Sample records for stream invertebrate detrital

  1. Stream invertebrate productivity linked to forest subsidies: 37 stream-years of reference and experimental data

    J. Bruce Wallace; Susan L Eggert; Judy L. Meyer; Jackson R. Webster


    Riparian habitats provide detrital subsidies of varying quantities and qualities to recipient ecosystems. We used long-term data from three reference streams (covering 24 stream-years) and 13-year whole-stream organic matter manipulations to investigate the influence of terrestrial detrital quantity and quality on benthic invertebrate community structure, abundance,...

  2. Crayfish impact desert river ecosystem function and litter-dwelling invertebrate communities through association with novel detrital resources.

    Eric K Moody

    Full Text Available Shifts in plant species distributions due to global change are increasing the availability of novel resources in a variety of ecosystems worldwide. In semiarid riparian areas, hydric pioneer tree species are being replaced by drought-tolerant plant species as water availability decreases. Additionally, introduced omnivorous crayfish, which feed upon primary producers, allochthonous detritus, and benthic invertebrates, can impact communities at multiple levels through both direct and indirect effects mediated by drought-tolerant plants. We tested the impact of both virile crayfish (Orconectes virilis and litter type on benthic invertebrates and the effect of crayfish on detrital resources across a gradient of riparian vegetation drought-tolerance using field cages with leaf litter bags in the San Pedro River in Southeastern Arizona. Virile crayfish increased breakdown rate of novel drought-tolerant saltcedar (Tamarix ramosissima, but did not impact breakdown of drought-tolerant seepwillow (Baccharis salicifolia or hydric Fremont cottonwood (Populus fremontii and Gooding's willow (Salix goodingii. Effects on invertebrate diversity were observed at the litter bag scale, but no effects were found at the cage scale. Crayfish decreased alpha diversity of colonizing macroinvertebrates, but did not affect beta diversity. In contrast, the drought-tolerant litter treatment decreased beta diversity relative to hydric litter. As drought-tolerant species become more abundant in riparian zones, their litter will become a larger component of the organic matter budget of desert streams which may serve to homogenize the litter-dwelling community and support elevated populations of virile crayfish. Through impacts at multiple trophic levels, crayfish have a significant effect on desert stream ecosystems.

  3. Convergence of detrital stoichiometry predicts thresholds of nutrient-stimulated breakdown in streams.

    Manning, David W P; Rosemond, Amy D; Gulis, Vladislav; Benstead, Jonathan P; Kominoski, John S; Maerz, John C


    Nutrient enrichment of detritus-based streams increases detrital resource quality for consumers and stimulates breakdown rates of particulate organic carbon (C). The relative importance of dissolved inorganic nitrogen (N) vs. phosphorus (P) for detrital quality and their effects on microbial- vs. detritivore-mediated detrital breakdown are poorly understood. We tested effects of experimental N and P additions on detrital stoichiometry (C:N, C:P) and total and microbial breakdown (i.e., with and without detritivorous shredders, respectively) of five detritus types (four leaf litter species and wood) with different initial C : nutrient content. We enriched five headwater streams continuously for two years at different relative availabilities of N and P and compared breakdown rates and detrital stoichiometry to pretreatment conditions. Total breakdown rates increased with nutrient enrichment and were predicted by altered detrital stoichiometry. Streamwater N and P, fungal biomass, and their interactions affected stoichiometry of detritus. Streamwater N and P decreased detrital C:N, whereas streamwater P had stronger negative effects on detrital C:P. Nutrient addition and fungal biomass reduced C:N by 70% and C:P by 83% on average after conditioning, compared to only 26% for C:N and 10% for C:P under pretreatment conditions. Detritus with lowest initial nutrient content changed the most and had greatest increases in total breakdown rates. Detrital stoichiometry was reduced and differences among detritus types were homogenized by nutrient enrichment. With enrichment, detrital nutrient content approached detritivore nutritional requirements and stimulated greater detritivore vs. microbial litter breakdown. We used breakpoint regression to estimate values of detrital stoichiometry that can potentially be used to indicate elevated breakdown rates. Breakpoint ratios for total breakdown were 41 (C:N) and 1518 (C:P), coinciding with total breakdown rates that were ~1.9

  4. Dynamics of Invertebrate Diversity in a Tropical Stream

    Richard G. Pearson


    Full Text Available Regional studies of biotic communities are important for characterising their normal spatial and temporal variation, but there are few such studies of tropical streams. This paper describes changes in invertebrate communities in Yuccabine Creek, a seasonal upland rainforest stream in tropical Australia, over three-year and decadal periods. Invertebrate abundance, richness and evenness were temporally stable, except after major drying or wet-season flows, from which they recovered quickly; however, three wet seasons contrasted in abundance patterns. Species’ responses to flood or drought varied depending on life-histories and habitat dynamics. Communities showed contrasts between wet, early-dry and late-dry seasons, with different characteristic species. Current velocity, leaf litter and substratum particle size were the main environmental correlates with species abundances and multivariate scores. Between-decade contrasts were due to antecedent rainfall and loss of canopy cover. Trophic composition varied seasonally, driven by abundances of predators and detritivores. Yuccabine Creek differs from comparable temperate streams in its high diversity of invertebrates, continual recruitment and spring-dominated continual leaf fall; and from some other tropical streams in its seasonal flow regime. Interpretation of invertebrate metrics in these streams needs to account for historical, antecedent and current conditions, but biannual samples would adequately characterise the fauna.

  5. Seasonal species composition of invertebrates in several Oregon streams.

    Pamela E. Porter; William R. Meehan


    The invertebrate communities ofeight Oregon streams were sampled seasonally from 1974 to 1976. Benthic, drift, and two types of aerial-trap samples were collected. Occurrence and percentage composition are summarized by sample type, season, and geographic area (coastal, Cascade, central, and eastern Oregon). Within 276 families, 426 taxa were identified; the 20...

  6. The ecology of chalk-stream invertebrates studied in a recirculating stream


    To study and qualify the factors influencing interactions between various trophic levels in natural hard-water streams, a recirculating artificial stream channel was constructed. This structure has enabled patterns of population change of stream fauna to be observed under partially controlled physical and chemical conditions. Initial colonization of the substratum by invertebrates and subsequent succession was studied along with depth distribution and growth and production studies of inverteb...

  7. Hydrologic variability enhances stream biofilm grazing by invertebrates

    Ceola, S.; Hödl, I.; Adlboller, M.; Singer, G.; Bertuzzo, E.; Mari, L.; Botter, G.; Battin, T. J.; Gatto, M.; Rinaldo, A.


    The temporal variability of streamflows is a key feature structuring and controlling ecological communities and ecosystem processes. The magnitude, frequency and predictability of streamflows, and thus of velocity and near-bed shear stress fields, control structure and function of benthic invertebrates and biofilms - attached and matrix-enclosed microbial communities at the base of the food chain. Although alterations of streamflow regime due to climate change, habitat fragmentation or other anthropogenic factors are ubiquitous, their ecological implications remain poorly understood. Here, by experimenting with two contrasting flow regimes in stream microcosms, we show how flow variability affects invertebrate grazing of phototrophic biofilms (i.e. periphyton). In both flow regimes, we manipulated light availability as a key control on biofilm algal productivity and grazer activity, thereby allowing the test of flow regime effects across various biofilm biomass to grazing activity ratios. Average grazing rates were significantly enhanced under variable flow conditions and highest at intermediate light availability. Our results suggest that stochastic flow regime offers increased opportunity for grazing under more favorable shear stress conditions, with implications for trophic carbon transfer in stream food webs.

  8. Aquatic and terrestrial invertebrate drift in southern Appalachian Mountain streams: implications for trout food resources

    Eric D. Romaniszyn; John J. Jr. Hutchens; J. Bruce Wallance


    We characterised aquatic and terrestrial invertebrate drift in six south-western North Carolina streams and their implications for trout production. Streams of this region typically have low standing stock and production of trout because of low benthic productivity. However, little is known about the contribution of terrestrial invertebrates entering drift, the factors...

  9. Detrital microbial community development and phosphorus dynamics in a stream ecosystem

    Perkins, R.E.; Elwood, J.W.; Sayler, G.S.


    Detrital microbial community development and phosphorus dynamics in a lotic system were investigated in non-recirculating laboratory streams contains leaf detritus. Temporal patterns of microbial colonization, as determined by scanning electron microscopy, indicate leaf species dependency and that bacteria were the first colonizers followed by fungi. An extensive glycocalyx layer developed. Phosphorus incorporation rates of both the whole community and intracellular components were determined by time-course measurements of /sup 33/PO/sub 4/ or /sup 32/PO/sub 4/. Phosphorus turnover rates were determined by a sequential double-labeling procedure using /sup 33/PO/sub 4/ and /sup 32/PO/sub 4/, in which the microbiota were labeled with /sup 33/P until in isotopic equilibrium, then /sup 32/P was added. The turnover rate was determined by time-course measurements of the ratio /sup 32/P to /sup 33/P. Snail grazing resulted in an increase in phosphorus metabolism per unit microbial biomass; however, per unit area of leaf surface no increase was observed. Grazing also caused a two-fold reduction in microbial biomass. The results indicate that microbiota associated with decomposing leaves slowly recycle phosphorus, are slowly growing, and have a low metabolic activity. The spiraling length is shortened by microbiota on a short-term basis; however, it may increase on a long-term basis due to hydrological transport of detritus downstream.

  10. Storm-event-transport of urban-use pesticides to streams likely impairs invertebrate assemblages.

    Carpenter, Kurt D; Kuivila, Kathryn M; Hladik, Michelle L; Haluska, Tana; Cole, Michael B


    Insecticide use in urban areas results in the detection of these compounds in streams following stormwater runoff at concentrations likely to cause toxicity for stream invertebrates. In this 2013 study, stormwater runoff and streambed sediments were analyzed for 91 pesticides dissolved in water and 118 pesticides on sediment. Detections included 33 pesticides, including insecticides, fungicides, herbicides, degradates, and a synergist. Patterns in pesticide occurrence reveal transport of dissolved and sediment-bound pesticides, including pyrethroids, from upland areas through stormwater outfalls to receiving streams. Nearly all streams contained at least one insecticide at levels exceeding an aquatic-life benchmark, most often for bifenthrin and (or) fipronil. Multiple U.S. EPA benchmark or criterion exceedances occurred in 40 % of urban streams sampled. Bed sediment concentrations of bifenthrin were highly correlated (p transport of pesticides from urban landscapes and linking impaired benthic invertebrate assemblages in urban streams with exposure to pyrethroid insecticides.

  11. Storm-event-transport of urban-use pesticides to streams likely impairs invertebrate assemblages

    Carpenter, Kurt; Kuivila, Kathryn M.; Hladik, Michelle L.; Haluska, Tana L.; Michael B. Cole,


    Insecticide use in urban areas results in the detection of these compounds in streams following stormwater runoff at concentrations likely to cause toxicity for stream invertebrates. In this 2013 study, stormwater runoff and streambed sediments were analyzed for 91 pesticides dissolved in water and 118 pesticides on sediment. Detections included 33 pesticides, including insecticides, fungicides, herbicides, degradates, and a synergist. Patterns in pesticide occurrence reveal transport of dissolved and sediment-bound pesticides, including pyrethroids, from upland areas through stormwater outfalls to receiving streams. Nearly all streams contained at least one insecticide at levels exceeding an aquatic-life benchmark, most often for bifenthrin and (or) fipronil. Multiple U.S. EPA benchmark or criterion exceedances occurred in 40 % of urban streams sampled. Bed sediment concentrations of bifenthrin were highly correlated (p flatworms, nematodes, and oligochaetes dominated streams with relatively high concentrations of bifenthrin in bed sediments, whereas insects, sensitive invertebrates, and mayflies were much more abundant at sites with no or low bifenthrin concentrations. The abundance of sensitive invertebrates, % EPT, and select mayfly taxa were strongly negatively correlated with organic-carbon normalized bifenthrin concentrations in streambed sediments. Our findings from western Clackamas County, Oregon (USA), expand upon previous research demonstrating the transport of pesticides from urban landscapes and linking impaired benthic invertebrate assemblages in urban streams with exposure to pyrethroid insecticides.

  12. Behavioral and catastrophic drift of invertebrates in two streams in northeastern Wyoming

    Wangsness, David J.; Peterson, David A.


    Invertebrate drift samples were collected in August 1977 from two streams in the Powder River structural basin in northeastern Wyoming. The streams are Clear Creek, a mountain stream, and the Little Powder River, a plains stream. Two major patterns of drift were recognized. Clear Creek was sampled during a period of normal seasonal conditions. High drift rates occurred during the night indicating a behavioral drift pattern that is related to the benthic invertebrate density and carrying capacity of the stream substrates. The mayfly genes Baetis, a common drift organism, dominated the peak periods of drift in Clear Creek. The Little Powder River has a high discharge during the study period. Midge larvae of the families Chironomidae and Ceratopogonidae, ususally not common in drift, dominated the drift community. The dominance of midge larvae, the presence of several other organisms not common in drift, and the high discharge during the study period caused a catastrophic drift pattern. (USGS)

  13. Benthic invertebrates of benchmark streams in agricultural areas of eastern Wisconsin, Western Lake Michigan Drainages

    Rheaume, S.J.; Lenz, B.N.; Scudder, B.C.


    This study describes the benthic invertebrate communities of 20 benchmark streams in agricultural areas of eastern Wisconsin. Streams with minimal adverse effects from human activity were selected from four agricultural areas with differing surficial deposits and bedrock types (relatively homogeneous units, or RHU's). Most aquatic invertebrate orders were well represented in the 20 benchmark stream samples; 217 species and 151 genera within 56 families were identified. Diptera was the best represented order (96 species), followed by Trichoptera (42 species) and Ephemeroptera (26 species). Diptera were the most abundant organisms in terms of numbers of individuals in the sample (28 percent of the total) followed by Trichoptera (25 percent) and Ephemeroptera (13 percent). Nine species of freshwater mussels were found, but only in 5 of the 20 benchmark streams.

  14. Downstream changes in spring-fed stream invertebrate communities: the effect of increased temperature range?

    Russell G. DEATH


    Full Text Available Reduced thermal amplitude has been highlighted as a limiting factor for aquatic invertebrate diversity in springs. Moving downstream water temperature range increases and invertebrate richness is expected to change accordingly. In the present study temperature patterns were investigated in seven spring-fed streams, between April 2001 and November 2002, and compared to five run-off-fed streams to assess the degree of crenic temperature constancy. Temperature and physico-chemical characteristics of the water, and food resource levels were measured, and the invertebrate fauna collected at 4 distances (0, 100, 500 m and 1 km from seven springs in the North and South Islands of New Zealand. Temperature variability was greater for run-off-fed streams than for springs, and increased in the spring-fed streams with distance from the source. Periphyton and physico-chemical characteristics of the water did not change markedly over the 1 km studied, with the exception of water velocity and organic matter biomass, which increased and decreased, respectively. The rate of increase in temperature amplitude differed greatly for the studied springs, probably being affected by flow, altitude, and the number and type of tributaries (i.e., spring- or run-off-fed joining the spring-fed stream channel. Longitudinal changes in the number and evenness of invertebrate taxa were positively correlated to thermal amplitude (rs = 0.8. Moving downstream, invertebrate communities progressively incorporated taxa with higher mobility and taxa more common in nearby run-off-fed streams. Chironomids and non-insect taxa were denser at the sources. Chironomid larvae also numerically dominated communities 100 and 500 m downstream from the sources, together with Pycnocentria spp. and Zelolessica spp., while taxa such as Hydora sp. and Hydraenidae beetles, the mayflies Deleatidium spp. and Coloburiscus humeralis, and the Trichoptera Pycnocentrodes spp., all had greater abundances 1 km

  15. Structure and function of a benthic invertebrate stream community as influenced by beaver (Castor canadensis).

    McDowell, Donald M; Naiman, Robert J


    Beaver (Castor canadensis) affect the benthic invertebrate community of small woodland streams in Quebec through habitat modifications. Their activities influence community structure through the replacement of lotic taxa by lentic forms and community function by increasing the absolute importance of collectors and predators while decreasing the relative importance of shredders and scrapers in impounded sites. At our study site during the 1983 ice-free season, standing stocks of coarse particulate organic matter (>1 mm) were 2-5 times greater (Podonates, Tubificidae, and filtering pelycopods. Our results suggest that current paradigms applied to lotic ecosystems need to be reevaluated to incorporate the influence of beaver upon invertebrate communities.

  16. [Effects of benthic macro-invertebrate on decomposition of Acer buergerianum leaf litter in streams].

    Jiang, Li-Hong; Wang, Bei-Xin; Chen, Ai-Qing; Lan, Ce-Jie


    By using composite mesh bag method, the effects of benthic macro-invertebrate in an undisturbed stream and an ecologically restored stream on the decomposition process of Acer buergerianum leaf litter from the Purple Mountain of Nanjing in winter were studied. After 112 days of decomposition, the remaining rate of A. buergerianum leaf litter based on ash-free dry mass was 31-62%, and the decomposition rate followed a declined exponential equation (P Shredders (mainly Asellus sp.) had the highest abundance (70.4%) in the flowing water of undisturbed stream, while filterers (mainly Tanytarsus sp.) were dominant (37.8%) in the flowing water of ecologically restored stream. The decomposition rate of the leaf litter was significantly correlated with the richness and abundance of shredder species in flowing water (P shredders, suggesting that the decomposition of A. buergerianum leaf litter in streams in winter was more dependent on the richness and abundance of shredders.

  17. Evaluation of stream ecological integrity using litter decomposition and benthic invertebrates

    Castela, Jose [Departamento de Zoologia and IMAR-CIC, Universidade de Coimbra, Largo Marques de Pombal, 3004-517 Coimbra (Portugal)], E-mail:; Ferreira, Veronica [Departamento de Zoologia and IMAR-CIC, Universidade de Coimbra, Largo Marques de Pombal, 3004-517 Coimbra (Portugal)], E-mail:; Graca, Manuel A.S. [Departamento de Zoologia and IMAR-CIC, Universidade de Coimbra, Largo Marques de Pombal, 3004-517 Coimbra (Portugal)], E-mail:


    Biomonitoring programs to access the ecological integrity of freshwaters tend to rely exclusively on structural parameters. Here we evaluated stream ecological integrity using (a) benthic macroinvertebrate derived metrics and a biotic index as measures of structural integrity and (b) oak litter decomposition and associated fungal sporulation rates as measures of functional integrity. The study was done at four sites (S1, S2, S3 and S4) along a downstream increasing phosphorus and habitat degradation gradient in a small stream. The biotic index, invertebrate metrics, invertebrate and fungal communities' structure and sporulation rates discriminated upstream and downstream sites. Decomposition rates classified sites S4 and S2 as having a compromised ecosystem functioning. Although both functional and structural approaches gave the same results for the most impacted site (S4), they were complementary for moderately impacted sites (S2 and S3), and we therefore support the need for incorporating functional measures in evaluations of stream ecological integrity. - This study supports the need for incorporating functional measures in evaluations of stream ecological integrity.

  18. Structural and functional responses of benthic invertebrates to imidacloprid in outdoor stream mesocosms

    Pestana, J.L.T., E-mail: jpestana@ua.p [CESAM and Departamento de Biologia, Universidade de Aveiro, Campus Universitario de Santiago, 3810-193 Aveiro (Portugal); Environment Canada at Canadian Rivers Institute, Department of Biology, University of New Brunswick, 10 Bailey Drive, Fredericton, NB (Canada); Alexander, A.C., E-mail: alexa.alexander@unb.c [Environment Canada at Canadian Rivers Institute, Department of Biology, University of New Brunswick, 10 Bailey Drive, Fredericton, NB (Canada); Culp, J.M., E-mail: jculp@unb.c [Environment Canada at Canadian Rivers Institute, Department of Biology, University of New Brunswick, 10 Bailey Drive, Fredericton, NB (Canada); Baird, D.J., E-mail: djbaird@unb.c [Environment Canada at Canadian Rivers Institute, Department of Biology, University of New Brunswick, 10 Bailey Drive, Fredericton, NB (Canada); Cessna, A.J., E-mail: asoares@ua.p [Environment Canada, National Hydrology Research Centre, 11 Innovation Boulevard, Saskatoon, SK (Canada); Soares, A.M.V.M., E-mail: asoares@ua.p [CESAM and Departamento de Biologia, Universidade de Aveiro, Campus Universitario de Santiago, 3810-193 Aveiro (Portugal)


    Structural and functional responses of a benthic macroinvertebrate assemblage to pulses of the insecticide imidacloprid were assessed in outdoor stream mesocosms. Imidacloprid pulses reduced invertebrate abundance and community diversity in imidacloprid-dosed streams compared to control streams. These results correlated well with effects of imidacloprid on leaf litter decomposition and feeding rates of Pteronarcys comstocki, a stonefly, in artificial streams. Reductions in oxygen consumption of stoneflies exposed to imidacloprid were also observed in laboratory experiments. Our findings suggest that leaf litter degradation and single species responses can be sensitive ecotoxicological endpoints that can be used as early warning indicators and biomonitoring tools for pesticide contamination. The data generated illustrates the value of mesocosm experiments in environmental assessment and how the consideration of functional and structural endpoints of natural communities together with in situ single species bioassays can improve the evaluation and prediction of pesticide effects on stream ecosystems. - Combining organism-level responses with community-level processes for the evaluation and prediction of pesticide effects on stream ecosystems.

  19. Development of invertebrate community indexes of stream quality for the islands of Maui and Oahu, Hawaii

    Wolff, Reuben H.


    In 2009-10 the U.S. Geological Survey (USGS) collected physical habitat information and benthic macroinvertebrates at 40 wadeable sites on 25 perennial streams on the Island of Maui, Hawaiʻi, to evaluate the relations between the macroinvertebrate assemblages and environmental characteristics and to develop a multimetric invertebrate community index (ICI) that could be used as an indicator of stream quality. The macroinvertebrate community data were used to identify metrics that could best differentiate among sites according to disturbance gradients such as embeddedness, percent fines (silt and sand areal coverage), or percent agricultural land in the contributing basin area. Environmental assessments were conducted using land-use/land-cover data and reach-level physical habitat data. The Maui data were first evaluated using the previously developed Preliminary-Hawaiian Benthic Index of Biotic Integrity (P-HBIBI) to determine if existing metrics would successfully differentiate stream quality among the sites. Secondly, a number of candidate invertebrate metrics were screened and tested and the individual metrics that proved the best at discerning among the sites along one or more disturbance gradients were combined into a multimetric invertebrate community index (ICI) of stream quality. These metrics were: total invertebrate abundance, Class Insecta relative abundance, the ratio of Trichoptera abundance to nonnative Diptera abundance, native snail (hihiwai) presence or absence, native mountain shrimp (′δpae) presence or absence, native torrent midge (Telmatogeton spp.) presence or absence, and native Megalagrion damselfly presence or absence. The Maui ICI classified 15 of the 40 sites (37.5 percent) as having "good" quality communities, 17 of the sites (42.5 percent) as having "fair" quality communities, and 8 sites (20 percent) as having "poor" quality communities, a classification that may be used to initiate further investigation into the causes of the poor

  20. Land use and the structure of western US stream invertebrate assemblages: Predictive models and ecological traits

    Carlisle, D.M.; Hawkins, C.P.


    Inferences drawn from regional bioassessments could be strengthened by integrating data from different monitoring programs. We combined data from the US Geological Survey National Water-Quality Assessment (NAWQA) program and the US Environmental Protection Agency Wadeable Streams Assessment (WSA) to expand the scope of an existing River InVertebrate Prediction and Classification System (RIVPACS)-type predictive model and to assess the biological condition of streams across the western US in a variety of landuse classes. We used model-derived estimates of taxon-specific probabilities of capture and observed taxon occurrences to identify taxa that were absent from sites where they were predicted to occur (decreasers) and taxa that were present at sites where they were not predicted to occur (increasers). Integration of 87 NAWQA reference sites increased the scope of the existing WSA predictive model to include larger streams and later season sampling. Biological condition at 336 NAWQA test sites was significantly (p tolerance values) than did increasers. We could predict whether a taxon was a decreaser or an increaser based on just a few traits, e.g., desiccation resistance, timing of larval development, habit, and thermal preference, but we were unable to predict the type of basin land use from trait states present in invertebrate assemblages. Refined characterization of traits might be required before bioassessment data can be used routinely to aid in the diagnoses of the causes of biological impairment. ?? 2008 by The North American Benthological Society.

  1. Invasive European bird cherry disrupts stream-riparian linkages: effects on terrestrial invertebrate prey subsidies for juvenile coho salmon

    Roon, David A.; Wipfli, Mark S.; Wurtz, Tricia L.; Blanchard, Arny L.


    The spread of invasive species in riparian forests has the potential to affect both terrestrial and aquatic organisms linked through cross-ecosystem resource subsidies. However, this potential had not been explored in regards to terrestrial prey subsidies for stream fishes. To address this, we examined the effects of an invasive riparian tree, European bird cherry (EBC, Prunus padus), spreading along urban Alaskan salmon streams, by collecting terrestrial invertebrates present on the foliage of riparian trees, their subsidies to streams, and their consumption by juvenile coho salmon (Oncorhynchus kisutch). Riparian EBC supported four to six times less terrestrial invertebrate biomass on its foliage and contributed two to three times lower subsidies relative to native deciduous trees. This reduction in terrestrial invertebrate biomass was consistent between two watersheds over 2 years. In spite of this reduction in terrestrial prey resource input, juvenile coho salmon consumed similar levels of terrestrial invertebrates in stream reaches bordered by EBC. Although we did not see ecological effects extending to stream salmonids, reduced terrestrial prey subsidies to streams are likely to have negative consequences as EBC continues to spread.

  2. Studies on the impacts of hydropeaking on hyporheic invertebrates of an Alpine stream

    Bruno, Maria Cristina; Silveri, Luana; Maiolini, Bruno


    Changes in flow regime associated with sharp discharge fluctuations when water is released from the hydropower plants into the streams (hydropeaking) have cascading effects on the ecological integrity of riverine ecosystems. Hydropeaking modifies the specific composition and longitudinal zonation of invertebrate populations downstream of the power plants through direct impacts on the benthic fauna due to scouring, which removes the animals through drift (i.e. the downstream transport of aquatic organisms under the effect of current velocity) and indirect impacts on the hyporheic zone, i.e. clogging of the interstitial spaces. Clogging occurs due to the reduction of flow and extreme flood events and by deposition of the fine material transported by the release of hypolimnetic water. Clogging reduces the throughflow and the concomitant delivery of resources, as well as the usable pore space for interstitial fauna, impacting the colonization dynamics of interstitial animals. While the impacts of hydropeaking on benthic organisms have been widely investigated so far those on hyporheic fauna have seldom been studied. In a previous research conducted in the same stations discussed here, we investigated the effects of one single hydropeaking event on benthic and hyporheic invertebrates, and assessed that the hyporheic habitat was used as a refuge to avoid drift by part of the benthic organisms, and that hydropeaking reduced hyporheic diversity and abundance in impacted sites, especially affecting the stygobites (specialised subterranean forms, obligatory hypogean), which were significantly more abundant at the non-impacted site. We continued the investigations by studying the spatial (downstream from the disturbance) and temporal effects of repeated hydropeaking events on hyporheic communities. We focussed on the specialization level of the organisms to life in the groundwater, based on the assumption that a reduction of the available habitat for stygobite taxa due to

  3. Laser Ablation Split Stream (LASS) U-Pb & Lu-Hf Isotope Analysis of Detrital Zircons from the Old Red Sandstone, NW Svalbard: Implications for Northern Caledonian Paleogeography

    Beranek, L. P.; Gee, D. G.; Fisher, C. M.


    The Svalbard archipelago consists of three Caledonian provinces that were assembled by thrusting and transcurrent faulting during the Silurian and Devonian in a location directly northeast of the Greenland Caledonides. Syn- to post-orogenic alluvial strata, referred to as the Old Red Sandstones, filled pull-apart basins adjacent to the transcurrent faults and comprise cover assemblages that help constrain the timing of the Caledonian orogeny. To further investigate the tectonic history and paleogeography of the Raudfjorden-Liefdefjorden-Woodfjorden area of Spitsbergen, NW Svalbard, we analyzed rock samples of the Old Red Sandstones and underlying Precambrian basement complexes for detrital zircon analysis. Laboratory studies of the Old Red Sandstones include the novel Laser Ablation Split Stream (LASS) technique, which allows for simultaneous U-Pb & Lu-Hf isotope analysis of zircon crystals. Lower Devonian Red Bay Group strata contain a range of early Neoproterozoic to Neoarchean detrital zircons with prominent age peaks c. 960, 1050, 1370, 1450, 1650, and 2700 Ma; subordinate Ordovician (c. 460-490 Ma) and Cryogenian (c. 650 Ma) detrital zircons occur in a subset of the samples. Underlying Precambrian metasedimentary rocks are composed of similar earliest Neoproterozoic to Neoarchean age populations, which argues for much of the Red Bay Group to be derived from local basement rocks during thrusting and other faulting. The U-Pb ages and Hf isotope compositions of Paleozoic to Neoarchean detrital zircons are consistent with Arctic crustal evolution, and support the hypothesis that northwestern and northeastern provinces of the Svalbard Caledonides are extruded fragments of the northeast Greenland allochthons. The new Hf isotope results further allow paleogeographic and stratigraphic comparisons with rock assemblages proximal to the North Atlantic Caledonides during the Silurian-Devonian, including the Pearya terrane of Ellesmere Island, Alexander terrane of NW

  4. Bridging the gap between theoretical ecology and real ecosystems: modeling invertebrate community composition in streams.

    Schuwirth, Nele; Reichert, Peter


    For the first time, we combine concepts of theoretical food web modeling, the metabolic theory of ecology, and ecological stoichiometry with the use of functional trait databases to predict the coexistence of invertebrate taxa in streams. We developed a mechanistic model that describes growth, death, and respiration of different taxa dependent on various environmental influence factors to estimate survival or extinction. Parameter and input uncertainty is propagated to model results. Such a model is needed to test our current quantitative understanding of ecosystem structure and function and to predict effects of anthropogenic impacts and restoration efforts. The model was tested using macroinvertebrate monitoring data from a catchment of the Swiss Plateau. Even without fitting model parameters, the model is able to represent key patterns of the coexistence structure of invertebrates at sites varying in external conditions (litter input, shading, water quality). This confirms the suitability of the model concept. More comprehensive testing and resulting model adaptations will further increase the predictive accuracy of the model.

  5. Scale-dependence of the correlation between human population and the species richness of stream macro-invertebrates

    Pecher, C.; Fritz, Susanne; Marini, L.


    . This is surprising as EPT are bio-indicators of stream pollution and most local studies report higher species richness of these macro-invertebrates where human influences on water quality are lower. Using a newly collated taxonomic dataset, we studied whether the species richness of EPT is related to human...

  6. The effects of riparian forestry on invertebrate drift and brown trout in upland streams of contrasting acidity

    S. J. Ormerod


    Full Text Available Variations in macroinvertebrate drift and benthic invertebrate abundance were assessed in 30 upland Welsh streams of varying acidity (pH Salmo trutta were also assessed. As expected from previous studies, there were significant reductions in benthic invertebrate abundance, aquatic drift density (by >60%, aquatic drift biomass (by >35%, total drift density (by >35% and total drift biomass (by >20% at acid sites by comparison with circumneutral sites due largely to the scarcity of mayflies. Absolute drift from terrestrial sources was unrelated to stream pH but formed a significantly greater proportion of total drift at acid sites (30-65% of density than at circumneutral sites (20-40% as aquatic contributions declined. Most of this apparent land use effect reflected significantly increased terrestrial drift under broadleaves. There was no significant reduction in terrestrial or aquatic drift at conifer forest sites per se after accounting for low pH. Trout diet varied substantially between locations partly reflecting variations in drift: significantly fewer mayflies and stoneflies were eaten at acid sites, and significantly more terrestrial prey were eaten under broadleaves. However, acidity did not reduce trout condition or gut-fullness. Unexpectedly, trout condition was significantly enhanced at conifer sites, irrespective of their pH. Hence, acidity has greater effects on the benthic abundance and drift density of invertebrates in upland streams than does riparian land use. However, trout forage flexibly enough to offset any possible food deficit, for example by switching to chironomids and terrestrial invertebrates. Enhanced terrestrial contributions to invertebrate drift from riparian broadleaf trees may be important in supplementing foraging opportunities for trout where aquatic prey are scarce. These data illustrate the value of native tree species in riparian locations in upland Britain and the energy subsidy they provide might well be

  7. Hydrologic variability affects invertebrate grazing on phototrophic biofilms in stream microcosms.

    Serena Ceola

    Full Text Available The temporal variability of streamflow is known to be a key feature structuring and controlling fluvial ecological communities and ecosystem processes. Although alterations of streamflow regime due to habitat fragmentation or other anthropogenic factors are ubiquitous, a quantitative understanding of their implications on ecosystem structure and function is far from complete. Here, by experimenting with two contrasting flow regimes in stream microcosms, we provide a novel mechanistic explanation for how fluctuating flow regimes may affect grazing of phototrophic biofilms (i.e., periphyton by an invertebrate species (Ecdyonurus sp.. In both flow regimes light availability was manipulated as a control on autotroph biofilm productivity and grazer activity, thereby allowing the test of flow regime effects across various ratios of biofilm biomass to grazing activity. Average grazing rates were significantly enhanced under variable flow conditions and this effect was highest at intermediate light availability. Our results suggest that stochastic flow regimes, characterised by suitable fluctuations and temporal persistence, may offer increased windows of opportunity for grazing under favourable shear stress conditions. This bears important implications for the development of comprehensive schemes for water resources management and for the understanding of trophic carbon transfer in stream food webs.

  8. Associations among land-use, habitat characteristics, and invertebrate community structure in nine streams on the island of Oahu, Hawaii

    Brasher, Anne M.D.; Wolff, Reuben H.; Luton, Corene D.


    The island of Oahu is one of 51 study units established as part of the U.S. Geological Surveys National Water-Quality Assessment (NAWQA) program to assess the status and trends of the Nations surface and ground-water resources, and to link status and trends with an understanding of the natural and human factors that affect water quality. As part of the NAWQA program, benthic invertebrate communities were surveyed at ten sites in nine streams representing the three main types of land use on Oahu: urban, agriculture, and forested. At each sampling site, habitat characteristics were determined at a range of spatial scales including drainage basin, segment, reach, transect, and point. Associations among land use, habitat characteristics, and benthic invertebrate community structure were examined. The rapid population growth and increasing urbanization on Oahu has resulted in substantial stream habitat alteration. Instream habitat characteristics at the urban and mixed (urban and agriculture) land-use sites were markedly different from those at the forested sites. Urban and mixed land-use sites, most of which were channelized, tended to have less riparian vegetation, higher water temperatures, smaller substrate, and higher levels of embeddedness and siltation than sites in forested watersheds. The majority of invertebrate taxa identified during this study were non-native. Invertebrate abundance was lower at urban and mixed land-use sites than at forested sites, while species richness (the number of different species) showed the opposite pattern. Multivariate analyses indicated that invertebrate species composition was similar at sites with similar land use. Aquatic insects of the orders Diptera and Trichoptera were the most common insects in all samples. The ratio of Diptera to Trichoptera abundance varied with urbanization. Forested sites were dominated by Trichoptera, and urban and mixed land-use sites were dominated by Diptera. Molluscs typically occurred in

  9. Using propensity scores to estimate the effects of insecticides on stream invertebrates from observational data

    Yuan, L.L.; Pollard, A.I.; Carlisle, D.M.


    Analyses of observational data can provide insights into relationships between environmental conditions and biological responses across a broader range of natural conditions than experimental studies, potentially complementing insights gained from experiments. However, observational data must be analyzed carefully to minimize the likelihood that confounding variables bias observed relationships. Propensity scores provide a robust approach for controlling for the effects of measured confounding variables when analyzing observational data. Here, we use propensity scores to estimate changes in mean invertebrate taxon richness in streams that have experienced insecticide concentrations that exceed aquatic life use benchmark concentrations. A simple comparison of richness in sites exposed to elevated insecticides with those that were not exposed suggests that exposed sites had on average 6.8 fewer taxa compared to unexposed sites. The presence of potential confounding variables makes it difficult to assert a causal relationship from this simple comparison. After controlling for confounding factors using propensity scores, the difference in richness between exposed and unexposed sites was reduced to 4.1 taxa, a difference that was still statistically significant. Because the propensity score analysis controlled for the effects of a wide variety of possible confounding variables, we infer that the change in richness observed in the propensity score analysis was likely caused by insecticide exposure. ?? 2009 SETAC.

  10. The effect of the macroconsumer Aegla longirostri (Crustacea, Decapoda on the invertebrate community in a subtropical stream

    Gláucia Bolzan Cogo


    Full Text Available AIM: This study tested whether the macroconsumer Aegla longirostri is able to modify the invertebrate community associated with decomposing leaves. METHODS: The study was performed in a first-order stream located in central Rio Grande do Sul state. Two types of channels containing leaf litter of Ficus luschnathiana were placed in the stream; one type allowed aeglids to access the leaf litter (PA, and the other type did not (AA. Both types allowed aquatic insects to access the leaf litter. In addition, a control treatment (C was established, in which no channel was used. After 3, 7, 11, 15 and 19 days, a litter bag was removed from each replicate of each treatment. RESULTS: A total of 926 organisms belonging to 19 families were identified. The most common taxon in all treatments was Chironomidae, which comprised 71% of the total and was represented by 16 genera. The presence of aeglids decreased the total abundance of organisms by 89% and the taxonomic richness by 35%. The presence of A. longirostri altered the taxonomic composition of the invertebrates and the structure of the trophic groups, causing a decrease in the abundance of all groups, except for shredders and predators. The gathering-collectors trophic group was the most important (65%, in both the presence and absence of A. longirostri. CONCLUSION: Our study showed that A. longirostri, as well as other macroconsumers, was able to modify the structure of the invertebrate community associated with decomposing leaves in the stream.

  11. Streamflow characteristics and benthic invertebrate assemblages in streams across the western United States

    Brasher, Anne M.D.; Konrad, Chris P.; May, Jason T.; Edmiston, C. Scott; Close, Rebecca N.


    Hydrographic characteristics of streamflow, such as high-flow pulses, base flow (background discharge between floods), extreme low flows, and floods, significantly influence aquatic organisms. Streamflow can be described in terms of magnitude, timing, duration, frequency, and variation (hydrologic regime). These characteristics have broad effects on ecosystem productivity, habitat structure, and ultimately on resident fish, invertebrate, and algae communities. Increasing human use of limited water resources has modified hydrologic regimes worldwide. Identifying the most ecologically significant hydrographic characteristics would facilitate the development of water-management strategies.Benthic invertebrates include insects, mollusks (snails and clams), worms, and crustaceans (shrimp) that live on the streambed. Invertebrates play an important role in the food web, consuming other invertebrates and algae and being consumed by fish and birds. Hydrologic alteration associated with land and water use can change the natural hydrologic regime and may affect benthic invertebrate assemblage composition and structure through changes in density of invertebrates or taxa richness (number of different species).This study examined associations between the hydrologic regime and characteristics of benthic invertebrate assemblages across the western United States and developed tools to identify streamflow characteristics that are likely to affect benthic invertebrate assemblages.

  12. Evaluation of coal-mining impacts using numerical classification of benthic invertebrate data from streams draining a heavily mined basin in eastern Tennessee

    Bradfield, A.D.


    Coal-mining impacts on Smoky Creek, eastern Tennessee were evaluated using water quality and benthic invertebrate data. Data from mined sites were also compared with water quality and invertebrate fauna found at Crabapple Branch, an undisturbed stream in a nearby basin. Although differences in water quality constituent concentrations and physical habitat conditions at sampling sites were apparent, commonly used measures of benthic invertebrate sample data such as number of taxa, sample diversity, number of organisms, and biomass were inadequate for determining differences in stream environments. Clustering algorithms were more useful in determining differences in benthic invertebrate community structure and composition. Normal (collections) and inverse (species) analyses based on presence-absence data of species of Ephemeroptera, Plecoptera, and Tricoptera were compared using constancy, fidelity, and relative abundance of species found at stations with similar fauna. These analyses identified differences in benthic community composition due to seasonal variations in invertebrate life histories. When data from a single season were examined, sites on tributary streams generally clustered separately from sites on Smoky Creek. These analyses compared with differences in water quality, stream size, and substrate characteristics between tributary sites and the more degraded main stem sites, indicated that numerical classification of invertebrate data can provide discharge-independent information useful in rapid evaluations of in-stream environmental conditions. (Author 's abstract)

  13. Catchment and in-stream influences on iron-deposit chemistry, algal-bacterial biomass and invertebrate richness in upland streams, Northern Ireland.

    Macintosh, Katrina Ann; Griffiths, David


    The density and composition of upland stream bed iron-deposits is affected by physical, chemical and biological processes. The basic chemical processes producing ochre deposits are well known. Mobilisation of iron and manganese is influenced by bedrock weathering, the presence of acidic and/or reducing conditions and the concentration of dissolved organic carbon. Ferromanganese-depositing bacteria are significant biogenic agents and can cause/enhance the deposition of metals in streams as (hydr)oxides. Metal concentrations from stream waters in two geological blocks in Northern Ireland were compared to determine the contributions of catchment characteristics and in-stream conditions. One block is composed of metamorphosed schist and unconsolidated glacial drift, with peat or peaty podzol (mainly humic) soils, while the other block consists of tertiary basalt with brown earth and gley soils. Water samples were collected from 52 stream sites and analysed for iron, manganese and aluminium as well as a range of other chemical determinands known to affect metal solubility. Stone deposit material was analysed for metal concentrations, organic matter content and epilithic algae, chlorophyll a concentration. Invertebrates were collected by area-standardised kick samples and animals identified to family and numbers counted. Higher conductivities and concentrations of bicarbonate, alkalinity, calcium and magnesium occurred on basalt than on schist. Despite higher iron and manganese oxide concentrations in basalt-derived non-humic soils, stream water concentrations were much lower and stone deposit concentrations only one third of those occurring on schist overlain by humic soils. Peat-generated acidity and the limited acid neutralising capacity of base-poor metamorphosed schist has resulted in elevated concentrations of metals and ochre deposit in surface waters. Algal biomass was determined by catchment level factors whereas in-stream conditions affected bacterial biomass

  14. [Litter decomposition and associated macro-invertebrate functional feeding groups in a third-order stream of northern Guangdong].

