary ponds. This fixed strategy meant S. arguta was intolerant of drying and, in permanent lakes, was found only in shallow refuges from fish. Neither species differed in adult size across the permanence gradient. Our study shows how life-history strategies enable generalists to achieve broad distributions in a heterogeneous waterscape, and that resilience and flexibility to local selection pressures depend on the constraints of their phenologies. [ABSTRACT FROM AUTHOR]

1. Termites are one of the most important invertebrate ecosystem engineers in tropical regions, which may be quantified using termite biomass data. However, biomass data are particularly difficult to collect as they rely on termites being weighed in the field, which may neither be possible nor convenient. Local scale linear regression models, based on termite head widths (mm) and body masses (mg), have been used in the past to estimate termite biomass using head width and abundance data. However, these models represent very limited numbers of termite taxa from single sites. In the present study, I provide one of the most representative linear regression models available based on 90 samples from three different countries (Peru, Kenya, and Malaysia). 2. Although the linear regression model under- or overestimated body weights of taxa with characteristic features (e.g. large heads of Odontotermes workers or elongated abdomens of Kalotermitidae) it provides a robust method for estimating termite biomass at the community level. Additionally, while there are limitations related to the general model, which may be solved by focusing on taxa specific data and the use of higher accuracy equipment, it is the first model to facilitate termite biomass estimates using the head with and abundance data only. 3. This study encourages the use of termite biomass data to gain a better understanding of termites in ecosystem processes and calls for comparative data to be gathered for the purpose of creating models that may be representative of the variability among termite taxa. [ABSTRACT FROM AUTHOR]

Interdisciplinary research in the fields of ecohydrology and ecogeomorphology is becoming increasingly important as a way to understand how biological and physical processes interact with each other in river systems. The objectives of the current study were 1) to determine changes in invertebrate community due to hydrological stages, 2) to link local physical features [flow configuration, sediment composition and morphological feature) with the ecological structure between and within dissimilar morphological units (meander and confluence), and 3) to determine the existence and the origin of bed hydro-geomorphic patches, determining their ecological structure. Results were discussed in the frame of prevailing ecological models and concepts. The study site extends over a floodplain area of the large Paraná River (Argentina), including minor and major secondary channels as well as the main channel. Overall results suggested that hydrodynamics was the driving force determining distribution patterns of benthic assemblages in the floodplain. However, while the invertebrates living in minor secondary channels seem to benefit from flooding, this hydrological phase had the opposite effect on organisms from the main and major secondary channels. We also found a clear linkage between physical features and invertebrate ecology, which caused a dissimilar fauna structure between and within the meander and the confluence. Furthermore, several sandy-patches were recorded in the confluence. These patches were colonized by the particular benthic assemblage recorded in the main channel, supported the view of rivers as patchy discontinua, under uncertain ecological equilibrium. [ABSTRACT FROM AUTHOR]

Given the widespread degradation of aquatic systems caused by land-use changes associated with palm oil production in South-East Asia, it is imperative to identify and study the remaining undisturbed rivers and streams. Stream macroinvertebrates are reliable indicators of environmental health. Linking the community structure of these organisms to natural hydraulic and geomorphic conditions (categorized as biotopes) is vital for the conservation and restoration of streams. This study characterizes the effects of biotopes on macroinvertebrate community structure in three streams within Ulu Temburong National Park in northern Borneo. Biotopes within these streams were categorized as either bedrock (waterfalls and cascades) or mixed substrate (riffles and pools). In total, 119 taxa were collected from all sampled biotopes, but not all taxa were collected from each stream. Biotopes were statistically distinct in terms of taxonomic richness, but not mean individual density or average community biomass. There were differences in community structure between waterfalls, cascades, pools, and riffles. The survey suggests that pool and riffle biotopes were more vulnerable to scouring flows and had similar community structure, while waterfalls and cascades likely experienced lower sheer stress during floods and had similar macroinvertebrate communities. This study has found that classification and mapping of macroinvertebrates with biotope theory in pristine, tropical streams is a useful framework for simplifying the many linkages between ecology, geomorphology, and hydrology. These natural patterns increase our understanding of tropical streams and can be used to assess the impacts of forest degradation. [ABSTRACT FROM AUTHOR]

Climate changes, geomorphologic modifications and the rise in water demand for human uses contribute to 'aperiodic summer drought' (ASD) events in Mediterranean-type rivers. ASD results in a reach that flows in one summer, dries in next or more summers, and then flowing again. The ecological structure and function of streams affected by ASD are understudied, especially with respect to permanent and regular intermittent streams. We tested the drying memory in a reach of Aterno River (Italy) disturbed by ASD. Leaf litter breakdown of Phragmites australis and macroinvertebrate assemblages were studied. Discharge was monitored since 2006. The experiment was performed during summer 2010 using the litterbag technique, and was replicated four times. The disturbed site was affected by drought in the three previous summers while the control was always flowing. Taxonomic diversity indices, abundance and structure of macroinvertebrate assemblages varied significantly between sites. Instead, leaf litter breakdown wasn't influenced by ASD. Therefore ASD events seem to affect the structure of macroinvertebrate assemblages, confirming the role of drying memory of the systems. The resilience of leaf litter breakdown in reach affected by ASD seems to be high, probably depending on the activity of selected microbial communities and macroinvertebrate features like metabolism and biomass. [ABSTRACT FROM AUTHOR]

Studies of venom variability have advanced from describing the mechanisms of action and relative potency of medically important toxins to understanding the ecological and evolutionary causes of the variability itself. While most studies have focused on differences in venoms among taxa, populations, or age-classes, there may be intersexual effects as well. Striped bark scorpions (Centruroides vittatus) provide a good model for examining sex differences in venom composition and efficacy, as this species exhibits dramatic sexual dimorphism in both size and defensive behavior; when threatened by an enemy, larger, slower females stand and fight while smaller, fleeter males prefer to run. We here add evidence suggesting that male and female C. vittatus indeed have different defensive propensities; when threatened via an electrical stimulus, females were more likely to sting than were males. We reasoned that intersexual differences in defensive phenotypes would select for venoms with different functions in the two sexes; female venoms should be effective at predator deterrence, whereas male venoms, less utilized defensively, might be better suited to capturing prey or courting females. This rationale led to our predictions that females would inject more venom and/or possess more painful venom than males. We were wrong. While females do inject more venom than males in a defensive sting, females are also larger; when adjusted for body size, male and female C. vittatus commit equal masses of venom in a sting to a potential enemy. Additionally, house mice (Mus musculus) find an injection of male venom more irritating than an equal amount of female venom, likely because male venom contains more of the toxins that induce pain. Taken together, our results suggest that identifying the ultimate causes of venom variability will, as we move beyond adaptive storytelling, be hard-won. [ABSTRACT FROM AUTHOR]

Environmental filtering, including the influence of environmental constraints and biological interactions on species' survival, is known to significantly affect patterns of community assembly in terrestrial ecosystems. However, its role in regulating patterns and processes of community assembly in deep-sea environments is poorly studied. Here we investigated the role of wood characteristics in the assembly of deep-sea wood fall communities. Ten different wood species (substrata) that varied in structural complexity were sunk to a depth of 3,100 m near Monterey Bay, CA. In total, 28 wood parcels were deployed on the deep-sea bed. After 2 yr, the wood parcels were recovered with over 7,000 attached or colonizing macroinvertebrates. All macroinvertebrates were identified to the lowest taxonomic level possible, and included several undescribed species. Diversity indices and multivariate analyses of variance detected significant variation in the colonizing community assemblages among different wood substrata. Structural complexity seemed to be the primary factor altering community composition between wood substrata. For example, wood-boring clams were most abundant on solid logs, while small arthropods and limpets were more abundant on bundles of branches that provided more surface area and small, protected spaces to occupy. Other factors such as chemical defenses, the presence of bark, and wood hardness likely also played a role. Our finding that characteristics of woody debris entering the marine realm can have significant effects on community assembly supports the notion of ecological and perhaps evolutionarily significant links between land and sea. [ABSTRACT FROM AUTHOR]

Macroinvertebrates are widely used as indicators to detect and assess anthropogenic impacts on freshwater ecosystems. However, despite being considered useful in indicating effects of environmental change in alpine catchments, little is known about species preferences for local conditions in such environments. In exploring the occurrence of 59 taxa within the dipteran family Chironomidae in relation to key-environmental variables in alpine and sub-alpine streams, we showed that sediment load, water temperature, periphyton density, and fine particulate organic matter mostly explain assemblage structures. Two-way-cluster analyses identified stream-type specific assemblages, indicator value analysis defined indicator species for glacial and non-glacial streams, and weighted averaging regression models confined preferences for local environmental conditions by summing their optima and tolerance widths regarding environmental key factors. The definition of habitat requirements identified stenoecious taxa with preferences for high and low values of respective variables thus identified most suitable indicators for future studies. Our work reveals manifold preferences within the dominant benthic invertebrate family, underlines their enormous potential for monitoring purposes, and is a step forward in better understanding ecosystem properties and biodiversity. Fundamental requirements for these kinds of indicative traits, essential to understand cause-effect relationships in environmental change issues, are a robust taxonomy and a comprehensive set of physical and chemical data. [ABSTRACT FROM AUTHOR]

Urban rivers in developing countries, including South Africa, are increasingly being impacted by human activities. The Bloukrans and Palmiet Rivers, where the current study was undertaken, are no exception. The Bloukrans River, the main object of this study, was impacted by wastewater effluent discharges and run-off from informal settlements and agricultural activities. The present study was aimed at evaluating the ecological health of the Bloukrans River using macroinvetebrate-based biomonitoring approaches, including the biotic index (i.e. the South African Scoring System version 5), multimetric and multivariate analyses of the assemblage structure. 18 metrics were selected and their potential for discriminating between the control and impaired sites evaluated. Macroinvertebrates were sampled bi-monthly (April – August 2013) at one control site (i.e. Site 1) in the Palmiet River and four impaired sites (i.e. Sites 2, 3, 4 and 5) in the Bloukrans River. The Scoring index indicated that the river health condition at the control site was good, whereas apart from Site 5, conditions at Sites 2, 3 and 4 were either poor or critically modified. Twelve metrics discriminated between Site 1 and the four impaired sites. Canonical correspondence analysis indicated that dissolved oxygen, electrical conductivity, nutrients and turbidity exerted the greatest influenced on the assemblage structure. Overall, the study indicated that pollution in the Bloukrans River had significant impact on the river health, influencing metrics in the diversity, composition and richness categories. The 12 metrics that proved sensitive to deteriorating water quality, enabling the discrimination of the control site from the impacted sites, could be used with the Scoring index to assess river health in the Bloukrans River. However, although using metrics in addition to the Scoring index provided greater understanding, where analytical resources are limited the summary biotic Scoring index can provide an acceptable rapid indication of river health. [ABSTRACT FROM AUTHOR]

Habitat heterogeneity can influence biological communities by providing a diversity of areas that can be occupied by different species. Sandy beach surf zones are often considered homogenous environments; however, sand bars moved by currents and waves can produce trench-like shapes or troughs that provide heterogeneity. The influence of habitat heterogeneity produced by sand movement is unclear despite the fact that surf zones are an important habitat for larval and juvenile fish and macrocrustaceans. To determine if, and how, the fish and macroinvertebrate communities present in trough and non-trough or flat areas of Oregon surf zones differ, we compared species assemblages in both areas at three beaches adjacent to estuary mouths over 2 years. Troughs had different communities compared with flat areas, with higher total catch (mean ± SD = 123.2 ± 122.1 versus 43.6 ± 44.5 individuals × 100 m−2) and taxon richness (6.7 ± 2.7 versus 4.0 ± 2.3 taxa); these differences were potentially due to water movement, prey availability and sediment size. The fish and macroinvertebrate communities did not vary between years but there were significant differences among beaches, with the most distinct community present at the only beach adjacent to an estuary without a jetty at its mouth, which was possibly due to higher species movement between the surf zones and estuary. Fish and macrocrustacean surf zone communities varied spatially within and among beaches in relation to habitat heterogeneity provided by sand movement and, potentially, the influence of adjacent habitats. [ABSTRACT FROM AUTHOR]

It is increasingly evident that cryptic stages of many parasites cause asymptomatic infections in a diversity of hosts. This review examines what may cause these infectious agents to persist as asymptomatic infections in invertebrates and how environmental change is linked with the subsequent development of overt infection and disease. In many systems, disease dynamics are closely associated with host condition which, in turn, is linked with environmental change. Symbionts (commensals and mutualists) display similar dynamics when environmental change causes them to exert negative effects on their hosts. Although such asymptomatic infections are demonstrated in a range of invertebrate hosts they are greatly undersampled because most invertebrate diseases are uninvestigated, infections are difficult to detect, and many parasite groups are poorly characterized. A better understanding of the diversity and distribution of parasites that cause asymptomatic infections and of their complex relationships with invertebrate hosts will enable a fuller appreciation of context-dependent host-parasite interactions and will address the biased focus on diseases of invertebrates of practical importance. The existence of such infections could underlie novel disease outbreaks that might otherwise be attributed to invasives while altered disease dynamics may provide an additional and complementary indicator of ecosystem change. [ABSTRACT FROM AUTHOR]