    Yan, Ling; Zhao, Ying; Han, Cui-xiang; Tong, Xiao-li


    By placing 5 mm- and 0.1 mm mesh bags with Dracontomelon duperreanum (Anacardiaceae) and Syzygium jambos (Myrtaceae) litters in the Hengshishui Stream, a third-order stream in northern Guangdong of China, this paper studied the decomposition of the litters and the colonization of macro-invertebrates over a 101-day period. The results showed that the decomposition rate of D. duperreanum litter in 5 mm- and 0.1 mm mesh bags was 0.0247 d(-1) and 0.0151 d(-1), while that of S. jambos litter was 0.0108 d(-1) and 0.0095 d(-1), respectively, indicating that D. duperreanum litter decomposed faster than S. jambos litter, and the decomposition rates of these two kinds of litters were higher in coarse mesh bag than in fine mesh bag. Among the colonized macro-invertebrate functional feeding groups, scraper occupied the highest proportion (36%), followed by collector (33%), predator (25%), and shredder (6%). At the middle and late stages of the experiment, the total number of individuals and the numbers and densities of dominant groups of macroinvertebrates on D. duperreanum litter were significantly higher than those on S. jambos litter. It was suggested that in the subtropical medium-size streams where shredders are few or absent, scrapers play an important role in the breakdown of litter. The low decomposition rate of S. jambos litter was mainly due to its high content of polyphenols which inhibits microbial activity and makes the litter less eatable to the macro-invertebrates.

  15. Scale-dependent effects of river habitat quality on benthic invertebrate communities--Implications for stream restoration practice.

    Stoll, Stefan; Breyer, Philippa; Tonkin, Jonathan D; Früh, Denise; Haase, Peter


    Although most stream restoration projects succeed in improving hydromorphological habitat quality, the ecological quality of the stream communities often remains unaffected. We hypothesize that this is because stream communities are largely determined by environmental properties at a larger-than-local spatial scale. Using benthic invertebrate community data as well as hydromorphological habitat quality data from 1087 stream sites, we investigated the role of local- (i.e. 100 m reach) and regional-scale (i.e. 5 km ring centered on each reach) stream hydromorphological habitat quality (LQ and RQ, respectively) on benthic invertebrate communities. The analyses showed that RQ had a greater individual effect on communities than LQ, but the effects of RQ and LQ interacted. Where RQ was either good or poor, communities were exclusively determined by RQ. Only in areas of intermediate RQ, LQ determined communities. Metacommunity analysis helped to explain these findings. Species pools in poor RQ areas were most depauperated, resulting in insufficient propagule pressure for species establishment even at high LQ (e.g. restored) sites. Conversely, higher alpha diversity and an indication of lower beta dispersion signals at mass effects occurring in high RQ areas. That is, abundant neighboring populations may help to maintain populations even at sites with low LQ. The strongest segregation in species co-occurrence was detected at intermediate RQ levels, suggesting that communities are structured to the highest degree by a habitat/environmental gradient. From these results, we conclude that when restoring riverine habitats at the reach scale, restoration projects situated in intermediate RQ settings will likely be the most successful in enhancing the naturalness of local communities. With a careful choice of sites for reach-scale restoration in settings of intermediate RQ and a strategy that aims to expand areas of high RQ, the success of reach-scale restoration in promoting the

  16. Persistent effects of wildfire and debris flows on the invertebrate prey base of rainbow trout in Idaho streams

    Rosenberger, A.E.; Dunham, J.B.; Buffington, J.M.; Wipfli, M.S.


    Wildfire and debris flows are important physical and ecological drivers in headwater streams of western North America. Past research has primarily examined short-term effects of these disturbances; less is known about longer-term impacts. We investigated wildfire effects on the invertebrate prey base for drift-feeding rainbow trout (Oncorhynchus mykiss, Walbaum) in Idaho headwater streams a decade after wildfire. Three stream types with different disturbance histories were examined: 1) unburned, 2) burned, and 3) burned followed by debris flows that reset channel morphology and riparian vegetation. The quantity of macroinvertebrate drift (biomass density) was more variable within than among disturbance categories. Average body weight and taxonomic richness of drift were significantly related to water temperature and influenced by disturbance history. During the autumn sampling period, the amount of terrestrial insects in rainbow trout diets varied with disturbance history and the amount of overhead canopy along the stream banks. Results indicate that there are detectable changes to macroinvertebrate drift and trout diet a decade after wildfire, and that these responses are better correlated with specific characteristics of the stream (water temperature, canopy cover) than with broad disturbance classes.

  17. Long-term changes in temperate stream invertebrate communities reveal a synchronous trophic amplification at the turn of the millennium.

    Van Looy, Kris; Floury, Mathieu; Ferréol, Martial; Prieto-Montes, Marta; Souchon, Yves


    The positive effects of water quality improvement on stream biodiversity in the temperate regions are expected to be at risk with the projected climatic changes. However, the processes and mechanisms behind the predicted threats remain uncertain. From long-term series of benthic invertebrate samples from temperate rivers and streams in France, we analyzed diversity and composition shifts over time in relation to geographic elements and human stressors. Mechanisms for community changes were investigated with a trait-based analysis for the entire dataset and for a selected caddisfly community module. We observed a 42% increase in the taxonomic richness of stream invertebrate communities over the last 25years. A gradual trend induced by water quality improvement was distinguished from a more abrupt climate change-induced shift in communities around the year 2000. Trophic amplification - the intensification of trophic interactions and pathways through the food web - was identified as the mechanism behind the strong community shift. Four lines of evidence for this trophic amplification are highlighted: (i) higher dissolved oxygen concentrations indicated a shift in primary production, (ii) the trait-based analysis of entire communities showed a bottom-up food web amplification, (iii) the trait-based analysis of the community module evidenced feeding strategy shifts and increased food web interactions, and (iv) the abundance analysis of the community module showed a productivity increase. These results lend credit to persistent investments in water quality for improving stream biodiversity, and contrary to expectation, climate change impacts seem so far to have reinforced these positive effects.

  18. Forest-stream linkages: effects of terrestrial invertebrate input and light on diet and growth of brown trout (Salmo trutta) in a boreal forest stream.

    Erős, Tibor; Gustafsson, Pär; Greenberg, Larry A; Bergman, Eva


    Subsidies of energy and material from the riparian zone have large impacts on recipient stream habitats. Human-induced changes, such as deforestation, may profoundly affect these pathways. However, the strength of individual factors on stream ecosystems is poorly understood since the factors involved often interact in complex ways. We isolated two of these factors, manipulating the flux of terrestrial input and the intensity of light in a 2×2 factorial design, where we followed the growth and diet of two size-classes of brown trout (Salmo trutta) and the development of periphyton, grazer macroinvertebrates, terrestrial invertebrate inputs, and drift in twelve 20 m long enclosed stream reaches in a five-month-long experiment in a boreal coniferous forest stream. We found that light intensity, which was artificially increased 2.5 times above ambient levels, had an effect on grazer density, but no detectable effect on chlorophyll a biomass. We also found a seasonal effect on the amount of drift and that the reduction of terrestrial prey input, accomplished by covering enclosures with transparent plastic, had a negative impact on the amount of terrestrial invertebrates in the drift. Further, trout growth was strongly seasonal and followed the same pattern as drift biomass, and the reduction of terrestrial prey input had a negative effect on trout growth. Diet analysis was consistent with growth differences, showing that trout in open enclosures consumed relatively more terrestrial prey in summer than trout living in covered enclosures. We also predicted ontogenetic differences in the diet and growth of old and young trout, where we expected old fish to be more affected by the terrestrial prey reduction, but we found little evidence of ontogenetic differences. Overall, our results showed that reduced terrestrial prey inputs, as would be expected from forest harvesting, shaped differences in the growth and diet of the top predator, brown trout.

  19. Forest-stream linkages: effects of terrestrial invertebrate input and light on diet and growth of brown trout (Salmo trutta in a boreal forest stream.

    Tibor Erős

    Full Text Available Subsidies of energy and material from the riparian zone have large impacts on recipient stream habitats. Human-induced changes, such as deforestation, may profoundly affect these pathways. However, the strength of individual factors on stream ecosystems is poorly understood since the factors involved often interact in complex ways. We isolated two of these factors, manipulating the flux of terrestrial input and the intensity of light in a 2×2 factorial design, where we followed the growth and diet of two size-classes of brown trout (Salmo trutta and the development of periphyton, grazer macroinvertebrates, terrestrial invertebrate inputs, and drift in twelve 20 m long enclosed stream reaches in a five-month-long experiment in a boreal coniferous forest stream. We found that light intensity, which was artificially increased 2.5 times above ambient levels, had an effect on grazer density, but no detectable effect on chlorophyll a biomass. We also found a seasonal effect on the amount of drift and that the reduction of terrestrial prey input, accomplished by covering enclosures with transparent plastic, had a negative impact on the amount of terrestrial invertebrates in the drift. Further, trout growth was strongly seasonal and followed the same pattern as drift biomass, and the reduction of terrestrial prey input had a negative effect on trout growth. Diet analysis was consistent with growth differences, showing that trout in open enclosures consumed relatively more terrestrial prey in summer than trout living in covered enclosures. We also predicted ontogenetic differences in the diet and growth of old and young trout, where we expected old fish to be more affected by the terrestrial prey reduction, but we found little evidence of ontogenetic differences. Overall, our results showed that reduced terrestrial prey inputs, as would be expected from forest harvesting, shaped differences in the growth and diet of the top predator, brown trout.

  20. Macro Invertebrates As Bio Indicators Of Water Quality In Nzovwe Stream In Mbeya Tanzania

    Fredrick Ojija


    Full Text Available This study was carried out to assess the water quality of Nzovwe stream using macroinvertebrates as bioindicators. Biological monitoring working party BMWP scoring system was the index used to assess the ecosystem health of Nzovwe stream. A total of 584 aquatic macroinvertebrates were identified from Nzovwe stream. They belonged to 22 families. The most abundant taxa were Odonata 35.959 Hemiptera 25.514 Coleoptera 18.493 and Diptera 12.842. Whereas the least abundant taxa were Ephemeroptera and Gastropoda each constituting 1.028 of all macroinvertebrates. The most abundant macroinvertebrates were Dragonflies 27.226 Water striders 13.185 and Creeping water bugs 10.274 whereas the least abundant were Giant water bugs 0.514 and Backswimmers 0.514. The BMWP score of Nzovwe stream was 115. Based on this score the water of Nzovwe stream is neither very clean nor significantly altered aquatic environment. Hence the Nzovwe stream is moderately polluted due to non-point source pollution from several sources. Moreover it was found that agricultural activities washing and bathing could alter physico-chemical parameters of the stream and hence changing the abundance of macroinvertebrates as well as the quality of water. This study therefore recommends that the source of pollutants should be controlled and the stream regularly monitored by the relevant authorities. Additionally biological indicators and their indices are suggested to be used in assessing the condition of a stream ecosystem.

  1. Estimating terrestrial contribution to stream invertebrates and periphyton using a gradient-based mixing model for delta13C.

    Rasmussen, Joseph B


    1. This paper outlines a gradient-based model that can be used for isotopic signature source partitioning, even if source signatures are not distinct, as long as their spatial gradients differ. A model of this type is applied to the partitioning of autochthonous vs. allochthonous contribution to stream invertebrate delta(13)C signatures, which has often been confounded by overlap in source signatures. 2. delta(13)C signatures of inorganic carbon and most autochthonous production exhibit pronounced gradients along rivers, being depleted relative to terrestrial signatures in upstream reaches, and enriched downstream. Terrestrial detritus, by contrast, exhibits no gradient. Thus terrestrial food consumption reduces downstream signature slopes in proportion to the amount of terrestrial food consumed. 3. The gradient-based mixing model produces estimates of the proportion of terrestrial consumption (p(T)) from signature slopes of consumers; p(T) estimates for invertebrate primary consumers were: herbivore/grazers (0.15) shredders (0.85). 4. Periphyton (epilithon), a mixture of attached algae, bacteria and detritus, exhibited a weaker downstream slope than attached algae. p(T) values calculated for periphyton relative to pure algal signatures were 0.32 implying approximately 30% allochthonous content. The slope for herbivore/grazers calculated relative to periphyton signatures was >1, indicating selective assimilation of the autochthonous component from the biofilms.

  2. Invertebrate metacommunity structure and dynamics in an andean glacial stream network facing climate change

    Cauvy-Fraunié, Sophie; Espinosa, Rodrigo; Andino, Patricio


    theory as a conceptual framework to better understand how river network structure influences the spatial organization of aquatic communities in glacierized catchments. At 51 stream sites in an Andean glacierized catchment (Ecuador), we sampled benthic macroinvertebrates, measured physico...... community variation. Overland spatial variables based on geographical and altitudinal distances significantly affected community variation. Watercourse spatial variables based on glaciality distances had a unique significant effect on community variation. Within alpine catchment, glacial meltwater affects...

  3. Hydrologic and light variability as drivers of stream biofilm-invertebrate dynamics

    Ceola, Serena; Bertuzzo, Enrico; Mari, Lorenzo; Botter, Gianluca; Hödl, Iris; Battin, Tom; Gatto, Marino; Montanari, Alberto; Rinaldo, Andrea


    Among all abiotic controlling factors, hydrology and light availability are the key drivers that influence and affect space and time organization, structure and function of stream ecosystems. To analyze from both an experimental and a modeling perspective the coupled effect of light and flow variability on the interactions between stream biofilm (i.e. the main component of benthic algae) and macroinvertebrates, a flume experiment and a modeling analysis have been carried out. In order to explore the impacts of flow alterations, two alternative discharge regimes have been performed, mainly a stochastic time-varying and a constant discharge sequence, reproducing the natural streamflow fluctuations of a river and an anthropogenic flow modification, respectively. In addition, given that light availability typically changes along the fluvial continuum as a function of the vegetation coverage and consequently affects biofilm primary production and macroinvertebrate foraging activity, four different light treatments characterized by 90%, 65%, 50% and 27% transmission of incident light radiation, have been introduced. Average grazing activity was significantly enhanced under variable flow conditions and highest at intermediate light availability. These results suggest that stochastic flow regime offers increased opportunity for grazing under favorable shear stress conditions, with implications for trophic carbon transfer in stream food webs. Alterations of natural streamflow regimes may have severe effects on the structure and function of stream ecosystems. Indeed future environmental impact criteria should include assessments of impacts on ecosystem processes. Our experimental evidence reveals hitherto unknown effects of flow regime changes on ecosystem functioning, and suggests that alterations simply maintaining minimum flowrates are inadequate to fully preserve ecosystem integrity. In addition, the results of a modeling analysis of the observed biofilm

  4. Acute toxicity of cadmium, lead, zinc, and their mixtures to stream-resident fish and invertebrates

    Mebane, Christopher A.; Dillon, Frank S.; Hennessy, Daniel P.


    The authors conducted 150 tests of the acute toxicity of resident fish and invertebrates to Cd, Pb, and Zn, separately and in mixtures, in waters from the South Fork Coeur d'Alene River watershed, Idaho, USA. Field-collected shorthead sculpin (Cottus confusus), westslope cutthroat trout (Oncorhynchus clarkii lewisi), two mayflies (Baetis tricaudatus and Rhithrogena sp.), a stonefly (Sweltsa sp.), a caddisfly (Arctopsyche sp.), a snail (Gyraulus sp.), and hatchery rainbow trout (Oncorhynchus mykiss), were tested with all three metals. With Pb, the mayflies (Drunella sp., Epeorus sp., and Leptophlebiidae), a Simuliidae black fly, a Chironomidae midge, a Tipula sp. crane fly, a Dytiscidae beetle, and another snail (Physa sp.), were also tested. Adult westslope cutthroat trout were captured to establish a broodstock to provide fry of known ages for testing. With Cd, the range of 96-h median effect concentrations (EC50s) was 0.4 to >5,329μg/L, and the relative resistances of taxa were westslope cutthroat trout ≈ rainbow trout ≈ sculpin toxicities of the three metals were less than additive on a concentration-addition basis.

  5. Acute toxicity of cadmium, lead, zinc, and their mixtures to stream-resident fish and invertebrates.

    Mebane, Christopher A; Dillon, Frank S; Hennessy, Daniel P


    The authors conducted 150 tests of the acute toxicity of resident fish and invertebrates to Cd, Pb, and Zn, separately and in mixtures, in waters from the South Fork Coeur d'Alene River watershed, Idaho, USA. Field-collected shorthead sculpin (Cottus confusus), westslope cutthroat trout (Oncorhynchus clarkii lewisi), two mayflies (Baetis tricaudatus and Rhithrogena sp.), a stonefly (Sweltsa sp.), a caddisfly (Arctopsyche sp.), a snail (Gyraulus sp.), and hatchery rainbow trout (Oncorhynchus mykiss), were tested with all three metals. With Pb, the mayflies (Drunella sp., Epeorus sp., and Leptophlebiidae), a Simuliidae black fly, a Chironomidae midge, a Tipula sp. crane fly, a Dytiscidae beetle, and another snail (Physa sp.), were also tested. Adult westslope cutthroat trout were captured to establish a broodstock to provide fry of known ages for testing. With Cd, the range of 96-h median effect concentrations (EC50s) was 0.4 to >5,329 µg/L, and the relative resistances of taxa were westslope cutthroat trout ≈ rainbow trout ≈ sculpin fish size was observed. In metal mixtures, the toxicities of the three metals were less than additive on a concentration-addition basis.

  6. Hawaii ESI: INVERTPT (Invertebrate Points)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for native stream invertebrates, anchialine pool invertebrates, and threatened/endangered terrestrial...

  7. Invertebrate metacommunity structure and dynamics in an andean glacial stream network facing climate change

    Cauvy-Fraunié, Sophie; Espinosa, Rodrigo; Andino, Patricio;


    theory as a conceptual framework to better understand how river network structure influences the spatial organization of aquatic communities in glacierized catchments. At 51 stream sites in an Andean glacierized catchment (Ecuador), we sampled benthic macroinvertebrates, measured physico......-chemical and food resource conditions, and calculated geographical, altitudinal and glaciality distances among all sites. Using partial redundancy analysis, we partitioned community variation to evaluate the relative strength of environmental conditions (e.g., glaciality, food resource) vs. spatial processes (e.......g., overland, watercourse, and downstream directional dispersal) in organizing the aquatic metacommunity. Results revealed that both environmental and spatial variables significantly explained community variation among sites. Among all environmental variables, the glacial influence component best explained...

  8. Assessing streamflow characteristics as limiting factors on benthic invertebrate assemblages in streams across the western United States

    Konrad, C.P.; Brasher, A.M.D.; May, J.T.


    1. Human use of land and water resources modifies many streamflow characteristics, which can have significant ecological consequences. Streamflow and invertebrate data collected at 111 sites in the western U.S.A. were analysed to identify streamflow characteristics (magnitude, frequency, duration, timing and variation) that are probably to limit characteristics of benthic invertebrate assemblages (abundance, richness, diversity and evenness, functional feeding groups and individual taxa) and, thus, would be important for freshwater conservation and restoration. Our analysis investigated multiple metrics for each biological and hydrological characteristic, but focuses on 14 invertebrate metrics and 13 streamflow metrics representing the key associations between streamflow and invertebrates.

  9. Short-Term Impacts of Road Crossing Restoration on Alluvial Streams in the Klamath National Forest, California: Fine Sediment, Channel Morphology and Aquatic Invertebrates

    Lawrence, J. E.; Cover, M. R.; Lacan, I.; May, C. L.; Resh, V. H.


    In mountainous terrain, road crossings may increase sediment delivery to stream channels, alter surface and subsurface flow paths and impair fish passage. Road crossing improvements are a common restoration practice that aim to (1) improve fish passage by replacing undersized culverts, and (2) reduce the risk of catastrophic failures of road crossings by reducing the volume of fill material. The long-term benefits are self-evident, but the short-term impacts, i.e., those that may occur one to two years after construction, are not well understood, as reflected by lack of consensus from past studies. We used a Before-After-Control- Impact (BACI) design that spanned four years, 2004-2007, to analyze potential short-term physical and biological impacts of six road crossing reconstructions in the Klamath National Forest of northern California. Within the hydrological context observed, we describe the impact of these six restoration projects on sediment deposition, channel morphology and aquatic invertebrate communities in the first two years after construction. Preliminary analyses indicate that there was relatively little change in fine sediment deposition or in aquatic invertebrate communities following road-crossing reconstruction in these steep headwater streams.

  10. Studies on mountain streams in the English lake district I. PH, calcium and the distribution of invertebrates in the River Duddon

    Sutcliffe, D.W.; Carrick, T.R.


    The River Duddon and its tributaries rarely exceed pH 7.0. There are three types of acid regime; pH>5.7 and pH<5.7 independent of season or rainfall, and fluctuating acidity with pH<5.7 in winter and wet periods, pH>5.7 in summer or dry periods. PH in the River Duddon fluctuates for most of its length. Ph>5.7 is characteristic of tributaries in the lower drainage basin, but pH<5.7 occurs in the headwaters of two of these tributaries. With five exceptions, pH<5.7 or fluctuating pH are characteristic of tributaries in the upper drainage basin. A very close relationship exists between the pH regime of stream water and the benthis cauna. Apart from oligochaetes and flatworms, streams with pH<5.7 or fluctuating pH are characterized by thirteen common or abundant taxa; six plecoptera, four trichoptera and three diptera. These taxa are also common in streams with pH>5.7 but in addition these streams contain ephemeroptera, the trichopterans wormaldia and hydropsyche, the mollusc Ancylus and the amphipod gammarus. It is concluded that the calcium concentration is less important than the pH-bicarbonate concentrations in limiting the qualitative distribution of benthic invertebrates. The limiting effect of pH<5.7 on an extensive range of taxa in the duddon also occurs in other areas. The affected taxa are generally herbivores. It is suggested that in the case of insects the limiting effects of low pH may indirectly operate through changes in food supply.

  11. Effects of invasive European bird cherry (Prunus padus) on leaf litter processing by aquatic invertebrate shredder communities in urban Alaskan streams

    Roon, David A.; Wipfli, Mark S.; Wurtz, Tricia L.


    European bird cherry (Prunus padus) (EBC) is an invasive ornamental tree that is spreading rapidly in riparian forests of urban Alaska. To determine how the spread of EBC affects leaf litter processing by aquatic invertebrate shredders, we conducted complementary leaf pack experiments in two streams located in Anchorage, Alaska. The first experiment contrasted invasive EBC with three native tree species—thin-leaf alder (Alnus tenuifolia), paper birch (Betula neoalaskana), and black cottonwood (Populus trichocarpa)—in one reach of Chester Creek; finding that EBC leaf litter broke down significantly faster than birch and cottonwood, but at a similar rate to alder. The second experiment contrasted EBC with alder in four reaches of Campbell and Chester creeks; finding that while EBC leaf litter broke down significantly faster than alder in Chester Creek, EBC broke down at a similar rate to alder in Campbell Creek. Although EBC sometimes supported fewer shredders by both count and mass, shredder communities did not differ significantly between EBC and native plants. Collectively, these data suggest that invasive EBC is not currently exhibiting strong negative impacts on leaf litter processing in these streams, but could if it continues to spread and further displaces native species over time.

  12. Relative importance of bacteria and fungi in a tropical headwater stream: leaf decomposition and invertebrate feeding preference.

    Wright, M S; Covich, A P


    Bacteria and fungi provide critical links between leaf detritus and higher trophic levels in forested headwater food webs, but these links in tropical streams are not well understood. We compared the roles of bacteria and fungi in the leaf decomposition process and determining feeding preference for two species of freshwater shrimp found in the Luquillo Experimental Forest, Puerto Rico, using experimental microcosms. We first tested the effects of four treatments on decomposition rates for leaves from two common riparian species, Cecropia scheberiana (Moraceae) and Dacryodes excelsa (Burseraceae), in laboratory microcosms. Treatments were designed to alter the microbial community by minimizing the presence of bacteria or fungi. The fastest decay rate was the control treatment for D. excelsa where both bacteria and fungi were present (k = -0.0073 day(-1)) compared to the next fastest rate of k = -0.0063 day(-1) for the bacterial-conditioned D. excelsa leaves. The fastest decay rate for C. scheberiana was also the control treatment (k = -0.0035 day(-1)), while the next fastest rate was for fungal-conditioned leaves (k = -0.0029 day(-1)). The nonadditive effect for leaf decomposition rates observed in the control treatments where both fungi and bacteria were present indicate that bacteria and fungi perform different functions in processing leaf litter. Additionally, leaf types differed in microbial colonization patterns. We next tested feeding preference for leaf type and microbe treatment in microcosms using two species of freshwater shrimp: Xiphocaris elongata, a shredder, and Atya lanipes, a scraper/filterer. To estimate feeding preferences of individual shrimp, we measured change in leaf surface area and the amount of particles generated during 5-day trials in 16 different two-choice combinations. X. elongata preferred D. excelsa over C. scheberiana, and leaves with microbial conditioning over leaves without conditioning. There was no clear preference for fungal

  13. Leaf breakdown in a natural open tropical stream

    Elisa A.C.C. Alvim


    Full Text Available Leaf breakdown is a primary process of nutrient cycling and energy flow, contributing to the functioning of aquatic ecosystems. In the present study, leaves of Baccharis platypoda and Coccoloba cereifera were incubated in a high-altitude stream in a rupestrian field. Two hypotheses were tested: i intrinsic factors (quality of detritus are more important than extrinsic factors (decomposer communities in decomposition; and ii low detritus quality hinders microbial colonization, thereby altering the composition and structure of the associated invertebrate community and slowing leaf breakdown. The breakdown coefficients of B. platypoda and C. cereifera leaves were low (k = -0.0019 day-1 and k = -0.0008 day-1, respectively and the proportions of structural compounds were high, delaying the remobilization of energy and nutrients into the aquatic ecosystem. Fungal biomass was higher at the end of the experiment, suggesting favorable conditions for colonization. The densities of invertebrates associated with the detritus increased coincident with the peak concentration of ergosterol, with the trophic groups collector-gatherer and scraper having the highest densities. The distribution of these groups was likely related to the growth of biofilm on the surface of the litters. As described for tropical streams, shredders had the lowest densities of any invertebrate group, suggesting a reduced participation of these invertebrates in leaf processing. The results suggest that slow decomposing species are important to both invertebrates and microorganisms as substrates and sources of particulate organic matter. The low palatability and nutritional quality of the detritus in the present study, associated with low dissolved nutrient concentrations in water, delayed the leaf conditioning process by microorganisms. Decomposition rates and invertebrate participation were reduced as a result, leading to major physical decomposition. Headwater tropical streams have

  14. Benthic-invertebrate, fish-community, and streambed-sediment-chemistry data for streams in the Indianapolis metropolitan area, Indiana, 2009–2012

    Voelker, David C.


    Aquatic-biology and sediment-chemistry data were collected at seven sites on the White River and at six tributary sites in the Indianapolis metropolitan area of Indiana during the period 2009 through 2012. Data collected included benthic-invertebrate and fish-community information and concentrations of metals, insecticides, herbicides, and semivolatile organic compounds adsorbed to streambed sediments. A total of 120 benthic-invertebrate samples were collected, of which 16 were replicate samples. A total of 26 fish-community samples were collected in 2010 and 2012. Thirty streambed-sediment chemistry samples were collected in 2009 and 2011, of which four were concurrent duplicate samples

  15. Invertebrate neurophylogeny

    Richter, Stefan; Loesel, Rudi; Purschke, Günter


    Invertebrate nervous systems are highly disparate between different taxa. This is reflected in the terminology used to describe them, which is very rich and often confusing. Even very general terms such as 'brain', 'nerve', and 'eye' have been used in various ways in the different animal groups, ...

  16. Zoology: Invertebrates that Parasitize Invertebrates.

    Giribet, Gonzalo


    The genome of an orthonectid, a group of highly modified parasitic invertebrates, is drastically reduced and compact, yet it shows the bilaterian gene toolkit. Phylogenetic analyses place the enigmatic orthonectids within Spiralia, although their exact placement remains uncertain. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Grazer traits, competition, and carbon sources to a headwater-stream food web.

    McNeely, Camille; Finlay, Jacques C; Power, Mary E


    We investigated the effect of grazing by a dominant invertebrate grazer (the caddisfly Glossosoma penitum) on the energy sources used by other consumers in a headwater-stream food web. Stable isotope studies in small, forested streams in northern California have shown that G. penitum larvae derive most of their carbon from algae, despite low algal standing crops. We hypothesized that the caddisfly competes with other primary consumers (including mayflies) for algal food and increases their reliance on terrestrial detritus. Because Glossosoma are abundant and defended from predators by stone cases, their consumption of algal energy may reduce its transfer up the food chain. We removed Glossosoma (natural densities >1000 caddisflies/m2) from five approximately 4 m2) stream sections during the summer of 2000 and measured responses of algae, invertebrate primary consumers, and invertebrate predators. The treatment reduced Glossosoma biomass by 80-90%. We observed a doubling in chlorophyll a per area in sections with reduced Glossosoma abundance and aggregative increases in the biomass of undefended primary consumers. Heptageniid mayfly larvae consumed more algae (as measured by stable carbon isotope ratios and gut content analysis) in caddisfly removal plots at the end of the 60-day experiment, although not after one month. We did not see isotopic evidence of increased algal carbon in invertebrate predators, however. Patterns of caddisfly and mayfly diets in the surrounding watershed suggested that mayfly diets are variable and include algae and detrital carbon in variable proportions, but scraping caddisflies consume primarily algae. Caddisfly and mayfly diets are more similar in larger, more productive streams where the mayflies assimilate more algae. Isotopic analysis, in combination with measurements of macroinvertebrate abundance and biomass in unmanipulated plots, suggested that a substantial portion of the invertebrate community (>50% of biomass) was supported

  18. STREAM

    Godsk, Mikkel

    This paper presents a flexible model, ‘STREAM’, for transforming higher science education into blended and online learning. The model is inspired by ideas of active and collaborative learning and builds on feedback strategies well-known from Just-in-Time Teaching, Flipped Classroom, and Peer...... Instruction. The aim of the model is to provide both a concrete and comprehensible design toolkit for adopting and implementing educational technologies in higher science teaching practice and at the same time comply with diverse ambitions. As opposed to the above-mentioned feedback strategies, the STREAM...

  19. Temporal trends in algae, benthic invertebrate, and fish assemblages in streams and rivers draining basins of varying land use in the south-central United States, 1993-2007

    Miller, Matthew P.; Kennen, Jonathan G.; Mabe, Jeffrey A.; Mize, Scott V.


    Site-specific temporal trends in algae, benthic invertebrate, and fish assemblages were investigated in 15 streams and rivers draining basins of varying land use in the south-central United States from 1993–2007. A multivariate approach was used to identify sites with statistically significant trends in aquatic assemblages which were then tested for correlations with assemblage metrics and abiotic environmental variables (climate, water quality, streamflow, and physical habitat). Significant temporal trends in one or more of the aquatic assemblages were identified at more than half (eight of 15) of the streams in the study. Assemblage metrics and abiotic environmental variables found to be significantly correlated with aquatic assemblages differed between land use categories. For example, algal assemblages at undeveloped sites were associated with physical habitat, while algal assemblages at more anthropogenically altered sites (agricultural and urban) were associated with nutrient and streamflow metrics. In urban stream sites results indicate that streamflow metrics may act as important controls on water quality conditions, as represented by aquatic assemblage metrics. The site-specific identification of biotic trends and abiotic–biotic relations presented here will provide valuable information that can inform interpretation of continued monitoring data and the design of future studies. In addition, the subsets of abiotic variables identified as potentially important drivers of change in aquatic assemblages provide policy makers and resource managers with information that will assist in the design and implementation of monitoring programs aimed at the protection of aquatic resources.

  20. Introduction: Invertebrate Neuropeptides XIV

    This publication represents an introduction to the thirteenth in a series of special issues of the Peptides journal dedicated to invertebrate neuropeptides. The issue addresses a number of aspects of invertebrate neuropeptide research including identification of novel invertebrate neuropeptide sequ...

  1. Introduction: Invertebrate Neuropeptides XV

    This publication represents an introduction to the fifteenth in a series of special issues of the Peptides journal dedicated to invertebrate neuropeptides. The issue addresses a number of aspects of invertebrate neuropeptide research including identification of novel invertebrate neuropeptide seque...

  2. Introduction: Invertebrate Neuropeptides XIII

    This publication represents an introduction to the thirteenth in a series of special issues of the Peptides journal dedicated to invertebrate neuropeptides. The issue addresses a number of aspects of invertebrate neuropeptide research including identification of novel invertebrate neuropeptide sequ...

  3. Introduction: Invertebrate Neuropeptides XVI

    This publication represents an introduction to the sixteenth in a series of special issues of the Peptides journal dedicated to invertebrate neuropeptides. The issue addresses a number of aspects of invertebrate neuropeptide research including identification of novel invertebrate neuropeptide seque...

  4. Tumors in invertebrates

    F Tascedda


    Full Text Available Tumors are ectopic masses of tissue formed by due to an abnormal cell proliferation. In this review tumors of several invertebrate species are examined. The description of tumors in invertebrates may be a difficult task, because the pathologists are usually inexperienced with invertebrate tissues, and the experts in invertebrate biology are not familiar with the description of tumors. As a consequence, the terminology used in defining the tumor type is related to that used in mammalian pathology, which can create misunderstandings in some occasions.

  5. Combining taxonomy and function in the study of stream macroinvertebrates

    Kenneth W. Cummins


    Full Text Available Over the last fifty years, research on freshwater macroinvertebrates has been driven largely by the state of the taxonomy of these animals. In the great majority of studies conducted during the 2000s macroinvertebrates have been operationally defined by investigators as invertebrates retained by a 250 μ mesh in field sampling devices. Significant advances have been and continue to be made in developing ever more refined keys to macroinvertebrate groups. The analysis by function is a viable alternative when advances in macroinvertebrate ecological research is restricted by the level of detail in identifications. Focus on function, namely adaptations of macroinvertebrates to habitats and the utilization of food resources, has facilitated ecological evaluation of freshwater ecosystems (Functional feeding groups; FFG. As the great stream ecologist Noel Hynes observed, aquatic insects around the world exhibit similar morphologies and behaviors, even though they are in very different taxonomic groups. This is the basis for the FFG analysis that was initially developed in the early 1970s. FFG analysis applies taxonomy only to the level of detail that allows assignment to one of six FFG categories: scrapers adapted to feed on periphyton, detrital shredders adapted to feed on coarse (CPOM riparian-derived plant litter that has been colonized by microbes, herbivore shredders that feed on live, rooted aquatic vascular plants, filtering collectors adapted to remove fine particle detritus (FPOM from the water column, gathering collectors adapted to feed on FPOM where it is deposited on surfaces or in crevices in the sediments, and predators that capture live prey. The interacting roles of these FFGs in stream ecosystems were originally depicted in a conceptual model. Thus, there are a limited number of adaptations exhibited by stream macroinvertebrates that exploit these habitats and food resources. This accounts for the wide range of macroinvertebrate taxa

  6. Cosmogenic 3He in detrital gold

    Stuart, Finlay; Yakubovich, Olga; Caracedo, Ana; Nesterenok, Alexander


    Since the measurement of cosmogenic He in an alluvial diamond by McConville and Reynolds (1996) the application of cosmogenic noble gases to individual detrital grains to quantify surface processes has not been vigorously pursued. The likely low rate of diffusion of cosmogenic He in native metals, and their resistance to weathering and disintegration during erosion and transport, makes them a potential record of long-term Earth surface processes. In an effort to assess the extent that detrital refractory metals record the exposure history during transport and storage we have undertaken a reconnaissance study of the He isotope composition in 18 grains (2-200 mg) of native gold, copper, silver, and PtPd, Pt3Fe and OsIr alloys from alluvial placer deposits from around the world. 4He is dominantly the result of U and Th decay within the grains, or decay of 190Pt in the Pt-rich alloys. 3He is measurable in 13 grains, concentrations range up to 2.7E+6 atoms/g. 3He/4He are always in excess of the crustal radiogenic ratio, up to 306 Ra. Although nucleogenic 3He produced by (n,α) reactions on 6Li, and 3He from trapped hydrothermal fluids, are present, the majority of the 3He is cosmogenic in origin. Using newly calculated cosmogenic 3He production rates in heavy metals, and a determination of the effect of implantation based on the stopping distances of spallogenic 3He and 3H, the grains have 3Hecos concentrations that are equivalent to 0.35 to 1.5 Ma exposure at Earth's surface. In a study of detrital gold grains from several sites in Scotland we have found that 10 % have 3He concentrations that are significantly in excess of that generated since the Last Glacial Maximum. These studies demonstrate that, with refinement, cosmogenic 3He in refractory detrital minerals can be used to quantify sediment transport and storage on the 1-10 Ma timescale. P. McConville & J.H. Reynolds (1989). Geochim. Cosmochim. Acta, 53, 2365-75.

  7. Immune memory in invertebrates.

    Milutinović, Barbara; Kurtz, Joachim


    Evidence for innate immune memory (or 'priming') in invertebrates has been accumulating over the last years. We here provide an in-depth review of the current state of evidence for immune memory in invertebrates, and in particular take a phylogenetic viewpoint. Invertebrates are a very heterogeneous group of animals and accordingly, evidence for the phenomenon of immune memory as well as the hypothesized molecular underpinnings differ largely for the diverse invertebrate taxa. The majority of research currently focuses on Arthropods, while evidence from many other groups of invertebrates is fragmentary or even lacking. We here concentrate on immune memory that is induced by pathogenic challenges, but also extent our view to a non-pathogenic context, i.e. allograft rejection, which can also show forms of memory and can inform us about general principles of specific self-nonself recognition. We discuss definitions of immune memory and a number of relevant aspects such as the type of antigens used, the route of exposure, and the kinetics of reactions following priming. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Invertebrate FMRFamide related peptides.

    Krajniak, Kevin G


    In 1977 the neuropeptide FMRFamide was isolated from the clam, Macrocallista nimbosa. Since then several hundred FMRFamide-related peptides (FaRPs) have been isolated from invertebrate animals. Precursors to the FaRPs likely arose in the cnidarians. With the transition to a bilateral body plan FaRPs became a fixture in the invertebrate phyla. They have come to play a critical role as neurotransmitters, neuromodulators, and neurohormones. FaRPs regulate a variety of body functions including, feeding, digestion, circulation, reproduction, movement. The evolution of the molecular form and function of these omnipresent peptides will be considered.

  9. Statistics of large detrital geochronology datasets

    Saylor, J. E.; Sundell, K. E., II


    Implementation of quantitative metrics for inter-sample comparison of detrital geochronological data sets has lagged the increase in data set size, and ability to identify sub-populations and quantify their relative proportions. Visual comparison or application of some statistical approaches, particularly the Kolmogorov-Smirnov (KS) test, that initially appeared to provide a simple way of comparing detrital data sets, may be inadequate to quantify their similarity. We evaluate several proposed metrics by applying them to four large synthetic datasets drawn randomly from a parent dataset, as well as a recently published large empirical dataset consisting of four separate (n = ~1000 each) analyses of the same rock sample. Visual inspection of the cumulative probability density functions (CDF) and relative probability density functions (PDF) confirms an increasingly close correlation between data sets as the number of analyses increases. However, as data set size increases the KS test yields lower mean p-values implying greater confidence that the samples were not drawn from the same parent population and high standard deviations despite minor decreases in the mean difference between sample CDFs. We attribute this to the increasing sensitivity of the KS test when applied to larger data sets, which in turn limits its use for quantitative inter-sample comparison in detrital geochronology. Proposed alternative metrics, including Similarity, Likeness (complement to Mismatch), and the coefficient of determination (R2) of a cross-plot of PDF quantiles, point to an increasingly close correlation between data sets with increasing size, although they are the most sensitive at different ranges of data set sizes. The Similarity test is most sensitive to variation in data sets with n < 100 and is relatively insensitive to further convergence between larger data sets. The Likeness test reaches 90% of its asymptotic maximum at data set sizes of n = 200. The PDF cross-plot R2 value

  10. Detrital geochronology of unroofing magmatic complexes

    Malusà, Marco Giovanni; Villa, Igor Maria; Vezzoli, Giovanni; Garzanti, Eduardo


    Tectonic reconstructions performed in recent years are increasingly based on petrographic (Dickinson & Suczek, 1979; Garzanti et al., 2007) and geochronological (Brandon et al., 1998; DeCelles et al., 2004) analyses of detrital systems. Detrital age patterns are traditionally interpreted as a result of cooling induced by exhumation (Jäger, 1967; Dodson, 1973). Such an approach can lead to infer extremely high erosion rates (Giger & Hurford 1989) that conflict with compelling geological evidence (Garzanti & Malusà, 2008). This indicates that interpretations solely based on exhumational cooling may not have general validity (Villa, 2006). Here we propose a new detrital geochronology model that takes into account the effects of both crystallization and exhumational cooling on geochronometers, from U-Pb on zircon to fission tracks on apatite. This model, specifically designed for unroofing magmatic complexes, predicts both stationary and moving mineral-age peaks. Because its base is the ordinary interaction between endogenic and exogenic processes, it is applicable to any geological setting. It was tested on the extremely well-studied Bregaglia-Bergell pluton in the Alps, and on the sedimentary succession derived from its erosion. The consistency between predicted and observed age patterns validates the model. Our results demonstrate that volcanoes were active on top of the growing Oligocene Alps, and resolve a long-standing paradox in quantitative erosion-sedimentation modelling, the scarcity of sediment during apparently fast erosion. Dickinson, W. R. & Suczek, C. A. Plate tectonics and sandstone composition. Am. Assoc. Petrol. Geol. Bull. 63, 2164-2172 (1979). Garzanti, E., Doglioni, C., Vezzoli. G. & Andò, S. Orogenic belts and orogenic sediment provenance. J. Geol. 115, 315-334 (2007). Brandon, M. T., Roden-Tice, M. K. & Garver, J. I. Cenozoic exhumation of the Cascadia accretionary wedge in the Olympic Mountains, northwest Washington State. Geol. Soc. Am. Bull

  11. Evaluating macroinvertebrate community shifts in the confluence of freestone and limestone streams

    Jennifer K. Hellmann


    Full Text Available Aquatic macroinvertebrates are critical to ecosystem functioning through their regulation of many essential top-down and bottom-up ecosystem processes such as energy translocation, nutrient flow, and detrital decomposition. However, specific preferences by macroinvertebrates for certain ranges of abiotic and biotic characteristics mean that changes in these factors often create large differences in benthic community structure. Investigations into drivers of community structure have found distinct patterns of variation between ecosystems, but drivers of macroscale variation may differ from drivers of microscale variation. Such microscale variation in macroinvertebrate community structure as a function of abiotic conditions may be found in the confluence of two geologically distinct freshwater streams. Variation in the origin, underlying bedrock, and watershed of a stream results in drastically different physical and chemical characteristics and correspondingly distinct macroinvertebrate community structures. In areas where water from geologically distinct streams flows together, a mixing zone emerges with unique chemical and physical characteristics. There is little information on how invertebrate communities are structured within this mixing zone. To investigate this, we examined how the structure of the macroinvertebrate community changed downstream of the confluence. Up to thirty metres downstream, we found distinct stream sections that mirrored physical and chemical conditions found in limestone and freestone streams, and a mixing zone with emergent properties. These physical and chemical changes between sites were accompanied by shifts in macroinvertebrate community composition. Diversity indices indicated significantly higher diversity in freestone sites than in limestone sites or the mixing zone and there was a unique composition of genera in the mixing zone that were distinct from both limestone and freestone sites. Factors driving

  12. Headwater riparian forest-floor invertebrate communities associated with alternative forest management practices.

    Rykken, Jessica J; Moldenke, Andrew R; Olson, Deanna H


    Headwater streams and their riparian zones are a common, yet poorly understood, component of Pacific Northwest, USA, landscapes. We describe the ecological importance of headwater stream riparian zones as habitat for forest-floor invertebrate communities and assess how alternative management strategies for riparian zones may impact these communities. We compared community composition of forest-floor invertebrates at increasing distances along trans-riparian (stream edge to upslope) transects in mature forests, clearcuts, and riparian buffers of approximately 30-m width with upslope clearcuts. Invertebrates were collected using pitfall traps in five replicate blocks of three treatments each in the Willamette National Forest, Oregon, USA. We measured microclimate and microhabitat variables at pitfall locations. Despite strong elevation and block effects on community composition, community analyses revealed a distinct "riparian" invertebrate community within 1 m of the stream edge in mature forest treatments, which was strongly related to cool, humid microclimate conditions. Invertebrate community composition in buffer treatments was far more similar to that of mature forests than to clearcuts; a pattern mirrored by microclimate. These results suggest that, within our study sites, forest-floor invertebrate distributions are strongly associated with microclimate and that riparian buffers of approximately 30-m width do provide habitat for many riparian and forest species. Riparian reserves may serve as effective forest refugia and/or dispersal corridors for invertebrates and other taxa, and their incorporation into watershed management plans likely will contribute to meeting persistence and connectivity objectives.