Copyright of Brazilian Journal of Oceanography is the property of Instituto Oceanografico da Universidade de Sao Paulo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Arsenic (As) can play an important role in the contamination of soils, waters, and air. The toxicity of As to most organisms is well established, but little is known about the interactions between environmental As and terrestrial invertebrates and the fate of As through trophic levels. Pteris vittata L. (Polypodiales: Pteridaceae), a fern that hyperaccumulates arsenic, serves as a potential mechanism to facilitate interactions between environmental arsenic and other biota. We compared invertebrate arsenic concentrations (hereafter as [As]) and bioaccumulation factors associated with soil and fern [As] to elucidate relationships between invertebrate and environmental As exposure. We collected invertebrates in pitfall traps from field sites associated with P. vittata, and identified them to order for whole body arsenic analysis and subsequently family for classification into functional feeding groups. We found that overall [As] in invertebrates increased with soil [As], but not with fern [As]. The absence of a relationship between fern [As] and invertebrate [As] may indicate invertebrates are avoiding the fern. Individual taxonomic groups significantly differed in whole body [As], and individual taxa also varied in their relationship between whole body [As] relative to soil and fern [As]. Overall invertebrate abundance decreased as invertebrate [As] load increased but varied across taxa. One particular herbivore, Callopistria floridensis (Florida fern caterpillar), associated with relatively low environmental As exposure contained over 4,000mg kg-1 As. Our results show that As bioaccumulates into higher trophic levels and invertebrate body [As] covary with exposure to naturally occurring environmental [As] associated with P. vittata. [ABSTRACT FROM AUTHOR]

The paper evaluates the relationships among invertebrate communities, land uses and chemical and microbiological groundwater properties, in a loessic unconfined aquifer in Argentina. Two surveys were conducted and seven wells were selected based on land use and unsaturated zone (USZ) thickness. Groundwater was characterized mainly as freshwater of sodium bicarbonate type. Invertebrates collected belong to Crustacea, Acari, Insecta, Collembola, Oligochaeta, Collembola, Pauropoda, and Nematoda. Crustacea was the most abundant group. The wells differed in terms of invertebrate composition and abundance. The lowest abundance was observed at sites with thickest USZ. No direct relationship was found between invertebrate abundance and any particular physicochemical parameter. In the only well where bacteria were detected, total invertebrate abundance, especially of copepods, was high in both surveys. Both USZ thickness and land use have a significant influence on abundance and composition of invertebrate communities in terms of organic matter inputs into the aquifer. [ABSTRACT FROM PUBLISHER]

Many recent studies have searched to integrate species' functions and phylogenies in the measurement of biodiversity. To obtain easily interpretable measures, some researchers recommended diversity indices expressed in terms of equivalent numbers of species: the number of equally likely and maximally dissimilar species needed to produce the given value of diversity. Then, biodiversity is often calculated at three scales: within communities (α diversity), among communities (β diversity) and in a region (γ diversity). These three scales are, however, insufficient to tackle the organization of biodiversity in space because, for most organisms, there is a nested hierarchy of multiple scales characterized by different patterns and processes, from the small neighbourhood to the biosphere., We developed methodologies for analysing species, functional, taxonomic or phylogenetic diversity in a hierarchy of multiple scales using equivalent numbers of species. As an example, we analysed the taxonomic and functional diversity of macroinvertebrate assemblages in the Loire River, France, at four levels: within sites (α diversity), among sites within geological regions (β1 diversity), among geological regions (β2 diversity) and at the river scale (γ diversity). The new hierarchical approaches of biodiversity revealed very low differences among sites within regions and among regions in terms of taxonomy and functional traits (size and diet), despite moderate, significant species turnover among geological regions., We compare our framework with those other authors have developed. We argue that different definitions of α, β, γ diversities are used in the literature reflecting different points of view on biodiversity. We make recommendations on how to normalize functional (or phylogenetic) dissimilarities among species to render sites and regions comparable, and discuss the pros and cons of our approach., The hierarchical approaches of biodiversity in terms of 'equivalent numbers' respond to current demands to obtain intuitive, easily interpretable components of biodiversity. The approaches we propose go beyond current developments by considering a hierarchy of spatial scales and unbalanced sampling design. They will provide powerful tools to detect the ecological and evolutionary processes that act differently at different scales. [ABSTRACT FROM AUTHOR]

Coral reefs are increasingly threatened by global and local anthropogenic stressors such as rising seawater temperature, nutrient enrichment, sedimentation, and overfishing. Although many studies have investigated the impacts of local and global stressors on coral reefs, we still do not fully understand how these stressors influence coral community structure, particularly across environmental gradients on a reef system. Here, we investigate coral community composition across three different temperature and productivity regimes along a nearshore-offshore gradient on lagoonal reefs of the Belize Mesoamerican Barrier Reef System (MBRS). A novel metric was developed using ultra-high-resolution satellite-derived estimates of sea surface temperatures (SST) to classify reefs as exposed to low (lowTP), moderate (modTP), or high (highTP) temperature parameters over 10 years (2003 to 2012). Coral species richness, abundance, diversity, density, and percent cover were lower at highTP sites relative to lowTP and modTP sites, but these coral community traits did not differ significantly between lowTP and modTP sites. Analysis of coral life history strategies revealed that highTP sites were dominated by hardy stress-tolerant and fast-growing weedy coral species, while lowTP and modTP sites consisted of competitive, generalist, weedy, and stress-tolerant coral species. Satellite-derived estimates of Chlorophyll-a (chl-a) were obtained for 13-years (2003–2015) as a proxy for primary production. Chl-a concentrations were highest at highTP sites, medial at modTP sites, and lowest at lowTP sites. Notably, thermal parameters correlated better with coral community traits between site types than productivity, suggesting that temperature (specifically number of days above the thermal bleaching threshold) played a greater role in defining coral community structure than productivity on the MBRS. Dominance of weedy and stress-tolerant genera at highTP sites suggests that corals utilizing these two life history strategies may be better suited to cope with warmer oceans and thus may warrant protective status under climate change. [ABSTRACT FROM AUTHOR]