  13. Detrital mica 40Ar/39Ar dating approach for provenance and exhumation of the Eastern Alps.

    Gemignani, Lorenzo; Sun, Xilin; Van Gerve, Thomas; Braun, Jean; Wijbrans, Jan Robert


    The use of thermochronological techniques on detrital minerals, such as (U-Th)/He on apatite and zircon, zircon fission-tracks and Ar-dating on mica and microcline, can be used to constrain the lateral variation of the exhumation rate and the sediment provenance of large sectors of an actively deforming mountain belt. Analysis of modern river sands yields an inventory of ages of rocks currently cropping out and eroding in the hinterland of a river drainage basin. So far, only few studies have focused on testing the consistency of the detrital mineral age distributions and the surface bed-rock thermochronology. We present here new detrital 40Ar/39Ar biotite and muscovite age distributions for nineteen modern river sands from rivers draining the Eastern Alps north of the Periadriatic line. The ages, interpreted to reflect cooling of the source rock under the closure temperature of muscovite and biotite respectively, were compared with the in-situ ages for the bedrock in the hinterland from literature. The results were generally comparable with the bedrocks ages for both the target minerals and represent three main clusters of ages that record the main exhumation pulses in this sector of the Alps. We have applied two numerical methods to the cooling ages to a) quantify the rates of exhumation of the Tauern Window during Paleocene-Miocene period of the Alpine orogeny, b) linearly compute the spatial variability of the present-day exhumation rates of a set of 4 detrital mineral sample drainage basins along the Inn river stream. Our results suggest a 0.17-0.52 mm/yr range in exhumation rates for the Tauern Window since the Miocene. The results from modelling constrained the downstream evolution of the detrital signal in the Inn river and realistically predicts higher erosion rates in the downstream basin where young cooling ages from the Penninic units of the Tauern are drained into the system, forming a characteristic peak. Our data define more inclusive trends in

  14. Invertebrate models of alcoholism.

    Scholz, Henrike; Mustard, Julie A


    For invertebrates to become useful models for understanding the genetic and physiological mechanisms of alcoholism related behaviors and the predisposition towards alcoholism, several general requirements must be fulfilled. The animal should encounter ethanol in its natural habitat, so that the central nervous system of the organism will have evolved mechanisms for responding to ethanol exposure. How the brain adapts to ethanol exposure depends on its access to ethanol, which can be regulated metabolically and/or by physical barriers. Therefore, a model organism should have metabolic enzymes for ethanol degradation similar to those found in humans. The neurons and supporting glial cells of the model organism that regulate behaviors affected by ethanol should share the molecular and physiological pathways found in humans, so that results can be compared. Finally, the use of invertebrate models should offer advantages over traditional model systems and should offer new insights into alcoholism-related behaviors. In this review we will summarize behavioral similarities and identified genes and mechanisms underlying ethanol-induced behaviors in invertebrates. This review mainly focuses on the use of the nematode Caenorhabditis elegans, the honey bee Apis mellifera and the fruit fly Drosophila melanogaster as model systems. We will discuss insights gained from those studies in conjunction with their vertebrate model counterparts and the implications for future research into alcoholism and alcohol-induced behaviors.

  15. Provenance and sediment dynamics within river basins in Western Peru through detrital zircons U-Pb ages

    Camille, Litty; Pierre, Lanari; Marco, Burn; Fritz, Schlunegger


    U-Pb dating of detrital zircons from clastic sediments by LA-ICPMS has become a popular method in sedimentary correlation and provenance studies. Because of remarkable durability, detrital zircons may be reworked through multiple sedimentary cycles and provide an ideal material to study the sedimentary provenance in rivers and the erosional characteristics. The Western side of the Peruvian Andes has experienced multiple pluvial periods induced phases of erosion and the formation of subsequent cut-and-fill terrace sequences since the Pleistocene. The aim of the study is to estimate the source areas of the terrace and modern deposits to infer changes in sediment dynamics through time and correlate them with the climatic change and especially precipitation patterns. To this extent, we determined the provenance of 4 dated terrace deposits along with modern sediments from the same streams by matching detrital-zircon ages with crystallization ages of source rocks. Age populations of detrital zircons are derived using U-Pb LA-ICP-MS analysis of about 50 zircons. Results show changes in the sediment provenance through time. Nowadays, sediment source areas are mainly located on the uppermost reach of the rivers whereas during the Pleistocene, sediment source areas were both located in the headwaters and along the middle reach of the rivers. These differences in terms of provenance could correlate with a change in precipitation locations and rates. Indeed a scenario where the locus of precipitation occurrence shifted from the middle reaches including the Altiplano during the past, to the Altiplano only as observed today, along with higher precipitation rates during the periods of terraces formation, offers an explanation to explain the erosional patterns recorded by detrital zircons.

  16. Biogeochemistry of Decomposition and Detrital Processing

    Sanderman, J.; Amundson, R.


    Decomposition is a key ecological process that roughly balances net primary production in terrestrial ecosystems and is an essential process in resupplying nutrients to the plant community. Decomposition consists of three concurrent processes: communition or fragmentation, leaching of water-soluble compounds, and microbial catabolism. Decomposition can also be viewed as a sequential process, what Eijsackers and Zehnder (1990) compare to a Russian matriochka doll. Soil macrofauna fragment and partially solubilize plant residues, facilitating establishment of a community of decomposer microorganisms. This decomposer community will gradually shift as the most easily degraded plant compounds are utilized and the more recalcitrant materials begin to accumulate. Given enough time and the proper environmental conditions, most naturally occurring compounds can completely be mineralized to inorganic forms. Simultaneously with mineralization, the process of humification acts to transform a fraction of the plant residues into stable soil organic matter (SOM) or humus. For reference, Schlesinger (1990) estimated that only ˜0.7% of detritus eventually becomes stabilized into humus.Decomposition plays a key role in the cycling of most plant macro- and micronutrients and in the formation of humus. Figure 1 places the roles of detrital processing and mineralization within the context of the biogeochemical cycling of essential plant nutrients. Chapin (1991) found that while the atmosphere supplied 4% and mineral weathering supplied no nitrogen and internal nutrient recycling is the source for >95% of all the nitrogen and phosphorus uptake by tundra species in Barrow, Alaska. In a cool temperate forest, nutrient recycling accounted for 93%, 89%, 88%, and 65% of total sources for nitrogen, phosphorus, potassium, and calcium, respectively ( Chapin, 1991). (13K)Figure 1. A decomposition-centric biogeochemical model of nutrient cycling. Although there is significant external input (1

  17. Determinants of the detrital arthropod community structure

    Lessard, J.P.; Sackett, Tara E.; Reynolds, William N.;


    Understanding the factors that shape community structure, and whether those factors vary geographically, has a long history in ecology. Because the abiotic environment often varies in predictable ways along elevational gradients, montane systems are ideal to study geographic variation in the dete......Understanding the factors that shape community structure, and whether those factors vary geographically, has a long history in ecology. Because the abiotic environment often varies in predictable ways along elevational gradients, montane systems are ideal to study geographic variation...... in the determinants of community structure. In this study, we first examined the relative importance of environmental gradients, microclimate, and food resources in driving spatial variation in the structure of detrital communities in forests of the southeastern USA. Then, in order to assess whether the determinants...... for the effect of climatic variation along the elevational gradient, food resource addition and microclimate alteration influenced the richness and abundance of some taxa. However, the effect of food resource addition and microclimate alteration on the richness and abundance of arthropods did not vary...

  18. Invertebrate welfare: an overlooked issue

    Kelsey Horvath


    Full Text Available While invertebrates make up the majority of animal species, their welfare is overlooked compared to the concern shown to vertebrates. This fact is highlighted by the near absence of regulations in animal research, with the exception of cephalopods in the European Union. This is often justified by assumptions that invertebrates do not experience pain and stress while lacking the capacity for higher order cognitive functions. Recent research suggests that invertebrates may be just as capable as vertebrates in experiencing pain and stress, and some species display comparable cognitive capacities. Another obstacle is the negative view of invertebrates by the public, which often regards them as pests with no individual personalities, gastronomic entities, or individuals for scientific experimentation without rules. Increasingly, studies have revealed that invertebrates possess individual profiles comparable to the personalities found in vertebrates. Given the large economic impact of invertebrates, developing certain attitude changes in invertebrate welfare may be beneficial for producers while providing higher welfare conditions for the animals. While the immense number and type of species makes it difficult to suggest that all invertebrates will benefit from increased welfare, in this review we provide evidence that the topic of invertebrate welfare should be revisited, more thoroughly investigated, and in cases where appropriate, formally instituted.

  19. Functional neuropeptidomics in invertebrates.

    De Haes, Wouter; Van Sinay, Elien; Detienne, Giel; Temmerman, Liesbet; Schoofs, Liliane; Boonen, Kurt


    Neuropeptides are key messengers in almost all physiological processes. They originate from larger precursors and are extensively processed to become bioactive. Neuropeptidomics aims to comprehensively identify the collection of neuropeptides in an organism, organ, tissue or cell. The neuropeptidome of several invertebrates is thoroughly explored since they are important model organisms (and models for human diseases), disease vectors and pest species. The charting of the neuropeptidome is the first step towards understanding peptidergic signaling. This review will first discuss the latest developments in exploring the neuropeptidome. The physiological roles and modes of action of neuropeptides can be explored in two ways, which are largely orthogonal and therefore complementary. The first way consists of inferring the functions of neuropeptides by a forward approach where neuropeptide profiles are compared under different physiological conditions. Second is the reverse approach were neuropeptide collections are used to screen for receptor-binding. This is followed by localization studies and functional tests. This review will focus on how these different functional screening methods contributed to the field of invertebrate neuropeptidomics and expanded our knowledge of peptidergic signaling. This article is part of a Special Issue entitled: Neuroproteomics: Applications in Neuroscience and Neurology.

  20. [Effects of invertebrate bioturbation on vertical hydraulic conductivity of streambed for a river].

    Ren, Chao-Liang; Song, Jin-Xi; Yang, Xiao-Gang; Xue, Jian


    Streambed hydraulic conductivity is a key factor influencing water exchange between surface water and groundwater. However, the streambed invertebrate bioturbation has a great effect on the hydraulic conductivity. In order to determine the impact of invertebrate bioturbation on streambed hydraulic conductivity, the investigation of invertebrate bioturbation and in-situ test of vertical hydraulic conductivity of streambed are simultaneously conducted at five points along the main stream of the Weihe River. Firstly, correlation between the streambed vertical hydraulic conductivity and grain size distribution is analyzed. Secondly, type and density of the invertebrate and their correlation to hydraulic conductivity are determined. Finally, the effect of invertebrate bioturbation on the streambed hydraulic conductivity is illustrated. The results show that the vertical hydraulic conductivity and biological density of invertebrate are 18.479 m x d(-1) and 139 ind x m(-2), respectively for the Caotan site, where sediment composition with a large amount of sand and gravel particles. For Meixian site, the sediment constitutes a large amount of silt and clay particles, in which the vertical hydraulic conductivity and biological density of invertebrate are 2.807 m x d(-1) and 2 742 ind x m(-2) respectively. Besides, for the low permeability of four sites (Meixian, Xianyang, Lintong and Huaxian), grain size particles are similar while the vertical hydraulic conductivity and biological density of invertebrate are significantly different from one site to another. However, for each site, the vertical hydraulic conductivity closely related to biological density of invertebrate, the Pearson correlation coefficient is 0.987. It can be concluded that both grain size particles and invertebrate bioturbation influence sediment permeability. For example, higher values of streambed hydraulic conductivity from strong permeability site mainly due to the large amount of large-size particles

  1. Detrital Zircon of 4100 Ma in Quartzite in Burang, Tibet

    DUO Ji; WEN Chunqi; FAN Xiaoping; GUO Jianci; NI Zhiyao; LI Xiaowen; SHI Yuruo; WEN Quan


    A detrital zircon aged 4.1 Ga is discovered by the SHRIMP U-Pb method in a quartzite in Burang County, western Tibet. This is presently the oldest single-grain detrital zircon in China. The Th-U ratios of the two testing points of the >4.0 Ga zircon are between 0.76 and 0.86, indicating their magmatic origin. This discovery has offered an important age for investigating the geological evolution of the Qinghai-Tibet Plateau.


    We present empirical models for estimating the status of fish and aquatic invertebrate communities in all second to fourth-order streams (1:100,000 scale; total stream length = 6476 km) throughout the Willamette River Basin, Oregon. The models project fish and invertebrate status...

  3. Louisiana ESI: INVERT (Invertebrate Polygons)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for marine and estuarine invertebrate species, and major concentration areas for harvested or potentially...

  4. Virginia ESI: INVERT (Invertebrate Polygons)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for marine, estuarine, and rare invertebrate species in Virginia. Vector polygons in this data set...

  5. Alabama ESI: INVERT (Invertebrate Polygons)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for marine and estuarine invertebrate species in Alabama. Vector polygons in this data set represent...

  6. Invertebrate diversity in southern California

    National Oceanic and Atmospheric Administration, Department of Commerce — This shapefile displays mean invertebrate diversity within 5 minute grid cells. The Shannon Index of diversity was calculated from Southern California Coastal Water...

  7. Detrital carbon pools in temperate forests: magnitude and potential for landscape-scale assessment

    John Bradford; Peter Weishampel; Marie-Louise Smith; Randall Kolka; Richard A. Birdsey; Scott V. Ollinger; Michael G. Ryan


    Reliably estimating carbon storage and cycling in detrital biomass is an obstacle to carbon accounting. We examined carbon pools and fluxes in three small temperate forest landscapes to assess the magnitude of carbon stored in detrital biomass and determine whether detrital carbon storage is related to stand structural properties (leaf area, aboveground biomass,...

  8. Acid-stress effects on stream biology

    Herrmann, J. (Kalmar Univ. (Sweden). Dept. of Natural Sciences); Degerman, E. (Inst. of Freshwater Research, Drottningholm (Sweden)); Gerhardt, A. (Lund Univ. (Sweden). Dept. of Ecology); Johansson, Catarina (Statistics Sweden, Stockholm (Sweden)); Lingdell, P.E. (Gunilbo, Skinnskatteberg (Sweden)); Muniz, I. (Norvegian Inst. for Nature Research (NINA), Oslo (Norway))


    This paper reports and discusses the results of Swedish freshwater acidification research, for the period 1988.1993 and earlier. Changed biotic patterns are exemplified by increased occurrence of those green algae that indicate an increase in nutrients, reduced species richness of invertebrates, a general shift in proportion from invertebrate grazers towards shredders, decreasing populations of fish. Impact on birds appears less validated. The mechanisms for the changes in individual, population and community levels include elevated hydrogen, aluminium and cadmium concentrations that affect ion balance and respiration in fish and invertebrates, but also various behavior patterns, and development stages. Al can ameliorate low pH temporarily but does not biomagnify along food chains, and neither predatory insects nor flycatchers seem to accumulate Al. Iron precipitation can affect feeding ability and respiration of mayfly nymphs. That humic substances may mitigate metals still seems uncertain for fish and invertebrates. Generally, most changes in the biotic patterns of streams seem to be related to abiotic impact routes. Relevant and sufficient knowledge seems to be lacking in three research fields of acidification impact on streams; viz. increasing occurrence of green algae in acidified streams; role of invertebrates in decomposition of leaves in acid waters; and recovery processes of fish and invertebrates after liming. (94 refs., 4 figs.)

  9. Gondwana to Pangea: a detrital zircons tale from NW Iberia

    Pastor-Galán, Daniel; Gutiérrez-Alonso, Gabriel; Brendan Murphy, J.; Fernández-Suárez, Javier; Hofmann, Mandy; Linnemann, Ulf


    The Cantabrian Zone of NW Iberia preserves a voluminous, almost continuous, sedimentary sequence that ranges from Neoproterozoic to Early Permian in age. Its tectonic setting is controversial and recent hypotheses include (i) passive margin deposition along the northern margin of Gondwana or (ii) an active continental margin or (iii) a drifting ribbon continent. In this paper we present detrital zircon U-Pb laser ablation age data from 13 samples from the Cantabrian Zone sequence ranging from Early Silurian to Early Permian in depositional age, which, together with previously published detrital zircon ages from Ediacaran-Ordovician strata, allow a comprehensive analysis of changing provenance through time. Laser ablation U-Pb geochronological analysis of detrital zircons in thirteen samples of the Cantabrian Zone of the NW Iberian Variscan belt reveal that this portion of Iberia was part of the northern passive-margin of Gondwana from the Ordovician to Late Devonian, until the onset of collision between Gondwana and Laurentia. Zircon populations in these samples show important similarities with zircons found in coeval detrital rocks from central North Africa. Additionally, the populations found in NW Iberia are coherent with a Saharan source. We suggest that NW Iberia was situated from Ordovician to Late Devonian along the Gondwana northern passive margin close to the paleoposition of central North Africa and Saharan craton. Additionally, the Carboniferous-Permian samples studied record the provenance changes produced during the Variscan collision and basement exhumation, the Cantabrian orocline formation and the subsequent detachment of the lithospheric mantle. The provenance changes reflect major topographic variations due to the afore mentioned processes during Late Devonian to Early Permian times. Detrital zircon studies are a useful tool that can complement regional syntheses in deducing paleogeographic locations, the occurrence of major tectonic events such

  10. Disponibilidade de invertebrados aquáticos para peixes bentófagos de dois riachos da bacia do rio Iguaçu, Estado do Paraná, Brasil Aquatic invertebrates disponibility for bentophagous fishes in two streams at the Iguaçu River basin, state of Paraná, Brazil

    Anderson Ferreira


    Full Text Available Assumindo que os organismos que os peixes consomem refletem sua disponibilidade no ambiente, os objetivos deste trabalho foram verificar, através da dieta, quais os principais organismos que compõem a bentofauna disponível para peixes bentófagos, e analisar as variações espaço-temporais e ontogenéticas na dieta deste grupo de peixes. As coletas foram realizadas mensalmente de março/2000 a fevereiro/2001 através de pesca elétrica em dois riachos da bacia do rio Iguaçu e os estômagos (n=329 analisados pelo método volumétrico. A análise da dieta revelou uma grande diversidade de invertebrados bênticos, principalmente insetos de várias ordens, sendo as mais consumidas Ephemeroptera, representada por três famílias, Diptera por onze e Trichoptera por nove famílias, sendo esses, os organismos mais disponíveis para a alimentação, além de diversos organismos menos representativos. Os resultados de correlação de Spearman foram altamente significativos, revelando forte similaridade espacial, temporal e ontogenética. Essa grande disponibilidade de recursos aquáticos, provavelmente seja a maior responsável pela elevada abundância de indivíduos do gênero Trichomycterus (Siluriformes, Trichomyspteridae nos ambientes analisados.Analyzing aquatic organisms present in fish stomachs is a good way to determine their availability in the environment. This paper aims to determine aquatic organism availability (especially benthos for bentophagous fishes and to analyze spatial, temporal and ontogenetic changes in their diets. Samples were monthly taken from March 2000 to February 2001, through electrofishing, in two streams of the Iguaçu River. The stomachs were analyzed (329 units and the results expressed through volumetric method. The diet was composed of benthic invertebrates, especially insects from several orders, being Ephemeroptera (3 families, diptera (11 families and Trichoptera (9 families the most consumed ones. Therefore

  11. Aquatic Invertebrate Development Working Group

    Meyers, D.


    Little definitive evidence exists to show that gravity plays a major role in embyrogenesis of aquatic invertebrates. Two reasons for this may be: (1) few studies have been done that emphasize the role of gravity; and (2) there simply may not be any gravity effect. The buoyant nature of the aquatic environment could have obscured any evolutionary effect of gravity. The small size of most eggs and their apparent lack of orientation suggests reduced gravitational influence. Therefore, it is recommended that the term development, as applied to aquatic invertebrates, be loosely defined to encompass behavioral and morphological parameters for which baseline data already exist.

  12. Invertebrates control metals and arsenic sequestration as ecosystem engineers.

    Schaller, Jörg; Weiske, Arndt; Mkandawire, Martin; Dudel, E Gert


    Organic sediments are known to be a significant sink of inorganic elements in polluted freshwater ecosystems. Hence, we investigated the role of invertebrate shredders (the freshwater shrimp Gammarus pulex L.) in metal and arsenic enrichment into organic partitions of sediments in a wetland stream at former uranium mining site. Metal and metalloid content in leaf litter increased significantly during decomposition, while at the same time the carbon content decreased. During decomposition, G. pulex as a ecosystem engineer facilitated significantly the enrichment of magnesium (250%), manganese (560%), cobalt (310%), copper (200%), zinc (43%), arsenic (670%), cadmium (100%) and lead (1340%) into small particle sizes. The enrichments occur under very high concentrations of dissolved organic carbon. Small particles have high surface area that results in high biofilm development. Further, the highest amounts of elements were observed in biofilms. Therefore, invertebrate shredder like G. pulex can enhance retention of large amounts of metal and arsenic in wetlands.

  13. Quantifying modern and ancient drainage basin erosion with detrital thermochronology

    Ehlers, T. A.; Stock, G. M.; Rahl, J. M.; Farley, K. A.; van der Pluijm, B. A.


    Studies of drainage basin erosion and landform evolution are often limited by not knowing where sediment is sourced from and how erosion rates vary over different time scales. Detrital thermochronometer cooling ages collected from modern river sediments and basin deposits provide a promising tool to address these problems. We present two applications of detrital thermochronology to quantify: (1) spatial variations in erosion using modern river sediments; and (2) temporal variations in erosion calculated using syntectonic sedimentary deposits. In our first application, the elevation dependence of detrital apatite (U-Th)/He (AHe) ages is used to track the elevations where sediment is produced from bedrock. The ages are measured in river sediments from the mouth of two catchments in the Sierra Nevada, California, and used as sediment tracers to quantify spatial variations in erosion. We measured ~54 AHe single grain ages from each catchment. Measured AHe age probability density functions (PDFs) were compared with predicted PDFs, calculated by convolving catchment hypsometry with bedrock age-elevation relationships. Statistical comparison of the PDFs evaluates the spatial distribution of erosion in the catchments. Predicted and observed PDFs are statistically identical for the nonglaciated Inyo Creek catchment, indicating uniform erosion. However, a statistically significant lack of older ages is observed in the recently deglaciated Lone Pine catchment, suggesting sediment is derived from the lower half of the catchment; possibly due to sediment storage at higher elevations and/or enhanced erosion at intermediate elevations. Second, we evaluate the ability of detrital thermochronology to record transients in drainage basin erosion on million year time scales. A transient 1D thermal model is used to predict cooling ages in a syntectonic stratigraphic section where sediment is sourced from a region with temporally variable erosion. In simulations with transient erosion

  14. Benthic invertebrate metals exposure, accumulation, and community-level effects downstream from a hard-rock mine site

    Beltman, D.J.; Lipton, J.; Cacela, D. [Hagler Bailly, Boulder, CO (United States); Clements, W.H. [Colorado State Univ., Fort Collins, CO (United States). Dept. of Fishery and Wildlife Biology


    This study quantitatively evaluated the relationships among As, Co, and Cu concentrations in exposure media (surface water, sediment, and aufwuchs), As, Co, and Cu concentrations in aquatic macroinvertebrates, and invertebrate community structure in a mine-affected stream. Concentrations of As, Co, and Cu were significantly elevated in both exposure media and invertebrate tissue downstream from the mine. Copper in invertebrates was significantly correlated only with Cu in aufwuchs, and Co in invertebrates was significantly correlated only with dissolved Co in water, suggesting different mechanisms of invertebrate accumulation for these two metals. The invertebrate community was severely affected downstream from the mine, with a loss of metals-sensitive species and reductions in both total biomass and number of species. Total abundance was not affected. Principal components analysis was performed on the invertebrate community data to develop a simplified description of community response to mine inputs. Based on this index, metal concentrations in invertebrates were poor predictors of community structure. Copper concentrations in water, combined with an estimate of invertebrate drift from clean tributaries, were statistically significant predictors of community structure.

  15. Influence of land-use on structural and functional macroinvertebrate composition communities associated on detritus in Subtropical Atlantic Forest streams

    Luiz Ubiratan Hepp

    Full Text Available Abstract Aim Our aim in this study was to evaluate the effects of land use in drainage basins of the streams on the taxonomic and functional composition of aquatic invertebrate communities associated in leaf litter. Methods We evaluated the colonisation of invertebrates in the incubated plant debris in streams with presence and absence of riparian vegetation and different land-uses in the drainage area. We used the litter bags approach. Results The taxonomic and functional composition invertebrate associated with leaf litter ranged between streams. In addition, streams with presence of vegetation showed less variation taxonomic and functional composition communities. Still, the density of shredders invertebrates were lower in streams without vegetation. Conclusions The riparian vegetation is an important environmental factor in the composition of invertebrates. However, the land-use throughout the drainage basin should be considered as relevant factor in structuring aquatic biota.

  16. Predicting, Measuring, and Monitoring Aquatic Invertebrate Biodiversity on Dryland Military Bases


    challenges for predicting how management decisions on military lands could affect landscape -scale patterns of aquatic invertebrate biodiversity. This...sites in dryland streams .............. 89 Figure 7.3 Pairwise correlations among all local and landscape distance metrics ....................... 94...Water Assessment Tool USDA: United States Department of Agriculture USGS: United States Geological Survey WSMR: White Sands Missile Range

  17. Reliability of a method of sampling stream invertebrates

    Chutter, FM


    Full Text Available In field ecological studies inferences must often be drawn from dissimilarities in numbers and species of organisms found in biological samples collected at different times and under various conditions....

  18. Streams with Strahler Stream Order

    Minnesota Department of Natural Resources — Stream segments with Strahler stream order values assigned. As of 01/08/08 the linework is from the DNR24K stream coverages and will not match the updated...

  19. GPCRs in invertebrate innate immunity.

    Reboul, Jerome; Ewbank, Jonathan J


    G-protein coupled receptors (GPCRs) represent a privileged point of contact between cells and their surrounding environment. They have been widely adopted in vertebrates as mediators of signals involved in both innate and adaptive immunity. Invertebrates rely on innate immune defences to resist infection. We review here evidence from a number of different species, principally the genetically tractable Caenorhabditis elegans and Drosophila melanogaster that points to an important role for GPCRs in modulating innate immunity in invertebrates too. In addition to examples of GPCRs involved in regulating the expression of defence genes, we discuss studies in C. elegans addressing the role of GPCR signalling in pathogen aversive behaviour. Despite the many lacunae in our current knowledge, it is clear that GPCR signalling contributes to host defence across the animal kingdom.

  20. Marine Invertebrates: Communities at Risk

    Jennifer Mather


    Full Text Available Our definition of the word ‘animal’ centers on vertebrates, yet 99% of the animals on the planet are invertebrates, about which we know little. In addition, although the Census of Marine Life ( has recently conducted an extensive audit of marine ecosystems, we still do not understand much about the animals of the seas. Surveys of the best-known ecosystems, in which invertebrate populations often play a key role, show that the invertebrate populations are affected by human impact. Coral animals are the foundation of coral reef systems, which are estimated to contain 30% of the species in the ocean. Physical impact and chemical changes on the water severely damage these reefs, and may lead to the removal of these important habitats. Tiny pteropod molluscs live in huge numbers in the polar seas, and their fragile shells are particularly vulnerable to ocean acidification. Their removal would mean that fishes on which we depend would have a hugely diminished food supply. In the North Sea, warming is leading to replacement of colder water copepods by warmer water species which contain less fat. This is having an effect on the birds which eat them, who enrich the otherwise poor land on which they nest. Conversely, the warming of the water and the loss of top predators such as whales and sharks has led to an explosion of the jumbo squid of the Pacific coast of North America. This is positive in the development of a squid fishery, yet negative because the squid eat fish that have been the mainstay of the fishery along that coast. These examples show how invertebrates are key in the oceans, and what might happen when global changes impact them.

  1. Alternative adaptive immunity in invertebrates

    Kurtz, Joachim; Armitage, Sophie Alice Octavia


    Vertebrate adaptive immunity is characterized by challenge-specific long-term protection. This specific memory is achieved through the vast diversity of somatically rearranged immunological receptors such as antibodies. Whether or not invertebrates are capable of a comparable phenotypic plasticity...... and memory has long been a matter of debate. A recent study on Anopheles gambiae mosquitoes now establishes Down syndrome cell adhesion molecule (Dscam) as a key immune surveillance factor with characteristics analogous to antibodies....

  2. Impacts of marine-derived nutrients on stream ecosystem functioning.

    Zhang, Yixin; Negishi, Junjiro N; Richardson, John S; Kolodziejczyk, Renata


    Energy and nutrient subsidies transported across ecosystem boundaries are increasingly appreciated as key drivers of consumer-resource dynamics. As purveyors of pulsed marine-derived nutrients (MDN), spawning salmon are one such cross-ecosystem subsidy to freshwaters connected to the north Pacific. We examined how salmon carcasses influenced detrital processing in an oligotrophic stream. Experimental manipulations of MDN inputs revealed that salmon carcasses indirectly reduced detrital processing in streams through temporarily decoupling the detrital resource-consumer relationship, in which detrital consumers shifted their diet to the high-nutrient resource, i.e. salmon carcasses. The average decomposition rate of alder leaves with salmon carcass addition was significantly lower than that without the carcass, which was associated with lower abundance and biomass of detritivorous Trichoptera on the carcass-treated leaves. There were generally larger in size Trichopteran detritivores on the carcasses than on leaves. These results imply that cross-boundary MDN subsidies indirectly retard the ecosystem processing of leaf litter within the short term, but may enhance those food-limited detritivorous consumers. Because unproductive freshwaters in the Pacific northwest are highly dependent upon the organic matter inputs from surrounding forests, this novel finding has implications for determining conservation and management strategies of salmon-related aquatic ecosystems, in terms of salmon habitat protection and fisheries exploitation.

  3. How Reliable is Your Detrital Geothermochronological Data? Quantifying the Influence of Abrasion on Detrital Heavy Minerals Through Numerical Modelling

    Lavarini, C.; Attal, M.; Kirstein, L. A.


    Detrital heavy minerals, particularly zircon, have been used to learn about the early evolution of the Earth and are often the only record we have of events that have affected the geological evolution of rocks at the Earth's surface (Watson and Harrison, 2005). Recently, many studies have focused on the investigation of natural and artificial bias in detrital mineral analysis in order to enhance the technique's reliability (e.g., Moecher and Samson, 2006). However, in spite of the widely-known influence of physical abrasion, no attempts have been made to quantitatively assess how it potentially biases abrasion-driven products such as the mineral assemblages on which geothermochronology relies. Here, through numerical modelling, we explore how varying a series of parameters (rock erodibility, zircon fertility, sediment travel distance, source area lithology, and initial bedload ratio) yields different river loads and zircon signatures over the fluvial system. We assume that pebbles are abraded according to the commonly used Sternberg's law (1875) and that fining due to selective sorting is negligible as well as all abrasion products are in the sand size fraction. Our results highlight that the spatial location of lithologies and variations in erodibility strongly influence the release of zircon grains into the sand fraction. Even in a scenario where a catchment is made of two lithologies with identical properties, the one further from the outlet contributes relatively more zircon to the sand fraction collected at the outlet. The experiments also show the strong influence of fertility on zircon abundance in sands, and that bias increases with basin size due to the exponential nature of abrasion. These results highlight that abrasion must be carefully accounted as a natural bias in the investigation of detrital zircons for provenance research.

  4. The Stream-Catchment (StreamCat) and Lake-Catchment ...

    Background/Question/MethodsLake and stream conditions respond to both natural and human-related landscape features. Characterizing these features within contributing areas (i.e., delineated watersheds) of streams and lakes could improve our understanding of how biological conditions vary spatially and improve the use, management, and restoration of these aquatic resources. However, the specialized geospatial techniques required to define and characterize stream and lake watersheds has limited their widespread use in both scientific and management efforts at large spatial scales. We developed the StreamCat and LakeCat Datasets to model, predict, and map the probable biological conditions of streams and lakes across the conterminous US (CONUS). Both StreamCat and LakeCat contain watershed-level characterizations of several hundred natural (e.g., soils, geology, climate, and land cover) and anthropogenic (e.g., urbanization, agriculture, mining, and forest management) landscape features for ca. 2.6 million stream segments and 376,000 lakes across the CONUS, respectively. These datasets can be paired with field samples to provide independent variables for modeling and other analyses. We paired 1,380 stream and 1,073 lake samples from the USEPAs National Aquatic Resource Surveys with StreamCat and LakeCat and used random forest (RF) to model and then map an invertebrate condition index and chlorophyll a concentration, respectively. Results/ConclusionsThe invertebrate

  5. Drift of aquatic microfauna in Logan Cave Stream, Benton County, Arkansas

    US Fish and Wildlife Service, Department of the Interior — Periodic drift of vertebrates and invertebrates is a known phenomenon in surface streams. Change in light intensity has generally been targeted as the trigger for...

  6. The relation between invertebrate drift and two primary controls, discharge and benthic densities, in a large regulated river

    Kennedy, Theodore A.; Yackulic, Charles B.; Cross, Wyatt F.; Grams, Paul E.; Yard, Michael D.; Copp, Adam J.


    1. Invertebrate drift is a fundamental process in streams and rivers. Studies from laboratory experiments and small streams have identified numerous extrinsic (e.g. discharge, light intensity, water quality) and intrinsic factors (invertebrate life stage, benthic density, behaviour) that govern invertebrate drift concentrations (# m−3), but the factors that govern invertebrate drift in larger rivers remain poorly understood. For example, while large increases or decreases in discharge can lead to large increases in invertebrate drift, the role of smaller, incremental changes in discharge is poorly described. In addition, while we might expect invertebrate drift concentrations to be proportional to benthic densities (# m−2), the benthic–drift relation has not been rigorously evaluated. 2. Here, we develop a framework for modelling invertebrate drift that is derived from sediment transport studies. We use this framework to guide the analysis of high-resolution data sets of benthic density and drift concentration for four important invertebrate taxa from the Colorado River downstream of Glen Canyon Dam (mean daily discharge 325 m3 s−1) that were collected over 18 months and include multiple observations within days. Ramping of regulated flows on this river segment provides an experimental treatment that is repeated daily and allowed us to describe the functional relations between invertebrate drift and two primary controls, discharge and benthic densities. 3. Twofold daily variation in discharge resulted in a >10-fold increase in drift concentrations of benthic invertebrates associated with pools and detritus (i.e. Gammarus lacustris and Potamopyrgus antipodarum). In contrast, drift concentrations of sessile blackfly larvae (Simuliium arcticum), which are associated with high-velocity cobble microhabitats, decreased by over 80% as discharge doubled. Drift concentrations of Chironomidae increased proportional to discharge. 4. Drift of all four taxa was

  7. Influence of shredder feeding and nutrients on fungal activity and community structure in headwater streams

    Namil Chung; Keller. Suberkropp


    In stream detrital food webs, interactions occur between aquatic hyphomycetes associated with decomposing leaves and shredders consuming those leaves. However, few studies have examined how the feeding activity of shredders affects aquatic hyphomycetes. We examined the effect of shredder feeding on aquatic hyphomycete communities associated with submerged leaves in two...

  8. Methods for collecting benthic invertebrate samples as part of the National Water-Quality Assessment Program

    Cuffney, Thomas F.; Gurtz, Martin E.; Meador, Michael R.


    Benthic invertebrate communities are evaluated as part of the ecological survey component of the U.S. Geological Survey's National Water-Quality Assessment Program. These biological data are collected along with physical and chemical data to assess water-quality conditions and to develop an understanding of the factors that affect water-quality conditions locally, regionally, and nationally. The objectives of benthic invertebrate community characterizations are to (1) develop for each site a list of tax a within the associated stream reach and (2) determine the structure of benthic invertebrate communities within selected habitats of that reach. A nationally consistent approach is used to achieve these objectives. This approach provides guidance on site, reach, and habitat selection and methods and equipment for qualitative multihabitat sampling and semi-quantitative single habitat sampling. Appropriate quality-assurance and quality-control guidelines are used to maximize the ability to analyze data within and among study units.

  9. Effects of Pollution on Freshwater Invertebrates.

    Buikema, A. L., Jr.; Herricks, E. E.


    Presents a literature review of the effects of pollution on freshwater invertebrates, covering publications of 1976-77. Some of the areas covered are: (1) toxicant effects on invertebrates; (2) microcosm and community effects, and (3) biological control of aquatic life. A list of 123 references is also presented. (HM)

  10. An invertebrate stomach's view on vertebrate ecology

    Calvignac-Spencer, Sebastien; Leendertz, Fabian H.; Gilbert, M. Thomas P.


    Recent studies suggest that vertebrate genetic material ingested by invertebrates (iDNA) can be used to investigate vertebrate ecology. Given the ubiquity of invertebrates that feed on vertebrates across the globe, iDNA might qualify as a very powerful tool for 21st century population...

  11. Invertebrates, ecosystem services and climate change.

    Prather, Chelse M; Pelini, Shannon L; Laws, Angela; Rivest, Emily; Woltz, Megan; Bloch, Christopher P; Del Toro, Israel; Ho, Chuan-Kai; Kominoski, John; Newbold, T A Scott; Parsons, Sheena; Joern, A


    The sustainability of ecosystem services depends on a firm understanding of both how organisms provide these services to humans and how these organisms will be altered with a changing climate. Unquestionably a dominant feature of most ecosystems, invertebrates affect many ecosystem services and are also highly responsive to climate change. However, there is still a basic lack of understanding of the direct and indirect paths by which invertebrates influence ecosystem services, as well as how climate change will affect those ecosystem services by altering invertebrate populations. This indicates a lack of communication and collaboration among scientists researching ecosystem services and climate change effects on invertebrates, and land managers and researchers from other disciplines, which becomes obvious when systematically reviewing the literature relevant to invertebrates, ecosystem services, and climate change. To address this issue, we review how invertebrates respond to climate change. We then review how invertebrates both positively and negatively influence ecosystem services. Lastly, we provide some critical future directions for research needs, and suggest ways in which managers, scientists and other researchers may collaborate to tackle the complex issue of sustaining invertebrate-mediated services under a changing climate. © 2012 The Authors. Biological Reviews © 2012 Cambridge Philosophical Society.

  12. Effects of Pollution on Freshwater Invertebrates.

    Buikema, A. L., Jr.; Herricks, E. E.


    Presents a literature review of the effects of pollution on freshwater invertebrates, covering publications of 1976-77. Some of the areas covered are: (1) toxicant effects on invertebrates; (2) microcosm and community effects, and (3) biological control of aquatic life. A list of 123 references is also presented. (HM)

  13. Detrital cave sediments record Late Quaternary hydrologic and climatic variability in northwestern Florida, USA

    Winkler, Tyler S.; van Hengstum, Peter J.; Horgan, Meghan C.; Donnelly, Jeffrey P.; Reibenspies, Joseph H.


    Detrital sediment in Florida's (USA) submerged cave systems may preserve records of regional climate and hydrologic variability. However, the basic sedimentology, mineralogy, stratigraphic variability, and emplacement history of the successions in Florida's submerged caves remains poorly understood. Here we present stratigraphic, mineralogical, and elemental data on sediment cores from two phreatic cave systems in northwestern Florida (USA), on the Dougherty Karst Plain: Hole in the Wall Cave (HITW) and Twin Cave. Water flowing through these caves is subsurface flow in the Apalachicola River drainage basin, and the caves are located just downstream from Jackson Blue (1st magnitude spring, > 2.8 m3 s- 1 discharge). Sedimentation in these caves is dominated by three primary sedimentary styles: (i) ferromanganese deposits dominate the basal recovered stratigraphy, which pass upsection into (ii) poorly sorted carbonate sediment, and finally into (iii) fine-grained organic matter (gyttja) deposits. Resolving the emplacement history of the lower stratigraphic units was hampered by a lack of suitable material for radiocarbon dating, but the upper organic-rich deposits have a punctuated depositional history beginning in the earliest Holocene. For example, gyttja primarily accumulated in HITW and Twin Caves from ~ 5500 to 3500 cal yr. BP, which coincides with regional evidence for water-table rise of the Upper Floridian Aquifer associated with relative sea-level rise in the Gulf of Mexico, and evidence for invigorated drainage through the Apalachicola River drainage basin. Gyttja sediments were also deposited in one of the caves during the Bølling/Allerød climate oscillation. Biologically, these results indicate that some Floridian aquatic cave (stygobitic) ecosystems presently receive minimal organic matter supply in comparison to prehistoric intervals. The pre-Holocene poorly sorted carbonate sediment contains abundant invertebrate fossils, and likely documents a period

  14. Grenville Zircon Fertility, Baby Boom, and Baby Boom Echo; Natural Bias in the Detrital Zircon Record

    Moecher, D. P.; Samson, S. D.


    Grenville-aged (~1150-1050 Ma) granitoids of eastern Laurentia exposed in Appalachian basement massifs are as much as 20 times more Zr-rich and much more fertile for crystallizing zircon compared to Paleozoic Laurentian granitoids of the Eastern Blue Ridge, Inner Piedmont, and Carolina terranes. Erosion of Grenville source rocks generates disproportionately large numbers and/or sizes of detrital zircon compared to less fertile magmatic sources. The latter are essentially undetectable by standard detrital zircon provenance methods (SHRIMP or LA-ICP-MS analysis of magmatic cores of >100 micron grains). Grenvillian zircon fertility biased the Neoproterozoic to Recent detrital record as a result of: (1) zircon durability and insolubility in aqueous fluids means detrital zircons eroded from Grenville basement terranes are recycled during repeated orogenesis; (2) inertness of zircon below upper amphibolite facies (onset of anatexis), and high Zr resulting from concentration of detrital zircon in sedimentary protoliths, means dominantly metasedimentary terranes will fail to generate sufficient new zircon corresponding in age to the time of accretion of those terranes to Laurentia. Zircon growth under incipient anatectic conditions generates new zircon as overgrowths on detrital magmatic cores; overgrowths are often too thin to analyze by ion or laser beam. In this case, metasedimentary terranes may be rendered essentially undetectable. New `magmatic' zircon may be generated with greater degrees of anatexis, but might be inferred to be of plutonic, not metamorphic, parentage. Grenville modes dominate detrital zircon age distributions for: Laurentian Neoproterozoic rift basins; Neoproterozoic to Lower Ordovician passive margin sequences; Appalachian Paleozoic syn-orogenic clastic sequences; Appalachian metasedimentary terranes; and modern rivers. The latter is surprising since Grenville terranes comprise baby boom' that echoed through later orogenies. The natural Grenville

  15. Shear Stress Drives Local Variation in Invertebrate Drift in a Large River

    Muehlbauer, J. D.; Kennedy, T.; Yackulic, C. B.


    Recent advances in physical stream flow measurements using acoustic Doppler current profilers (ADCPs) have yielded important insights in hydrology and geomorphology related to discharge and processes such as bed sediment incipient motion. These measurements also have underappreciated potential for use in ecological studies. For example, invertebrate drift, or the downstream transport of benthic-derived invertebrates, is a fundamental process in streams and rivers: it is both critical to the maintenance of benthic invertebrate populations and provides a key mechanism of resource delivery to drift-feeding fishes. However, there is substantial uncertainty regarding the factors that drive spatial variation in invertebrate drift, particularly in large rivers. While laboratory studies in flumes have demonstrated the importance of shear stress in initiating invertebrate drift (similar to studies of bed sediment critical shear stress in fluvial geomorphology), field-based evaluations of the relationship between shear stress and drift would be beneficial. Such field studies, however, are rare. Here, we evaluate the relationship between localized shear stress (N/m2) and invertebrate drift concentrations (#/m3) for the Colorado River downstream of Glen Canyon Dam (steady discharge of 228 m3/s during study). Invertebrate drift was quantified at 25 stations throughout the 25 km long Glen Canyon tailwater segment. We link these drift measurements to empirical measurements of water column shear stress derived from ADCP data, taken at the location of each drift sample and 250 m upstream of each drift sampling location (50 total profiles). Invertebrate drift concentrations varied strongly throughout the 25 km reach, and much of this variation can be explained by localized differences in shear stress. Species composition in the drift also varied with shear stress, suggesting that shear stress exerts a differential control on drift initiation for individual taxa. These results

  16. Viral diseases of marine invertebrates

    Johnson, P. T.


    Approximately 40 viruses are known from marine sponges; turbellarian and monogenetic flatworms; cephalopod, bivalve, and gastropod mollusks; nereid polychaetes; and isopod and decapod crustaceans. Most of the viruses can be tentatively assigned to the Herpesviridae, Baculoviridae, Iridoviridae, Adenoviridae, Papovaviridae, Reoviridae, “Birnaviridae”, Bunyaviridae, Rhabdoviridae, and Picornaviridae. Viruslike particles found in oysters might be representatives of the Togaviridae and Retroviridae. Enveloped single-stranded RNA viruses from crustaceans have developmental and morphological characteristics intermediate between families, and some show evidence of relationships to the Paramyxoviridae as well as the Bunyaviridae or Rhabdoviridae. Certain small viruses of shrimp cannot be assigned, even tentatively, to a particular family. Some viruses cause disease in wild and captive hosts, others are associated with disease states but may not be primary instigators, and many occur in apparently normal animals. The frequency of viral disease in natural populations of marine invertebrates is unknown. Several viruses that cause disease in captive animals, with or without experimental intervention, have also been found in diseased wild hosts, including herpeslike viruses of crabs and oysters, iridovirus of octopus, and reolike and bunyalike viruses of crabs. Iridolike viruses have been implicated in massive mortalities of cultured oysters. Baculoviruses, and IHHN virus, which is of uncertain affinities, cause economically damaging diseases in cultured penaeid shrimp. Double or multiple viral infection is common in crabs. For example, a reolike virus and associated rhabdolike virus act synergistically to cause paralytic and fatal disease in Callinectes sapidus. Information on host range, most susceptible stage, and viral latency is available only for viruses of shrimp. One baculovirus attacks five species of New World penaeid shrimp. IHHN virus infects three species of

  17. Invertebrate inventory of the Alaska Peninsula

    US Fish and Wildlife Service, Department of the Interior — The composition and distribution of invertebrate species on the Alaska Peninsula is not well known. This pilot project was intended to test methods and to document...

  18. American Samoa ESI: INVERT (Invertebrate Polygons)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for estuarine, reef-associated, and terrestrial invertebrate species in American Samoa. Vector polygons in...

  19. Columbia River ESI: INVERT (Invertebrate Polygons)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for clams, oysters, crabs, and other invertebrate species in Columbia River. Vector polygons in this data...

  20. Uncoupling proteins of invertebrates: A review.

    Slocinska, Malgorzata; Barylski, Jakub; Jarmuszkiewicz, Wieslawa


    Uncoupling proteins (UCPs) mediate inducible proton conductance in the mitochondrial inner membrane. Herein, we summarize our knowledge regarding UCPs in invertebrates. Since 2001, the presence of UCPs has been demonstrated in nematodes, mollusks, amphioxi, and insects. We discuss the following important issues concerning invertebrate UCPs: their evolutionary relationships, molecular and functional properties, and physiological impact. Evolutionary analysis indicates that the branch of vertebrate and invertebrate UCP4-5 diverged early in the evolutionary process prior to the divergence of the animal groups. Several proposed physiological roles of invertebrate UCPs are energy control, metabolic balance, and preventive action against oxidative stress. © 2016 IUBMB Life, 68(9):691-699, 2016. © 2016 International Union of Biochemistry and Molecular Biology.

  1. Marine Invertebrate assemblages in southern California

    National Oceanic and Atmospheric Administration, Department of Commerce — This is a point file of invertebrate site clusters calculated from benthic trawls completed by the Southern California Coastal Water Research Project (SCCWRP). Data...

  2. Western Alaska ESI: INVERT (Invertebrate Polygons)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for marine and estuarine invertebrate species in Western Alaska. Vector polygons in this data set represent...

  3. Effects of elevated CO2 on litter chemistry and subsequent invertebrate detritivore feeding responses.

    Matthew W Dray

    Full Text Available Elevated atmospheric CO2 can change foliar tissue chemistry. This alters leaf litter palatability to macroinvertebrate detritivores with consequences for decomposition, nutrient turnover, and food-web structure. Currently there is no consensus on the link between CO2 enrichment, litter chemistry, and macroinvertebrate-mediated leaf decomposition. To identify any unifying mechanisms, we presented eight invertebrate species from aquatic and terrestrial ecosystems with litter from Alnus glutinosa (common alder or Betula pendula (silver birch trees propagated under ambient (380 ppm or elevated (ambient +200 ppm CO2 concentrations. Alder litter was largely unaffected by CO2 enrichment, but birch litter from leaves grown under elevated CO2 had reduced nitrogen concentrations and greater C/N ratios. Invertebrates were provided individually with either (i two litter discs, one of each CO2 treatment ('choice', or (ii one litter disc of each CO2 treatment alone ('no-choice'. Consumption was recorded. Only Odontocerum albicorne showed a feeding preference in the choice test, consuming more ambient- than elevated-CO2 birch litter. Species' responses to alder were highly idiosyncratic in the no-choice test: Gammarus pulex and O. albicorne consumed more elevated-CO2 than ambient-CO2 litter, indicating compensatory feeding, while Oniscus asellus consumed more of the ambient-CO2 litter. No species responded to CO2 treatment when fed birch litter. Overall, these results show how elevated atmospheric CO2 can alter litter chemistry, affecting invertebrate feeding behaviour in species-specific ways. The data highlight the need for greater species-level information when predicting changes to detrital processing-a key ecosystem function-under atmospheric change.

  4. Invertebrate Iridovirus Modulation of Apoptosis

    Trevor Williams; Nllesh S. Chitnis; Sh(a)n L. Bilimoria


    Programmed cell death (apoptosis) is a key host response to virus infection. Viruses that can modulate host apoptotic responses are likely to gain important opportunities for transmission. Here we review recent studies that demonstrate that particles of Invertebrate iridescent virus 6 (IIV-6) (Iridoviridae, genus Iridovirus), or an IIV-6 virion protein extract, are capable of inducing apoptosis in lepidopteran and coleopteran cells, at concentrations 1000-fold lower than that required to shut-off host macromolecular synthesis. Induction of apoptosis depends on endocytosis of one or more heat-sensitive virion component(s). Studies with a JNK inh ibitor(SP600125) indicated that the JNK signaling pathway is significantly involved in apoptosis in IIV-6 infections of Choristoneurafumiferana ceils. The genome of IIV-6 codes for an inhibitor of apoptosis iap gene (193R) that encodes a protein of 208 aa with 15% identity and 28% similarity in its amino acid sequence to IAP-3 from Cydia pomonella ganulovirus (CpGV). Transcription of IIV-6 iap did not require prior DNA or protein synthesis, indicating that it is an immediate-early class gene. Transient expression and gene knockdown studies have confirmed the functional nature of the IIV-6 iap gene. We present a tentative model for IIV-6 induction and inhibition of apoptosis in insect cells and discuss the potential applications of these findings in insect pest control.

  5. Wood decomposition as influenced by invertebrates

    Michael D. Ulyshen


    The diversity and habitat requirements of invertebrates associated with dead wood have been the subjects of hundreds of studies in recent years but we still know very little about the ecological or economic importance of these organisms. The purpose of this review is to examine whether, how and to what extent invertebrates affect wood decomposition in terrestrial...

  6. INVHOGEN: a database of homologous invertebrate genes

    Paulsen, Ingo; von Haeseler, Arndt


    Classification of proteins into families of homologous sequences constitutes the basis of functional analysis or of evolutionary studies. Here we present INVertebrate HOmologous GENes (INVHOGEN), a database combining the available invertebrate protein genes from UniProt (consisting of Swiss-Prot and TrEMBL) into gene families. For each family INVHOGEN provides a multiple protein alignment, a maximum likelihood based phylogenetic tree and taxonomic information about the sequences. It is possib...

  7. Invertebrate Cells as Targets for Hazardous Substances

    Triebskorn, Rita; Köhler, Heinz-Rüdiger; Zahn, Thomas; Vogt, Günter; Ludwig, Mario; Rumpf, Silke; Kratzmann, Markus; Alberti, Gerd; Storch, Volker


    Electron microscopy is an established diagnostic method in pathology of man as well as of vertebrate animals. During the last decade, ultrastructural studies have also been performed in invertebrates to elucidate cellular injuries caused by hazardous substances (BAYNE et al. 1985, MOORE 1985, STORCH 1988, HOPKIN 1989). The interest in invertebrates has increased due to their suitability to monitor environmental pollution. For example field and laboratory studies have been performed using the ...

  8. Toll-like receptors of deuterostome invertebrates

    Honoo eSatake


    Full Text Available Defensive systems against pathogens are responsible not only for survival or lifetime of an individual but also for the evolution of a species. Innate immunity is expected to be more important for invertebrates than mammals, given that adaptive immunity has not been acquired in the former. Toll-like receptors (TLRs have been shown to play a crucial role in host defense of pathogenic microbes in innate immunity of mammals. Recent genome-wide analyses have suggested that TLR or their related genes are conserved in invertebrates. In particular, numerous TLR-related gene candidates were detected in deuterostome invertebrates including a sea urchin (222 TLR-related gene candidates and amphioxus (72 TLR-related gene candidates. Molecular phylogenetic analysis verified that most of sea urchin or amphioxus TLR candidates are paralogous, suggesting that these organisms expanded TLR-related genes in a species-specific manner. In contrast, another deuterostome invertebrate, an ascidian, Ciona intestinalis, was found to possess only two TLR genes. Moreover, Ciona TLRs, Ci-TLR1 and -2, were shown to possess hybrid functionality of mammalian TLRs. Such functionality of Ci-TLRs could not be predicted by sequence comparison with vertebrate TLRs, indicating the confounding evolutionary lineages of deuterostome invertebrate TLRs or their candidates. In this review article, we present recent advances in studies of TLRs or their candidates of deuterostome invertebrates, and provide insight into an evolutionary process of TLRs.

  9. Selection of Stream Insect Larvae for Indicating Anthropogenic Impact

    This study examined the total mercury concentrations, [Hg], and 15N values in macro-invertebrates collected from 35 stream sites in Rhode Island, USA, to determine the organism groups most suitable for use as indicators of anthropogenic impact. Site selection was designed to cov...

  10. Isotopic hysteresis in detrital cosmogenic nuclide-derived denudation rate studies (Invited)

    Willenbring, J.; Gasparini, N. M.; Crosby, B. T.; Brocard, G. Y.; Belmont, P.


    In equilibrium landscapes, the concentration of beryllium-10 (10Be) from fluvially transported material is expected to quantitatively reflect basin-wide denudation rates. No isotopic time-dependent path is considered because the concentrations reflect an integrated measurement over a sufficiently long period of time to be static. However, the responses of landscapes to changing conditions are often addressed with cosmogenic nuclides in transient landscapes to identify and quantify the primary topographic and climatic controls on erosion. With the advent of techniques that allow event-scale measurement of cosmogenic nuclide concentrations over the course of a flood wave, in the case of meteoric 10Be, or over the course of an uplift wave, in the case of in situ-produced 10Be, we can now evaluate the how the isotope changes and what the 'mean' denudation rate from a single time means. Meteoric 10Be concentrations can be extracted from, and measured in, milligram-sized sediment samples. This attribute enables us to measure suspended sediment through a hydrograph. Here, we give a case study in an agricultural setting. The meteoric 10Be concentration in river sediment changes with the source areas of the fine sediment and fluxes of material supplied to the stream. The average concentration from the couplet of the rising and falling limbs of the hydrograph can differ from the concentration of the sediment that is preserved in depo-centers. Using traditional in situ-produced 10Be, the timescale of the perturbation must be sufficiently long to change the isotopic composition of the bedload, but also for the landscape to respond to the forcing factor. Here, we give an example from a transient landscape where a wave of uplift moves through the basin and a wave of incision follows in its wake. In this setting, 10Be from detrital quartz is derived from both the incising, adjusting lowland and the unadjusted, relict upland, and the integrated 10Be concentrations still provide a

  11. Stream Evaluation

    Kansas Data Access and Support Center — Digital representation of the map accompanying the "Kansas stream and river fishery resource evaluation" (R.E. Moss and K. Brunson, 1981.U.S. Fish and Wildlife...

  12. Stream Lab

    Kummel, Miro; Bruder, Andrea; Powell, Jim; Kohler, Brynja; Lewis, Matt


    Dead leaves, ping-pong balls or plastic golf balls are floated down a small stream. The number of leaves/balls passing recording stations along the stream are tallied. Students are then challenged to develop a transport model for the resulting data. From this exercise students gain greater understanding of PDE modeling, conservation laws, parameter estimation as well as mass and momentum transport processes.

  13. The Global Invertebrate Genomics Alliance (GIGA). 2014. Developing Community Resources to Study Diverse Invertebrate Genomes

    Pomponi, S.A.


    Over 95% of all metazoan (animal) species comprise the “invertebrates,” but very few genomes from these organisms have been sequenced. We have, therefore, formed a “Global Invertebrate Genomics Alliance” (GIGA). Our intent is to build a collaborative network of diverse scientists to tackle major cha

  14. The Global Invertebrate Genomics Alliance (GIGA). 2014. Developing Community Resources to Study Diverse Invertebrate Genomes

    Pomponi, S.A.


    Over 95% of all metazoan (animal) species comprise the “invertebrates,” but very few genomes from these organisms have been sequenced. We have, therefore, formed a “Global Invertebrate Genomics Alliance” (GIGA). Our intent is to build a collaborative network of diverse scientists to tackle major

  15. A method for evaluating basement exhumation histories from closure age distributions of detrital minerals

    Lovera, Oscar M. [Department of Earth and Space Sciences and Institute of Geophysics and Planetary Physics, University of California, Los Angeles (United States); Grove, Marty [Department of Earth and Space Sciences and Institute of Geophysics and Planetary Physics, University of California, Los Angeles (United States); Kimbrough, David L. [Department of Geological Sciences, San Diego State University, San Diego, California (United States); Abbott, Patrick L. [Department of Geological Sciences, San Diego State University, San Diego, California (United States)


    We have developed a two-dimensional, thermokinetic model that predicts the closure age distributions of detrital minerals from pervasively intruded and differentially exhumed basement. Using this model, we outline a method to determine the denudation history of orogenic regions on the basis of closure age distributions in synorogenic to postorogenic forearc strata. At relatively high mean denudation rates of 0.5 km m.y.-1 sustained over millions of years, magmatic heating events have minimal influence upon the age distributions of detrital minerals such as K-feldspar that are moderately retentive of radiogenic Ar. At lower rates, however, the effects of batholith emplacement may be substantial. We have applied the approach to detrital K-feldspars from forearc strata derived from the deeply denuded Peninsular Ranges batholith (PRB). Agreement of the denudation history deduced from the detrital K-feldspar data with thermochronologic constraints from exposed PRB basement lead us to conclude that exhumation histories of magmatic arcs should be decipherable solely from closure age distributions of detrital minerals whose depositional age is known. (c) 1999 American Geophysical Union.

  16. Distributional Feature of Detrital Minerais in the Superficial Sediment of South Yellow Sea

    王红霞; 林振宏; 郭玉贵


    The composition of detrital minerals with grades of 0.063 - 0.25 mm in the superficial sediment of South Yellow Sea is mainly studied in the paper. The research result shows that the minerals can be divided into more than fifty sorts. The light minerals are mainly feldspar, quartz, mica, etc. The heavy minerals are mainly composed of amphibole, epidote, mica, autogeny pyrite, magnetite, hematite, garnet,zircon and so on, which mainly distribute in the sediments of silty clay and lutaceous silt. According to the content and distribution of the main minerals, the research area isdivided into five miteral combination provinces. The assembled types of minerals in every province have close relationship with its hydrodynamic conditions and sedimentary environment. And the sorts of detrital minerals also show that the detrital substances in the sedimentary areas mainly originate from the drainage areas of rivers,bedrock weathering, and transformed sediment, etc.

  17. Are invertebrates relevant models in ageing research?

    Erdogan, Cihan Suleyman; Hansen, Benni Winding; Vang, Ole


    Ageing is the organisms increased susceptibility to death, which is linked to accumulated damage in the cells and tissues. Ageing is a complex process regulated by crosstalk of various pathways in the cells. Ageing is highly regulated by the Target of Rapamycin (TOR) pathway activity. TOR...... the molecular mechanisms underlying the ageing process faster than mammal systems. Inhibition of the TOR pathway activity via either genetic manipulation or rapamycin increases lifespan profoundly in most invertebrate model organisms. This contribution will review the recent findings in invertebrates concerning...... the TOR pathway and effects of TOR inhibition by rapamycin on lifespan. Besides some contradictory results, the majority points out that rapamycin induces longevity. This suggests that administration of rapamycin in invertebrates is a promising tool for pursuing the scientific puzzle of lifespan...

  18. stream-stream: Stellar and dark-matter streams interactions

    Bovy, Jo


    Stream-stream analyzes the interaction between a stellar stream and a disrupting dark-matter halo. It requires galpy (ascl:1411.008), NEMO (ascl:1010.051), and the usual common scientific Python packages.

  19. Infertility in male aquatic invertebrates: a review.

    Lewis, Ceri; Ford, Alex T


    As a result of endocrine disruptor studies, there are numerous examples of male related reproductive abnormalities observed in vertebrates. Contrastingly, within the invertebrates there have been considerably less examples both from laboratory and field investigations. This has in part been due to a focus of female related endpoints, inadequate biomarkers and the low number of studies. Whether contaminant induced male infertility is an issue within aquatic invertebrates and their wider communities therefore remains largely unknown and represents a key knowledge gap in our understanding of pollutant impacts in aquatic wildlife. This paper reviews the current knowledge regarding pollutants impacting male infertility across several aquatic invertebrate phyla; which biomarkers are currently being used and where the science needs to be expanded. The limited studies conducted so far have revealed reductions in sperm numbers, examples of poor fertilisation success, DNA damage to spermatozoa and inhibition of sperm motility that can be induced by a range of environmental contaminants. This limited data is mainly comprised from laboratory studies with only a few studies of sperm toxicity in natural populations. Clearly, there is a need for further studies in this area, to include both laboratory and field studies from clean and reference sites, with a focus on broadcast spawners and those with direct fertilisation. Biomarkers developed for measuring sperm quantity and quality in vertebrates are easily transferable to invertebrates but require optimisation for particular species. We discuss how sperm tracking and techniques for measuring DNA strand breaks and sperm viability have been successfully transferred from human infertility clinics to aquatic invertebrate ecotoxicology. Linking sperm toxicity and male infertility effects to higher level impacts on the reproductive biology and dynamics of populations requires a much greater understanding of fertilisation dynamics and

  20. Toxicity of Engineered Nanoparticles to Aquatic Invertebrates

    Cupi, Denisa; Sørensen, Sara Nørgaard; Skjolding, Lars Michael


    ecotoxicity of aquatic invertebrates. The chapter focuses on how fullerenes affect the toxicity of other pollutants, but also reflect on the fate and behavior of C60 in the aquatic environment, as well as ecotoxicity to aquatic invertebrates. It presents the case of titanium dioxide nanoparticles (TiO2 NPs......), and considers the acute and chronic ecotoxicity. The chapter examines in more detail the processes that influence this toxicity, for example, agglomeration and aggregation, and photocatalytic activity upon exposure to UV light. It covers the longer-term effects of various nanomaterials by reviewing literature...

  1. Effects on water chemistry, benthic invertebrates and brown trout following forest fertilization in central Sweden

    Goethe, L.; Soederberg, H.; Sjoelander, E. (County Administrative Board of Vaesternorrland, Haernoesand (Sweden). Environmental Unit); Nohrstedt, H.Oe. (Inst. for Forest Improvement, Uppsala (Sweden))


    Two coniferous forest drainage areas in central Sweden were partially fertilized with ammonium nitrate and calcium ammonium nitrate respectively, both at a dose of 150 kg N per ha. During the following years observations were made on stream water chemistry, invertebrates and brown trout (Salmo trutta L.). Upstream stations were used as controls. Very high concentrations of inorganic N (up to 45 mg l[sup -1]) were recorded immediately after the fertilization. Thereafter, concentration decreased rapidly but remained elevated during the whole study period. Acidity conditions (pH, alkalinity, aluminium) were unaffected by both treatments. The only registered effect on the benthic fauna was a three- to five-fold increase of drifting invertebrates during the first four-five days after the treatment. However, this did not reduce the population density at the treated stations. No effects on population of trout were recorded. (22 refs., 6 figs., 3 tabs.).


    Although many studies in toxicologic pathology evaluate the effects of toxicants on fishes because of their similarities with other vertebrates, invertebrates can also provide insights into toxicant impacts on ecosystems. Invertebrates not only serve as food resources (e.g., ...


    Although many studies in toxicologic pathology evaluate the effects of toxicants on fishes because of their similarities with other vertebrates, invertebrates can also provide insights into toxicant impacts on ecosystems. Invertebrates not only serve as food resources (e.g., ...

  4. Urban development and stream ecosystem health—Science capabilities of the U.S. Geological Survey

    Reilly, Pamela A.; Szabo, Zoltan; Coles, James F.


    Urban development creates multiple stressors that can degrade stream ecosystems by changing stream hydrology, water quality, and physical habitat. Contaminants, habitat destruction, and increasing streamflow variability resulting from urban development have been associated with the disruption of biological communities, particularly the loss of sensitive aquatic biota. Understanding how algal, invertebrate, and fish communities respond to these physical and chemical stressors can provide important clues as to how streams should be managed to protect stream ecosystems as a watershed becomes increasingly urbanized. The U.S. Geological Survey continues to lead monitoring efforts and scientific studies on the effects of urban development on stream ecosystems in metropolitan areas across the United States.

  5. The Dabie Orogen as the early Jurassic sedimentary provenance: Constraints from the detrital zircon SHRIMP U-Pb dating

    LI Renwei; WAN Yusheng; CHENG Zhenyu; ZHOU Jianxiong; XU Yunhua; LI Zhong; JIANG Maosheng


    The SHRIMP U-Pb ages of detrital zircon from the oldest Mesozoic strata, the Fanghushan Fomation, in the Hefei Basin range from 200 Ma to ca. 2500 Ma, which indicates that the Dabie Orogen as the early Jurassic sedimentary provenance was complex. The composition of the Dabie Orogen includes: the Triassic high pressure-ultrahigh pressure metamorphic rocks, of which the detrital zircon ages are from 234 Ma to 200 Ma; the rocks possibly related to the Qinling and Erlangping Groups representing the southern margin of the Sino-Korean craton in the Qinling and Dabie area, of which the detrital zircon has an age of 481-378 Ma; the Neoproterozoic rocks originated from the Yangtze croton, of which the detrital zircon ages are 799-721 Ma old; and the rocks with the detrital zircon ages of ca. 2000 Ma and ca. 2500 Ma, which could be the old basement of the Yangtze craton.

  6. Roebuck Bay Invertebrate and bird Mapping 2006

    Piersma, Theunis; Pearson, Grant B.; Hickey, Robert; Dittmann, Sabine; Rogers, Danny I.; Folmer, Eelke; Honkoop, Pieter; Drent, Jan; Goeij, Petra de; Marsh, Loisette


    1. This is a report on a survey of the benthic ecology of the intertidal flats along the northern shores of Roebuck Bay in June 2006. In the period 11-20 June we mapped both the invertebrate macrobenthic animals (those retained by a 1 mm sieve) over the whole of the northern intertidal area of Roebu

  7. The Early Years: An Invertebrate Garden

    Ashbrook, Peggy


    For farmers and gardeners, slugs and snails may be serious pests that will limit the amount of harvest, but for a child, they represent a world to be explored. To teachers, however, invertebrates are tools for broadening students' understanding about animals, the connections between animals and habitats or plants, and an engaging subject to write…

  8. Roebuck Bay Invertebrate and bird Mapping 2006

    Piersma, Theunis; Pearson, Grant B.; Hickey, Robert; Dittmann, Sabine; Rogers, Danny I.; Folmer, Eelke; Honkoop, Pieter; Drent, Jan; Goeij, Petra de; Marsh, Loisette


    1. This is a report on a survey of the benthic ecology of the intertidal flats along the northern shores of Roebuck Bay in June 2006. In the period 11-20 June we mapped both the invertebrate macrobenthic animals (those retained by a 1 mm sieve) over the whole of the northern intertidal area of

  9. Temporal abiotic variability structures invertebrate communities in agricultural drainage ditches

    Whatley, M.H.; Vonk, J.A.; van der Geest, H.G.; Admiraal, W.


    Abiotic variability is known to structure lotic invertebrate communities, yet its influence on lentic invertebrates is not clear. This study tests the hypothesis that variability of nutrients and macro-ions are structuring invertebrate communities in agricultural drainage ditches. This was determine

  10. Temporal abiotic variability structures invertebrate communities in agricultural drainage ditches

    Whatley, M.H.; Vonk, J.A.; van der Geest, H.G.; Admiraal, W.


    Abiotic variability is known to structure lotic invertebrate communities, yet its influence on lentic invertebrates is not clear. This study tests the hypothesis that variability of nutrients and macro-ions are structuring invertebrate communities in agricultural drainage ditches. This was

  11. Surface-dwelling and subterranean invertebrate fauna associated with giant reed (Arundo donax Poaceae) in Southern California

    Lovich, Robert E.; Ervin, Edward L.; Fisher, Robert N.


    In the southwestern United States giant reed, Arundo donax, is a non-native invasive plant that has become widely established in moist places and forms its largest stands along riparian corridors. The most widely reported negative effects include competition with native species, increased rate of transpiration, increased potential for wildfires, and stream channel and bank alteration. However, little is known about the faunal communities associated with this plant and the potential effects on native fauna. In this study, we focused our efforts on determining the faunal composition specifically from rhizome clumps of A. donax from a site located along the Santa Margarita River in San Diego County, California. A total of 2590 individual macro-invertebrates were collected and identified, and represented 64 species from 7 classes. No sensitive species and few vertebrates were found to be in association with A. donax rhizome clumps. Four non-native invertebrate species made up 43% of the total number of captured invertebrates, and 31% of the sampled invertebrates were confirmed as native species. This study demonstrates that A. donax rhizome clumps, and the soils associated with them, provide habitat for several native macro-invertebrate species, but can be dominated by a greater abundance of non-native species.

  12. Shift in detrital sedimentation in the eastern Bay of Bengal during the late Quaternary

    PrakashBabu, C.; Pattan, J.N.; Dutta, K.; Basavaiah, N.; Prasad, G.V.K.; Ray, D.K.; Govil, P.

    the late Quaternary period. Units 2 (43-24 cm) and 1 (24-0 cm) represent enhanced and reduced supply of coarse-grained detrital sediments from the Ganges River during early and late Holocene period, respectively. Increased terrigenous supply dilutes calcium...

  13. Macroalgal assemblages of disturbed coastal detritic bottoms subject to invasive species

    Klein, Judith C.; Verlaque, Marc


    Characteristic flora and fauna that are highly sensitive to disturbances colonize coastal detritic bottoms in the Mediterranean Sea. In the present study, a comparison of the assemblage composition and colonization by invasive macroalgae was made between two coastal detritic macrophyte assemblages, one dominated by rhodoliths (free-living non-geniculate Corallinales) and the other dominated by fleshy algae, in an area that has been exposed to important levels of anthropogenic disturbance, mainly pollution (including changed sedimentation regimes) in the recent past (bay of Marseilles, France). In comparison with less strongly impacted Mediterranean regions, the macrophyte assemblages in the bay of Marseilles were characteristic in terms of species identity and richness of coastal detritic macrophyte assemblages. However, extremely low species abundance (cover) was observed. As far as invasive species were concerned, Caulerpa racemosa var. cylindracea was only abundant in the rhodolith assemblage whereas the two invasive Rhodophyta Asparagopsis armata and Womersleyella setacea were mainly found in the fleshy algae assemblage. The seasonality observed in the Rhodolith assemblage seemed to be related to the development of C. racemosa var. cylindracea and did not follow the typical pattern of other Mediterranean assemblages. This study represents the first study of coastal detritic assemblages invaded by C. racemosa var. cylindracea.

  14. Arsenic in stream waters is bioaccumulated but neither biomagnified through food webs nor biodispersed to land.

    Hepp, Luiz U; Pratas, João A M S; Graça, Manuel A S


    Human activities such as mining have contributed substantially to the increase of metals in aquatic environments worldwide. These metals are bioaccumulated by aquatic organisms and can be biomagnified along trophic webs. The dispersal of contaminants from water to land has been little investigated, even though most aquatic invertebrates in streams have aerial stages. We used field and laboratory approaches to investigate the effects of arsenic pollution on stream invertebrate assemblages, and its bioaccumulation, biomagnification and trophic transfer from aquatic to terrestrial environments by emergent insects. We conducted the study in an arsenic-impacted stream (40μgL(-1) As at the most polluted site) and a reference stream (0.3μgL(-1) As). Invertebrate abundance and richness were lowest at the most impacted site. Arsenic in biofilm and in invertebrates increased with the arsenic content in the water. The highest arsenic accumulators were bryophytes (1760μgg(-1)), followed by the biofilm (449μgg(-1)) and shredder invertebrates (313μgg(-1)); predators had the lowest arsenic concentration. Insects emerging from water and spiders along streambanks sampled from the reference and the impacted stream did not differ in their body arsenic concentrations. In the laboratory, the shredder Sericostoma vittatum had reduced feeding rates when exposed to water from the impacted stream in comparison with the reference stream (15.6 vs. 19.0mg leaves mg body mass(-1) day(-1); pfood, not through contact with water. We concluded that although arsenic is bioaccumulated, mainly by food ingestion, it is not biomagnified through food webs and is not transported from the aquatic to terrestrial environment when insects leave the stream water. Copyright © 2017. Published by Elsevier Inc.

  15. Effects of Detrital Subsidies on Soft-Sediment Ecosystem Function Are Transient and Source-Dependent.

    Rebecca V Gladstone-Gallagher

    Full Text Available Detrital subsidies from marine macrophytes are prevalent in temperate estuaries, and their role in structuring benthic macrofaunal communities is well documented, but the resulting impact on ecosystem function is not understood. We conducted a field experiment to test the effects of detrital decay on soft-sediment primary production, community metabolism and nutrient regeneration (measures of ecosystem function. Twenty four (2 m2 plots were established on an intertidal sandflat, to which we added 0 or 220 g DW m-2 of detritus from either mangroves (Avicennia marina, seagrass (Zostera muelleri, or kelp (Ecklonia radiata (n = 6 plots per treatment. Then, after 4, 17 and 46 d we measured ecosystem function, macrofaunal community structure and sediment properties. We hypothesized that (1 detrital decay would stimulate benthic primary production either by supplying nutrients to the benthic macrophytes, or by altering the macrofaunal community; and (2 ecosystem responses would depend on the stage and rate of macrophyte decay (a function of source. Avicennia detritus decayed the slowest with a half-life (t50 of 46 d, while Zostera and Ecklonia had t50 values of 28 and 2.6 d, respectively. However, ecosystem responses were not related to these differences. Instead, we found transient effects (up to 17 d of Avicennia and Ecklonia detritus on benthic primary production, where initially (4 d these detrital sources suppressed primary production, but after 17 d, primary production was stimulated in Avicennia plots relative to controls. Other ecosystem function response variables and the macrofaunal community composition were not altered by the addition of detritus, but did vary with time. By sampling ecosystem function temporally, we were able to capture the in situ transient effects of detrital subsidies on important benthic ecosystem functions.

  16. Early Paleozoic tectonic reconstruction of Iran: Tales from detrital zircon geochronology

    Moghadam, Hadi Shafaii; Li, Xian-Hua; Griffin, William L.; Stern, Robert J.; Thomsen, Tonny B.; Meinhold, Guido; Aharipour, Reza; O'Reilly, Suzanne Y.


    In this study we use detrital zircons to probe the Early Paleozoic history of NE Iran and evaluate the link between sediment sources and Gondwanan pre-Cadomian, Cadomian and younger events. U-Pb zircon ages and Hf isotopic compositions are reported for detrital zircons from Ordovician and Early Devonian sedimentary rocks from NE Iran. These clastic rocks are dominated by zircons with major age populations at 2.5 Ga, 0.8-0.6 Ga, 0.5 Ga and 0.5-0.4 Ga as well as a minor broad peak at 1.0 Ga. The source of 2.5 Ga detrital zircons is enigmatic; they may have been supplied from the Saharan Metacraton (or West African Craton) to the southwest or Afghanistan-Tarim to the east. The detrital zircons with age populations at 0.8-0.6 Ga probably originated from Cryogenian-Ediacaran juvenile igneous rocks of the Arabian-Nubian Shield; this inference is supported by their juvenile Hf isotopes, although some negative εHf (t) values suggest that other sources (such as the West African Craton) were also involved. The age peak at ca 0.5 Ga correlates with Cadomian magmatism reported from Iranian basement and elsewhere in north Gondwana. The variable εHf (t) values of Cadomian detrital zircons, resembling the εHf (t) values of zircons in magmatic Cadomian rocks from Iran and Taurides (Turkey), suggest an Andean-type margin and the involvement of reworked older crust in the generation of the magmatic rocks. The youngest age population at 0.5-0.4 Ga is interpreted to represent Gondwana rifting and the opening of Paleotethys, which probably started in Late Cambrian-Ordovician time. A combination of U-Pb dating and Hf-isotope data from Iran, Turkey and North Gondwana confirms that Iran and Turkey were parts of Gondwana at least until late Paleozoic time.

  17. Aquatic invertebrates of the Ribnica and Lepenica Rivers: Composition of the community and water quality

    Jović Aleksandra


    Full Text Available Results of investigating the community of aquatic invertebrates in the Ribnica and Lepenica Rivers (Kolubara River drainage area are given in the present work. Forty-three taxa are recorded. In relation to other studied streams in Serbia, the investigated rivers are characterized by high diversity of macroinvertebrates. Cluster analysis indicates that the locality on the Lepenica stands apart from those on the Ribnica, which is a consequence of the difference of habitats found at them. Results of saprobiological analysis of the macrozoobenthos in the given rivers indicate that their waters belong to quality classes I and II.

  18. Global pressures, specific responses: effects of nutrient enrichment in streams from different biomes

    Artigas, Joan; García-Berthou, Emili; Bauer, Delia E.; Castro, Maria I.; Cochero, Joaquín; Colautti, Darío C.; Cortelezzi, Agustina; Donato, John C.; Elosegi, Arturo; Feijoó, Claudia; Giorgi, Adonis; Gómez, Nora; Leggieri, Leonardo; Muñoz, Isabel; Rodrigues-Capítulo, Alberto; Romaní, Anna M.; Sabater, Sergi


    We assessed the effects of nutrient enrichment on three stream ecosystems running through distinct biomes (Mediterranean, Pampean and Andean). We increased the concentrations of N and P in the stream water 1.6-4-fold following a before-after control-impact paired series (BACIPS) design in each stream, and evaluated changes in the biomass of bacteria, primary producers, invertebrates and fish in the enriched (E) versus control (C) reaches after nutrient addition through a predictive-BACIPS approach. The treatment produced variable biomass responses (2-77% of explained variance) among biological communities and streams. The greatest biomass response was observed for algae in the Andean stream (77% of the variance), although fish also showed important biomass responses (about 9-48%). The strongest biomass response to enrichment (77% in all biological compartments) was found in the Andean stream. The magnitude and seasonality of biomass responses to enrichment were highly site specific, often depending on the basal nutrient concentration and on windows of ecological opportunity (periods when environmental constraints other than nutrients do not limit biomass growth). The Pampean stream, with high basal nutrient concentrations, showed a weak response to enrichment (except for invertebrates), whereas the greater responses of Andean stream communities were presumably favored by wider windows of ecological opportunity in comparison to those from the Mediterranean stream. Despite variation among sites, enrichment globally stimulated the algal-based food webs (algae and invertebrate grazers) but not the detritus-based food webs (bacteria and invertebrate shredders). This study shows that nutrient enrichment tends to globally enhance the biomass of stream biological assemblages, but that its magnitude and extent within the food web are complex and are strongly determined by environmental factors and ecosystem structure.

  19. The last millennia history of detrital sedimentation in the Lower Seine Valley geosystem (Normandy, NW France)

    Sechi-Sapowicz, S.; Sebag, D.; Laignel, B.; Lepert, T.


    Actually, the respective role of climate and Man in the Holocene environmental changes is still debated. It is obvious that those factors are together implicated in changes in hydrological balance, soil erosion and terrigenous sedimentation. Indeed regional synthesis showed the increasing human pressure in combination to climatic variability since the Neolithic time. Thus, in Northwest Europe, increasing land use is well documented as forest clearance or alternation of deforestation and farming periods and of forest recovery episodes. In this aim, the lower valleys were particularly sensitive to changes in recent mutation and provide valuable Holocene archives to track changes in sedimentary dynamics. In this way an accentuated fine alluviation is often associated with land human activities linked to erosive processes during climatic oscillation in Northwest European valleys. In the West Paris Basin, in Normandy, France, several studies emphasized a single forcing on the Quaternary and Holocene evolution: climate changes or sea level rise or human activities in the Lower Seine Valley (LSV). Research on Holocene sequences, field, palaeoenvironnemental data and archaeological investigations from the Lower Seine Valley and tributaries result in a global vision of the erosional processes at the origin of detrital inputs and terrigenous records. Reading on those records we define three main sectors of the Lower Seine Valley: Estuarine zone, Fluvial zone and Tributaries. We define seven erosional/detrital phases directly or indirectly triggered by the increase anthropogenic pressure combined, or not, to climate change. Those phases are the key periods of changes on major terrigenous sedimentation events. During the Early Holocene climate pejoration, a deep and linear under-scour of plateaus and changes in drainage network load to the "Mesolithic detritism". Those sediments with proximal origins, were firstly recorded in the estuarine zone and after in the fluvial zone

  20. Detrital Zircon Geochronology of Cretaceous and Paleogene Strata Across the South-Central Alaskan Convergent Margin

    Bradley, Dwight; Haeussler, Peter; O'Sullivan, Paul; Friedman, Rich; Till, Alison; Bradley, Dan; Trop, Jeff


    Ages of detrital zircons are reported from ten samples of Lower Cretaceous to Paleogene metasandstones and sandstones from the Chugach Mountains, Talkeetna Mountains, and western Alaska Range of south-central Alaska. Zircon ages are also reported from three igneous clasts from two conglomerates. The results bear on the regional geology, stratigraphy, tectonics, and mineral resource potential of the southern Alaska convergent margin. Chugach Mountains - The first detrital zircon data are reported here from the two main components of the Chugach accretionary complex - the inboard McHugh Complex and the outboard Valdez Group. Detrital zircons from sandstone and two conglomerate clasts of diorite were dated from the McHugh Complex near Anchorage. This now stands as the youngest known part of the McHugh Complex, with an inferred Turonian (Late Cretaceous) depositional age no older than 91-93 Ma. The zircon population has probability density peaks at 93 and 104 Ma and a smattering of Early Cretaceous and Jurassic grains, with nothing older than 191 Ma. The two diorite clasts yielded Jurassic U-Pb zircon ages of 179 and 181 Ma. Together, these findings suggest a Mesozoic arc as primary zircon source, the closest and most likely candidate being the Wrangellia composite terrane. The detrital zircon sample from the Valdez Group contains zircons as young as 69 and 77 Ma, consistent with the previously assigned Maastrichtian to Campanian (Late Cretaceous) depositional age. The zircon population has peaks at 78, 91, 148, and 163 Ma, minor peaks at 129, 177, 330, and 352 Ma, and no concordant zircons older than Devonian. A granite clast from a Valdez Group conglomerate yielded a Triassic U-Pb zircon age of 221 Ma. Like the McHugh Complex, the Valdez Group appears to have been derived almost entirely from Mesozoic arc sources, but a few Precambrian zircons are also present. Talkeetna Mountains - Detrital zircons ages were obtained from southernmost metasedimentary rocks of the

  1. INVHOGEN: a database of homologous invertebrate genes.

    Paulsen, Ingo; von Haeseler, Arndt


    Classification of proteins into families of homologous sequences constitutes the basis of functional analysis or of evolutionary studies. Here we present INVertebrate HOmologous GENes (INVHOGEN), a database combining the available invertebrate protein genes from UniProt (consisting of Swiss-Prot and TrEMBL) into gene families. For each family INVHOGEN provides a multiple protein alignment, a maximum likelihood based phylogenetic tree and taxonomic information about the sequences. It is possible to download the corresponding GenBank flatfiles, the alignment and the tree in Newick format. Sequences and related information have been structured in an ACNUC database under a client/server architecture. Thus, complex selections can be performed. An external graphical tool (FamFetch) allows access to the data to evaluate homology relationships between genes and distinguish orthologous from paralogous sequences. Thus, INVHOGEN complements the well-known HOVERGEN database. The databank is available at

  2. 1.8 Billion Years of Detrital Zircon Recycling Calibrates a Refractory Part of Earth's Sedimentary Cycle.