A surprisingly large number of European spider species have never been reliably rediscovered since their first description many decades ago. Most of these are probably synonymous with other species or unidentifiable, due to insufficient descriptions or missing type material. In this second part of a series on this topic, we discuss about 100 of these cases, focusing mainly on species described in the early 20th century by Pelegrín Franganillo Balboa and Gabor von Kolosváry, as well as a number of jumping spiders and various miscellaneous species. In most cases, the species turned out to be unidentifiable nomina dubia, but for some of them new synonymies could be established as follows: Alopecosa accentuata auct., nec (Latreille, 1817) = Alopecosa farinosa (Herman, 1879) syn. nov., comb. nov.; Alopecosa barbipes oreophila Simon, 1937 = Alopecosa farinosa (Herman, 1879) syn. nov., comb. nov.; Alopecosa mariae orientalis (Kolosváry, 1934) = Alopecosa mariae (Dahl, 1908) syn. nov.; Araneus angulatus afolius (Franganillo, 1909) and Araneus angulatus atricolor Simon, 1929 = Araneus angulatus Clerck, 1757 syn. nov.; Araneus angulatus castaneus (Franganillo, 1909) = Araneus pallidus (Olivier, 1789) syn. nov.; Araneus angulatus levifolius (Franganillo, 1909), Araneus angulatus niger (Franganillo, 1918) and Araneus angulatus nitidifolius (Franganillo, 1909) = Araneus angulatus Clerck, 1757 syn. nov.; Araneus angulatus pallidus (Franganillo, 1909), Araneus angulatus crucinceptus (Franganillo, 1909), Araneus angulatus fuscus (Franganillo, 1909) and Araneus angulatus iberoi (Franganillo, 1909) = Araneus pallidus (Olivier, 1789) syn. nov.; Araneus circe strandi (Kolosváry, 1935) = Araneus circe (Audouin, 1826) syn. nov.; Araneus diadematus nemorosus Simon, 1929 and Araneus diadematus soror (Simon, 1874) = Araneus diadematus Clerck, 1757 syn. nov.; Araneus pyrenaeus (Simon, 1874) = Araneus pallidus (Olivier, 1789) syn. nov.; Araneus sericinus (Roewer, 1942) = Aculepeira armida (Audouin, 1826) syn. nov.; Arctosa brevialva (Franganillo, 1913) = Arctosa villica (Lucas, 1846) syn. nov.; Arctosa cinerea (Franganillo, 1913) [nec Arctosa cinerea (Fabricius, 1777)] = Arctosa perita (Latreille, 1799) syn. nov.; Cresmatoneta eleonorae (Costa, 1883) and Cresmatoneta mutinensis orientalis (Strand, 1914) = Cresmatoneta mutinensis (Canestrini, 1868) syn. nov.; Cyclosa conica albifoliata Strand, 1907, Cyclosa conica defoliata Strand, 1907, Cyclosa conica leucomelas Strand, 1907, Cyclosa conica pyrenaica Strand, 1907, Cyclosa conica dimidiata Simon, 1929, Cyclosa conica rubricauda Simon, 1929 and Cyclosa conica triangulifera Simon, 1929 = Cyclosa conica (Pallas, 1772) syn. nov.; Dendryphantes lanipes C.L. Koch, 1846 = Philaeus chrysops (Poda, 1761) syn. nov.; Diplocephalus alpinus strandi Kolosváry, 1937 = Diplocephalus alpinus (O. Pickard- Cambridge, 1872) syn. nov.; Entelecara strandi Kolosváry, 1934 = Nusoncus nasutus (Schenkel, 1925) syn. nov.; Euophrys rosenhaueri L. Koch, 1856 = Menemerus semilimbatus (Hahn, 1829) syn. nov.; Evarcha falcata nigrofusca (Strand, 1900) = Evarcha falcata (Clerck, 1757) syn. nov.; Gibbaranea bituberculata strandiana (Kolosváry, 1936) = Gibbaranea bituberculata (Walckenaer, 1802) syn. nov.; Heliophanus auratus mediocinctus Kulczyński, 1898 = H. mediocinctus Kulczyński, 1898 stat. nov.; Larinioides sclopetarius jacobea (Franganillo, 1910) = Larinioides sclopetarius (Clerck, 1757) syn. conf.; Linyphia triangularis juniperina Kolosváry, 1933 = Linyphia triangularis (Clerck, 1757) syn. nov.; Myrmarachne formicaria tyrolensis (C. L. Koch, 1846) = Myrmarachne formicaria (De Geer, 1778) syn. conf.; Nuctenea umbratica obscura (Franganillo, 1909) = Nuctenea umbratica (Clerck, 1757) syn. nov.; Ozyptila strandi Kolosváry, 1939 = Ozyptila confluens (C. L. Koch, 1845) syn. nov.; Panamomops strandi Kolosváry, 1934 = Saloca diceros (O. Pickard-Cambridge, 1871) syn. nov.; Pardosa luctinosa marina (Kolosváry, 1940) and Pardosa luctinosa etsinensis Schenkel, 1963 = Pardosa luctinosa Simon, 1876 syn. nov.; Pardosa wagleri atra (Giebel, 1869) nomen oblitum = Pardosa saturatior Simon, 1937 syn. nov.; Poecilochroa hungarica Kolosváry, 1934 = Aphantaulax trifasciata (O. Pickard-Cambridge, 1872) syn. nov.; Philaeus albovariegatus (Simon, 1868) = Philaeus chrysops (Poda, 1761) syn. nov.; Philaeus superciliosus Bertkau, 1883 = Sandalodes superbus (Karsch, 1878) syn. nov.; Philaeus varicus (Simon, 1868) = Carrhotus xanthogramma (Latreille, 1819) syn. conf.; Salticus unispinus (Franganillo, 1910) = Pellenes nigrociliatus (Simon, 1875) syn. nov.; Sitticus manni (Doleschall, 1852) nomen oblitum = Heliophanus melinus L. Koch, 1867 syn. nov.; Sitticus sexsignatus (Franganillo, 1910) = Sitticus floricola (C. L. Koch, 1837) syn. nov.; Steatoda latrodectoides (Franganillo, 1913) = Steatoda paykulliana (Walckenaer, 1805) syn. nov.; Synema globosum clarum Franganillo, 1913, Synema globosum flavum Franganillo, 1913 and Synema globosum pulchellum Franganillo, 1926 = Synema globosum (Fabricius, 1775) syn. nov.; Uloborus pseudacanthus Franganillo, 1910 = Uloborus walckenaerius Latreille, 1806 syn. nov.; Zelotes similis hungaricus Kolosváry, 1944 = Zelotes similis (Kulczyński, 1887) syn. nov.; Zilla diodia embrikstrandi Kolosváry, 1938 = Zilla diodia (Walckenaer, 1802) syn. nov.; Zygiella x-notata chelata (Franganillo, 1909) and Zygiella x-notata parcechelata (Franganillo, 1909) = Zygiella x-notata (Clerck, 1757) syn. nov.; Teutana grossa obliterata Franganillo, 1913 = Steatoda grossa (C. L. Koch, 1838) syn. nov. [ABSTRACT FROM AUTHOR]