    Hadlari, Thomas; Swindles, Graeme T; Galloway, Jennifer M; Bell, Kimberley M; Sulphur, Kyle C; Heaman, Larry M; Beranek, Luke P; Fallas, Karen M


    Detrital zircon studies are providing new insights on the evolution of sedimentary basins but the role of sedimentary recycling remains largely undefined. In a broad region of northwestern North America, this contribution traces the pathway of detrital zircon sand grains from Proterozoic sandstones through Phanerozoic strata and argues for multi-stage sedimentary recycling over more than a billion years. As a test of our hypothesis, integrated palynology and detrital zircon provenance provides clear evidence for erosion of Carboniferous strata in the northern Cordillera as a sediment source for Upper Cretaceous strata. Our results help to calibrate Earth's sedimentary cycle by showing that recycling dominates sedimentary provenance for the refractory mineral zircon.

  3. Surprising characteristics of visual systems of invertebrates.

    González-Martín-Moro, J; Hernández-Verdejo, J L; Jiménez-Gahete, A E


    To communicate relevant and striking aspects about the visual system of some close invertebrates. Review of the related literature. The capacity of snails to regenerate a complete eye, the benefit of the oval shape of the compound eye of many flying insects as a way of stabilising the image during flight, the potential advantages related to the extreme refractive error that characterises the ocelli of many insects, as well as the ability to detect polarised light as a navigation system, are some of the surprising capabilities present in the small invertebrate eyes that are described in this work. The invertebrate eyes have capabilities and sensorial modalities that are not present in the human eye. The study of the eyes of these animals can help us to improve our understanding of our visual system, and inspire the development of optical devices. Copyright © 2016 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.

  4. Priority wetland invertebrates as conservation surrogates.

    Ormerod, S J; Durance, Isabelle; Terrier, Aurelie; Swanson, Alisa M


    Invertebrates are important functionally in most ecosystems, but seldom appraised as surrogate indicators of biological diversity. Priority species might be good candidates; thus, here we evaluated whether three freshwater invertebrates listed in the U.K. Biodiversity Action Plan indicated the richness, composition, and conservation importance of associated wetland organisms as defined respectively by their alpha diversity, beta diversity, and threat status. Sites occupied by each of the gastropods Segmentina nitida, Anisus vorticulus, and Valvata macrostoma had greater species richness of gastropods and greater conservation importance than other sites. Each also characterized species assemblages associated with significant variations between locations in alpha or beta diversity among other mollusks and aquatic macrophytes. Because of their distinct resource requirements, conserving the three priority species extended the range of wetland types under management for nature conservation by 18% and the associated gastropod niche-space by around 33%. Although nonpriority species indicated variations in richness, composition, and conservation importance among other organisms as effectively as priority species, none characterized such a wide range of high-quality wetland types. We conclude that priority invertebrates are no more effective than nonpriority species as indicators of alpha and beta diversity or conservation importance among associated organisms. Nevertheless, conserving priority species can extend the array of distinct environments that are protected for their specialized biodiversity and environmental quality. We suggest that this is a key role for priority species and conservation surrogates more generally, and, on our evidence, can best be delivered through multiple species with contrasting habitat requirements.

  5. The groundwater invertebrate fauna of the Channel Islands

    Lee R.F.D. Knight


    Full Text Available The Channel Islands are a small archipelago of British dependencies just off the coast of Normandy at the western end of the English Channel. There were only three records for stygobitic Crustacea [Niphargus fontanus Bate, 1859 and N. kochianus Bate, 1859 from Jersey and N. aquilex Schiődte, 1855 from Guernsey] from the archipelago and no systematic survey has been carried out of the islands for their groundwater fauna till present. Recently sampling was carried out in wells, boreholes and springs on the four largest islands, Jersey, Guernsey, Alderney and Sark during February 2012. Niphargus aquilex was widespread across all four islands and did not appear to be restricted to any particular geology. Niphargus ladmiraulti was present in large numbers in a single borehole on Jersey, the first record of this species from the archipelago. Niphargus kochianus was collected from two sites on Alderney and the syncarid Antrobathynella stammeri (Jakobi, 1954 from two sites on the west coast of Jersey. The records for A. stammeri are new for the Channel Islands and possibly represent the first records of this species from the French bio-geographical area. The presence of N. fontanus on the islands was not confirmed. Several species of stygophilic Cyclopoida were also recorded during the survey along with epigean freshwater invertebrate taxa, which were mostly present in springs and shallow wells close to surface streams.

  6. Monitoring ecological recovery in a stream impacted by contaminated groundwater

    Southworth, G.R.; Cada, G.F.; Kszos, L.A.; Peterson, M.J.; Smith, J.G. [and others


    Past in-ground disposal practices in Bear Creek Valley resulted in contamination of Bear Creek and consequent ecological damage. A biological monitoring program initiated in 1984 has evaluated the effectiveness of the extensive remedial actions undertaken to address contamination sources. Elements of the monitoring program included toxicity testing with fish and invertebrates, bioaccumulation monitoring, and instream monitoring of streambed invertebrate and fish communities. In the mid 1980`s, toxicity tests on stream water indicated that the headwaters of the stream were acutely toxic to fish and aquatic invertebrates as a result of infiltration of a metal-enriched groundwater from ponds used to dispose of acid wastes. Over a twelve year period, measurable toxicity in the headwaters decreased, first becoming non-toxic to larval fish but still toxic to invertebrates, then becoming intermittently toxic to invertebrates. By 1997, episodic toxicity was infrequent at the site that was acutely toxic at the start of the study. Recovery in the fish community followed the pattern of the toxicity tests. Initially, resident fish populations were absent from reaches where toxicity was measured, but as toxicity to fish larvae disappeared, the sites in upper Bear Creek were colonized by fish. The Tennessee dace, an uncommon species receiving special protection by the State of Tennessee, became a numerically important part of the fish population throughout the upper half of the creek, making Bear Creek one of the most significant habitats for this species in the region. Although by 1990 fish populations were comparable to those of similar size reference streams, episodic toxicity in the headwaters coincided with a recruitment failure in 1996. Bioaccumulation monitoring indicated the presence of PCBs and mercury in predatory fish in Bear Creek, and whole forage fish contained elevated levels of cadmium, lead, lithium, nickel, mercury, and uranium.

  7. Mercury bioaccumulation in a stream network.

    Tsui, Martin Tsz Ki; Finlay, Jacques C; Nater, Edward A


    Mercury (Hg) contamination is common in stream and river ecosystems, but factors mediating Hg cycling in the flowing waters are much less understood than inthe lakes and wetlands. In this study, we examined the spatial patterns of methylmercury (MeHg) concentrations in the dominant groups of aquatic insect larvae across a network of streams (drainage area ranging from 0.5 to 150 km2) in northern California during summer baseflow conditions. We found that, with the exception of water striders, all invertebrate groups showed significant (p South Fork Eel River, had the highest aqueous MeHg concentration (unfiltered: 0.13-0.17 ng L(-1)) while most of the upstream tributaries had aqueous MeHg concentrations close to or below the established detection limits (0.02 ng L(-1)). A filamentous alga abundant in South Fork Eel River (Cladophora glomerata) had an exceptionally high fraction of total-Hg as MeHg (i.e., %MeHg from 50-100%). Since other potential hotspots of in-stream Hg methylation (e.g., surface sediment and deep pools) had %MeHg lower than or similar to surface water (approximately 14%), we hypothesize that Cladophora and possibly other autotrophs may serve as hotspots of in-stream MeHg production in this bedrock-dominated stream. Recent studies in other regions concluded that wetland abundance in the watershed is the predominant factor in governing Hg concentrations of stream biota. However, our results show that in the absence of wetlands, substantial spatial variation of Hg bioaccumulation can arise in stream networks due to the influence of in-stream processes.

  8. Associations between iron concentration and productivity in montane streams of the Black Hills, South Dakota

    Hayer, Cari Ann; Holcomb, Benjamin M.; Chipps, Steven R.


    Iron is an important micronutrient found in aquatic systems that can influence nutrient availability (e.g., phosphorus) and primary productivity. In streams, high iron concentrations often are associated with low pH as a result of acid mine drainage, which is known to affect fish and invertebrate communities. Streams in the Black Hills of South Dakota are generally circumneutral in pH, yet select streams exhibit high iron concentrations associated with natural iron deposits. In this study, we examined relationships among iron concentration, priphyton biomass, macroinvertebrate abundance, and fish assemblages in four Black Hills streams. The stream with the highest iron concentration (~5 mg Fe/L) had reduced periphyton biomass, invertebrate abundance, and fish biomass compared to the three streams with lower iron levels (0.1 to 0.6 mg Fe/L). Reduced stream productivity was attributed to indirect effects of ferric iron Fe+++), owing to iron-hydroxide precipitation that influenced habitat quality (i.e., substrate and turbidity) and food availability (periphyton and invertebrates) for higher trophic levels (e.g., fish). Additionally, reduced primary and secondary production was associated with reduced standing stocks of salmonid fishes. Our findings suggested that naturally occurring iron deposits may constrain macroinvertebrate and fish production.

  9. SHRIMP U-Pb dating of detrital zircons in paragneiss from Oki-Dogo Island, western Japan

    TSUTSUMI, Yukiyasu; YOKOYAMA, Kazumi; HORIE, Kenji; TERADA, Kentaro; HIDAKA, Hiroshi


    We obtained the radiometric ages of detrital zircons from two samples of paragneiss from Oki-Dogo Island, Japan, from the 238U/206Pb ratio and isotopic composition of Pb determined using a Sensitive...

  10. SHRIMP U-Pb dating of detrital zircons in paragneiss from Oki-Dogo Island, western Japan

    TSUTSUMI, Yukiyasu; YOKOYAMA, Kazumi; HORIE, Kenji; TERADA, Kentaro; HIDAKA, Hiroshi


      We obtained the radiometric ages of detrital zircons from two samples of paragneiss from Oki-Dogo Island, Japan, from the 238U/206Pb ratio and isotopic composition of Pb determined using a Sensitive...

  11. Groundwater budgets for Detrital, Hualapai, and Sacramento Valleys, Mohave County, Arizona, 2007-08

    Garner, Bradley D.; Truini, Margot


    The United States Geological Survey, in cooperation with the Arizona Department of Water Resources, initiated an investigation of the hydrogeology and water resources of Detrital, Hualapai, and Sacramento Valleys in northwestern Arizona in 2005, and this report is part of that investigation. Water budgets were developed for Detrital, Hualapai, and Sacramento Valleys to provide a generalized understanding of the groundwater systems in this rural area that has shown some evidence of human-induced water-level declines. The valleys are within the Basin and Range physiographic province and consist of thick sequences of permeable alluvial sediment deposited into basins bounded by relatively less permeable igneous and metamorphic rocks. Long-term natural recharge rates (1940-2008) for the alluvial aquifers were estimated to be 1,400 acre-feet per year (acre-ft/yr) for Detrital Valley, 5,700 acre-ft/yr for Hualapai Valley, and 6,000 acre-ft/yr for Sacramento Valley. Natural discharge rates were assumed to be equal to natural recharge rates, on the basis of the assumption that all groundwater withdrawals to date have obtained water from groundwater storage. Groundwater withdrawals (2007-08) for the alluvial aquifers were less than 300 acre-ft/yr for Detrital Valley, about 9,800 acre-ft/yr for Hualapai Valley, and about 4,500 acre-ft/yr for Sacramento Valley. Incidental recharge from leaking water-supply pipes, septic systems, and wastewater-treatment plants accounted for about 35 percent of total recharge (2007-08) across the study area. Natural recharge and discharge values in this study were 24-50 percent higher than values in most previously published studies. Water budgets present a spatially and temporally "lumped" view of water resources and incorporate many sources of uncertainty in this study area where only limited data presently are available.

  12. Detrital zircon geochronology and provenance of the Chubut Group in the northeast of Patagonia, Argentina

    Navarro, Edgardo L.; Astini, Ricardo A.; Belousova, Elena; Guler, M. Verónica; Gehrels, George


    The Chubut Group constitutes the most widespread sedimentary unit in NE Patagonia, characterized by variable-energy fluvial deposits. U-Pb analysis of detrital zircons from two sections of the Chubut Group constraint the age of the oldest sedimentary rocks in the northeast of the Somuncurá - Cañadón Asfalto Basin. In the Cañadón Williams area, at San Jorge section, 20 km NW of Telsen locality, dating of 56 detrital zircons from a medium to coarse sandstone indicated a maximum depositional age of 109 ± 1 Ma (n = 4). These sandstones were interpreted to represent shallow channels, associated with a lacustrine system. In the Telsen locality, a laser ablation analysis of 115 detrital zircons from a medium to coarse-grained sandstone, from fluvial channel facies, yielded a maximum depositional age of ca. 106 ± 1 Ma (n = 8). Both ages are consistent with volcanic events of the Barremian to Albian age in the central Patagonian Andes Region. Cathodoluminescence images of zircons from the San Jorge sample suggest an igneous origin, which is further supported by Th/U values above 0.5 in most of the grains. The distribution of the statistical modes of the main age populations of detrital zircons for the two samples [182, 185 and 189 Ma for Telsen sample (T2S) and 181 ± 1 Ma for San Jorge sample (SJS)] matches the age of the volcanic Marifil Formation. The rocks of the Marifil Formation of these ages are exposed NE to SE of the study area. The abundance of zircons of similar Jurassic ages (n = 52 for SJS and n = 105 for T2S) and the external morphology of the zircons in the sample SJS, implies a close proximity of the source area. Suggestion that the Marifil Formation was the main provenance source is also supported by northeast-southeasterly paleocurrents measured at the San Jorge and Telsen sections.

  13. Detrital illite crystals identified from crystallite thickness measurements in siliciclastic sediments

    Aldega, L.; Eberl, D.D.


    Illite crystals in siliciclastic sediments are heterogeneous assemblages of detrital material coming from various source rocks and, at paleotemperatures >70 ??C, of superimposed diagenetic modification in the parent sediment. We distinguished the relative proportions of 2M1 detrital illite and possible diagenetic 1Md + 1M illite by a combined analysis of crystal-size distribution and illite polytype quantification. We found that the proportions of 1Md + 1M and 2M1 illite could be determined from crystallite thickness measurements (BWA method, using the MudMaster program) by unmixing measured crystallite thickness distributions using theoretical and calculated log-normal and/or asymptotic distributions. The end-member components that we used to unmix the measured distributions were three asymptotic-shaped distributions (assumed to be the diagenetic component of the mixture, the 1Md + 1M polytypes) calculated using the Galoper program (Phase A was simulated using 500 crystals per cycle of nucleation and growth, Phase B = 333/cycle, and Phase C = 250/ cycle), and one theoretical log-normal distribution (Phase D, assumed to approximate the detrital 2M1 component of the mixture). In addition, quantitative polytype analysis was carried out using the RockJock software for comparison. The two techniques gave comparable results (r2 = 0.93), which indicates that the unmixing method permits one to calculate the proportion of illite polytypes and, therefore, the proportion of 2M1 detrital illite, from crystallite thickness measurements. The overall illite crystallite thicknesses in the samples were found to be a function of the relative proportions of thick 2M1 and thin 1Md + 1M illite. The percentage of illite layers in I-S mixed layers correlates with the mean crystallite thickness of the 1Md + 1M polytypes, indicating that these polytypes, rather than the 2M1 polytype, participate in I-S mixed layering.

  14. Ontogenetic shifts in terrestrial reliance of stream-dwelling brown trout

    Javier Sánchez-Hernández


    Full Text Available This study focuses on terrestrial reliance of brown trout (Salmo trutta and compared it to the potential prey available (macrozoobenthos and drifting invertebrates in three temperate rivers (Galicia, NW Spain, with special emphasis on variations in terrestrial energy intake through the ontogeny of brown trout. Additionally, we paid particular attention to individual variation of terrestrial resource use within and between age classes. Prey items were grouped in four categories: i aquatic invertebrates; ii imagoes of aquatic invertebrates; iii terrestrial invertebrates; and iv fish prey. Next, energy composition was measured according to dry weight-energy equations for each individual in line with above-mentioned prey categories. Our findings illustrate that terrestrial invertebrates appeared to be scarce in the environment, whereas aquatic food resources were rather abundant and accessible. The use of terrestrial invertebrates tended to increase with age, but with a high degree of inter-individual variation in resource use. In fact, the individual reliance of brown trout on terrestrial invertebrates may vary considerably (between 0% and 76.9%. Besides, the frequency of terrestrial foragers, i.e., individuals with terrestrial invertebrates in their stomachs, increased with age, except in one population which had the maximum value in the age-2 class. The acquisition of terrestrial invertebrates thus appears to be a process strongly dependent upon the actual food availability in the environment, but with a high degree of individual variance in resource use within the same age class. Finally, we discuss that terrestrial invertebrates may largely contribute to cover the energy intake of the species, highlighting the interface between terrestrial and aquatic ecosystems, and thereby the importance of riparian canopy cover as a key factor for food supply of stream-dwelling salmonids species.

  15. Recovery of a mining-damaged stream ecosystem

    Mebane, Christopher A.; Robert J. Eakins; Brian G. Fraser; William J. Adams


    Abstract This paper presents a 30+ year record of changes in benthic macroinvertebrate communities and fish populations associated with improving water quality in mining-influenced streams. Panther Creek, a tributary to the Salmon River in central Idaho, USA suffered intensive damage from mining and milling operations at the Blackbird Mine that released copper (Cu), arsenic (As), and cobalt (Co) into tributaries. From the 1960s through the 1980s, no fish and few aquatic invertebrates could be...

  16. Microbially mediated detrital food web: The link between mangroves and coastal aquatic animal communities

    RaghuKumar, S.

    stream_size 8 stream_content_type text/plain stream_name Conserv_Mangrove_Forest_Genet_Resour_1994_263.pdf.txt stream_source_info Conserv_Mangrove_Forest_Genet_Resour_1994_263.pdf.txt Content-Encoding ISO-8859-1 Content-Type text...

  17. Detrital provenance of Early Mesozoic basins in the Jiangnan domain, South China: Paleogeographic and geodynamic implications

    Xu, Xianbing; Tang, Shuai; Lin, Shoufa


    Detrital provenance analysis is an effective way to understand paleogeographic change and geodynamics. In this paper, we present petrological, whole-rock geochemical and detrital zircon U-Pb geochronological analysis of Early and Middle Jurassic terrestrial clastic rocks in the Jingdezhen Basin and the Huangshan Basin in the Jiangnan domain, South China. Petrology and whole-rock geochemistry show that the source rocks are dominated by intermediate to acid component. The Chemical Index of Alteration ranges from 69 to 86, suggesting a moderate weathering history for the source rocks. The Early-Middle Jurassic sediments in the Jingdezhen and Huangshan basins were mostly sourced from magmatogenic greywackes and felsic magmatic rocks, respectively. Detrital zircons have seven age peaks at 240 Ma, 430 Ma, 1390 Ma, 1880 Ma, 2500 Ma, -3200 Ma and 788-999 Ma (a wide peak). Provenance analysis indicates that the source rocks are in the Jiangnan domain, the Northwest Zhejiang Basin and the Wuyishan domain. Combining these with previous results and paleocurrent directions, we infer that the NE-trending Wuyishan and Xuefengshan domains and the nearly E-W-Jiangnan domain and Nanling tectonic belt were orogenic uplifts and watersheds during the Late Triassic to Middle Jurassic. The Early Mesozoic geodynamics in the South China Block was related to the westward subduction of the Paleo-Pacific Plate and the northward continent-continent collision following the closure of the Paleo-Tethys Ocean.

  18. Associations of stream health to altered flow and water temperature in the Sierra Nevada, California

    Carlisle, Daren M.; S. Mark Nelson,; May, Jason


    Alteration of streamflow and thermal conditions may adversely affect lotic invertebrate communities, but few studies have assessed these phenomena using indicators that control for the potentially confounding influence of natural variability. We designed a study to assess how flow and thermal alteration influence stream health – as indicated by the condition of invertebrate communities. We studied thirty streams in the Sierra Nevada, California, that span a wide range of hydrologic modification due to storage reservoirs and hydroelectric diversions. Daily water temperature and streamflows were monitored, and basic chemistry and habitat conditions were characterized when invertebrate communities were sampled. Streamflow alteration, thermal alteration, and invertebrate condition were quantified by predicting site-specific natural expectations using statistical models developed using data from regional reference sites. Monthly flows were typically depleted (relative to natural expectations) during fall, winter, and spring. Most hydrologically altered sites experienced cooled thermal conditions in summer, with mean daily temperatures as much 12 °C below natural expectations. The most influential predictor of invertebrate community condition was the degree of alteration of March flows, which suggests that there are key interactions between hydrological and biological processes during this month in Sierra Nevada streams. Thermal alteration was also an important predictor – particularly at sites with the most severe hydrological alteration.

  19. Long Wall Mining Subsidence and Fluvial Stream Changes: an Ecological Perspective

    Spear, R.; Proch, T.


    Long wall mining is a high efficiency underground coal extraction technique that removes large panels of coal and causes immediate subsidence of the overburden. Surface subsidence may vary between 0.3 meters and 2 meters depending on the depth of the coal seam. Fractures in the overburden allow perched water tables to drain to greater depths and dries up their associated springs. Base flow in headwater streams is often eliminated. Subsidence also changes the physical characteristics of streams. Typical riffle pool sequences are replaced with long pools and glides. Benthic invertebrate and fish community assemblages reflect the physical habitat changes. EPT invertebrate taxa are replaced with Odonates and Diptera larvae associated with glide/pool habitat. Fish community diversity is negatively impacted. Diverse riffle dwelling assemblages are replaced and dominated by increasingly homogenous pool dwelling fish communities. Stream subsidence effectively increases the stream order without increasing its size or flow regime.

  20. Assessing land-use effects on water quality, in-stream habitat, riparian ecosystems and biodiversity in Patagonian northwest streams.

    Miserendino, María Laura; Casaux, Ricardo; Archangelsky, Miguel; Di Prinzio, Cecilia Yanina; Brand, Cecilia; Kutschker, Adriana Mabel


    Changes in land-use practices have affected the integrity and quality of water resources worldwide. In Patagonia there is a strong concern about the ecological status of surface waters because these changes are rapidly occurring in the region. To test the hypothesis that greater intensity of land-use will have negative effects on water quality, stream habitat and biodiversity we assessed benthic macroinvertebrates, riparian/littoral invertebrates, fish and birds from the riparian corridor and environmental variables of 15 rivers (Patagonia) subjected to a gradient of land-use practices (non-managed native forest, managed native forest, pine plantations, pasture, urbanization). A total of 158 macroinvertebrate taxa, 105 riparian/littoral invertebrate taxa, 5 fish species, 34 bird species, and 15 aquatic plant species, were recorded considering all sites. Urban land-use produced the most significant changes in streams including physical features, conductivity, nutrients, habitat condition, riparian quality and invertebrate metrics. Pasture and managed native forest sites appeared in an intermediate situation. The highest values of fish and bird abundance and diversity were observed at disturbed sites; this might be explained by the opportunistic behavior displayed by these communities which let them take advantage of increased trophic resources in these environments. As expected, non-managed native forest sites showed the highest integrity of ecological conditions and also great biodiversity of benthic communities. Macroinvertebrate metrics that reflected good water quality were positively related to forest land cover and negatively related to urban and pasture land cover. However, by offering stream edge areas, pasture sites still supported rich communities of riparian/littoral invertebrates, increasing overall biodiversity. Macroinvertebrates were good indicators of land-use impact and water quality conditions and resulted useful tools to early alert of

  1. Invertebrate grazers affect metal/metalloid fixation during litter decomposition.

    Schaller, Jörg; Brackhage, Carsten


    Plant litter and organic sediments are main sinks for metals and metalloids in aquatic ecosystems. The effect of invertebrates as key species in aquatic litter decomposition on metal/metalloid fixation by organic matter is described only for shredders, but for grazers as another important animal group less is known. Consequently, a laboratory batch experiment was conducted to examine the effect of invertebrate grazers (Lymnaea stagnalis L.) on metal/metalloid fixation/remobilization during aquatic litter decomposition. It could be shown that invertebrate grazers facilitate significantly the formation of smaller sizes of particulate organic matter (POM), as shown previously for invertebrate shredders. The metal/metalloid binding capacity of these smaller particles of POM is higher compared to leaf litter residuals. But element enrichment is not as high as shown previously for the effect by invertebrate shredders. Invertebrate grazers enhance also the mobilization of selected elements to the water, in the range also proven for invertebrate shredders but different for the different elements. Nonetheless invertebrate grazers activity during aquatic litter decomposition leads to a metal/metalloid fixation into leaf litter as part of sediment organic matter. Hence, the effect of invertebrate grazers on metal/metalloid fixation/remobilization contrasts partly with former assessments revealing the possibility of an enhanced metal/metalloid fixation.

  2. Invertebrates Collected on and around Carroll Island, Maryland.


  3. Natural invertebrate hosts of iridoviruses (Iridoviridae)

    Williams, Trevor [Instituto de Ecologia A.C., Veracruz (Mexico)]. E-mail:


    Invertebrate iridescent viruses (IIVs) are icosahedral DNA viruses that infect invertebrates, mainly insects and terrestrial isopods, in damp and aquatic habitats. Exhaustive searches of databases resulted in the identification of 79 articles reporting 108 invertebrate species naturally infected by confirmed or putative iridoviruses. Of these, 103 (95%) were arthropods and the remainder were molluscs, an annelid worm and a nematode. Nine species were from marine habitats. Of the 99 non-marine species, 49 were from terrestrial habitats and 50 were aquatic, especially the aquatic stages of Diptera (44 species). The abundance of records from species of Aedes, Ochlerotatus and Psorophora contrasts markedly with a paucity of records from species of Anopheles, Culex and Culiseta. Records from terrestrial isopods are numerous (19 species), although the diversity of IIVs that infect them is mostly unstudied. IIV infections have been reported from every continent, except Antarctica, but there are few records from Africa, southern Asia and Latin America. Most reports describe patent IIV infections as rare whereas inapparent (covert) infection may be common in certain species. The relationship between particle size and iridescent colour of the host is found to be consistent with optical theory in the great majority of cases. Only 24 reported IIVs from insect hosts have partial characterization data and only two have been subjected to complete genome sequencing. I show that the rate of publication on IIVs has slowed from 1990 to the present, and I draw a number of conclusions and suggestions from the host list and make recommendations for future research efforts. (author)

  4. Brain and behavioural lateralization in invertebrates.

    Elisa eFrasnelli


    Full Text Available Traditionally, only humans were thought to exhibit brain and behavioural asymmetries, but several studies have revealed that most vertebrates are also lateralized. Recently, evidence of left-right asymmetries in invertebrates has begun to emerge, suggesting that lateralization of the nervous system may be a feature of simpler brains as well as more complex ones. Here I present some examples in invertebrates of sensory and motor asymmetries, as well as asymmetries in the nervous system. I illustrate two cases where an asymmetric brain is crucial for the development of some cognitive abilities. The first case is the nematode C. elegans, which has asymmetric odour sensory neurons and taste perception neurons. In this worm left/right asymmetries are responsible for the sensing of a substantial number of salt ions, and lateralized responses to salt allow the worm to discriminate between distinct salt ions. The second case is the fruit fly D. melanogaster, where the presence of asymmetry in a particular structure of the brain is important in the formation or retrieval of long-term memory. Moreover, I distinguish two distinct patterns of lateralization that occur in both vertebrates and invertebrates: individual-level and population-level lateralization. Theoretical models on the evolution of lateralization suggest that the alignment of lateralization at the population level may have evolved as an evolutionary stable strategy in which individually-asymmetrical organisms must coordinate their behaviour with that of other asymmetrical organisms. This implies that lateralization at the population-level is more likely to have evolved in social rather than in solitary species. I evaluate this new hypothesis with specific focus on insects showing different level of sociality. In particular, I present a series of studies on antennal asymmetries in honeybees and other related species of bees, showing how insects may be extremely useful to test evolutionary

  5. Hybrid pigment organelles in an invertebrate.

    Schliwa, M; Euteneuer, U


    Observations of a number of vertebrate chromatophores have revealed the presence of more than one type of pigment organelles, suggesting that the different types are all derived from an equipotential organelle able to differentiate into any of the major pigment-containing organelles (Bagnara, 1972). Observations are presented concerning the occurrence of hybrid pigment inclusions, i.e., all kinds of intergrades between melanosomes, pterinosomes, and reflecting platelets in pigment cells of the daddy-long-legs. It therefore seems possible that pigment organelles in some invertebrates may also be derived from a common pluripotential primordial organelle.

  6. Quantifying transient erosion of orogens with detrital thermochronology from syntectonic basin deposits

    Rahl, Jeffrey M.; Ehlers, Todd A.; van der Pluijm, Ben A.


    The evolution of an orogen is marked by phases of topographic growth, equilibrium, and decay. During these phases erosion rates vary in response to temporal and spatial changes in climate, topographic relief and slope, and deformation. Detrital thermochronometer cooling-age data collected from syntectonic basin deposits are a promising tool for quantifying erosion histories during orogenic evolution. Previous studies typically assume steady-state erosion for interpreting detrital data, although in many situations this assumption is not justified. Here we present a new numerical modeling approach that predicts thermochronometer cooling ages in a stratigraphic section where sediment is sourced from a region with a temporally variable erosion history. Multiple thermochronometer cooling ages are predicted at different stratigraphic horizons as a function of variable erosion histories, rock cooling rates in the hinterland, and thermophysical material properties and boundary conditions. The modeling approach provides the context for the interpretation of natural data, including geologically realistic situations with a temporally varying erosion rate. The results of three end-member hinterland erosion histories are explored: (1) steady-state erosion; (2) increasing erosion rate with time; and (3) decreasing erosion rate with time. Results indicate that for steady erosion rates between 0.2 and 1.0 mm/yr, up to 30 m.y. will pass following a change in erosion rate before the detrital ages have adjusted to reflect a new erosion regime. In simulations with transient erosion, the estimation of erosion rates from a detrital record using assumption of thermal steady-state will generally be in error, often by as much as - 25 to 100%. These results highlight that assumptions of steady erosion in mountain belts should be used with caution. Application of the model to thermochronometer cooling ages preserved in syntectonic sediments sourced from the Nanga Parbat region, Himalaya

  7. Detrital zircon geochronology of pre- and syncollisional strata, Acadian orogen, Maine Appalachians

    Bradley, Dwight C.; O'Sullivan, Paul B.


    The Central Maine Basin is the largest expanse of deep-marine, Upper Ordovician to Devonian metasedimentary rocks in the New England Appalachians, and is a key to the tectonics of the Acadian Orogeny. Detrital zircon ages are reported from two groups of strata: (1) the Quimby, Rangeley, Perry Mountain and Smalls Falls Formations, which were derived from inboard, northwesterly sources and are supposedly older; and (2) the Madrid, Carrabassett and Littleton Formations, which were derived from outboard, easterly sources and are supposedly younger. Deep-water deposition prevailed throughout, with the provenance shift inferred to mark the onset of foredeep deposition and orogeny. The detrital zircon age distribution of a composite of the inboard-derived units shows maxima at 988 and 429 Ma; a composite from the outboard-derived units shows maxima at 1324, 1141, 957, 628, and 437 Ma. The inboard-derived units have a greater proportion of zircons between 450 and 400 Ma. Three samples from the inboard-derived group have youngest age maxima that are significantly younger than the nominal depositional ages. The outboard-derived group does not share this problem. These results are consistent with the hypothesised provenance shift, but they signal potential problems with the established stratigraphy, structure, and (or) regional mapping. Shallow-marine deposits of the Silurian to Devonian Ripogenus Formation, from northwest of the Central Maine Basin, yielded detrital zircons featuring a single age maximum at 441 Ma. These zircons were likely derived from a nearby magmatic arc now concealed by younger strata. Detrital zircons from the Tarratine Formation, part of the Acadian foreland-basin succession in this strike belt, shows age maxima at 1615, 980 and 429 Ma. These results are consistent with three episodes of zircon recycling beginning with the deposition of inboard-derived strata of the Central Maine Basin, which were shed from post-Taconic highlands located to the

  8. The Global Invertebrate Genomics Alliance (GIGA): Developing Community Resources to Study Diverse Invertebrate Genomes

    Bracken-Grissom, Heather


    Over 95% of all metazoan (animal) species comprise the invertebrates, but very few genomes from these organisms have been sequenced. We have, therefore, formed a Global Invertebrate Genomics Alliance (GIGA). Our intent is to build a collaborative network of diverse scientists to tackle major challenges (e.g., species selection, sample collection and storage, sequence assembly, annotation, analytical tools) associated with genome/transcriptome sequencing across a large taxonomic spectrum. We aim to promote standards that will facilitate comparative approaches to invertebrate genomics and collaborations across the international scientific community. Candidate study taxa include species from Porifera, Ctenophora, Cnidaria, Placozoa, Mollusca, Arthropoda, Echinodermata, Annelida, Bryozoa, and Platyhelminthes, among others. GIGA will target 7000 noninsect/nonnematode species, with an emphasis on marine taxa because of the unrivaled phyletic diversity in the oceans. Priorities for selecting invertebrates for sequencing will include, but are not restricted to, their phylogenetic placement; relevance to organismal, ecological, and conservation research; and their importance to fisheries and human health. We highlight benefits of sequencing both whole genomes (DNA) and transcriptomes and also suggest policies for genomic-level data access and sharing based on transparency and inclusiveness. The GIGA Web site () has been launched to facilitate this collaborative venture.

  9. The invertebrate Caenorhabditis elegans biosynthesizes ascorbate.

    Patananan, Alexander N; Budenholzer, Lauren M; Pedraza, Maria E; Torres, Eric R; Adler, Lital N; Clarke, Steven G


    l-Ascorbate, commonly known as vitamin C, serves as an antioxidant and cofactor essential for many biological processes. Distinct ascorbate biosynthetic pathways have been established for animals and plants, but little is known about the presence or synthesis of this molecule in invertebrate species. We have investigated ascorbate metabolism in the nematode Caenorhabditis elegans, where this molecule would be expected to play roles in oxidative stress resistance and as cofactor in collagen and neurotransmitter synthesis. Using high-performance liquid chromatography and gas-chromatography mass spectrometry, we determined that ascorbate is present at low amounts in the egg stage, L1 larvae, and mixed animal populations, with the egg stage containing the highest concentrations. Incubating C. elegans with precursor molecules necessary for ascorbate synthesis in plants and animals did not significantly alter ascorbate levels. Furthermore, bioinformatic analyses did not support the presence in C. elegans of either the plant or the animal biosynthetic pathway. However, we observed the complete (13)C-labeling of ascorbate when C. elegans was grown with (13)C-labeled Escherichia coli as a food source. These results support the hypothesis that ascorbate biosynthesis in invertebrates may proceed by a novel pathway and lay the foundation for a broader understanding of its biological role.

  10. Local adaptation in Trinidadian guppies alters stream ecosystem structure at landscape scales despite high environmental variability

    Simon, Troy N.; Bassar, Ronald D.; Binderup, Andrew J.; Flecker, Alex S.; Freeman, Mary C.; Gilliam, James F.; Marshall, Michael C.; Thomas, Steve A.; Travis, Joseph; Reznick, David N.; Pringle, Catherine M.


    While previous studies have shown that evolutionary divergence alters ecological processes in small-scale experiments, a major challenge is to assess whether such evolutionary effects are important in natural ecosystems at larger spatial scales. At the landscape scale, across eight streams in the Caroni drainage, we found that the presence of locally adapted populations of guppies (Poecilia reticulata) is associated with reduced algal biomass and increased invertebrate biomass, while the opposite trends were true in streams with experimentally introduced populations of non-locally adapted guppies. Exclusion experiments conducted in two separate reaches of a single stream showed that guppies with locally adapted phenotypes significantly reduced algae with no effect on invertebrates, while non-adapted guppies had no effect on algae but significantly reduced invertebrates. These divergent effects of phenotype on stream ecosystems are comparable in strength to the effects of abiotic factors (e.g., light) known to be important drivers of ecosystem condition. They also corroborate the results of previous experiments conducted in artificial streams. Our results demonstrate that local adaptation can produce phenotypes with significantly different effects in natural ecosystems at a landscape scale, within a tropical watershed, despite high variability in abiotic factors: five of the seven physical and chemical parameters measured across the eight study streams varied by more than one order of magnitude. Our findings suggest that ecosystem structure is, in part, an evolutionary product and not simply an ecological pattern.

  11. Leaf Degradation, Macroinvertebrate Shredders & Energy Flow in Streams: A Laboratory-Based Exercise Examining Ecosystem Processes

    Sparkes, Timothy C.; Mills, Colleen M.; Volesky, Lisa; Talkington, Jennifer; Brooke, Joanna


    A laboratory-based exercise that demonstrates mechanisms underlying leaf degradation in streams. Students examine the effects of "leaf conditioning" on the feeding behavior of invertebrate shredders. The exercise is completed in two sessions and can be adapted to both high school and college levels.

  12. Ecological consequences of antibiotic exposure to periphyton in naturally colonizing stream mesocosms

    Tetracycline and its derivatives are extensively used human and animal antibiotics, and enter stream ecosystems via point and non-point sources. Laboratory studies indicate that microbial organisms are more sensitive to antibiotics than invertebrates or fish, and may indicate t...

  13. Paleointensity-assisted chronostratigraphy of detrital layers on the Eirik Drift (North Atlantic) since marine isotope stage 11

    Evans, Helen F.; Channell, James E. T.; Stoner, Joseph S.; Hillaire-Marcel, Claude; Wright, James D.; Neitzke, Lauren C.; Mountain, Gregory S.


    Four piston cores collected in 1999 and 2002 from the Eirik Drift (southern Labrador Sea, off SE Greenland) provide paleomagnetic, environmental magnetic, and oxygen isotope records back to marine isotope stage 11. Age models for the cores are based on a combination of planktonic oxygen isotope data, relative geomagnetic paleointensity proxies, and the identification of geomagnetic excursions (Laschamp and Iceland Basin). Environmental magnetic data delineate two distinct detrital signals, interpreted to reflect the behavior of the surrounding ice sheets (Greenland and Laurentide) to orbital- and millennial-scale climate forcing. Broad decimeter-scale intervals of increased magnetic concentration and grain size occur during the early part of interglacial marine isotopic stages (MIS) 1, 5, 7, 9, and 11. Discrete centimeter-scale layers, recognized by magnetic concentration and grain-size sensitive parameters, gamma ray attenuation (GRA) bulk density, and carbonate content, are observed in glacial and interglacial stages as well as during terminations. On the basis of glacial reconstructions on Greenland during the last termination, the broad decimeter-scale coarser-grained intervals can be attributed to detrital influx associated with the retreat of the terrestrial-based Greenland Ice Sheet in the early Holocene. A similar magnetic signal observed within interglacial MIS 5, 7, 9, and 11 indicates similar Greenland Ice Sheet behavior during these time intervals. Two types of centimeter-scale detrital layers are also recognized back to MIS 11. Detrital carbonate (DC) layers reflect predominately ice-rafted debris (IRD) deposition, while the low detrital carbonate (LDC) layers reflect mass movement as evidenced by sharp basal contacts, graded bedding, and traction structures, likely from the Greenland slope. Some detrital layers on Eirik Drift, particularly the DC layers, can be tentatively correlated to detrital layers observed in the central North Atlantic and to

  14. Contributions of detrital subsidies to aboveground spiders during secondary succession, revealed by radiocarbon and stable isotope signatures.

    Haraguchi, Takashi F; Uchida, Masao; Shibata, Yasuyuki; Tayasu, Ichiro


    Prey subsidies originating from detritus add nutrients and energy to arboreal communities. Measurement of this subsidy is required in the understanding of how food web dynamics respond to changes in surrounding environments. Shrub spiders are one of the key predators involved in food web coupling. We evaluate the effects of potential changes in prey availabilities during secondary succession on the contribution of subsidy from detrital food webs to shrub spiders and how different spider feeding guilds used the subsidy of prey from detrital food webs. We measured the relative importance of the subsidy for the spider feeding guilds, using the ratios of stable isotopes of C (δ(13)C), and N (δ(15)N) and C isotope discrimination (Δ(14)C). Diet age was calculated from Δ(14)C values, because old diet ages of spiders indicate that the spiders consume prey from detrital food sources. Dominant aerial prey (Diptera) had a distinctively old diet age compared with arboreal prey, which indicates that aerial prey were subsidized from detrital food webs. Sit-and-wait spiders tended to have an older diet age than active hunting spiders, which indicates that sit-and-wait spiders depended more on subsidies. Diet age varied only slightly for spiders in stands of different ages, indicating that rates at which spiders use grazing and detrital prey are probably determined more by foraging strategies and not by stand age. A dominance of sit-and-wait predators will lead to higher detrital subsidy inputs in shrub habitats. This study highlights the effect of shrub spider community structure (feeding guild composition) on the volume of the subsidy received from the detrital food web.

  15. Toxicity of Derosal (active ingredient carbendazim) to aquatic invertebrates

    Wijngaarden, R.P.A.; Crum, S.J.H.; Decraene, K.; Hattink, J.; Kammen, van A.


    Short- and long-term laboratory single species toxicity tests were performed with eleven invertebrate species and the fungicide Derosal(R) (a.i. carbendazim). Toxicity values differed widely between the tested invertebrates. The most sensitive species we found was the flatworm Dugesia lugubris (96hr

  16. Biological control using invertebrates and microorganisms: plenty of new opportunities

    Lenteren, van Joop C.; Bolckmans, Karel; Kohl, Jurgen; Ravensberg, Willem J.; Urbaneja, Alberto


    In augmentative biological control (ABC), invertebrate and microbial organisms are seasonally released in large numbers to reduce pests. Today it is applied on more than 30 million ha worldwide. Europe is the largest commercial market for invertebrate biological control agents, while North America

  17. Detrital Shocked Minerals: A New Tool for Identifying Eroded Impacts in the Sedimentary Record

    Cavosie, A. J.; Quintero, R. R.; Radovan, H. A.; Moser, D. E.


    Impact processes dominated the Early Earth and are believed to have culminated in a Late Heavy Bombardment at ca. 3.9-3.8 Ga. No direct geologic evidence of this stage of planetary evolution has been found, however Hadean zircons up to 4.4 Ga have been identified. A new method for identifying impact evidence in siliciclastic sediments has recently been reported (Cavosie et al., 2008; Quintero et al., 2008 this volume), based on the discovery of detrital grains of shocked quartz and zircons eroded from the 2.02 Ga Vredefort Dome in channel sediments of the Vaal River. Here we describe grain scale characteristics of these shocked minerals, and discuss aspects of their preservation. In grain mount, detrital grains of shocked quartz range from sub-angular to round, and characteristically preserve a single set of parallel decorated planar deformation features (PDFs) with spacing of less than 5 microns, analogous to shocked quartz reported from Vredefort impactites. While the PDFs are continuous across most grains, numerous examples were found where a single orientation of PDFs is heterogeneously distributed in an optically continuous grain, such as only being preserved within 15 microns from a grain margin. Where sub-grains are present, PDFs can occur in multiple orientations, or in single isolated sub-grains as small as 100 microns that are surrounded by PDF-free sub-grains. Well-preserved PDFs are found in grains as small as 100 microns. In addition to quartz, detrital shocked zircons were also found. The shocked zircons are subhedral to anhedral, and show evidence of sedimentary abrasion. Planar fractures (PFs) were observed parallel to (010), (100), and in two {hkl} orientations. Up to three PF orientations are present in single zircons, with variable spacing that usually ranges from 5-20 microns. Despite the complex history of the shocked grains from the Vredefort Dome, including post-impact granulite facies metamorphism, exhumation, erosion, and fluvial transport

  18. The tectonic evolution of western Central Iran seen through detrital white mica

    Kargaranbafghi, Fariba; Neubauer, Franz; Genser, Johann


    A first order survey of 40Ar/39Ar dating of detrital white mica from Jurassic to Pliocene sandstones has been carried out in order to reveal the tectonic evolution of blocks in Central Iran. The Central Iran block was believed to represent a stable Precambrian block. Our results indicate that: (1) Only a very small proportion of Precambrian but abundant Paleozoic and Mesozoic detrital white mica indicate the Phanerozoic, mostly Mesozoic age of metamorphic crust exposed in Central Iran. The oldest but scarce detrital white mica grains have ages ranging from 524 to 826 Ma heralding a Late Precambrian and Cambrian crystalline basement or cannibalism from older clastic successions. (2) Jurassic and Cretaceous sandstones from the west and east of the Chapedony fault yield different age spectra, with a dominance of Variscan ages (ca. 308-385 Ma) in the Biabanak unit west of the Chapedony fault compared to coeval sandstones from the block east of the Chapedony fault, where Variscan ages are subordinate and Cimmerian ages predominate. The micas from the Biabanak unit are most likely derived from the Variscan accretionary complex exposed in the Anarak-Jandaq areas further northwest. This result underlines the importance of a major block boundary identified as the Chapedony fault, which is in extension of a fault previously proposed. (3) Two stages of Cimmerian events are visible in our data set from Cretaceous and Paleogene sandstones, a cluster around 170 Ma and at ca. 205 Ma. These clusters suggest a two-stage Cimmerian evolution of the largely amphibolite-grade metamorphic Posht-e-Badam and Boneh Shurow complexes. (4) The youngest micas in Paleogene conglomerates have an age of ca. 100 Ma and are most likely derived from the base of the Posht-e-Badam complex. No record of the uplifted Eocene Chapedony metamorphic core complex has been found in Eocene and Pliocene clastic rocks.

  19. Quartz types, authigenic and detrital, in the Upper Cretaceous Eagle Ford Formation, South Texas, USA

    Milliken, Kitty L.; Ergene, Suzan M.; Ozkan, Aysen


    Lithologic heterogeneity of the Eagle Ford Formation in South Texas arises from mixing of extrabasinal grains of siliciclastic composition with intrabasinal grain assemblages composed dominantly of marine carbonate with a lesser component of biosiliceous debris. Detrital quartz in particular is derived from both extrabasinal and intrabasinal sources, posing a challenge for the use of bulk compositional data for mudrock classification. Extrabasinal detrital quartz supplied along a major axis of siliciclastic influx, the Woodbine depositional system of East Texas, is reduced to a minor part of the grain assemblage in South Texas. Petrographic evidence and point-count results indicate that around 85 percent of total quartz in these rocks, equal to about 12.6 volume percent, is authigenic. Thus, significant quantities of authigenic silica are not restricted to siliceous mudrocks, but can be found in carbonate-rich mudrocks as well. Formerly opaline skeletons of radiolaria, the dominant source of silica for authigenic quartz precipitation, are only poorly preserved by replacements including calcite, dolomite, pyrite, and quartz. Dissolved silica released by dissolution of radiolarians, and perhaps also by volcanic glass dissolution is re-precipitated in a variety of forms, including matrix-dispersed microquartz cement, fillings within primary intragranular pores, and grain replacement of both calcareous and siliceous allochems. The mass balance of dissolved silica mobilized from radiolarians and other reactive silicates and the precipitation of authigenic quartz is uncertain because the initial volumes of now-dissolved detrital material versus the final volume of authigenic material (quartz and other authigenic silicates) cannot be determined with accuracy.

  20. Functional and phylogenetic relatedness in temporary wetland invertebrates: current macroecological patterns and implications for future climatic change scenarios.

    Ruhí, Albert; Boix, Dani; Gascón, Stéphanie; Sala, Jordi; Batzer, Darold P


    In freshwater ecosystems, species compositions are known to be determined hierarchically by large to small‑scale environmental factors, based on the biological traits of the organisms. However, in ephemeral habitats this heuristic framework remains largely untested. Although temporary wetland faunas are constrained by a local filter (i.e., desiccation), we propose its magnitude may still depend on large-scale climate characteristics. If this is true, climate should be related to the degree of functional and taxonomic relatedness of invertebrate communities inhabiting seasonal wetlands. We tested this hypothesis in two ways. First, based on 52 biological traits for invertebrates, we conducted a case study to explore functional trends among temperate seasonal wetlands differing in the harshness (i.e., dryness) of their dry season. After finding evidence of trait filtering, we addressed whether it could be generalized across a broader climatic scale. To this end, a meta-analysis (225 seasonal wetlands spread across broad climatic categories: Arid, Temperate, and Cold) allowed us to identify whether an equivalent climate-dependent pattern of trait richness was consistent between the Nearctic and the Western Palearctic. Functional overlap of invertebrates increased from mild (i.e., Temperate) to harsher climates (i.e., Arid and Cold), and phylogenetic clustering (using taxonomy as a surrogate) was highest in Arid and lowest in Temperate wetlands. We show that, (i) as has been described in streams, higher relatedness than would be expected by chance is generally observed in seasonal wetland invertebrate communities; and (ii) this relatedness is not constant but climate-dependent, with the climate under which a given seasonal wetland is located determining the functional overlap and the phylogenetic clustering of the community. Finally, using a space-for-time substitution approach we suggest our results may anticipate how the invertebrate biodiversity embedded in these

  1. Functional and phylogenetic relatedness in temporary wetland invertebrates: current macroecological patterns and implications for future climatic change scenarios.

    Albert Ruhí

    Full Text Available In freshwater ecosystems, species compositions are known to be determined hierarchically by large to small‑scale environmental factors, based on the biological traits of the organisms. However, in ephemeral habitats this heuristic framework remains largely untested. Although temporary wetland faunas are constrained by a local filter (i.e., desiccation, we propose its magnitude may still depend on large-scale climate characteristics. If this is true, climate should be related to the degree of functional and taxonomic relatedness of invertebrate communities inhabiting seasonal wetlands. We tested this hypothesis in two ways. First, based on 52 biological traits for invertebrates, we conducted a case study to explore functional trends among temperate seasonal wetlands differing in the harshness (i.e., dryness of their dry season. After finding evidence of trait filtering, we addressed whether it could be generalized across a broader climatic scale. To this end, a meta-analysis (225 seasonal wetlands spread across broad climatic categories: Arid, Temperate, and Cold allowed us to identify whether an equivalent climate-dependent pattern of trait richness was consistent between the Nearctic and the Western Palearctic. Functional overlap of invertebrates increased from mild (i.e., Temperate to harsher climates (i.e., Arid and Cold, and phylogenetic clustering (using taxonomy as a surrogate was highest in Arid and lowest in Temperate wetlands. We show that, (i as has been described in streams, higher relatedness than would be expected by chance is generally observed in seasonal wetland invertebrate communities; and (ii this relatedness is not constant but climate-dependent, with the climate under which a given seasonal wetland is located determining the functional overlap and the phylogenetic clustering of the community. Finally, using a space-for-time substitution approach we suggest our results may anticipate how the invertebrate biodiversity

  2. Morphological Characteristics of Detrital Zircon Grains from Source to Sink (Western Australia)

    Markwitz, V.; Kirkland, C.


    Detrital zircon studies have become the tool of choice to address a wide range of geological questions including basin evolution, geodynamic setting, paleogeographic reconstructions, and determining source-sink relationships. However, grain destruction during transportation may be critical in understanding the detrital zircon record, yet it has not been explored in detail. In the magmatic crystallization environment zircon crystal shape is effectively a function of the magma chemistry and temperature. We address to what extent the zircon population represents an artefact of preservation, or a meaningful record of the magmatic events within the source terrain. We use image analysis of previously SIMS U-Pb dated zircon crystals to quantify how zircon grain shapes relate to the chemical composition of magmatic and detrital zircon crystals. We achieve this by testing the correlation between shape factors and the uranium, thorium content, apparent alpha dose, and isotopic signature of individual zircons with statistical methods. We focus our investigation on two different areas of Western Australia: (1) the Archean of the Yilgarn Craton and (2) the Proterozoic of the Musgrave Province, and their associated Proterozoic basin sediments: (1) The Yilgarn craton represents a Neoarchean amalgamation of c. 3.8 Ga and 2.6 Ga granite-greenstone belts including a variety of gneisses, metasedimentary and metavolcanic rock formations, and granites. Along the northern edge of the craton a series of four Proterozoic basins, with variable tectonic and metamorphic overprinting overlay this basement. (2) The West Musgrave Province consists of an east-west trending Meso- to Neoproterozoic belt dominated by granites and volcanics deformed by several major orogenic events between c. 1.35 Ga and 350 Ma. Based on age and Hf isotopic relationships the bedrock of the Musgrave Province is the source for the Neoproterozoic to Early Carboniferous Amadeus Basin to its north. Using rigorous

  3. [Starvation and chemoreception in Antarctic benthic invertebrates].

    Rakusa-Suszczewski, S; Janecki, T; Domanov, M M


    Sensitivity (chemoreception) to different amino acids was studied in six invertebrate species: Serolis polita, Glyptonotus antarcticus, Abyssochromene plebs, Waldeckia obesa, Odontaster validus, and Sterechinus neumayeri. The sensitivity was estimated by the changes in basic metabolism (respiration rate). Starvation increased the sensitivity in all the species. The metabolism rates increased in the presence of L-glutamic acid in G. antarcticus, A. plebs, O. validus, and S. neumayeri. The serine and arginine amino acids had a significant impact on the metabolism of the necrophagous species S. polita and W. obesa. The chemical information may be mediated by means of L-glutamic acid via glutamate receptors, which can be blocked by kynurenic acid, as occurs in the experiments with G. antarcticus and A. plebs.

  4. Impacts of fish farm pollution on ecosystem structure and function of tropical headwater streams.

    Rosa, Rodrigo dos Santos; Aguiar, Anna Carolina Fornero; Boëchat, Iola Gonçalves; Gücker, Björn


    We investigated the impacts of effluent discharge from small flow-through fish farms on stream water characteristics, the benthic invertebrate community, whole-system nitrate uptake, and ecosystem metabolism of three tropical headwater streams in southeastern Brazil. Effluents were moderately, i.e. up to 20-fold enriched in particulate organic matter (POM) and inorganic nutrients in comparison to stream water at reference sites. Due to high dilution with stream water, effluent discharge resulted in up to 2.0-fold increases in stream water POM and up to 1.8-fold increases in inorganic nutrients only. Moderate impacts on the benthic invertebrate community were detected at one stream only. There was no consistent pattern of effluent impact on whole-stream nitrate uptake. Ecosystem metabolism, however, was clearly affected by effluent discharge. Stream reaches impacted by effluents exhibited significantly increased community respiration and primary productivity, stressing the importance of ecologically sound best management practices for small fish farms in the tropics.

  5. Rivers and streams: Ecosystem dynamics and integrating paradigms

    Cummins, K.W.; Wilzbach, M.A.


    Full understanding of running waters requires an ecosystem perspective, which encompasses the physical and chemical setting in interaction with dependent biological communities. Several conceptual models or paradigms of river and stream ecosystems that capture critical components of lotic ecosystems have been developed, including the ‘river continuum concept’, to describe fluxes of matter and energy within the stream or river channel together with exchanges between the channel and its terrestrial setting. A complete ecosystem perspective includes consideration of hierarchical spatial scales in a temporal context. Flow of energy in lotic ecosystems is driven by two alternative energy sources: sunlight regulating in-stream photosynthesis and plant litter derived from the stream-side riparian corridor or floodplain. Energy transfers within the ecosystem pass through micro- and macroproducers (algae and vascular hydrophytes) and micro- and macroconsumers (microorganisms, invertebrates, and vertebrates). Material fluxes encompass the cycling of key nutrients, such as nitrogen and phosphorus, and the transport, storage, and metabolism of dissolved (DOM) and particulate (POM) organic matter (OM). Growth of lotic periphyton (algae and associated microbes, microzoans, and detritus) and coarse (CPOM) and fine (FPOM) particulate organic matter constitute the food resources of nonpredaceous running-water invertebrates (e.g., shredders that consume CPOM and collectors that feed on FPOM and associated microbes of both).

  6. Settling distances of benthic invertebrates in a sediment mobilization simulation in semi-natural flumes

    Maria Cristina Bruno


    Full Text Available Drift time and distance depend on the ability of the drifting invertebrates to alter their body posture or by swimming, and these behaviors may change according to the local hydraulic environment, resulting in different distances travelled before exiting the drift. Such drift and settlement mediated invertebrate movement determine dispersal processes and ultimately generates distribution patterns within streams. We conducted an experiment in an open-air, artificial flume system directly fed by an Alpine stream, where we disturbed the sediment in the flumes, inducing catastrophic drift in the benthic community, and then assessed the settlement distances of benthic invertebrates. For each flume, we collected drift samples by disturbing the substrate at 1.5 m intervals, at increasing distance from the downstream end, for a total of 7 disturbances and a maximum settling distance of 10 m in each flume, with five replicates (i.e., five flumes for each disturbance. The disturbances induced a massive catastrophic drift in Ephemeroptera, Plecoptera and Trichoptera, always higher than the behaviorally-occurring basedrift. The Settling Index calculated over the total drift collected at each distance increased with increasing distance, and after 10 m, 90% of the drifting animals had settled. Evenness and taxa richness progressively decrease with increasing settling distance. All drifting taxa were represented mainly by young instars. We used the drift collected at 1 m from the disturbance to standardize the remaining samples, based on the assumption that 1 m is not a distance long enough to allow animals to settle at that water velocity. We calculated the percentage of possible drifters which settled by computing a Settling Index for each taxon. The drifting taxa listed by decreasing Settling Index scores were Epeorus sp., Rhithrogena semicolorata, Isoperla spp., Sericostoma spp., Ecdyonurus spp., Nemoura spp., Leuctra spp., Baetis spp., Hydropsyche spp

  7. Effects of flow scarcity on leaf-litter processing under oceanic climate conditions in calcareous streams.

    Martínez, Aingeru; Pérez, Javier; Molinero, Jon; Sagarduy, Mikel; Pozo, Jesús


    Although temporary streams represent a high proportion of the total number and length of running waters, historically the study of intermittent streams has received less attention than that of perennial ones. The goal of the present study was to assess the effects of flow cessation on litter decomposition in calcareous streams under oceanic climate conditions. For this, leaf litter of alder was incubated in four streams (S1, S2, S3 and S4) with different flow regimes (S3 and S4 with zero-flow periods) from northern Spain. To distinguish the relative importance and contribution of decomposers and detritivores, fine- and coarse-mesh litter bags were used. We determined processing rates, leaf-C, -N and -P concentrations, invertebrate colonization in coarse bags and benthic invertebrates. Decomposition rates in fine bags were similar among streams. In coarse bags, only one of the intermittent streams, S4, showed a lower rate than that in the other ones as a consequence of lower invertebrate colonization. The material incubated in fine bags presented higher leaf-N and -P concentrations than those in the coarse ones, except in S4, pointing out that the decomposition in this stream was driven mainly by microorganisms. Benthic macroinvertebrate and shredder density and biomass were lower in intermittent streams than those in perennial ones. However, the bags in S3 presented a greater amount of total macroinvertebrates and shredders comparing with the benthos. The most suitable explanation is that the fauna find a food substrate in bags less affected by calcite precipitation, which is common in the streambed at this site. Decomposition rate in coarse bags was positively related to associated shredder biomass. Thus, droughts in streams under oceanic climate conditions affect mainly the macroinvertebrate detritivore activity, although macroinvertebrates may show distinct behavior imposed by the physicochemical properties of water, mainly travertine precipitation, which can

  8. Altitudinal changes in diversity of macroinvertebrates from small streams in the Ecuadorian Andes

    Jacobsen, Dean


    Altitudinal patterns in diversity of macroinvertebrate families at different spatial scales (stone, stream and altitude) were studied by collecting stone samples from six streams at each of the three altitudes: lowlands (400m), midlands (2000m) and highlands (3800 m), in the equatorial Andes...... of Ecuador. Stream sites were characterised by a number of physico-chemical parameters and the fauna by several indices of richness, diversity and evenness. A MDS ordination on the composition of the fauna clearly separated the streams in three groups according to altitude. The invertebrate fauna......). Four of the five measures of stream diversity correlated significantly with altitude and temperature. In addition, seven environmental parameters were correlated with one or more of the diversity measures. Of these parameters, stream width, riparian vegetation cover and coarse detritus cover were inter...

  9. Identifying Catchment-Scale Predictors of Coal Mining Impacts on New Zealand Stream Communities

    Clapcott, Joanne E.; Goodwin, Eric O.; Harding, Jon S.


    Coal mining activities can have severe and long-term impacts on freshwater ecosystems. At the individual stream scale, these impacts have been well studied; however, few attempts have been made to determine the predictors of mine impacts at a regional scale. We investigated whether catchment-scale measures of mining impacts could be used to predict biological responses. We collated data from multiple studies and analyzed algae, benthic invertebrate, and fish community data from 186 stream sites, including un-mined streams, and those associated with 620 mines on the West Coast of the South Island, New Zealand. Algal, invertebrate, and fish richness responded to mine impacts and were significantly higher in un-mined compared to mine-impacted streams. Changes in community composition toward more acid- and metal-tolerant species were evident for algae and invertebrates, whereas changes in fish communities were significant and driven by a loss of nonmigratory native species. Consistent catchment-scale predictors of mining activities affecting biota included the time post mining (years), mining density (the number of mines upstream per catchment area), and mining intensity (tons of coal production per catchment area). Mining was associated with a decline in stream biodiversity irrespective of catchment size, and recovery was not evident until at least 30 years after mining activities have ceased. These catchment-scale predictors can provide managers and regulators with practical metrics to focus on management and remediation decisions.

  10. Identifying Catchment-Scale Predictors of Coal Mining Impacts on New Zealand Stream Communities.

    Clapcott, Joanne E; Goodwin, Eric O; Harding, Jon S


    Coal mining activities can have severe and long-term impacts on freshwater ecosystems. At the individual stream scale, these impacts have been well studied; however, few attempts have been made to determine the predictors of mine impacts at a regional scale. We investigated whether catchment-scale measures of mining impacts could be used to predict biological responses. We collated data from multiple studies and analyzed algae, benthic invertebrate, and fish community data from 186 stream sites, including un-mined streams, and those associated with 620 mines on the West Coast of the South Island, New Zealand. Algal, invertebrate, and fish richness responded to mine impacts and were significantly higher in un-mined compared to mine-impacted streams. Changes in community composition toward more acid- and metal-tolerant species were evident for algae and invertebrates, whereas changes in fish communities were significant and driven by a loss of nonmigratory native species. Consistent catchment-scale predictors of mining activities affecting biota included the time post mining (years), mining density (the number of mines upstream per catchment area), and mining intensity (tons of coal production per catchment area). Mining was associated with a decline in stream biodiversity irrespective of catchment size, and recovery was not evident until at least 30 years after mining activities have ceased. These catchment-scale predictors can provide managers and regulators with practical metrics to focus on management and remediation decisions.

  11. Different cesium-137 transfers to forest and stream ecosystems.

    Sakai, Masaru; Gomi, Takashi; Negishi, Junjiro N; Iwamoto, Aimu; Okada, Kengo


    Understanding the mechanisms of (137)Cs movement across different ecosystems is crucial for projecting the environmental impact and management of nuclear contamination events. Here, we report differential movement of (137)Cs in adjacent forest and stream ecosystems. The food webs of the forest and stream ecosystems in our study were similar, in that they were both dominated by detrital-based food webs and the basal energy source was terrestrial litter. However, the concentration of (137)Cs in stream litter was significantly lower than in forest litter, the result of (137)Cs leaching from litter in stream water. The difference in (137)Cs concentrations between the two types of litter was reflected in the (137)Cs concentrations in the animal community. While the importance of (137)Cs fallout and the associated transfer to food webs has been well studied, research has been primarily limited to cases in a single ecosystem. Our results indicate that there are differences in the flow of (137)Cs through terrestrial and aquatic ecosystems, and that (137)Cs concentrations are reduced in both basal food resources and higher trophic animals in aquatic systems, where primary production is subsidized by a neighboring terrestrial ecosystem.

  12. Shift in detrital sedimentation in the eastern Bay of Bengal during the late Quaternary

    C Prakash Babu; J N Pattan; K Dutta; N Basavaiah; G V Ravi Prasad; D K Ray; P Govil


    Down-core variations of granulometric, geochemical and mineral magnetism of a 70-cm long sediment core retrieved from the eastern Bay of Bengal abyssal region were studied to understand sedimentation pattern and sediment provenance during the last ∼12 kyr BP. Based on down-core physical and elemental variations, three units were identified: unit 3 (70–43 cm) is a ∼30 cm thick clayey silt organic carbon-rich (0.5–0.92%) turbidite probably delivered by the Brahmaputra River during the late Quaternary period. Units 2 (43–24 cm) and 1 (24–0 cm) represent enhanced and reduced supply of coarse-grained detrital sediments from the Ganges River during early and late Holocene period, respectively. Increased terrigenous supply dilutes calcium carbonate (CaCO3) and biogenic elements (P, Ba and Cu) in units 3 and 2. On the contrary, a reduction in detrital input enhances CaCO3 and biogenic elements in unit 1. Lithogenic elements (Ti, Al, K and Rb) and shale-normalized REE patterns in all three units suggest terrigenous source. The shift in provenance from the Brahmaputra to the Ganges derived sediments is evident by a sharp increase in sediment grain size, increased concentration and grain size assemblages of magnetic minerals, lithogenic elements concentration and Lan/Ybn ratio. This study highlights terrigenous dilution on biogenic sedimentation in the eastern Bay of Bengal sediments.

  13. Invertebrate-Based Water Quality Impairments and Associated Stressors Identified through the US Clean Water Act.

    Govenor, Heather; Krometis, Leigh Anne H; Hession, W Cully


    Macroinvertebrate community assessment is used in most US states to evaluate stream health under the Clean Water Act. While water quality assessment and impairment determinations are reported to the US Environmental Protection Agency, there is no national summary of biological assessment findings. The objective of this work was to determine the national extent of invertebrate-based impairments and to identify pollutants primarily responsible for those impairments. Evaluation of state data in the US Environmental Protection Agency's Assessment and Total Maximum Daily Load Tracking and Implementation System database revealed considerable differences in reporting approaches and terminologies including differences in if and how states report specific biological assessment findings. Only 15% of waters impaired for aquatic life could be identified as having impairments determined by biological assessments (e.g., invertebrates, fish, periphyton); approximately one-third of these were associated with macroinvertebrate bioassessment. Nearly 650 invertebrate-impaired waters were identified nationwide, and sediment was the most common pollutant in bedded (63%) and suspended (9%) forms. This finding is not unexpected, given previous work on the negative impacts of sediment on aquatic life, and highlights the need to more specifically identify the mechanisms driving sediment impairments in order to design effective remediation plans. It also reinforces the importance of efforts to derive sediment-specific biological indices and numerical sediment quality guidelines. Standardization of state reporting approaches and terminology would significantly increase the potential application of water quality assessment data, reveal national trends, and encourage sharing of best practices to facilitate the attainment of water quality goals.

  14. Trait-based structure of invertebrates along a gradient of sediment colmation: benthos versus hyporheos responses.

    Descloux, S; Datry, T; Usseglio-Polatera, P


    Streambed colmation by fine sediment, e.g. the deposition, accumulation and storage of fines in the substrate, is known to have severe effects on invertebrate assemblages in both the benthic and hyporheic zones but the changes in biological attributes of invertebrate assemblages related to colmation have never been considered simultaneously for these two zones. We studied the effects of colmation on the invertebrate assemblages of three rivers, testing a priori hypotheses on the biological attributes that should be more selected in communities subjected to different levels of colmation in both zones. Only the proportion of organisms with high fecundity increased and the proportion of small-sized organisms decreased along the colmation gradient in both zones simultaneously. As expected, a higher number of traits were significantly modified with colmation in the benthic vs. hyporheic assemblages. Most of the biological attributes impaired were different in the two zones. In the benthic zone, colmation mainly selected particular physiological or trophic characteristics of species and features related to their resistance or resilience capacities. In contrast, the morphological attributes of species were much more impaired by colmation in the hyporheic zone than in the benthic zone. In clogged benthic habitats, traits seemed to be more impaired by an increase in physico-chemical constraints (e.g. the reduction of oxygen availability) and a reduction of potential exchanges (including exchanges of food resources) due to a decline in stream bed conductivity. The morphological attributes of the hyporheic species were probably more influenced by changes in interstitial space characteristics. A potential indicator of the effects of colmation on river health may be based on the functional traits of benthic communities because they (i) satisfy the WFD recommendations, (ii) respond consistently along a colmation gradient and (iii) are comparable among assemblages even across

  15. Reconstructing the pace and pattern of glacial erosion with detrital thermochronology, Southern Alps of New Zealand

    Lang, Karl; Ehlers, Todd; Ring, Uwe; Kamp, Peter; Glotzbach, Christoph; Stübner, Konstanze


    Erosion by the expansion of mountain glaciers can fundamentally reshape mountain topography to alter local climate dynamics, reorganize river drainages and force allopatric speciation events. Characteristic U-shaped glacial valleys and well-preserved glacial landforms across the eastern flanks of the Southern Alps of New Zealand attest to the dramatic impact of Quaternary glaciation on this dynamic landscape. However, the progressive influence of glacial erosion on the evolution of this landscape, and the redistribution of glacial sediment at its peripheries, remains difficult to constrain from morphological analyses alone. To reconstruct the pace and pattern of glacial erosion within the Southern Alps, we present a comprehensive detrital thermochronological dataset including apatite fission-track and (U-Th)/He analyses from samples of modern river sediment and sedimentary basin units preserved along the eastern flanks of the mountains. We interpret erosion patterns in five catchments east of the main drainage divide from detrital cooling age populations in samples of modern river sediment. Published bedrock analyses demonstrate that partial annealing and partial retention zones for the apatite fission-track and (U-Th)/He mineral systems, respectively, have been exhumed within each catchment area. Consequently, cooling ages predictably increase from fully reset ages (typically ages (up to 80 Ma) with eastward distance from the Alpine Fault and increasing elevation. We exploit this predictive relationship between cooling age, eastward distance and elevation to map the source of modern sediment across the eastern flanks of the range. Exhumation of these partial annealing and retention zones east of the main drainage divide is further manifest in the appearance of reset cooling ages within peripheral basin sediments. To reconstruct the pace of Southern Alps exhumation, we further analyze detrital mineral lag-times preserved in late Miocene-Pleistocene peripheral basin

  16. Detrital zircon U-Pb geochronology and provenance of the Carboniferous-Permian glaciomarine pebbly slates in the Tibetan Plateau

    Wang, Q.; Zhu, D.; Zhao, Z.; Chung, S.; Li, C.; Sui, Q.; Fu, X.; Mo, X.


    Glaciomarine diamictites (including pebbly slate, pebbly siltstone, and pebbly sandstone) in the Tibetan Plateau are widely interpreted to have been associated with the deglaciation of the Indian continent. Guiding by zircon cathodoluminescence images, we determined U-Pb ages for detrital zircons from five typical Carboniferous-Permian pebbly slate samples from the Qiangtang, Lhasa, and Tethyan Himalaya of the Tibetan Plateau. The age distributions of detrital zircons from two samples (180 analyses) from Qiwu and Gangma Tso of the Qiangtang Terrane are similar, with two main age peaks ca. 579 and ca. 816 Ma and one minor age peak ca. 2490 Ma. Two samples (177 analyses) from Jiangrang and Damxung of the Lhasa Terrane define similar age distributions with two main age peaks ca. 539 and ca. 1175 Ma. Ages of detrital zircons from one sample (110 analyses) from Kangmar of the Tethyan Himalaya display main age peaks ca. 535, ca. 949, and ca. 2490 Ma. The ca. 816-Ma detrital zircons from the Qiangtang Terrane were most likely derived from the Lesser Himalaya, and the ca. 950-Ma detrital zircons from the Tethyan Himalaya might have been sourced from the High Himalaya, Eastern Ghats Province of the Indian plate and the Rayner Province of East Antarctica. The distinctive ca. 1175-Ma age population characteristic of zircons in the pebbly slates from the Lhasa Terrane is identical to the detrital zircons from the late Paleozoic sandstones (Zhu et al., 2011a) and the inherited zircons from the Mesozoic peraluminous granites (Zhu et al., 2011b) in this terrane, but significantly absent in the pebbly slates from both the Qiangtang and the Tethyan Himalayan terranes. The ca. 1175-Ma detrital zircons in the Lhasa Terrane were most likely sourced from the Albany-Fraser-Wilkes in southwestern Australia and East Antarctica. These new data obtained in this study reveal a distinct difference of detrital zircon provenance for the coeval Carboniferous-Permian glaciomarine pebbly slates

  17. Evaluating effects of potential changes in streamflow regime on fish and aquatic-invertebrate assemblages in the New Jersey Pinelands

    Kennen, Jonathan G.; Riskin, Melissa L.


    Changes in water demand associated with population growth and changes in land-use practices in the Pinelands region of southern New Jersey will have a direct effect on stream hydrology. The most pronounced and measurable hydrologic effect is likely to be flow reductions associated with increasing water extraction. Because water-supply needs will continue to grow along with population in the Pinelands area, the goal of maintaining a sustainable balance between the availability of water to protect existing aquatic assemblages while conserving the surficial aquifer for long-term support of human water use needs to be addressed. Although many aquatic fauna have shown resilience and resistance to short-term changes in flows associated with water withdrawals, sustained effects associated with ongoing water-development processes are not well understood. In this study, the U.S. Geological Survey sampled forty-three 100-meter-long stream reaches during high- and low-flow periods across a designed hydrologic gradient ranging from small- (4.1 square kilometers (1.6 square miles)) to medium- (66.3 square kilometers (25.6 square miles)) sized Pinelands stream basins. This design, which uses basin size as a surrogate for water availability, provided an opportunity to evaluate the possible effects of potential variation in stream hydrology on fish and aquatic-invertebrate assemblage response in New Jersey Pinelands streams where future water extraction is expected based on known build-out scenarios. Multiple-regression models derived from extracted non-metric multidimensional scaling axis scores of fish and aquatic invertebrates indicate that some variability in aquatic-assemblage composition across the hydrologic gradient is associated with anthropogenic disturbance, such as urbanization, changes in stream chemistry, and concomitant changes in high-flow runoff patterns. To account for such underlying effects in the study models, any flow parameter or assemblage attribute that

  18. Water Temperature, Invertebrate Drift, and the Scope for Growth for Juvenile Spring Chinook Salmon.

    Lovtang, J. C.; Li, H. W.


    We present a bioenergetic assessment of habitat quality based on the concept of the scope for growth for juvenile Chinook salmon. Growth of juvenile salmonids during the freshwater phase of their life history depends on a balance between two main factors: energy intake and metabolic costs. The metabolic demands of temperature and the availability of food play integral roles in determining the scope for growth of juvenile salmonids in stream systems. We investigated differences in size of juvenile spring Chinook salmon in relation to water temperature and invertebrate drift density in six unique study reaches in the Metolius River Basin, a tributary of the Deschutes River in Central Oregon. This project was initiated to determine the relative quality and potential productivity of habitat in the Metolius Basin prior to the reintroduction of spring Chinook salmon, which were extirpated from the middle Deschutes basin in the early 1970's due to the construction of a hydroelectric dam. Variations in the growth of juvenile Chinook salmon can be described using a multiple regression model of water temperature and invertebrate drift density. We also discuss the relationships between our bioenergetic model, variations of the ideal free distribution model, and physiological growth models.

  19. Seasonality, water quality trends and biological responses in four streams in the Cairngorm Mountains, Scotland

    C. Soulsby


    Full Text Available The chemical composition and invertebrate communities found in four streams in the Cairngorms, Scotland, were monitored between 1985-1997. Stream waters were mildly acidic (mean pH ca. 6.5, with low alkalinity (mean acid neutralising capacity varying from 35-117 meq l-1 and low ionic strength. Subtle differences in the chemistry of each stream were reflected in their invertebrate faunas. Strong seasonality in water chemistry occurred, with the most acid, low alkalinity waters observed during the winter and early spring. This was particularly marked during snowmelt between January and April. In contrast, summer flows were usually groundwater dominated and characterised by higher alkalinity and higher concentrations of most other weathering-derived solutes. Seasonality was also clear in the invertebrate data, with Canonical Correspondence Analysis (CCA separating seasonal samples along axes related to water temperature and discharge characteristics. Inter-annual hydrological and chemical differences were marked, particularly with respect to the winter period. Invertebrate communities found in each of the streams also varied from year to year, with spring communities significantly more variable (PHydrochemical trends over the study period were analysed using a seasonal Kendall test, LOcally WEighted Scatterplot Smoothing (LOWESS and graphical techniques. These indicated that a reduction in sulphate concentrations in stream water is occurring, consistent with declining levels of atmospheric deposition. This may be matched by increases in pH and declining calcium concentrations, though available evidence is inconclusive. Other parameters, such as chloride, total organic carbon and zinc, reveal somewhat random patterns, probably reflecting irregular variations in climatic factors and/or atmospheric deposition. Previous studies have shown that the stream invertebrate communities have remained stable over this period (i.e. no significant linear trends

  20. Prioritized Contact Transport Stream

    Hunt, Walter Lee, Jr. (Inventor)


    A detection process, contact recognition process, classification process, and identification process are applied to raw sensor data to produce an identified contact record set containing one or more identified contact records. A prioritization process is applied to the identified contact record set to assign a contact priority to each contact record in the identified contact record set. Data are removed from the contact records in the identified contact record set based on the contact priorities assigned to those contact records. A first contact stream is produced from the resulting contact records. The first contact stream is streamed in a contact transport stream. The contact transport stream may include and stream additional contact streams. The contact transport stream may be varied dynamically over time based on parameters such as available bandwidth, contact priority, presence/absence of contacts, system state, and configuration parameters.

  1. StreamCat

    U.S. Environmental Protection Agency — The StreamCat Dataset provides summaries of natural and anthropogenic landscape features for ~2.65 million streams, and their associated catchments, within the...

  2. Invertebrate sampling at Fish Springs National Wildlife Refuge

    US Fish and Wildlife Service, Department of the Interior — This document presents results from an invertebrate study conducted on Fish Springs National Wildlife Refuge. The purposes of this study were to: 1) quanitify...

  3. A Taxonomic and Ecological Survey of Aquatic Invertebrates

    US Fish and Wildlife Service, Department of the Interior — This study consisted of the identification and ecological distribution of macroscopic aquatic invertebrates from a pond, empounded by a beaver dam, located at the...

  4. South Florida Seagrass Fish and Invertebrate Assessment Network (FIAN)

    U.S. Geological Survey, Department of the Interior — The South Florida Fish and Invertebrate Assessment Network (FIAN) is a monitoring project within the Comprehensive Everglades Restoration Plan (CERP). It is an...

  5. Aquatic invertebrates doubly suspect in spreading duck malady : 1958

    US Fish and Wildlife Service, Department of the Interior — A 1958 news release providing a brief overview of the U.S. Fish and Wildlife Service's findings regarding the role aquatic invertebrates play in the spread of avian...

  6. Coastal Resources Atlas: Long Island: INVERT (Invertebrate Polygons)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for coastal, estuarine, and marine invertebrate species for Long Island, New York. Vector polygons in this...

  7. Macro-invertebrate and Avian Species Survey : Biological Summary Report

    US Fish and Wildlife Service, Department of the Interior — This was a survey effort to determine species diversity and density of macro-invertebrates and avian species inhabiting playa systems located in SW regions of Baca...

  8. Guam and the Northern Mariana Islands ESI: INVERT (Invertebrate Polygons)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for intertidal-, reef-, and mangrove-associated invertebrate species in Guam and the Northern Mariana...

  9. Soil invertebrates as bioindicators of urban soil quality.

    Santorufo, Lucia; Van Gestel, Cornelis A M; Rocco, Annamaria; Maisto, Giulia


    This study aimed at relating the abundance and diversity of invertebrate communities of urban soils to chemical and physical soil characteristics and to identify the taxa most sensitive or tolerant to soil stressors. The invertebrate community of five urban soils in Naples, Italy, was sampled. To assess soil quality invertebrate community indices (Shannon, Simpson, Menhinick and Pielou indices), Acarina/Collembola ratios, and the soil biological quality index (QBS) were calculated. The chemical and physical characteristics of the soils strongly differed. Abundance rather than taxa richness of invertebrates were more affected by soil characteristics. The community was more abundant and diverse in the soils with high organic matter and water content and low metal (Cu, Pb, Zn) concentrations. The taxa more resistant to the urban environment included Acarina, Enchytraeids, Collembola and Nematoda. Collembolans appeared particularly sensitive to changing soil properties. Among the investigated indices, QBS seems most appropriate for soil quality assessment. Copyright © 2011 Elsevier Ltd. All rights reserved.

  10. Bristol Bay, Alaska Subarea ESI: INVERT (Invertebrate Polygons)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for marine and estuarine invertebrate species in the Bristol Bay Subarea. The Subarea includes marine and...

  11. Immune-neuroendocrine biology of invertebrates: a collection of methods

    L Ballarin


    Full Text Available In the last decade there has been a considerable increase of interest towards the elucidation of several aspects of invertebrate biology, including immunity and neuroendocrinology. However, due to the difficulties connected to the great variety of morphology and adaptations displayed by invertebrates, and also in consideration of the number of techniques that are applied in the various laboratories, research on invertebrates still suffers from hampering that have been substantially overcome in vertebrate models, especially in mammals. The aim of this Technical Report is to provide the reader a useful list of well-established morphological and morpho-functional protocols in order to facilitate the design and make more homogeneous the realization of experiments in the field of invertebrate immune-neuroendocrinology.

  12. Querying JSON Streams

    Bo, Yang


    A data stream management system (DSMS) is similar to a database management system (DBMS) but can search data directly in on-line streams. Using its mediator-wrapper approach, the extensible database system, Amos II, allows different kinds of distributed data resource to be queried. It has been extended with a stream datatype to query possibly infinite streams, which provides DSMS functionality. Nowadays, more and more web applications start to offer their services in JSON format which is a te...

  13. Cryptic speciation in a model invertebrate chordate.

    Caputi, Luigi; Andreakis, Nikos; Mastrototaro, Francesco; Cirino, Paola; Vassillo, Mauro; Sordino, Paolo


    We applied independent species concepts to clarify the phylogeographic structure of the ascidian Ciona intestinalis, a powerful model system in chordate biology and for comparative genomic studies. Intensive research with this marine invertebrate is based on the assumption that natural populations globally belong to a single species. Therefore, understanding the true taxonomic classification may have implications for experimental design and data management. Phylogenies inferred from mitochondrial and nuclear DNA markers accredit the existence of two cryptic species: C. intestinalis sp. A, genetically homogeneous, distributed in the Mediterranean, northeast Atlantic, and Pacific, and C. intestinalis sp. B, geographically structured and encountered in the North Atlantic. Species-level divergence is further entailed by cross-breeding estimates. C. intestinalis A and B from allopatric populations cross-fertilize, but hybrids remain infertile because of defective gametogenesis. Although anatomy illustrates an overall interspecific similarity lacking in diagnostic features, we provide consistent tools for in-field and in-laboratory species discrimination. Finding of two cryptic taxa in C. intestinalis raises interest in a new tunicate genome as a gateway to studies in speciation and ecological adaptation of chordates.