Cheiracanthium rupestre Herman, 1879, and Xysticus albomaculatus Kulczyński, 1891, both originally described from Hungary, are among the most rarely reported species of their genera in Europe. Here we report that both of these species have very close relationships to similarly uncommon species originally described from France at about the same time. The specimens currently considered as Cheiracanthium rupestre turn out to be very closely related to, but distinct from, Cheiracanthium striolatum Simon, 1878. However, the original description of C. rupestre does not match these specimens nor any other known species of Cheiracanthium. We therefore consider C. rupestre a nomen dubium and suggest that all previous records of this species after the original description actually refer to Cheiracanthium macedonicum Drensky, 1921. Xysticus albomaculatus, on the other hand, turns out to be a junior synonym of Bassaniana baudueri (Simon, 1877) syn. nov., expanding the range of this species considerably to the East and at the same time confirming that it is a genuine European species, rather than a recent immigrant from North America as previously suspected. [ABSTRACT FROM AUTHOR]

A new humped orb-weaver, Gibbaranea bruuni Lissner spec. nov., is described from specimens collected in Majorca, Spain. The new species is most closely related to two other western Palaearctic species, Gibbaranea gibbosa (Walckenaer, 1802) and Gibbaranea occidentalis Wunderlich, 1989. Araneus dromedarius cuculliger Simon, 1909 (= Gibbaranea bituberculata cuculliger) is synonymized with Gibbaranea bituberculata (Walckenaer, 1802), syn. nov. [ABSTRACT FROM AUTHOR]

A new nematode species belonging to the family Alloionematidae was originally isolated by Dr Marie Anne Felix on 16 December 2007 from a rotting coconut at the boat boarding point in Estuary island resort, Poovar, Kerala, India. Both morphologically and molecularly, the new isolate resembles Neoalloionema tricaudatum but, unlike N. tricaudatum this species has no phasmidial 'horns' in the juvenile stage, even though prominent structures in the mid-tail of dauer juveniles were observed. Females are characterised by a body length of 947 (869-1030) pm, vulva in the mid-body region, long, and tapering tail with a minute post-anal swelling. Males are 678 (606-757) pm long with a long tapering tail that is very thick at base. They are further characterised by seven pairs of genital papillae and a single genital papilla. Dauer juveniles are only 391 (364-434) µm long, thin and almost straight when heat-killed. Large, prominent phasmids are located laterally at the mid-tail region and lateral fields consisting of a single ridge are present. Several morphological and molecular differences encouraged us to describe the nematode as N. indicum n. sp. The ecology of the newly described species is unknown, but it is probably a saprophytic bacteriophagous nematode preferring rotting organic material. [ABSTRACT FROM AUTHOR]

In a field study carried out in 2011 and 2014 adult dragonflies were identified as a rapid and easy-to-use means of assessing habitat quality and biological integrity of Mediterranean streams and rivers in the province of Barcelona (Region Catalonia, Iberian Peninsula). The study included sampling sites from five different river catchments: Besòs, Foix, Llobregat, Ter and Tordera. Multivariate statistical procedures and indicator species analysis were used to investigate the relationship between river ecological status, study sites and dragonfly species or species assemblages’ occurrence. The dragonfly association identified with western Mediterranean permanent streams, i.e.Cordulegaster boltonii,Boyeria irene,Onychogomphus uncatusandCalopteryx virgo meridionalis, was found only at the sites with the highest status. All these taxa were identified as indicator species of sites with the best scores for the macroinvertebrate based IBMWP index and for the combined IASPT index, which reflects the sensitivity of the macroinvertebrate families present to environmental changes; besides,B.ireneandC.virgo meridionalisalso proved to be indicator species of the riparian forest quality index andC. boltoniiof the more inclusive ECOSTRIMED, which assesses the overall conservation status of the riverine habitats. The information obtained on habitat preferences and indicator value showed that adults of these taxa may constitute a valuable tool for preliminary or complementary cost-effective monitoring of river status and restoration practices as part of a broader set of indices reflecting biodiversity and ecosystem integrity. [ABSTRACT FROM PUBLISHER]

Studies assessing stream restoration of acid mine drainage ( AMD) usually use community metrics that emphasize only a few attributes of ecological integrity. We used a variety of measures to examine recovery of macroinvertebrate communities in a watershed receiving passive treatment for AMD. We measured density, richness, functional diversity ( FD), taxonomic diversity (Δ, a measure of taxonomic relatedness), and community taxonomic composition at 4 stream sites over an 11-year period: 1 reference not affected by AMD, 2 downstream of treatment systems, and 1 AMD-impacted site with no treatment. Our objectives were to determine if communities have responded to remediation, and examine whether FD and Δ provided additional insights into ecology integrity. Richness, FD, and Δ at the reference site were significantly higher than for other sites, but did not consistently differentiate treated and untreated sites. Additional information provided by FD and Δ on attributes related to functional redundancy and taxonomic relatedness was self-evident given the simplicity of nonreference communities. Ordination of community composition incorporating knowledge of taxa autecologies indicated that treated sites were slightly less impacted than the untreated site, and trend analysis indicated slight improvement at 1 treated site. However, communities below treatment remained taxonomically distinct, with much lower densities than reference condition. Macroinvertebrate communities showed less recovery than was determined for benthic diatom communities at the same sites in a previous study. Several attributes of ecological integrity for different types of stream organisms should be incorporated into bioassessment of AMD restoration because they can vary in their response. [ABSTRACT FROM AUTHOR]