  14. Mephedrone ("bath salt") pharmacology: insights from invertebrates.

    Ramoz, L; Lodi, S; Bhatt, P; Reitz, A B; Tallarida, C; Tallarida, R J; Raffa, R B; Rawls, S M


    Psychoactive bath salts (also called meph, drone, meow meow, m-CAT, bounce, bubbles, mad cow, etc.) contain a substance called mephedrone (4-methylcathinone) that may share psychostimulant properties with amphetamine and cocaine. However, there are only limited studies of the neuropharmacological profile of mephedrone. The present study used an established invertebrate (planarian) assay to test the hypothesis that acute and repeated mephedrone exposure produces psychostimulant-like behavioral effects. Acute mephedrone administration (50-1000 μM) produced stereotyped movements that were attenuated by a dopamine receptor antagonist (SCH 23390) (0.3 μM). Spontaneous discontinuation of mephedrone exposure (1, 10 μM) (60 min) resulted in an abstinence-induced withdrawal response (i.e. reduced motility). In place conditioning experiments, planarians in which mephedrone (100, 500 μM) was paired with the non-preferred environment during conditioning displayed a shift in preference upon subsequent testing. These results suggest that mephedrone produces three behavioral effects associated with psychostimulant drugs, namely dopamine-sensitive stereotyped movements, abstinence-induced withdrawal, and environmental place conditioning.

  15. Insight into Invertebrate Defensin Mechanism of Action

    Schmitt, Paulina; Wilmes, Miriam; Pugnière, Martine; Aumelas, André; Bachère, Evelyne; Sahl, Hans-Georg; Schneider, Tanja; Destoumieux-Garzón, Delphine


    Three oyster defensin variants (Cg-Defh1, Cg-Defh2, and Cg-Defm) were produced as recombinant peptides and characterized in terms of activities and mechanism of action. In agreement with their spectrum of activity almost specifically directed against Gram-positive bacteria, oyster defensins were shown here to be specific inhibitors of a bacterial biosynthesis pathway rather than mere membrane-active agents. Indeed, at lethal concentrations, the three defensins did not compromise Staphylococcus aureus membrane integrity but inhibited the cell wall biosynthesis as indicated by the accumulation of the UDP-N-acetylmuramyl-pentapeptide cell wall precursor. In addition, a combination of antagonization assays, thin layer chromatography, and surface plasmon resonance measurements showed that oyster defensins bind almost irreversibly to the lipid II peptidoglycan precursor, thereby inhibiting the cell wall biosynthesis. To our knowledge, this is the first detailed analysis of the mechanism of action of antibacterial defensins produced by invertebrates. Interestingly, the three defensins, which were chosen as representative of the oyster defensin molecular diversity, bound differentially to lipid II. This correlated with their differential antibacterial activities. From our experimental data and the analysis of oyster defensin sequence diversity, we propose that oyster defensin activity results from selective forces that have conserved residues involved in lipid II binding and diversified residues at the surface of oyster defensins that could improve electrostatic interactions with the bacterial membranes. PMID:20605792

  16. An invertebrate model for CNS drug discovery

    Al-Qadi, Sonia; Schiøtt, Morten; Hansen, Steen Honoré


    BACKGROUND: ABC efflux transporters at the blood brain barrier (BBB), namely the P-glycoprotein (P-gp), restrain the development of central nervous system (CNS) drugs. Consequently, early screening of CNS drug candidates is pivotal to identify those affected by efflux activity. Therefore, simple,...... barriers. CONCLUSION: Findings suggest a conserved mechanism of brain efflux activity between insects and vertebrates, confirming that this model holds promise for inexpensive and high-throughput screening relative to in vivo models, for CNS drug discovery......., high-throughput and predictive screening models are required. The grasshopper (locust) has been developed as an invertebrate in situ model for BBB permeability assessment, as it has shown similarities to vertebrate models. METHODS: Transcriptome profiling of ABC efflux transporters in the locust brain......BACKGROUND: ABC efflux transporters at the blood brain barrier (BBB), namely the P-glycoprotein (P-gp), restrain the development of central nervous system (CNS) drugs. Consequently, early screening of CNS drug candidates is pivotal to identify those affected by efflux activity. Therefore, simple...

  17. Long-term effects of beach nourishment on intertidal invertebrates

    Wooldridge, Tyler Brock


    Although beach nourishment is an increasingly popular means to remediate coastal erosion, no consensus exists regarding how long nourishment affects sandy beach intertidal invertebrates, key components of sandy beach ecosystems. We monitored the intertidal invertebrate community for fifteen months following a nourishment project at eight beaches across San Diego County. Each beach was split into nourished and control sections. Nearly all taxa showed major declines in abundance immediately fol...

  18. Effects of neonicotinoids and fipronil on non-target invertebrates.

    Pisa, L W; Amaral-Rogers, V; Belzunces, L P; Bonmatin, J M; Downs, C A; Goulson, D; Kreutzweiser, D P; Krupke, C; Liess, M; McField, M; Morrissey, C A; Noome, D A; Settele, J; Simon-Delso, N; Stark, J D; Van der Sluijs, J P; Van Dyck, H; Wiemers, M


    We assessed the state of knowledge regarding the effects of large-scale pollution with neonicotinoid insecticides and fipronil on non-target invertebrate species of terrestrial, freshwater and marine environments. A large section of the assessment is dedicated to the state of knowledge on sublethal effects on honeybees (Apis mellifera) because this important pollinator is the most studied non-target invertebrate species. Lepidoptera (butterflies and moths), Lumbricidae (earthworms), Apoidae sensu lato (bumblebees, solitary bees) and the section "other invertebrates" review available studies on the other terrestrial species. The sections on freshwater and marine species are rather short as little is known so far about the impact of neonicotinoid insecticides and fipronil on the diverse invertebrate fauna of these widely exposed habitats. For terrestrial and aquatic invertebrate species, the known effects of neonicotinoid pesticides and fipronil are described ranging from organismal toxicology and behavioural effects to population-level effects. For earthworms, freshwater and marine species, the relation of findings to regulatory risk assessment is described. Neonicotinoid insecticides exhibit very high toxicity to a wide range of invertebrates, particularly insects, and field-realistic exposure is likely to result in both lethal and a broad range of important sublethal impacts. There is a major knowledge gap regarding impacts on the grand majority of invertebrates, many of which perform essential roles enabling healthy ecosystem functioning. The data on the few non-target species on which field tests have been performed are limited by major flaws in the outdated test protocols. Despite large knowledge gaps and uncertainties, enough knowledge exists to conclude that existing levels of pollution with neonicotinoids and fipronil resulting from presently authorized uses frequently exceed the lowest observed adverse effect concentrations and are thus likely to have large

  19. Biological control using invertebrates and microorganisms: plenty of new opportunities

    Lenteren, van, J.C.; Bolckmans,Karel; Kohl, Jurgen; Ravensberg, Willem J.; Urbaneja, Alberto


    In augmentative biological control (ABC), invertebrate and microbial organisms are seasonally released in large numbers to reduce pests. Today it is applied on more than 30 million ha worldwide. Europe is the largest commercial market for invertebrate biological control agents, while North America has the largest sales of microbials. A strong growth in use of ABC, particularly of microbial agents, is taking place in Latin America, followed by Asia. The current popularity of ABC is due to (1) ...

  20. Importance of terrestrial arthropods as subsidies in lowland Neotropical rain forest stream ecosystems

    Small, Gaston E.; Torres, Pedro J.; Schwizer, Lauren M.; Duff, John H.; Pringle, Catherine M.


    The importance of terrestrial arthropods has been documented in temperate stream ecosystems, but little is known about the magnitude of these inputs in tropical streams. Terrestrial arthropods falling from the canopy of tropical forests may be an important subsidy to tropical stream food webs and could also represent an important flux of nitrogen (N) and phosphorus (P) in nutrient-poor headwater streams. We quantified input rates of terrestrial insects in eight streams draining lowland tropical wet forest in Costa Rica. In two focal headwater streams, we also measured capture efficiency by the fish assemblage and quantified terrestrially derived N- and P-excretion relative to stream nutrient uptake rates. Average input rates of terrestrial insects ranged from 5 to 41 mg dry mass/m2/d, exceeding previous measurements of aquatic invertebrate secondary production in these study streams, and were relatively consistent year-round, in contrast to values reported in temperate streams. Terrestrial insects accounted for half of the diet of the dominant fish species, Priapicthys annectens. Although terrestrially derived fish excretion was found to be a small flux relative to measured nutrient uptake rates in the focal streams, the efficient capture and processing of terrestrial arthropods by fish made these nutrients available to the local stream ecosystem. This aquatic-terrestrial linkage is likely being decoupled by deforestation in many tropical regions, with largely unknown but potentially important ecological consequences.

  1. Leaf Breakdown in a Tropical Stream

    Gonçalves, José Francisco, Jr.; França, Juliana S.; Medeiros, Adriana O.; Rosa, Carlos A.; Callisto, Marcos


    The objectives of this study were to investigate leaf breakdown in two reaches of different magnitudes, one of a 3rd (closed riparian vegetation) order and the other of a 4th (open riparian vegetation) order, in a tropical stream and to assess the colonization of invertebrates and microorganisms during the processing of detritus. We observed that the detritus in a reach of 4th order decomposed 2.4 times faster than the detritus in a reach of 3rd order, in which, we observed that nitrate concentration and water velocity were greater. This study showed that the chemical composition of detritus does not appear to be important in evaluating leaf breakdown. However, it was shown to be important to biological colonization. The invertebrate community appeared not to have been structured by the decomposition process, but instead by the degradative ecological succession process. With regards to biological colonization, we observed that the density of bacteria in the initial stages was more important while fungi appeared more in the intermediate and final stages.

  2. Productivity of Stream Definitions

    Endrullis, Jörg; Grabmayer, Clemens; Hendriks, Dimitri; Isihara, Ariya; Klop, Jan


    We give an algorithm for deciding productivity of a large and natural class of recursive stream definitions. A stream definition is called ‘productive’ if it can be evaluated continuously in such a way that a uniquely determined stream is obtained as the limit. Whereas productivity is undecidable

  3. Productivity of stream definitions

    Endrullis, J.; Grabmayer, C.A.; Hendriks, D.; Isihara, A.; Klop, J.W.


    We give an algorithm for deciding productivity of a large and natural class of recursive stream definitions. A stream definition is called ‘productive’ if it can be evaluated continually in such a way that a uniquely determined stream in constructor normal form is obtained as the limit. Whereas prod

  4. Impact of mineral fertility and bedrock erosion on single-mineral detrital studies: insights from trace-element and Nd-isotope systematics of detrital apatite from the Po River catchment

    Malusa', Marco Giovanni; Wang, Jiangang; Garzanti, Eduardo; Villa, Igor M.; Wittman, Hella


    The detrital record provides an archive of mountain erosion that preserves key information for paleotectonic and paleoclimatic reconstructions. Detrital studies are often based on single-mineral analyses (e.g., geo/thermochronologic analyses on apatite and zircon). Their geologic interpretation can be challenging, because the impact of each eroding source on the detrital record is controlled by a range of factors including the rate of erosion and the fertility of chosen minerals in eroded bedrock. Here, we combine (i) a state-of-the art dataset of trace element and Nd isotope fingerprints of detrital apatite, (ii) a comprehensive dataset of apatite-fertility measurements (Malusà et al. 2016), (iii) fission-track data, and (iv) cosmogenic-derived erosion rates from the Po River catchment (Wittmann et al. 2016), to test the impact of mineral fertility and bedrock erosion on the single-mineral detrital signal preserved in the final sediment sink. Our results show that the information provided by accessory minerals, when complemented with accurate mineral fertility measurements, are fully consistent with information provided by the analysis of more abundant framework minerals. We found that trace element and Nd isotope analyses provide a reliable tool to disentangle the complex single-mineral record of orogenic erosion, and demonstrate that such a record is largely determined by high-fertility source rocks exposed within the drainage. Detrital thermochronology studies based on the lag-time approach should thus preferably include independent provenance discriminations and a full mineral fertility characterization of the potential source areas, in order to ensure a correct identification of the sediment sources and of the exogenic and endogenic processes monitored in the stratigraphic archive. Malusà M.G., Resentini A., Garzanti E., 2016. Hydraulic sorting and mineral fertility bias in detrital geochronology. Gondwana Res., 31, 1-19 Wittmann H., Malusà M.G., Resentini

  5. Diagenetic and detrital origin of moretane anomalies through the Permian-Triassic boundary

    French, Katherine L.; Tosca, Nicholas J.; Cao, Changqun; Summons, Roger E.


    Many biogeochemical anomalies coincide with the Late Permian Extinction (LPE; 252.28 Ma). Several mechanisms have been proposed to explain the moretane/hopane anomaly that has been identified in samples from Meishan GSSP section in southeastern China. Here, we report homohopane, 2α- and 3β-methylhomohopane and lithological data for a drill core from the Meishan section in southeastern China. Three intervals of elevated C30 moretane/hopane ratios are recorded in the Lungtan, Yinkeng and Helongshan Formations. Moretane/hopane ratios of C31-34 homohopanes and the 2α- and 3β-methylhomohopanes display the same stratigraphic patterns as the C30 moretane/hopane record. In light of the multiple and parallel moretane anomalies for the homohopane and 2α- and 3β-methylhomohopane series, enhanced input from higher plant organic matter, such as coal and peat, does not adequately explain the observed isomer patterns. Correlation of high moretane/hopane ratios with low C35 Homohopane Index (HHI) and high hopane/sterane values suggest increased input of hopanoids from oxic soils. Additionally, moretane/hopane ratios show excellent correlations with total clay percentages and specific clay types, particularly chlorite, illite, and mixed layer illite/smectite. We conclude that a combination of episodic hopanoid input from soil bacteria and diagenetic effects related to redox and detrital clays generated the unique moretane/hopane patterns at Meishan. Similar relationships of Ts/(Ts + Tm) with redox, source indicators, and lithology indicate that Ts/(Ts + Tm) is affected by the same factors controlling the moretane/hopane ratios. Berthierine, a clay that requires reducing conditions for formation, was detected in samples from the Lungtan Formation. We are unable to determine from our results whether the berthierine is authigenic or detrital, but future determination of the origin of berthierine at Meishan may offer additional environmental insight. No link between diasteranes

  6. A thorium isotope proxy for reconstructing dissolved detrital inputs to the ocean

    McManus, J. F.; Robinson, L. F.; Noble, T. L.; Henderson, G. M.


    We have developed a tracer of dissolved detrital inputs to seawater based on thorium isotopes adsorbed from seawater onto settling marine particles. Thorium is extremely insoluble, yet occurs in all ocean waters in abundances that are measurable by ICP-MS mass spectrometry. Thorium-232 is derived exclusively from the partial dissolution of detritus, which in distal open-ocean settings is predominantly delivered through eolian transport. Thorium-230 is produced everywhere in the ocean at a well-constrained rate by the decay of dissolved uranium. The 232/230 ratio of adsorbed thorium, isolated from lattice-bound thorium, may be used to reconstruct the local water column thorium profiles, which are in turn controlled by dissolved detrital input. The water column reconstructions are independent of detrital accumulation records, including those captured in high latitude ice cores, and can thus be focused on relevant regions of the ocean. This new tracer may be used to evaluate a variety of scenarios regarding the ocean and atmosphere of the past, including dust fertilization schemes that link variations in paleo-productivity with changes in atmospheric carbon dioxide and global climate. The half-lives of both thorium isotopes are long enough to allow us to use our approach on sediments that span several glacial-interglacial cycles. Initial investigations indicate that we are successful in isolating the adsorbed (seawater) thorium using a range of progressively vigorous chemical leaching steps with variable yield, but constant isotopic ratio. Recent sediments from a N-S transect of the Southern Ocean, the subpolar North Pacific, the subtropical North Atlantic, and the tropical Atlantic yield thorium ratios that are similar to nearby water column profiles. Preliminary downcore results display higher thorium 232/230 ratios that are consistent with enhanced ice-age dust deposition. However the two- to four-fold glacial increases indicated by the thorium isotope proxy are

  7. Conservation and monitoring of invertebrates in terrestrial protected areas

    Melodie A. McGeoch


    Full Text Available Invertebrates constitute a substantial proportion of terrestrial and freshwater biodiversity and are critical to ecosystem function. However, their inclusion in biodiversity monitoring and conservation planning and management has lagged behind better-known, more widely appreciated taxa. Significant progress in invertebrate surveys, systematics and bioindication, both globally and locally, means that their use in biodiversity monitoring and conservation is becoming increasingly feasible. Here we outline challenges and solutions to the integration of invertebrates into biodiversity management objectives and monitoring in protected areas in South Africa. We show that such integration is relevant and possible, and assess the relative suitability of seven key taxa in this context. Finally, we outline a series of recommendations for mainstreaming invertebrates in conservation planning, surveys and monitoring in and around protected areas.Conservation implications: Invertebrates constitute a substantial and functionally significant component of terrestrial biodiversity and are valuable indicators of environmental condition. Although consideration of invertebrates has historically been neglected in conservation planning and management, substantial progress with surveys, systematics and bioindication means that it is now both feasible and advisable to incorporate them into protected area monitoring activities.

  8. Chemical elements in invertebrate orders for environmental quality studies

    Magalhaes, Marcelo R.L.; Franca, Elvis J.; Paiva, Jose D.S.; Hazin, Clovis A., E-mail:, E-mail:, E-mail:, E-mail: [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Fonseca, Felipe Y.; Fernandes, Elisabete A. de Nadai; Bacchi, Marcio A., E-mail:, E-mail:, E-mail: [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil)


    Among the biomonitors of environmental quality, there is a lack of studies on using invertebrates to evaluate quantitatively chemical elements in ecosystems. This group of animals is quite numerous, widely distributed and adaptable to the most diverse environmental conditions. These features are very useful for the environmental quality assessment, as well as the several occurring insect-plant interactions performing essential functions in ecosystems. The objective of this work is to study the variability of chemical composition of invertebrate orders for using in environmental quality monitoring studies. Instrumental neutron activation analysis - INAA was applied to determine some nutrients and trace elements in invertebrate samples. Sampling by pitfall traps was carried out in riverine ecosystems from the urban area from the Piracicaba Municipality, State of Sao Paulo, Brazil. Invertebrate and reference material samples were irradiated in the nuclear research reactor IEA-R1, Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN. Fragments of a Ni-Cr alloy were irradiated for monitoring the thermal neutron flux. Hymenoptera order was considered the most representative according to the total number of sampled species (about 60%). Significant amounts of Ba, Br, Fe and Sc were found in invertebrates of the order Opiliones. Potassium, rubidium and zinc were highly accumulated in species from Blattodea order, indicating a consistent pattern of accumulation for this invertebrate order. Taking into account the abundance of Hymenoptera order, the chemical composition of its species was significant different at the 95% confidence level for Br and Na in the sampled locals. (author)

  9. Invertebrate distribution patterns and river typology for the implementation of the water framework directive in Martinique, French Lesser Antilles

    Bernadet C.


    Full Text Available Over the past decade, Europe’s Water Framework Directive provided compelling reasons for developing tools for the biological assessment of freshwater ecosystem health in member States. Yet, the lack of published study for Europe’s overseas regions reflects minimal knowledge of the distribution patterns of aquatic species in Community’s outermost areas. Benthic invertebrates (84 taxa and land-cover, physical habitat and water chemistry descriptors (26 variables were recorded at fifty-one stations in Martinique, French Lesser Antilles. Canonical Correspondence Analysis and Ward’s algorithm were used to bring out patterns in community structure in relation to environmental conditions, and variation partitioning was used to specify the influence of geomorphology and anthropogenic disturbance on invertebrate communities. Species richness decreased from headwater to lowland streams, and species composition changed from northern to southern areas. The proportion of variation explained by geomorphological variables was globally higher than that explained by anthropogenic variables. Geomorphology and land cover played key roles in delineating ecological sub-regions for the freshwater biota. Despite this and the small surface area of Martinique (1080 km2, invertebrate communities showed a clear spatial turnover in composition and biological traits (e.g., insects, crustaceans and molluscs in relation to natural conditions.

  10. Toxicity, sublethal effects, and potential modes of action of select fungicides on freshwater fish and invertebrates

    Elskus, Adria A.


    Despite decades of agricultural and urban use of fungicides and widespread detection of these pesticides in surface waters, relatively few data are available on the effects of fungicides on fish and invertebrates in the aquatic environment. Nine fungicides are reviewed in this report: azoxystrobin, boscalid, chlorothalonil, fludioxonil, myclobutanil, fenarimol, pyraclostrobin, pyrimethanil, and zoxamide. These fungicides were identified as emerging chemicals of concern because of their high or increasing global use rates, detection frequency in surface waters, or likely persistence in the environment. A review of the literature revealed significant sublethal effects of fungicides on fish, aquatic invertebrates, and ecosystems, including zooplankton and fish reproduction, fish immune function, zooplankton community composition, metabolic enzymes, and ecosystem processes, such as leaf decomposition in streams, among other biological effects. Some of these effects can occur at fungicide concentrations well below single-species acute lethality values (48- or 96-hour concentration that effects a response in 50 percent of the organisms, that is, effective concentration killing 50 percent of the organisms in 48 or 96 hours) and chronic sublethal values (for example, 21-day no observed adverse effects concentration), indicating that single-species toxicity values may dramatically underestimate the toxic potency of some fungicides. Fungicide modes of toxic action in fungi can sometimes reflect the biochemical and (or) physiological effects of fungicides observed in vertebrates and invertebrates; however, far more studies are needed to explore the potential to predict effects in nontarget organisms based on specific fungicide modes of toxic action. Fungicides can also have additive and (or) synergistic effects when used with other fungicides and insecticides, highlighting the need to study pesticide mixtures that occur in surface waters. For fungicides that partition to

  11. Habitat-mediated cannibalism and microhabitat restriction in the stream invertebrate Gammarus pulex

    McGrath, K.E.; Peeters, E.T.H.M.; Beijer, J.A.J.; Scheffer, M.


    In cannibalistic species, small individuals often shift habitats to minimize risk of predation by larger conspecifics. The availability of diverse size-structured habitats may mediate the incidence of cannibalism by larger individuals on smaller individuals and increase fitness of smaller individual

  12. Spatial distribution of detrital resources determines the outcome of competition between bacteria and a facultative detritivorous worm

    Van Nugteren, P.; Herman, P.M.J.; Moodley, L.; Middelburg, J.J.; Vos, M.; Heip, C.H.R.


    Macrobenthic deposit feeders and bacteria compete for the same detrital food resources. We hypothesize that the spatial scale at which food is distributed in the sediment is an important factor determining the outcome of this competition. Macrobenthic deposit feeders are better adapted for fast

  13. In situ monitoring of the effects of water quality on benthic detrital decomposition

    Lee, J.J.; Mastropaolo, C.; McEnery, M.; Tietjen, J.H.; Garrison, J.


    Detrital decomposition is an important marine benthic process which contributes to the fertility of seas, particularly in estuarian and coastal waters. The process involves a complex community of microorganisms and small animals which interact with each other in a manner similar to that which occurs in forest litter and in composts. Plastic chambers for measuring decomposition rates of Spartina alterniflora were placed on the bottom of the sea at four sites in the northeast: Towd Point, Southampton, New York; the effluent quarry of the Millstone power plant on Niantic Bay, Long Island Sound; Winsor Cove, Cataumet, Massachusetts (the site of an oil spill); and Sippewissett marsh, Falmouth, Massachusetts (a control site for Winsor Cove). The stations were visited monthly. By various means we measured the rates of decomposition and growth of sediment microbial and animal populations.

  14. Implications for the evolution of continental crust from Hf isotope systematics of Archean detrital zircons

    Stevenson, Ross K.; Patchett, P. Jonathan


    Results from the fractionation of zircon by sedimentary processes into continental margin sandstone yield information on the preservation of preexisting continental crust in the form of zircon, making it possible to distinguish between the contrasting theories of gradual growth versus constant volume of continental crust over geologic time. In this work, Hf-176/Hf-177 ratios were determined for detrital zircon fractions from 2.0-2.5, 2.6-3.0, and pre-3.0 Gyr old sandstones from the Canadian-Shield, the North-Atlantic, the Wyoming, and the Kaapvaal Cratons. Results pointed to small amounts of continental crust prior to 3.0 Gyr ago and a rapid addition of continental crust between 2.5 and 3.0 Gyr ago, consistent with the gradual growth of continental crust, and giving evidence against no-growth histories.

  15. Detrital Zircon Ages of Hanjiang River:Constraints on Evolution of Northern Yangtze Craton, South China

    Yang Jie; Gao Shan; Yuan Honglin; Gong Hujun; Zhang Hong; Xie Shiwen


    Clastic sedimentary rocks are natural samples of the exposed continental crust over large ideal sample for studying the formation and evolution of the northern Yangtze craton. Here we report laser ablation inductively coupled plasma mass spectrometer U-Pb ages of 122 detrital zircons from one sand sample of the Hanjiang River. The 110 concordant zircons reveal four major age groups of 768,444, 212, and 124 Ma, which well correlate with known magmatic events in the northern Yangtze craton. A minor group is present at 1 536 Ma, which is less known in the study area. Only seven zircons have ages of >1 750 Ma. Our results show that the Early Paleozoic, Late Triassic, and Early Cretaceous are important episodes of zircon growth and crustal growth/reworking in addition to the previously documented Neoproterozoic event. Our results suggest very limited exposures of Paleoproterozoic and Archean rocks in the northern parts of the Yangtze craton.

  16. Persistent Temporal Streams

    Hilley, David; Ramachandran, Umakishore

    Distributed continuous live stream analysis applications are increasingly common. Video-based surveillance, emergency response, disaster recovery, and critical infrastructure protection are all examples of such applications. They are characterized by a variety of high- and low-bandwidth streams as well as a need for analyzing both live and archived streams. We present a system called Persistent Temporal Streams (PTS) that supports a higher-level, domain-targeted programming abstraction for such applications. PTS provides a simple but expressive stream abstraction encompassing transport, manipulation and storage of streaming data. In this paper, we present a system architecture for implementing PTS. We provide an experimental evaluation which shows the system-level primitives can be implemented in a lightweight and high-performance manner, and an application-based evaluation designed to show that a representative high-bandwidth stream analysis application can be implemented relatively simply and with good performance.

  17. Pyrethroid insecticides in urban salmon streams of the Pacific Northwest

    Weston, D.P., E-mail: [Department of Integrative Biology, University of California, 3060 Valley Life Sciences Bldg., Berkeley, CA 94720-3140 (United States); Asbell, A.M., E-mail: [Department of Integrative Biology, University of California, 3060 Valley Life Sciences Bldg., Berkeley, CA 94720-3140 (United States); Hecht, S.A., E-mail: [NOAA Fisheries, Office of Protected Resources, 510 Desmond Drive S.E., Lacey, WA 98503 (United States); Scholz, N.L., E-mail: [NOAA Fisheries, Northwest Fisheries Science Center, 2725 Montlake Blvd. E., Seattle, WA 98112 (United States); Lydy, M.J., E-mail: [Fisheries and Illinois Aquaculture Center and Department of Zoology, Southern Illinois University, 171 Life Sciences II, Carbondale, IL 62901 (United States)


    Urban streams of the Pacific Northwest provide spawning and rearing habitat for a variety of salmon species, and food availability for developing salmon could be adversely affected by pesticide residues in these waterbodies. Sediments from Oregon and Washington streams were sampled to determine if current-use pyrethroid insecticides from residential neighborhoods were reaching aquatic habitats, and if they were at concentrations acutely toxic to sensitive invertebrates. Approximately one-third of the 35 sediment samples contained measurable pyrethroids. Bifenthrin was the pyrethroid of greatest concern with regards to aquatic life toxicity, consistent with prior studies elsewhere. Toxicity to Hyalella azteca and/or Chironomus dilutus was found in two sediment samples at standard testing temperature (23 deg. C), and in one additional sample at a more environmentally realistic temperature (13 deg. C). Given the temperature dependency of pyrethroid toxicity, low temperatures typical of northwest streams can increase the potential for toxicity above that indicated by standard testing protocols. - Highlights: > Salmon-bearing creeks can be adversely impacted by insecticides from urban runoff. > Pyrethroid insecticides were found in one-third of the creeks in Washington and Oregon. > Two creeks contained concentrations acutely lethal to sensitive invertebrates. > Bifenthrin was of greatest concern, though less than in prior studies. > Standard toxicity testing underestimates the ecological risk of pyrethroids. - Pyrethroid insecticides are present in sediments of urban creeks of Oregon and Washington, though less commonly than in studies elsewhere in the U.S.


    MARY N. J.


    Full Text Available Forty-one sites located on 14 New Caledonian streams were surveyed four times between October 1996 and October 1997 in order to examine the spatial and temporal changes in the structure of the benthic macroinvertebrate communities. About 250 000 invertebrates representing 167 taxa were collected in the streams. Seventy-five percent of identified taxa and 67% of individuals were insects. Major spatial and temporal changes in the composition of the fauna were detected by multivariate analyses (ordination and classification. Overall, the number of individuals was significantly higher in the dry season (October than in the wetter seasons (January and June. However, a low temporal variability was detected in the structure of benthic communities during the sampling period. A cluster analysis based on taxonomic composition separated five groups of sites in relation with rock type, land use, and geographic characteristics. Several metrics (total invertebrate density, taxon richness, relative abundance of major invertebrate groups, diversity indices were used to characterize each group of sites. Forested streams, where the highest specific diversity occurred, represented the most speciose habitat for benthic fauna. A less rich and abundant fauna occurred in streams draining ultramafic rocks probably because of their low content in food resources and organic matter.

  19. Provenance and drainage system of the Early Cretaceous volcanic detritus in the Himalaya as constrained by detrital zircon geochronology

    Xiu-Mian Hu; Eduardo Garzanti; Wei An


    The age range of the major intra-plate volcanic event that affected the northern Indian margin in the Early Cretaceous is here deifned precisely by detrital zircon geochronol-ogy. U–Pb ages of Early Cretaceous detrital zircons found in the Cretaceous to the Paleocene sandstones cluster mainly between 142 Ma and 123 Ma in the northern Tethys Himalayan unit, and between 140 Ma and 116 Ma in the southern Tethys Himalayan unit. The youngest and oldest detrital zircons within this group indicate that volcanism in the source areas started in the latest Jurassic and ended by the early Albian. Stratigraphic data indicate that volcaniclastic sedimentation began signiifcantly earlier in southern Tibet (Tithonian) than in Nepal (Valangin-ian), and considerably later in Spiti and Zanskar (Aptian/Albian) to the west. This apparent westward migration of magmatism was explained with progressive westward propagation of extensional/transtensional tectonic activity and development of fractures cutting deeply across the Indian continental margin crust. However, detrital zircon geochronology provides no indi-cation of heterochroneity in magmatic activity in the source areas from east to west, and thus lends little support to such a scenario. Westward migration of volcaniclastic sedimentation may thus relfect instead the westward progradation of major drainage systems supplying vol-canic detritus sourced from the same volcanic centers in the east. Development of multiple radial drainage away from the domal surface uplift associated with magmatic upwelling, as observed for most large igneous provinces around the world, may also explain why U–Pb ages of detrital zircons tend to cluster around 133–132 Ma (the age of the Comei igneous province) in Tethys Himalayan units, but around 118–117 Ma (the age of the Rajmahal igneous province) in Lesser Himalayan units.

  20. A model-based comparison of organic matter dynamics between riparian-forested and open-canopy streams

    Stenroth Karolina


    Full Text Available The food webs of forest streams are primarily based upon inputs of organic matter from adjacent terrestrial ecosystems. However, streams that run through open landscapes generally lack closed riparian canopies, and an increasing number of studies indicate that terrestrial organic matter may be an important resource in these systems as well. Combining key abiotically-controlled factors (stream discharge, water temperature, and litter input rate with relevant biotic processes (e.g. macroinvertebrate CPOM consumption, microbial processing, we constructed a model to predict and contrast organic matter dynamics (including temporal variation in CPOM standing crop, CPOM processing rate, FPOM production, and detritivore biomass in small riparian-forested and open-canopy streams. Our modeled results showed that the standing crop of CPOM was similar between riparian-forested and open-canopy streams, despite considerable differences in litter input rate. This unexpected result was partly due to linkages between CPOM supply and consumer abundance that produced higher detritivore biomass in the forest stream than the open-canopy stream. CPOM standing crop in the forest stream was mainly regulated by top-down consumer control, depressing it to a level similar to that of the open-canopy stream. In contrast, CPOM standing crop in the open-canopy stream was primarily controlled by physical factors (litter input rates and discharge, not consumption. This suggests that abiotic processes (e.g. discharge may play a greater role in limiting detrital resource availability and consumer biomass in open-canopy streams than in forest streams. These model results give insight on functional differences that exists among streams and they can be used to predict effects of anthropogenic influences such as forestry, agriculture, urbanization, and climate change on streams and how riparian management and conservation tools can be employed to mitigate undesirable effects.

  1. The many streams of the Magellanic Stream

    Stanimirovic, Snezana; Heiles, Carl; Douglas, Kevin A; Putman, Mary; Peek, Joshua E G


    We present results from neutral hydrogen (HI) observations of the tip of the Magellanic Stream (MS), obtained with the Arecibo telescope as a part of the on-going survey by the Consortium for Galactic studies with the Arecibo L-band Feed Array. We find four large-scale, coherent HI streams, extending continously over a length of 20 degrees, each stream possessing different morphology and velocity gradients. The newly discovered streams provide strong support for the tidal model of the MS formation by Connors et al. (2006), which suggested a spatial and kinematic bifurcation of the MS. The observed morphology and kinematics suggest that three of these streams could be interpreted as a 3-way splitting of the main MS filament, while the fourth stream appears much younger and may have originated from the Magellanic Bridge. We find an extensive population of HI clouds at the tip of the MS. Two thirds of clouds have an angular size in the range 3.5'--10'. We interpret this as being due to thermal instability, which...

  2. Shifts in the trophic base of intermittent stream food webs

    Dekar, Matthew P.; Magoulick, Daniel D.; Huxel, G.R.


    Understanding spatial and temporal variation in the trophic base of stream food webs is critical for predicting population and community stability, and ecosystem function. We used stable isotope ratios (13C/12C, and 15N/14N) to characterize the trophic base of two streams in the Ozark Mountains of northwest Arkansas, U.S.A. We predicted that autochthonous resources would be more important during the spring and summer and allochthonous resources would be more important in the winter due to increased detritus inputs from the riparian zone during autumn leaf drop. We predicted that stream communities would demonstrate increased reliance on autochthonous resources at sites with larger watersheds and greater canopy openness. The study was conducted at three low-order sites in the Mulberry River Drainage (watershed area range: 81-232 km2) seasonally in 2006 and 2007. We used circular statistics to examine community-wide shifts in isotope space among fish and invertebrate consumers in relation to basal resources, including detritus and periphyton. Mixing models were used to quantify the relative contribution of autochthonous and allochthonous energy sources to individual invertebrate consumers. Significant isotopic shifts occurred but results varied by season and site indicating substantial variation in the trophic base of stream food webs. In terms of temporal variation, consumers shifted toward periphyton in the summer during periods of low discharge, but results varied during the interval between summer and winter. Our results did not demonstrate increased reliance on periphyton with increasing watershed area or canopy openness, and detritus was important at all the sites. In our study, riffle-pool geomorphology likely disrupted the expected spatial pattern and stream drying likely impacted the availability and distribution of basal resources.

  3. Recovery of a mining-damaged stream ecosystem

    Mebane, Christopher A.; Eakins, Robert J.; Fraser, Brian G.; Adams, William J.


    This paper presents a 30+ year record of changes in benthic macroinvertebrate communities and fish populations associated with improving water quality in mining-influenced streams. Panther Creek, a tributary to the Salmon River in central Idaho, USA suffered intensive damage from mining and milling operations at the Blackbird Mine that released copper (Cu), arsenic (As), and cobalt (Co) into tributaries. From the 1960s through the 1980s, no fish and few aquatic invertebrates could be found in 40 km of mine-affected reaches of Panther Creek downstream of the metals contaminated tributaries, Blackbird and Big Deer Creeks.

  4. The Puzzling Ophiuchus Stream

    Kohler, Susanna


    Dwarf galaxies or globular clusters orbiting the Milky Way can be pulled apart by tidal forces, leaving behind a trail of stars known as a stellar stream. One such trail, the Ophiuchus stream, has posed a serious dynamical puzzle since its discovery. But a recent study has identified four stars that might help resolve this streams mystery.Conflicting TimescalesThe stellar stream Ophiuchus was discovered around our galaxy in 2014. Based on its length, which appears to be 1.6 kpc, we can calculate the time that has passed since its progenitor was disrupted and the stream was created: ~250 Myr. But the stars within it are ~12 Gyr old, and the stream orbits the galaxy with a period of ~350 Myr.Given these numbers, we can assume that Ophiuchuss progenitor completed many orbits of the Milky Way in its lifetime. So why would it only have been disrupted 250 million years ago?Fanning StreamLed by Branimir Sesar (Max Planck Institute for Astronomy), a team of scientists has proposed an idea that might help solve this puzzle. If the Ophiuchus stellar stream is on a chaotic orbit common in triaxial potentials, which the Milky Ways may be then the stream ends can fan out, with stars spreading in position and velocity.The fanned part of the stream, however, would be difficult to detect because of its low surface brightness. As a result, the Ophiuchus stellar stream could actually be longer than originally measured, implying that it was disrupted longer ago than was believed.Search for Fan StarsTo test this idea, Sesar and collaborators performed a search around the ends of the stream, looking for stars thatare of the right type to match the stream,are at the predicted distance of the stream,are located near the stream ends, andhave velocities that match the stream and dont match the background halo stars.Histogram of the heliocentric velocities of the 43 target stars. Six stars have velocities matching the stream velocity. Two of these are located in the main stream; the other


    Anju Rana


    Full Text Available  Macroinvertebrates are widely considered as indicators of water quality. The present research work was conducted in Bhalu khola, a tributary of Budhigandaki River, Nepal, to identify water quality using macro invertebrates with Nepalese Biotic Score (NEPBIOS, and examine its applicability by comparing with Water Quality Index (WQI.The diversity of macro invertebrates in the studied river was high as depicted by Shannon Wiener Diversity Index. Altogether, 103 macro invertebrates were identified from 11 families and five orders. There were no dominant species, and most of the species were in clumped distribution. According to NEPBIOS index, river water was found to comply with the characteristics of WQ class I-II that means water quality of the river was good. Other indices such as Hilsenhoff and Lincoln quality index (LQI index also supported this result. Similarly, water quality index (WQI also showed similarity with NEPBIOS index, indicating water appropriate for drinking purpose. Thus, it is concluded that the macro invertebrates can be used as economic tools for determining water quality of streams and rivers as efficient water quality indicators.International Journal of Environment Volume-4, Issue-3, June-August 2015Page: 55-68

  6. Conservation of estrogen receptor function in invertebrate reproduction.

    Jones, Brande L; Walker, Chris; Azizi, Bahareh; Tolbert, Laren; Williams, Loren Dean; Snell, Terry W


    Rotifers are microscopic aquatic invertebrates that reproduce both sexually and asexually. Though rotifers are phylogenetically distant from humans, and have specialized reproductive physiology, this work identifies a surprising conservation in the control of reproduction between humans and rotifers through the estrogen receptor. Until recently, steroid signaling has been observed in only a few invertebrate taxa and its role in regulating invertebrate reproduction has not been clearly demonstrated. Insights into the evolution of sex signaling pathways can be gained by clarifying how receptors function in invertebrate reproduction. In this paper, we show that a ligand-activated estrogen-like receptor in rotifers binds human estradiol and regulates reproductive output in females. In other invertebrates characterized thus far, ER ligand binding domains have occluded ligand-binding sites and the ERs are not ligand activated. We have used a suite of computational, biochemical and biological techniques to determine that the rotifer ER binding site is not occluded and can bind human estradiol. Our results demonstrate that this mammalian hormone receptor plays a key role in reproduction of the ancient microinvertebrate Brachinous manjavacas. The presence and activity of the ER within the phylum Rotifera indicates that the ER structure and function is highly conserved throughout animal evolution.

  7. Lysosomal enzymes and their receptors in invertebrates: an evolutionary perspective.

    Kumar, Nadimpalli Siva; Bhamidimarri, Poorna M


    Lysosomal biogenesis is an important process in eukaryotic cells to maintain cellular homeostasis. The key components that are involved in the biogenesis such as the lysosomal enzymes, their modifications and the mannose 6-phosphate receptors have been well studied and their evolutionary conservation across mammalian and non-mammalian vertebrates is clearly established. Invertebrate lysosomal biogenesis pathway on the other hand is not well studied. Although, details on mannose 6-phosphate receptors and enzymes involved in lysosomal enzyme modifications were reported earlier, a clear cut pathway has not been established. Recent research on the invertebrate species involving biogenesis of lysosomal enzymes suggests a possible conserved pathway in invertebrates. This review presents certain observations based on these processes that include biochemical, immunological and functional studies. Major conclusions include conservation of MPR-dependent pathway in higher invertebrates and recent evidence suggests that MPR-independent pathway might have been more prominent among lower invertebrates. The possible components of MPR-independent pathway that may play a role in lysosomal enzyme targeting are also discussed here.

  8. A generalized model for estimating the energy density of invertebrates

    James, Daniel A.; Csargo, Isak J.; Von Eschen, Aaron; Thul, Megan D.; Baker, James M.; Hayer, Cari-Ann; Howell, Jessica; Krause, Jacob; Letvin, Alex; Chipps, Steven R.


    Invertebrate energy density (ED) values are traditionally measured using bomb calorimetry. However, many researchers rely on a few published literature sources to obtain ED values because of time and sampling constraints on measuring ED with bomb calorimetry. Literature values often do not account for spatial or temporal variability associated with invertebrate ED. Thus, these values can be unreliable for use in models and other ecological applications. We evaluated the generality of the relationship between invertebrate ED and proportion of dry-to-wet mass (pDM). We then developed and tested a regression model to predict ED from pDM based on a taxonomically, spatially, and temporally diverse sample of invertebrates representing 28 orders in aquatic (freshwater, estuarine, and marine) and terrestrial (temperate and arid) habitats from 4 continents and 2 oceans. Samples included invertebrates collected in all seasons over the last 19 y. Evaluation of these data revealed a significant relationship between ED and pDM (r2  =  0.96, p calorimetry approaches. This model should prove useful for a wide range of ecological studies because it is unaffected by taxonomic, seasonal, or spatial variability.