Fine sediments in excess of natural background conditions are one of most globally common causes of stream degradation, with well documented impacts on aquatic communities. The lack of agreement on methods for monitoring fine sediments makes it difficult to share data, limiting assessments of stream conditions across jurisdictions. We present a model that circumvents these limitations by inferring fine sediments in Oregon streams through sampling of macroinvertebrates. Tolerances to fine sediments (<0.06 mm diameter) were calculated for 240 macroinvertebrate taxa, from a calibration dataset of 446 sites across Oregon, as well as an independent validation dataset of 50 samples. Weighted averaging methods were used to infer fine sediment levels in streams by weighting the tolerances of modeled taxa observed in a sample by their abundances. The final model, the Biological Sediment Tolerance Index (BSTI), showed a strong relationship to measured fine sediments (calibration r 2 = 0.49, validation r 2 = 0.58). Root-mean-squared-error was small in the calibration dataset (2% fines), but larger in the validation dataset (14% fines). Repeatability was assessed by examining variability in BSTI at 14 sites across Oregon. Because field methods for sampling macroinvertebrates are standardized across resource agencies in Oregon and the responses of macroinvertebrates represent the actual effects of fine sediments on stream ecosystems, the BSTI may offer water resource managers’ a cost-effective method for assessing fine sediment conditions in their ongoing efforts to improve water quality across the state. [ABSTRACT FROM AUTHOR]

The Brazilian semiarid region has a clear distinction between the dry season, which can last up to nine months, and the rainy season. Caves are connected to different extents to surface ecosystems, although they are idealized as stable environments due to their isolation. Furthermore, little is known about the effects of wet and dry seasonal variations on underground biological assemblages. Invertebrate communities were analyzed during dry and rainy seasons in 24 caves in the semiarid region of northeastern Brazil. We also investigated whether the environmental stability of caves attenuates the effects of seasonality in this particular region. Morphospecies richness and abundance and the diversity indexes of caves were significantly higher during the rainy season. In addition, more stable caves showed less variation in the community composition between seasons. Our data point to a clear influence of the surface ecosystems on the caves in Caatinga. However, the intensity of this influence apparently depends on the environmental stability of the cave, and the most stable caves present smaller changes in the structure of their invertebrate communities during different seasons. [ABSTRACT FROM AUTHOR]

The aim of the study was to estimate the impact of oxygen depletion on macroinvertebrate community structure in benthic space. Macroinvertebrate assemblages and potential of dissolved oxygen (DO) consumption were investigated simultaneously in the plain rivers of the Ziya River Basin. The degree of DO depletion was represented by sediment oxygen demand (SOD) and DO, chemical oxygen demand (COD), and ammonia nitrogen (NH-N) in the overlying water. The results showed an all-around hypoxia environment formed, and the values of DO, SOD, COD, and NH-N were separately 0.11-4.03 mg L, 0.41-2.60 g m day, 27.50-410.00 mg L, and 1.79-101.41 mg L. There was an abnormal macroinvertebrate assemblage, and only 3 classes, Insecta, Gastropoda, and Oligochaeta, were found, which included 9 orders, 30 families, and 54 genera. The biodiversity was at a low level, and Shannon-Wiener index was 0.00-1.72. SOD, and NH-N had major impact on the macroinvertebrate community, and the former had negative effect on most taxa, for instance, Nais, Branchiura, Paraleptophlebia, etc., which were sensitive or had a moderate-high tolerance to pollution. NH-N had both positive and negative impacts on benthic animals, for instance, Dicrotendipes, Gomphus, Cricotopus, etc., for the former, and Procladius, Limnodrilus, Hippeutis, etc., for the latter. They all had a moderate-high tolerance to pollution. It is significant to improve DO condition and macroinvertebrate diversity in river harnessing and management. [ABSTRACT FROM AUTHOR]

We analyzed the effects of sewage discharge on a subtropical estuary by comparing the functional diversity of intertidal macroinvertebrate assemblages in contaminated with non-contaminated reference areas. Functional structure was assessed using biological traits analysis (BTA) and four multivariate indices (FRic, FEve, FDis and Rao's Q) of functional diversity. Our results showed clear and temporally consistent changes in macrobenthic functional structure in contaminated areas. However, these results depended on whether abundance- or biomass-based measurements were used, with abundance-based analyses distinguishing most clearly between sewage contamination conditions. Differences between contaminated and non-contaminated conditions were also displayed by BTA for all the functional trait categories. FDis (functional divergence) and Rao's Q (functional dispersion) were higher in the non-contaminated condition and increased with higher benthic environmental health, as measured by the AMBI index. These patterns of higher functional divergence and dispersion were driven by the numerical dominance of opportunistic annelids in the contaminated condition. We suggest that abundance-based BTA, and the FDis and/or Rao's Q indices are reliable approaches to detect changes in functional structure with respect to sewage pollution. They have a great potential for environmental assessment and monitoring of subtropical estuarine ecosystems. [ABSTRACT FROM AUTHOR]

1. Nature conservation legislation affords different degrees of protection to specifically named species, ranging from recognition within the planning system to strict protection from harm and habitat loss. This review considers two groups of species that do not have strict protection but are recognised within 'development control' (the process that regulates the planning of land use and new buildings), namely Annex II species of the Habitats Directive (HD) and Species of Principal Importance identified under UK legislation and policy. 2. A critical point often forgotten by the HD's detractors is that Annex II is not only a list of species that require protection but also a list of species that represent criteria for the designation of protected sites. It is not feasible for all threatened species to be protected due to administrative and legal ramifications, so the subset of species listed need to have wider merit as umbrella species. 3. The selection of widespread species on Annex II results in the creation of a better network of Special Areas of Conservation than if geographically localised or endemic species are used, and benefits a suite of rare and scarce species beyond those named in Annex II. Species of Principal Importance enable recognition of invertebrates in the UK planning system even though many of them are not directly threatened with national loss. 4. Given the intense scrutiny to which nature conservation legislation is exposed, it is important for critics to understand the function of legislation and its application in the sociopolitical arena. [ABSTRACT FROM AUTHOR]

Seventeen specimens representing three of the four asterozoan classes (Stenuroidea, Asteroidea, Ophiuroidea) are recorded from Ordovician and Silurian strata of the western United States and northwest France; only the Somasteroidea is not represented. New taxa are: the stenuroids Lopidiaster jamisoni nov. gen. and sp. and Lehmannaster spinosus nov. gen. and sp.; the asteroids Meturaster belli nov. gen. and sp., Petraster crozonensis nov. sp., and Schuchertia sprinklei , nov. sp.; Lepidactis ? sp. also is recognized. The Ophiuroidea is represented by Stenaster sp., Protaster sp., and an arm tip is of unknown familial and generic affinities. Class level assignments of all specimens are clear, and all but Lopidiaster are similar to earlier-known representatives of their respective classes; phylogenetic differentiation within the subphylum was well-established early in the Paleozoic. Ordovician asterozoans are both geographically widely distributed and morphologically clearly separable from modern asterozoans, yet overall structural similarities favor ecologic roles paralleling those known today. [ABSTRACT FROM AUTHOR]

This study describes the composition and temporal variation of the spider assemblage (Arachnida: Araneae) associated with canopies of Vochysia divergens Pohl. (Vochysiaceae) in the northern region of the Brazilian Pantanal. Three V. divergens plants were sampled in 2004, at each seasonal period of the northern Pantanal (high water, receding water, dry season and rising water), using thermonebulization of the canopies with insecticide, totaling 396 m² of sampled canopies. Analysis of abundance and richness of spider families were based on Non-Metric Multidimensional Scaling (NMDS) and Variance Analysis (ANOVA and MANOVA). A total of 7,193 spiders were collected (6,330 immatures; 88.0%; 863 adults, 12.0%) distributed in 30 families. Araneidae (1,676 individuals), Anyphaenidae (1,631 individuals), Salticidae (1,542 individuals) and Pisauridae (906 individuals), were predominant, representing 80.0% of the sample. Ten different guilds were registered: aerial hunters, orb-weavers, nocturnal aerial runners and diurnal space web weavers dominated, sharing most ecological niches. The spider assemblage is affected by changes in the habitat structure, especially by the seasonal hydrological regime and variations in the phenology of V. divergens. The assemblage is composed of different groups of spiders. The dominant taxa and behavioral guilds differ in the different seasonal periods. Spiders were more abundant during the dry and rising water seasons, most likely reflecting a greater supply of potential prey, associated with new foliage and flowering at the canopy. The displacement of soil dwelling spiders to the trunks and canopies before and during the seasonal floods can change the structure and composition of the canopy assemblages. Oonopidae, Gnaphosidae and Caponiidae, were more frequent during the rising and high water seasons, which indicates that these taxa use the canopies of V. divergens as a refuge during the seasonal flooding in the Pantanal. [ABSTRACT FROM AUTHOR]

The ecological integrity of freshwater ecosystems is regularly examined through assessment of their macroinvertebrate assemblages. The various methods used in such biomonitoring all have one characteristic in common – the neglect of water mites. Even though this group perfectly fulfills all necessary requisites for successful bioindicators, these invertebrates are either completely ignored or lumped together as “Acari”. This study, for the first time, uses water mites (Hydrachnidia) as bioindicators in the Neotropics to compare the anthropogenic stress in 15 streams at three different levels of contamination (pristine, rural, urban). In total, 4371 water mite specimens, belonging to 31 genera and 14 families, were collected. Diversity, abundance, and richness of water mite assemblages were significantly reduced with increasing levels of contamination. These differences were clearest in the dry season. Atractidella turned out to be, by far, the most tolerant water mite genus, having the greatest abundance at the most contaminated sites. In contrast, Pseudotorrenticola was found only in pristine waters, while Hydrodroma , Limnesia , Koenikea , Torrenticola, Monatractides and the family Aturidae showed clear preferences for pristine waters. Our data show, that water mites, identified to genus level, are well suited for water quality assessment in neotropical lowland streams, clearly distinguishing different levels of contamination/anthropogenic stress. [ABSTRACT FROM AUTHOR]

The ecological knowledge of large rivers is still scarce or highly fragmented mainly because of complex, laborious and expensive procedures to collect informative samples from the benthic biota. Standard sampling protocols for macroinvertebrates were mainly developed and calibrated for wadeable streams, while a number of heterogeneous non-standard sampling procedures are available for large rivers. We propose the new, easy-to-build and cost-effective leaf-nets (LN) method to quantitatively sample benthic invertebrates in non-wadeable waterways. The LN method uses Phragmites australis leaves as substrate and combines the characteristics of the leaf-bags and the Hester-Dendy (HD) multiplates methods. We compared the effectiveness of the LN and HD methods in a near-pristine and in an impacted stream-reach (downstream an aquaculture plant) of a non-wadeable second-order stream of Central Apennines (Italy). Twenty-five of the 34 cumulatively collected macroinvertebrate taxa were common to both methods, while seven taxa were found only on LN and two only on HD. Taxonomic richness and total macroinvertebrate abundance were higher for LN assemblages. Number of Ephemeroptera, Plecoptera and Trichoptera taxa (EPT) also tended to be higher on LN. Assemblage composition was different on LN and HD. Both methods documented a significant decrease in EPT taxa and a concomitant increase in the total abundance of more pollution-tolerant taxa in the impacted stream-reach, but the LN method was more sensitive to impact-associated changes in macroinvertebrate assemblage structure. In contrast to the hardboard plates of HD, the assembled leaves of the LN may act as a direct or indirect food source and may better mimic the texture and composition of more heterogeneous natural substrates thus favouring the migration-colonization process from both bottom and littoral benthic invertebrates. The sampling efficiency, cost effectiveness and simplicity warrant the routine use of the new LN method in large-river ecological assessment. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The ecological impact of fine sediments is one of the major causes of ecological degradation affecting lotic systems. Interestingly, many studies have investigated the impact of increased sediment loads on specific compartments of the lotic system, but little or no information is available about the overall impact of sedimentation. Aim of this paper was to analyse the influence of fine sedimentation on allochthonous and autochthonous energy inputs and on the structural and functional characteristics of diatom and macroinvertebrate communities. Data were collected in two Alpine streams in NW Italy, one interested by the presence of an intense mining area and the other pristine, used as a control. The two rivers greatly differed in terms of suspended solids and bed load characteristics. From 10 stations, we analysed main physico-chemical characteristics, fine sediment indicators (using 60 sediment traps), coarse particulate organic matter (CPOM) and photosynthetic pigments amounts, taxonomic and functional characteristics of macroinvertebrate communities. We tested several causal models via path analysis. Functional traits seem to better reflect the integrated impact originating from quarries in the river basin than traditional community metrics like total abundance and specific richness. This outcome was enforced through the co-inertia analysis, which took in consideration also metrics based on diatom communities. Our study yielded quantitative relations between sediment loads induced by quarrying activities and the degree of biological impairment and suggests which metrics are more suitable to assess this specific impact. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The mechanisms underlying responses of stream invertebrates to low flows are poorly understood. To clarify the strategies used to tolerate and survive low flow periods, we tested associations between patch-scale invertebrate densities and velocity within riffle habitats during moderate and low flows. We focused on filter-feeding and respiration traits because they have a mechanistic link to invertebrate low flow responses. 228 samples were collected from 3 riffles at 2 low and 2 moderate flow periods. Maximum densities of filter-feeders were positively associated with the highest velocities during low flows, but not moderate flows, partly consistent with our prediction that they would be structured along velocity gradients to meet nutritional requirements. Gill-respiring invertebrate densities were inversely related to velocity during both flows, probably attributable to organic matter accumulated in low velocity areas. O requirements during low flows did not constrain tegument-respirers to higher velocity patches, inconsistent with perceived views of their response to low flows. We found high velocity areas could act as refuges for some invertebrates during low flows, while low velocity patches, which are vulnerable to rapid flow recession, are important habitats for other invertebrates. Environmental flow management should focus on strategies that preserve these habitats during low flows. [ABSTRACT FROM AUTHOR]

The prevailing paradigm in subterranean ecology is that below-ground food webs are simple, limited to one or two trophic levels, and composed of generalist species because of spatio-temporally patchy food resources and pervasive energy limitation. This paradigm is based on relatively few studies of easily accessible, air-filled caves. However, in some subterranean ecosystems, chemolithoautotrophy can subsidize or replace surface-based allochthonous inputs of photosynthetically derived organic matter ( OM) as a basal food resource and promote niche specialization and evolution of higher trophic levels. Consequently, the current subterranean trophic paradigm fails to account for variation in resources, trophic specialization, and food chain length in some subterranean ecosystems. We reevaluated the subterranean food web paradigm by examining spatial variation in the isotopic composition of basal food resources and consumers, food web structure, stygobiont species diversity, and chromophoric organic matter ( CDOM), across a geochemical gradient in a large and complex groundwater system, the Edwards Aquifer in Central Texas ( USA). Mean δ13C values of stygobiont communities become increasingly more negative along the gradient of photosynthetic OM sources near the aquifer recharge zone to chemolithoautotrophic OM sources closer to the freshwater-saline water interface ( FWSWI) between oxygenated freshwater and anoxic, sulfide-rich saline water. Stygobiont community species richness declined with increasing distance from the FWSWI. Bayesian mixing models were used to estimate the relative importance of photosynthetic OM and chemolithoautotrophic OM for stygobiont communities at three biogeochemically distinct sites. The contribution of chemolithoautotrophic OM to consumers at these sites ranged between 25% and 69% of total OM utilized and comprised as much as 88% of the diet for one species. In addition, the food web adjacent to the FWSWI had greater trophic diversity when compared to the other two sites. Our results suggest that diverse OM sources and in situ, chemolithoautotrophic OM production can support complex groundwater food webs and increase species richness. Chemolithoautotrophy has been fundamental for the long-term maintenance of species diversity, trophic complexity, and community stability in this subterranean ecosystem, especially during periods of decreased photosynthetic production and groundwater recharge that have occurred over geologic time scales. [ABSTRACT FROM AUTHOR]

African savannas are highly seasonal with a diverse array of both mammalian and invertebrate herbivores, yet herbivory studies have focused almost exclusively on mammals. We conducted a 2-yr exclosure experiment in South Africa's Kruger National Park to measure the relative impact of these two groups of herbivores on grass removal at both highly productive patches (termite mounds) and in the less productive savanna matrix. Invertebrate and mammalian herbivory was greater on termite mounds, but the relative importance of each group changed over time. Mammalian offtake was higher than invertebrates in the dry season, but can be eclipsed by invertebrates during the wet season when this group is more active. Our results demonstrate that invertebrates play a substantial role in savanna herbivory and should not be disregarded in attempts to understand the impacts of herbivory on ecosystems. [ABSTRACT FROM AUTHOR]

Nassariidae are a group of scavenging, predominantly marine, snails that are diversified on soft bottoms as well as on rocky shores, and are the subject of numerous research papers in ecology, ecotoxicology or paleontology. A weak and/or apparently continuous variation in shell characters has resulted in an intimidating taxonomy, with complex synonymy lists. Over 1320 extant nominal species have been described, of which 442 are currently regarded as valid. Above species level, the state of the art is equally hazy, with four subfamilies and twelve genera currently accepted, and many other names in the graveyard of synonymy. A molecular analysis based on three mitochondrial (COI, 16S, 12S) and two nuclear (28S, H3) markers was conducted. Our dataset includes 218 putative nassariid species, comprising 9 of the 12 valid genera, and 25 nominal genera represented by their type species. The monophyly of the Nassariidae as classically construed is not confirmed. Species of Antillophos , Engoniophos , Phos , Nassaria , Tomlinia and Anentome (formerly considered Buccinidae) are included inside the Nassariidae clade. Within the Nassariinae, the tree unexpectedly demonstrates that species from the Atlantic and the Indo-Pacific form different clades which represent several independent diversification events. Through an integrative approach, the reconstruction of ancestral states was addressed for eight characters supposedly informative for taxonomy. Using numerous fossil calibration points, Nassariidae appear to have originated 120 MYA ago in Atlantic temperate waters during the Lower Cretaceous. Our results have a profound impact on nassariid taxonomy, especially with regard to the validity of subfamily- and genus-level names. [ABSTRACT FROM AUTHOR]

The study evaluated the response of macroinvertebrate assemblages to changes in water quality in different land-use settings in Manyame catchment, Zimbabwe. Four land-use categories were identified: forested commercial farming, communal farming, Great Dyke mining (GDM) and urban areas. Macroinvertebrate community structure and physicochemical variables data were collected in two seasons from 41 sites following standard methods. Although not environmentally threatening, urban and GDM areas were characterised by higher conductivity, total dissolved solids, salinity, magnesium and hardness. Chlorides, total phosphates, total nitrogen, calcium, potassium and sodium were significantly highest in urban sites whilst dissolved oxygen (DO) was significantly higher in the forested commercial faming and GDM sites. Macroinvertebrate communities followed the observed changes in water quality. Macroinvertebrates in urban sites indicated severe pollution (e.g. Chironomidae) whilst those in forested commercial farming sites and GDM sites indicated relatively clean water (e.g. Notonemouridae). Forested watersheds together with good farm management practices are important in mitigating impacts of urbanisation and agriculture. Strategies that reduce oxygen-depleting substances must be devised to protect the health of Zimbabwean streams. The study affirms the wider applicability of the South African Scoring System in different land uses. [ABSTRACT FROM AUTHOR]

Meiofauna sampling on the continental shelf of the northern Gulf of Mexico has been ongoing since 2007, on annual cruises in collaboration with the National Marine Fisheries Service laboratory in Pascagoula, Mississippi. This sampling has resulted in numerous new species of kinorhynchs from the shelf sediment, two of which are described in detail in this paper. Other species descriptions from this research effort include Echinoderes augustae, E. skipperae, and E. charlotteae. We now describe Echinoderes romanoi sp. n. and E. joyceae sp. n., which are unique in their spine, tube, and glandular cell outlet patterns. [ABSTRACT FROM AUTHOR]