  9. Retinoid metabolism in invertebrates: when evolution meets endocrine disruption.

    André, A; Ruivo, R; Gesto, M; Castro, L Filipe C; Santos, M M


    Recent genomic and biochemical evidence in invertebrate species pushes back the origin of the retinoid metabolic and signaling modules to the last common ancestor of all bilaterians. However, the evolution of retinoid pathways are far from fully understood. In the majority of non-chordate invertebrate lineages, the ongoing functional characterization of retinoid-related genes (metabolism and signaling pathways), as well as the characterization of the endogenous retinoid content (precursors and active retinoids), is still incomplete. Despite limited, the available data supports the presence of biologically active retinoid pathways in invertebrates. Yet, the mechanisms controlling the spatial and temporal distribution of retinoids as well as their physiological significance share similarities and differences with vertebrates. For instance, retinol storage in the form of retinyl esters, a key feature for the maintenance of retinoid homeostatic balance in vertebrates, was only recently demonstrated in some mollusk species, suggesting that such ability is older than previously anticipated. In contrast, the enzymatic repertoire involved in this process is probably unlike that of vertebrates. The suggested ancestry of active retinoid pathways implies that many more metazoan species might be potential targets for endocrine disrupting chemicals. Here, we review the current knowledge about the occurrence and functionality of retinoid metabolic and signaling pathways in invertebrate lineages, paying special attention to the evolutionary origin of retinoid storage mechanisms. Additionally, we summarize existing information on the endocrine disruption of invertebrate retinoid modules by environmental chemicals. Research priorities in the field are highlighted. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. Key factors for the emergence of collective decision in invertebrates.

    Jeanson, Raphaël; Dussutour, Audrey; Fourcassié, Vincent


    In many species of group living invertebrates, in particular arthropods, collective decisions can emerge from the combined actions of individuals and the direct or indirect interactions between individuals. These decisions allow groups of individuals to respond quickly and accurately to changes that occur in their environment. Examples of such decisions are found in a variety of invertebrate taxa and in many different contexts, e.g., exploring a new territory, foraging for food, finding a suitable location where to aggregate or to establish a nest, defending oneself against predators, etc. In this paper we review the collective decisions that have been documented in different invertebrate taxa where individuals are known to live temporarily or permanently in social or gregarious groups. We first present some simple examples of collective decisions involving the choice between two alternatives. We then define the fundamental rules required for these collective decisions to emerge throughout the invertebrate taxon, from simple organisms such as caterpillars, to animals endowed with highly developed perceptive and cognitive capacities such as ants and bees. The presentation of these rules gives us the opportunity to illustrate one of the pitfalls of the study of collective choice in animals by showing through computer simulations how a choice between two alternatives can be misinterpreted as the result of the action of self-organized mechanisms. In the second part, we discuss the peculiarities of collective decisions in invertebrates, their properties, and characteristics. We conclude by discussing the issue of individual complexity in collective decision-making process.

  11. The use of invertebrates as indicators of environmental change in alpine rivers and lakes

    Khamis, K.; Hannah, D.M. [School of Geography Earth and Environmental Science, University of Birmingham, Birmingham B15 2TT (United Kingdom); Brown, L.E. [School of Geography/water@leeds, University of Leeds, Woodhouse Lane, Leeds LS2 9JT (United Kingdom); Tiberti, R. [DSTA, Dipartimento di Scienze della Terra e dell' Ambiente, University of Pavia, Via Ferrata 9, 27100 Pavia (Italy); Alpine Wildlife Research Centre, Gran Paradiso National Park, Degioz 11, I-1101 Valsavarenche, Aosta (Italy); Milner, A.M., E-mail: [School of Geography Earth and Environmental Science, University of Birmingham, Birmingham B15 2TT (United Kingdom); Institute of Arctic Biology, University of Alaska, Fairbanks, AK 99775 (United States)


    In alpine regions climatic change will alter the balance between water sources (rainfall, ice-melt, snowmelt, and groundwater) for aquatic systems, particularly modifying the relative contributions of meltwater, groundwater and rain to both rivers and lakes. While these changes are expected to have implications for alpine aquatic ecosystems, little is known about potential ecological tipping points and associated indicator taxa. We examined changes in biotic communities along a gradient of glacier influence for two study systems: (1) a stream network in the French Pyrénées; and (2) a network of lakes in the Italian Alps, with the aim of identifying potential indicator taxa (macroinvertebrates and zooplankton) of glacier retreat in these environments. To assess parallels in biotic responses across streams and lakes, both primary data and findings from other publications were synthesised. Using TITAN (Threshold Indicator Taxa ANalysis) changes in community composition of river taxa were identified at thresholds of < 5.1% glacier cover and < 66.6% meltwater contribution. Below these thresholds the loss of cold stenothermic benthic invertebrate taxa, Diamesa spp. and the Pyrenean endemic Rhyacophila angelieri was apparent. Some generalist taxa including Protonemura sp., Perla grandis, Baetis alpinus, Rhithrogena loyolaea and Microspectra sp. increased when glacier cover was < 2.7% and < 52% meltwater. Patterns were not as distinct for the alpine lakes, due to fewer sampling sites; however, Daphnia longispina grp. and the benthic invertebrate groups Plectopera and Planaria were identified as potential indicator taxa. While further work is required to assess potential indicator taxa for alpine lake systems, findings from alpine river systems were consistent between methods for assessing glacier influence (meltwater contribution/glacier cover). Hence, it is clear that TITAN could become a useful management tool, enabling: (i) the identification of taxa particularly

  12. The Andromeda Stream

    Lewis, G F; Ferguson, A M N; Ibata, R A; Irwin, M J; McConnachie, A W; Tanvir, N


    The existence of a stream of tidally stripped stars from the Sagittarius Dwarf galaxy demonstrates that the Milky Way is still in the process of accreting mass. More recently, an extensive stream of stars has been uncovered in the halo of the Andromeda galaxy (M31), revealing that it too is cannibalizing a small companion. This paper reports the recent observations of this stream, determining it spatial and kinematic properties, and tracing its three-dimensional structure, as well as describing future observations and what we may learn about the Andromeda galaxy from this giant tidal stream.

  13. Hydrography - Streams and Shorelines

    California Department of Resources — The hydrography layer consists of flowing waters (rivers and streams), standing waters (lakes and ponds), and wetlands -- both natural and manmade. Two separate...

  14. The case against streaming

    Natalia Mironova


    .... Cassidy, the safety coordinator at the Airline Pilots Association, says Levine and others advocating for live data streaming are oversimplifying the issue and overlooking the logistical concerns...

  15. Inventory of miscellaneous streams

    Lueck, K.J.


    On December 23, 1991, the US Department of Energy, Richland Operations Office (RL) and the Washington State Department of Ecology (Ecology) agreed to adhere to the provisions of the Department of Ecology Consent Order. The Consent Order lists the regulatory milestones for liquid effluent streams at the Hanford Site to comply with the permitting requirements of Washington Administrative Code. The RL provided the US Congress a Plan and Schedule to discontinue disposal of contaminated liquid effluent into the soil column on the Hanford Site. The plan and schedule document contained a strategy for the implementation of alternative treatment and disposal systems. This strategy included prioritizing the streams into two phases. The Phase 1 streams were considered to be higher priority than the Phase 2 streams. The actions recommended for the Phase 1 and 2 streams in the two reports were incorporated in the Hanford Federal Facility Agreement and Consent Order. Miscellaneous Streams are those liquid effluents streams identified within the Consent Order that are discharged to the ground but are not categorized as Phase 1 or Phase 2 Streams. This document consists of an inventory of the liquid effluent streams being discharged into the Hanford soil column.

  16. Nitrous oxide production associated with coastal marine invertebrates

    Heisterkamp, Ines Maria; Schramm, Andreas; de Beer, Dirk


    with an experimentally cleaned shell. Thus, the N2O production associated with marine invertebrates is apparently not due to gut denitrification in every species, but may also result from microbial activity on the external surfaces of animals. The high abundance and potential N2O emission rates of many marine......Several freshwater and terrestrial invertebrate species emit the greenhouse gas nitrous oxide (N2O). The N2O production associated with these animals was ascribed to incomplete denitrification by ingested sediment or soil bacteria. The present study shows that many marine invertebrates also emit N2...... gut by incomplete denitrification. Statistical analysis revealed that body weight, habitat, and exoskeletal biofilms were important determinants of animal-associated N2O production. The snail Hinia reticulata emitted about 3.5 times more N2O with an intact exoskeletal biofilm on its shell than...

  17. Protozoa interaction with aquatic invertebrate: interest for watercourses biomonitoring.

    Palos Ladeiro, M; Bigot, A; Aubert, D; Hohweyer, J; Favennec, L; Villena, I; Geffard, A


    Toxoplasma gondii, Cryptosporidium parvum, and Giardia duodenalis are human waterborne protozoa. These worldwide parasites had been detected in various watercourses as recreational, surface, drinking, river, and seawater. As of today, water protozoa detection was based on large water filtration and on sample concentration. Another tool like aquatic invertebrate parasitism could be used for sanitary and environmental biomonitoring. In fact, organisms like filter feeders could already filtrate and concentrate protozoa directly in their tissues in proportion to ambient concentration. So molluscan shellfish can be used as a bioindicator of protozoa contamination level in a site since they were sedentary. Nevertheless, only a few researches had focused on nonspecific parasitism like protozoa infection on aquatic invertebrates. Objectives of this review are twofold: Firstly, an overview of protozoa in worldwide water was presented. Secondly, current knowledge of protozoa parasitism on aquatic invertebrates was detailed and the lack of data of their biological impact was pointed out.

  18. Isolation of key retinoid signalling and metabolic modules in invertebrates

    Ana André


    Full Text Available Retinoids are a class of molecules related to vitamin A (Retinol that are required for regulation of critical chordate ndocrine-mediated process, such as embryonic development, reproduction, and vision. To maintain such physiological process, chordates have a complex mechanism to regulate the spatial and temporal distribution of retinoids that includes metabolic and signalling modules. Initially, retinoid modules were seen as a chordate novelty. However, emerging biochemical and genomic evidences have challenged this view, clearly pointing to a more basal ancestry than previously thought. However, for the majority of non-chordate invertebrate lineages a clearly characterization of the main enzymatic/molecular players is still missing. Despite limited, the available evidence supports the presence of biologically active retinoid pathways in invertebrates. In order to enhance our insights on retinoid biology, evolution, and its putative disruption by environmental chemicals, the isolation and functional characterization of key retinoid metabolic players in marine invertebrates has been carried out.

  19. The genetics of host-virus coevolution in invertebrates.

    Obbard, Darren J; Dudas, Gytis


    Although viral infection and antiviral defence are ubiquitous, genetic data are currently unavailable from the vast majority of animal phyla-potentially biasing our overall perspective of the coevolutionary process. Rapid adaptive evolution is seen in some insect antiviral genes, consistent with invertebrate-virus 'arms-race' coevolution, but equivalent signatures of selection are hard to detect in viruses. We find that, despite the large differences in vertebrate, invertebrate, and plant immune responses, comparison of viral evolution fails to identify any difference among these hosts in the impact of positive selection. The best evidence for invertebrate-virus coevolution is currently provided by large-effect polymorphisms for host resistance and/or viral evasion, as these often appear to have arisen and spread recently, and can be favoured by virus-mediated selection.

  20. Experimental evidence of pollination in marine flowers by invertebrate fauna.

    van Tussenbroek, Brigitta I; Villamil, Nora; Márquez-Guzmán, Judith; Wong, Ricardo; Monroy-Velázquez, L Verónica; Solis-Weiss, Vivianne


    Pollen transport by water-flow (hydrophily) is a typical, and almost exclusive, adaptation of plants to life in the marine environment. It is thought that, unlike terrestrial environments, animals are not involved in pollination in the sea. The male flowers of the tropical marine angiosperm Thalassia testudinum open-up and release pollen in mucilage at night when invertebrate fauna is active. Here we present experimental evidence that, in the absence of water-flow, these invertebrates visit the flowers, carry and transfer mucilage mass with embedded pollen from the male flowers to the stigmas of the female flowers. Pollen tubes are formed on the stigmas, indicating that pollination is successful. Thus, T. testudinum has mixed abiotic-biotic pollination. We propose a zoobenthophilous pollination syndrome (pollen transfer in the benthic zone by invertebrate animals) which shares many characteristics with hydrophily, but flowers are expected to open-up during the night.

  1. Detrital dating on drill-core records from McMurdo Sound, Ross Sea (Antarctica)

    Zattin, M.; Andreucci, B.; Balestrieri, M.; Olivetti, V.; Pace, D.; Reiners, P. W.; Rossetti, F.; Talarico, F.; Thomson, S. N.


    The influence of Antarctic ice sheets on the global climate system during the Cenozoic has been intensely investigated in the last years, especially after the successful drilling projects off-shore the western Ross Sea. While the role of the Western Ice Sheet (WAIS) during the Miocene it is not clear, the East Antarctic Ice Sheet (EAIS) has been suggested to be more or less stable and cold for the last 14 Ma. Records from drilling projects in syn-tectonic basins located on the continental shelf along the western margin of the West Antarctica Rift System (DSDP, CIROS, CRP and ANDRILL projects) may provide crucial information on the tectonic and paleo-climatic evolution of that region during Cenozoic. The drilled sedimentary records have been therefore investigated by detrital geochronology which, integrated by sandstone and gravel petrography, can provide valuable information on the dynamics of the ice sheets as provenance data are sensitive to variations in the ice-flow patterns. Apatite fission-track (AFT) data from ANDRILL and CRP records show multiple peaks in most of the samples. In the AND-2A well, whose stratigraphic record spans the last 20 Ma, the grain-age distributions are dominated by grains between 20 and 40 Ma. A young peak with a comparable age has been also episodically detected in CRP wells where conversely the most relevant population is made by grain ages between 45 and 70 Ma. Samples from Late Miocene-Pleistocene sediments of AND-1B well show a completely different AFT age distribution as a single peak is usually detected and ages are younger than 20 Ma. The AFT age range is well represented in bedrock data along the entire Transantarctic Mountains (TAM). The main denudation phase in the TAM began at 55-50 Ma but the occurrence of a young peak in the detrital data at ca. 35 Ma indicates the presence of an Oligocene pulse, as testified also by the small gap between AFT and some (U-Th-Sm)/He ages that have been detected on AND-2A samples. Such

  2. Detrital minerals from source to sink : tracing Orange River sand from Lesotho to Angola

    Garzanti, Eduardo; Vermeesch, Pieter; Andò, Sergio; Resentini, Alberto; Vezzoli, Giovanni; Lustrino, Michele; Padoan, Marta; Pereira, Alcides


    Quantitative provenance analysis based on high-resolution bulk-petrography and heavy-mineral data on beach and dune sands, integrated with detrital-zircon geochronology and chemical analyses of pyroxene, garnet and staurolite, demonstrates that sand carried by the Orange River and derived from Lesotho and South Africa is carried by powerful and persistent longshore currents as far as southern Angola (Garzanti et al., 2014a). This is the longest cell of littoral sand transport documented so far on Earth, and a great test case for investigating physical controls on sand texture and composition. We have monitored textural, mineralogical and geochemical variability of beach and eolian-dune sands along a 1750 km stretch of the Atlantic coast of southern Africa by using an integrated set of techniques, including image analysis, laser granulometry, optical microscopy, Raman spectroscopy and bulk-sediment geochemistry (Garzanti et al., 2014b). Our results contrast with previous reports that feldspars and volcanic detritus break down during transport, that sand grains are rounded rapidly in shallow-marine environments, and that quartzose sands may be produced by physical processes alone. We demonstrate that basaltic rock fragments and pyroxenes, traditionally believed to be rapidly destroyed, survive healthily the 4000 km-long multistep hazardous journey from Lesotho volcanic highlands to Angola. Feldspar abundance remains remarkably constant from the Orange mouth to southern Angola, and quartz increases only very slightly, possibly as a result of local recycling. Among sedimentary and metasedimentary rock fragments, unconsolidated or strongly foliated types are readily comminuted when they enter the high-energy marine environment, but cemented sandstone/siltstone grains can survive the travel from the Karoo Basin of South Africa to northern Namibia and beyond. No detrital mineral displays a significant increase in grain roundness after 300-350 km of longshore transport in

  3. Urban development results in stressors that degrade stream ecosystems

    Bell, Amanda H.; Coles, James F.; McMahon, Gerard; Woodside, Michael D.


    In 2003, eighty-three percent of Americans lived in metropolitan areas, and considerable population increases are predicted within the next 50 years. Nowhere are the environmental changes associated with urban development more evident than in urban streams. Contaminants, habitat destruction, and increasing streamflow flashiness resulting from urban development have been associated with the disruption of biological communities, particularly the loss of sensitive aquatic biota. Every stream is connected downstream to other water bodies, and inputs of contaminants and (or) sediments to streams can cause degradation downstream with adverse effects on biological communities and on economically valuable resources, such as fisheries and tourism. Understanding how algal, invertebrate, and fish communities respond to physical and chemical stressors associated with urban development can provide important clues on how multiple stressors may be managed to protect stream health as a watershed becomes increasingly urbanized. This fact sheet highlights selected findings of a comprehensive assessment by the National Water-Quality Assessment Program of the U.S. Geological Survey (USGS) of the effects of urban development on stream ecosystems in nine metropolitan study areas.

  4. Quality of streams in Johnson County, Kansas, 2002--10

    Rasmussen, Teresa J.; Stone, Mandy S.; Poulton, Barry C.; Graham, Jennifer L.


    significantly negatively correlated with biological conditions. Specific conductance of water and sum of PAH concentrations in streambed sediment also were significantly negatively correlated with biological conditions. Total nitrogen in water and total phosphorus in streambed sediment were correlated with most of the invertebrate variables, which is a notable difference from previous analyses using smaller datasets, in which nutrient relations were weak or not detected. The most important habitat variables were sinuosity, length and continuity of natural buffers, riffle substrate embeddedness, and substrate cover diversity, each of which was correlated with all invertebrate metrics including a 10-metric combined score. Correlation analysis indicated that if riparian and in-stream habitat conditions improve then so might invertebrate communities and stream biological quality. Sixty-two percent of the variance in macroinvertebrate community metrics was explained by the single environmental factor, percent impervious surface. Invertebrate responses to urbanization in Johnson County indicated linearity rather than identifiable thresholds. Multiple linear regression models developed for each of the four macroinvertebrate metrics used to determine aquatic-life-support status indicated that percent impervious surface, as a measure of urban land use, explained 34 to 67 percent of the variability in biological communities. Results indicate that although multiple factors are correlated with stream quality degradation, general urbanization, as indicated by impervious surface area or urban land use, consistently is determined to be the fundamental factor causing change in stream quality. Effects of urbanization on Johnson County streams are similar to effects described in national studies that assess effects of urbanization on stream health. Individually important environmental factors such as specific conductance of water, PAHs in streambed sediment, and stream buffer conditions, are

  5. An Assessment of Stream Health in Urban Creeks with Community Led Improvement Projects

    Sanchez, L.; Mercado, M.


    Small-scale restoration and improvement projects along urban creeks have become increasingly common and the need to assess their impact on stream health is necessary. Courtland and Peralta Creek have been subject to a variety of community, non-profit and city sponsored improvement projects. Assessment of nutrient contamination in the form of ammonia and nitrate indicate that these urban creeks have been impacted by human activity (Water Quality of Peralta and Courtland Creeks Oakland, CA, A. Ahumada). Continued assessment of the stream health through nitrate, ammonia and phosphate concentrations, benthic invertebrate derived biotic index and E. coli concentrations were used to assess site improvements. Youth and community site improvement project at Courtland Creek has resulted in the decline of nitrate contamination and an overall increase in benthic invertebrates species. Peralta Creek has a group of dedicated community volunteers that participate in clean up events but is just now implementing a planned restoration project increasing native plant diversity at the site.

  6. Nematomorph parasites indirectly alter the food web and ecosystem function of streams through behavioural manipulation of their cricket hosts.

    Sato, T.; Egusa, T.; Fukushima, K.; Oda, T.; Ohte, N.; Tokuchi, Naoko; Watanabe, Katsutoshi; Kanaiwa, Minoru; Murakami, Isaya; Lafferty, Kevin D.


    Nematomorph parasites manipulate crickets to enter streams where the parasites reproduce. These manipulated crickets become a substantial food subsidy for stream fishes. We used a field experiment to investigate how this subsidy affects the stream community and ecosystem function. When crickets were available, predatory fish ate fewer benthic invertebrates. The resulting release of the benthic invertebrate community from fish predation indirectly decreased the biomass of benthic algae and slightly increased leaf break-down rate. This is the first experimental demonstration that host manipulation by a parasite can reorganise a community and alter ecosystem function. Nematomorphs are common, and many other parasites have dramatic effects on host phenotypes, suggesting that similar effects of parasites on ecosystems might be widespread.

  7. The pre-orogenic detrital zircon record of the Variscan orogeny: Preliminary results

    Stephan, Tobias; Kroner, Uwe


    To test plate-tectonic constellations in consideration of the long-term development of sedimentary transport paths, temporally and spatially highly resolved records of provenance analysis are mandatory. The interpretation of existing studies focus on small-scale areas within an orogen thereby neglecting the differing distribution of provenance data in the entire orogenic system. This study reviews a large data set of compiled geochronological data to document the development of pre-orogenic tectonic units on the example of the Variscan orogeny. Constrained by tectonic and geological models, the temporal distribution of U-Pb detrital zircon ages, used as a proxy for sedimentary provenance, shows that some minima and maxima of zircon abundance are nearly synchronous for thousands of kilometres along the orogeny. Age spectra of Precambrian to Lower Palaeozoic samples were constructed on the basis of 38729 U-Pb ages from 685 samples that were compiled from 102 publications. The age compilation combines thermal ionization mass spectrometry (TIMS), laser ablation-inductively coupled plasma-mass spectrometer (LA-ICP-MS), sensitive high-resolution ion microprobe (SHRIMP), and secondary ion mass spectrometry (SIMS) analyses. The data was re-processed using a common age calculation and concordance filter to ensure comparability. The concordance of each zircon grain was calculated from 206Pb/238U and 207Pb/235U ages to guarantee that only concordant grains, i.e., with 3) is used for the maximum age of deposition. In addition to the location of >600 samples, the precise depositional ages result in a spatially and temporally high resolution. To avoid the different levels of analytical precision of the compiled TIMS, LA-ICP-MS, SHRIMP, and SIMS data, detrital zircon ages are plotted as kernel density estimates. Spatial and temporal distribution of the kernel density estimates, as well as further statistical techniques (e.g. multidimensional scaling) are used to discriminate

  8. Detrital zircon geochronology of the Cretaceous succession from the Iberian Atlantic Margin: palaeogeographic implications

    Dinis, Pedro A.; Dinis, Jorge; Tassinari, Colombo; Carter, Andy; Callapez, Pedro; Morais, Manuel


    Detrital zircon U-Pb data performed on eight Cretaceous sandstone samples (819 age isotopic results) from the Lusitanian basin (west Portugal) constrain the history of uplift and palaeodrainage of western Iberia following break-up of Pangaea and opening of the North Atlantic Ocean. We examined the links between shifts in provenance and known basinwide unconformities dated to the late Berriasian, Barremian, late Aptian and Cenomanian-Turonian. The detrital zircon record of sedimentary rocks with wider supplying areas is relatively homogenous, being characterized by a clear predominance of late Palaeozoic ages (c. 375-275 Ma) together with variable proportions of ages in the range c. 800-460 Ma. These two groups of ages are diagnostic of sources within the Variscan Iberian Massif. A few samples also reveal significant amounts of middle Palaeozoic (c. 420-385 Ma) and late Mesoproterozoic to early Neoproterozoic (c. 1.2-0.9 Ga) zircon, which are almost absent in the basement to the east of the Lusitanian basin, but are common in terranes with a Laurussia affinity found in NW Iberia and the conjugate margin (Newfoundland). The Barremian unconformity marks a sudden rise in the proportion of c. 375-275 Ma zircon ages accompanied by a decrease in the abundance of the c. 420-385 Ma and c. 1.2-0.9 Ga ages. This shift in the zircon signature, which is contemporaneous with the separation of the Galicia Bank from Flemish Cap, reflects increased denudation of Variscan crystalline rocks and a reduction in source material from NW Iberia and adjoining areas. The late Aptian unconformity, which represents the largest hiatus in the sedimentary record, is reflected by a shift in late Palaeozoic peak ages from c. 330-310 Ma (widespread in Iberia) to c. 310-290 Ma (more frequent in N Iberia). It is considered that this shift in the age spectra resulted from a westward migration of catchment areas following major uplift in northern Iberia and some transport southward from the Bay of

  9. Detrital zircon geochronology and Nd isotope geochemistry of an early Paleozoic succession in Korea:

    Lee, Yong Il; Choi, Taejin; Lim, Hyoun Soo; Orihashi, Yuji


    This study reports the results of an analysis of U-Pb ages of detrital zircons and Nd isotope compositions from the well-established lower Paleozoic platform succession developed on the Precambrian gneiss and metasedimentary rocks in South Korea. The three stratigraphic units in the basal part of the succession are the Jangsan, Myeonsan, and Myobong Formations. The unfossiliferous Jangsan (white­to­pink quartz sandstone) and Myeonsan (dark-gray ilmenite-rich sandstone/shale) Formations are in fault contact and are generally considered to be coeval (Early Cambrian). Both formations are also generally considered to be conformably overlain by the dark­ gray, fossiliferous, fine-grained Myobong Formation (late Early-early Middle Cambrian). We here report U-Pb ages of detrital zircons and Nd isotopic data from the Jangsan, Myeonsan, and Myobong Formations. The Jangsan and Myeonsan Formations provide Archean-Paleoproterozoic U-Pb ages, but the former is characterized by Archean Sm-Nd model ages and the latter by late Paleoproterozoic Sm-Nd model ages, which is indicative of a significant change in provenance. This suggests that the Jangsan Formation predates the Myeonsan Formation. The Myobong Formation provides dominantly Meso- to Neoproterozoic U-Pb ages and Sm-Nd model ages that are slightly younger than those of the Myeonsan Formation. Contrary to the conventional wisdom, the combined evidence of unconformable contact and marked changes in zircon U-Pb ages and Nd isotopic compositions suggests that the Myobong Formation overlies the Jangsan and Myeonsan Formations unconformably. Considering the metamorphic age of the immediately underlying Precambrian basement metasediments (0.8 to 0.9 Ga), this stratigraphic relationship strongly suggests that the Jangsan Formation may be Neoproterozoic in age and that the Myeonsan Formation may be latest Neoproterozoic to Early Cambrian and calls for reevaluation of Precambrian-Paleozoic history of the Korean Peninsula. The

  10. Detrital zircon evidence for progressive underthrusting in Franciscan metagraywackes, west-central California

    Snow, C.A.; Wakabayashi, J.; Ernst, W.G.; Wooden, J.L.


    We present new U/Pb ages for detrital zircons separated from six quartzose metagraywackes collected from different Franciscan Complex imbricate nappes around San Francisco Bay. All six rocks contain a broad spread of Late Jurassic-Cretaceous grains originating from the Klamath-Sierra Nevada volcanic-plutonic arc. Units young structurally downward, consistent with models of progressive underplating and offscraping within a subduction complex. The youngest specimen is from the structurally lowest San Bruno Mountain sheet; at 52 Ma, it evidently was deposited during the Eocene. None of the other metagraywackes yielded zircon ages younger than 83 Ma. Zircons from both El Cerrito units are dominated by ca. 100-160 Ma grains; the upper El Cerrito also contains several grains in the 1200-1800 Ma interval. These samples are nearly identical to 97 Ma metasedimentary rock from the Hunters Point shear zone. Zircon ages from this m??lange block exhibit a broad distribution, ranging from 97 to 200 Ma, with only a single pre-Mesozoic age. The Albany Hill specimen has a distribution of pre-Mesozoic grains from 1300 to 1800 Ma, generally similar to that of the upper El Cerrito sheet; however, it contains zircons as young as 83 Ma, suggesting that it is significantly younger than the upper El Cerrito unit. The Skaggs Spring Schist is the oldest studied unit; its youngest analyzed grains were ca. 144 Ma, and it is the only investigated specimen to display a significant Paleozoic detrital component. Sedimentation and subduction-accretion of this tract of the trench complex took place along the continental margin during Early to early-Late Cretaceous time, and perhaps into Eocene time. Franciscan and Great Valley deposition attests to erosion of an Andean arc that was active over the entire span from ca. 145 to 80 Ma, with an associated accretionary prism built by progressive underthrusting. We use these new data to demonstrate that the eastern Franciscan Complex in the northern and

  11. Applications of detrital geochronology and thermochronology from glacial deposits to the Paleozoic and Mesozoic thermal history of the Ross Embayment, Antarctica

    Welke, Bethany; Licht, Kathy; Hennessy, Andrea; Hemming, Sidney; Pierce Davis, Elizabeth; Kassab, Christine


    Till from moraines at the heads of six major outlet glaciers in the Transantarctic Mountains (TAM) and from till beneath three West Antarctic ice streams have a ubiquitous zircon U-Pb age population spanning the time of the Ross/Pan-African Orogenies (610-475 Ma). Geochronology and thermochronology of detrital minerals in these Antarctic glacial tills reveal two different thermal histories for the central and southern TAM. Double-dating of the zircons reveals a geographically widespread (U-Th)/He (ZHe) population of 180-130 Ma in most of the till samples. Sandstone outcrops at Shackleton Glacier, and three Beacon Supergroup sandstone clasts from three moraines, have ZHe ages that fall entirely within this range. The similar population and proximity of many of the till samples to Beacon outcrops lead us to suggest that this extensive ZHe population in the tills is derived from Beacon Supergroup rocks and reflects the thermal response of the Beacon Basin to the breakup of Gondwana. A second population of older (>200 Ma) ZHe ages in tills at the head of Byrd, Nimrod, and Reedy Glaciers. For the tills at the head of the Nimrod and Byrd Glaciers, integrating the double-dated zircon results with 40Ar/39Ar of hornblende, muscovite and biotite, and U-Pb and (U-Th-Sm)/He double-dates on apatite yields a typical pattern of early rapid orogenic cooling (˜4-10°C/Myr) 590-475 Ma after the emplacement of the Granite Harbour Intrusives. Low temperature thermochronometers at these sites yield variable but quite old ages (ZHe 480-70 Ma and AHe 200-70 Ma) that require a long history at low temperature.

  12. Thinking beyond the Bioreactor Box: Incorporating Stream Ecology into Edge-of-Field Nitrate Management.

    Goeller, Brandon C; Febria, Catherine M; Harding, Jon S; McIntosh, Angus R


    Around the world, artificially drained agricultural lands are significant sources of reactive nitrogen to stream ecosystems, creating substantial stream health problems. One management strategy is the deployment of denitrification enhancement tools. Here, we evaluate the factors affecting the potential of denitrifying bioreactors to improve stream health and ecosystem services. The performance of bioreactors and the structure and functioning of stream biotic communities are linked by environmental parameters like dissolved oxygen and nitrate-nitrogen concentrations, dissolved organic carbon availability, flow and temperature regimes, and fine sediment accumulations. However, evidence of bioreactors' ability to improve waterway health and ecosystem services is lacking. To improve the potential of bioreactors to enhance desirable stream ecosystem functioning, future assessments of field-scale bioreactors should evaluate the influences of bioreactor performance on ecological indicators such as primary production, organic matter processing, stream metabolism, and invertebrate and fish assemblage structure and function. These stream health impact assessments should be conducted at ecologically relevant spatial and temporal scales. Bioreactors have great potential to make significant contributions to improving water quality, stream health, and ecosystem services if they are tailored to site-specific conditions and implemented strategically with land-based and stream-based mitigation tools within watersheds. This will involve combining economic, logistical, and ecological information in their implementation.

  13. Detrital Thermochronology of the Indus-Yarlung suture zone and implications for the tectonic and surface evolution of southern Tibet

    Carrapa, B.; Hassim, F.; Kapp, P. A.


    Detrital thermochronology has the unique potential to resolve the timing of source cooling associated with magmatic, tectonic and surface processes. Correct interpretation of the detrital signature requires a multi-dating approach involving chronometers sensitive to different temperatures and processes. A multi-dating study of modern river sands from southern Tibet reveals distinct cooling signals that provide significant information about tectonic and erosional evolution of the Indus-Yarlung suture (IYS) after the India-Asia collision with implications for the Cenozoic topographic evolution of the Tibetan Plateau. Modern sands from tributaries of the Yarlung River provide an opportunity to broadly sample source rocks exposed within the suture zone, including the Gangdese batholith, Xigaze forearc, Cenozoic basins, and Tethyan Himalayan rocks, and to investigate their regional geochemical signatures. Samples from rivers along the IYS in southern Tibet, between Xigaze and Mt. Kailas, were analyzed for detrital geochronology and low-temperature thermochronology. Comparison between ages recorded in the source and the detrital signature indicates that both the ages and their proportions directly reflect the ages and relative areas of source rocks in the catchment basins. Apatite fission track ages show two main cooling signals at 22-18 Ma and 12 Ma, which are consistent with accelerated exhumation of the Gangdese batholith and Oligo-Miocene Kailas basin and indicate significant regional exhumation of the IYS during the Miocene. Regional exhumation recorded throughout the IYS is likely the combined product of active Miocene tectonics and erosion of a paleo-Yarlung River. Efficient incision and evacuation of material from the IYS zone by a paleo-Yarlung River during the Miocene suggests a significantly different paleoenvironment than that which exists today. Miocene capture of the Yarlung River by the Brahmaputra River may have enhanced erosion in the IYS zone.

  14. Provenance and Detrital-Zircon Studies of the Mint Canyon Formation and its Correlation to the Caliente Formation, Southern California

    hoyt, johanna


    The Middle Miocene Mint Canyon and Caliente formations represent sedimentation after triple-junction extension in southern California. Sandstone and conglomerate petrology, combined with detrital-zircon analysis, determines provenance of the Mint Canyon and Caliente formations. These data indicate that most detritus is locally derived, rather than being derived from the Chocolate Mountains across the San Andreas fault. The Mint Canyon and Caliente formations received Proterozoic anorthosite-s...

  15. Invertebrate footprints on detritus processing, bacterial community structure, and spatiotemporal redox profiles

    Hunting, E.R.; Whatley, M.H.; van der Geest, H.G.; Mulder, C.; Kraak, M.H.S.; Breure, A.M.; Admiraal, W.


    Detritus processing is driven by a complex interplay between macroinvertebrate and microbial activities. Bioturbation/feeding activities of invertebrates in sediments are known to influence decomposition rates. However, direct effects of invertebrates on bacterial communities and detritus processing

  16. Transport of Exogenous Organic Substances by Invertebrate Integuments: The Field Revisited

    Gomme, Jørgen


    Transport, organic substances, monosaccharides, amino acids, marine invertebrates, integument, DOM, marine animals, L-alanine, D-glucos......Transport, organic substances, monosaccharides, amino acids, marine invertebrates, integument, DOM, marine animals, L-alanine, D-glucos...

  17. Invertebrate footprints on detritus processing, bacterial community structure, and spatiotemporal redox profiles

    Hunting, E.R.; Whatley, M.H.; van der Geest, H.G.; Mulder, C.; Kraak, M.H.S.; Breure, A.M.; Admiraal, W.


    Detritus processing is driven by a complex interplay between macroinvertebrate and microbial activities. Bioturbation/feeding activities of invertebrates in sediments are known to influence decomposition rates. However, direct effects of invertebrates on bacterial communities and detritus processing

  18. Invertebrate resources in Mississippi hardwood bottomlands, moist-soil habitat, and flooded cropland: Completion report

    US Fish and Wildlife Service, Department of the Interior — Assessment of invertebrate resources in green tree reservoirs and seasonally-flooded crop fields at Noxubee National Wildlife Refuge. Mean winter invertebrate...

  19. Sediment flux in the modern Indus River inferred from the trace element composition of detrital amphibole grains

    Lee, Jae Il; Clift, Peter D.; Layne, Graham; Blum, Joel; Khan, Ali Athar


    The drainage basin of the modern Indus River is composed of tectonic blocks that include oceanic arc units in the Indus Suture, reworked components of the Indian Plate and various parts of the former southern margin of Eurasia against which India collided. We investigate how these source units contribute to the modern bedload of the Indus River using the major and trace element composition of single detrital amphibole grains. Sediments from rivers eroding restricted drainage areas were analyzed to characterize the major potential source units. Samples taken at various localities downstream in the main Indus River allow the evolving provenance to be assessed. When coupled with existing bulk sediment Nd isotope data, a basic mass balance for the river can be constructed. The rapidly exhuming Southern Karakoram Metamorphic Complex is the dominant sediment source to the deep-sea Indus Fan. Although the Nanga Parbat Massif, located adjacent to the river's course is also rapidly exhuming, this is not an important source of sediment, probably because of its small area and the tectonic mechanism for its exhumation. The trace element composition of detrital amphibole grains can be a useful provenance indicator, especially in the identification of dominant sources in a complex mixed sediment environment. Trace element ratios Nb/Zr and Ba/Y were identified as being especially useful in discriminating detrital amphibole grains from various sources.

  20. Single-grain detrital-muscovite ages from Lower Cretaceous sandstones, Scotian Basin, and their implications for provenance

    Reynolds, P.H.; Grist, A.M. [Dalhousie Univ., Halifax, NS (Canada). Dept. of Earth Sciences; Pe-Piper, G. [Saint Mary' s Univ., Halifax, NS (Canada). Dept. of Geology; Piper, D.J.W. [Geological Survey of Canada, Bedford Inst. of Oceanography, Dartmouth, NS (Canada). Atlantic Geoscience Center


    Detrital muscovite is relatively abundant in the Lower Cretaceous rocks of the Scotian Basin, where the deltaic sandstones form important gas reservoirs. This paper reported on a study that used the single-grain geochronology dating technique to re-examine the significance of muscovite as a detrital mineral in the Scotian Basin. The objective was to better understand the sources of sediments in the offshore reservoir sandstone and to identify sediment dispersal patterns. Information on the detrital petrology and sediment provenance of the Lower Cretaceous sandstone is important for exploration models and for determining diagenesis and reservoir quality. One hundred muscovite grains were dated from a transect of wells near Sable Island. An additional 17 grains were dated from the Naskapi N-30 well in the western part of the basin. In general, the muscovite ranges in age from ca. 420 to 240 Ma, suggesting that ages were not reset by post-depositional alteration. The principal sources were rocks that had experienced resetting during Alleghenian deformation and Late Triassic, earliest Jurassic rifting. According to the distribution of ages and mass balance calculations, the sources were primarily Meguma metasedimentary rocks on the inner Scotian Shelf. The age distribution at Naskapi N-30 is similar to that in the South Mountain batholith, except for some grains younger than 360 Ma that suggest an offshore source with Alleghenian resetting. This paper also provided evidence that the inner shelf was an erosional area during the Early Cretaceous. 59 refs., 2 tabs., 7 figs., 1 appendix.

  1. SHRIMP U-Pb geochronology of the detrital zircons from the Longshoushan Group and its tectonic significance

    KuoAn TUNG; HoungYi YANG; LIU DunYi; ZHANG JianXin; ChienYuan TSENG; WAN YuSheng


    Sixty-two geologically meaningful U-Pb dates were obtained by using SHRIMP technique for the detrital zircons in three mettasedimentary rocks from stratigraphically uppermost parts of the Longshoushan Group in the present study.Eighty percents of these dates range from 1.7 Ga to 2.2 Ga with a peak at 1.8-2.0 Ga and twenty percents from 2.3 Ga to 2.7 Ga.The youngest detrital zircon is dated at 1724±19Ma which is interpreted as the maximum depositional age of the metasedimentary rocks.Therefore,the age for the diagenesis and lithification of the original sedimentary rocks of the Longshoushan Group before the metamorphism must be younger than 1724±19 Ma.Comparison of the age histograms of these detrital zircons with the ages of the igneous rocks on the surrounding older massifs suggests that the sediments of the Longshoushan Group were most likely derived from the Alaxa Block and Tarim Craton.This implies that the affinity between Alaxa Block and Tarim Craton was strong and that they might have been a unified craton during middle-early Proterozoic time

  2. Late Cenozoic deformation subsequence in northeastern margin of Tibet --Detrital AFT records from Linxia Basin

    ZHENG; Dewen; (郑德文); ZHANG; Peizhen; (张培震); WAN; Jinglin; (万景林); LI; Chuanyou; (李传友); CAO; Jixiu; (曹继秀)


    Two events of Tibet uplifting are revealed by detrital apatite fission track (AFT) age data from Linxia Basin. They occurred at about 14 and 5.4-8.0 MaBP respectively. We interpret the first one to be related to the uplifting of the northern Tibet, which might have resulted from convectively removing the thickened lower lithosphere. The second one is a result of Laji Mountain uplifting. Numerous studies of the Tibetan Plateau suggest that the onset time of the deformation in the northeastern margin of Tibetan Plateau and the time of Tibet attaining to its present elevation is about 8 MaBP. They are approximately coincident with the uplift of Lajishan Mountain. It suggests that the northeastern margin of Tibet propagated northeastwardly to its present site in about 8 MaBP for accommodating the sustained convergence between India-Eurasia plate and for keeping its high elevation. The active block pattern dominating the strong earthquake distribution of Chinese continent probably formed at about 8.0-5.4 MaBP.

  3. Detrital record of initial basement exhumation along the Laramide deformation front, southern Rocky Mountains

    Bush, Meredith A.; Horton, Brian K.; Murphy, Michael A.; Stockli, Daniel F.


    New geochronological constraints on upper crustal exhumation in the southern Rocky Mountains help delineate the latest Cretaceous-Paleogene history of drainage reorganization and landscape evolution during Laramide flat-slab subduction beneath western North America. Detrital zircon U-Pb results for the Raton basin of southern Colorado and northern New Mexico define the inception of coarse-grained siliciclastic sedimentation and a distinctive shift in provenance, from distal to proximal sources, that recorded shortening-related uplift and unroofing along the Laramide deformation front of the northern Sangre de Cristo Mountains. This Maastrichtian-early Paleocene ( 70-65 Ma) change—from distal foreland accumulation of sediment derived from the thin-skinned Cordilleran (Sevier) fold-thrust belt to coarse-grained sedimentation proximal to a Laramide basement block uplift—reflects cratonward (eastward) deformation advance and reorganization of drainage systems that supplied a large volume of Paleocene-lower Eocene sediments to the Gulf of Mexico. The timing of unroofing along the eastern deformation front is synchronous with basement-involved shortening across the interior of the Laramide province, suggesting abrupt wholesale uplift rather than a systematic inboard advance of deformation. The growth and infilling of broken foreland basins within the interior and margins of the Laramide province had a significant impact on continental-scale drainage systems, as several ponded/axial Laramide basins trapped large volumes of sediment and induced reorganization of major source-to-sink sediment pathways.

  4. A High-resolution Detrital and Oxygen Isotope Record from Flemish Pass, Labrador Sea

    deJesus, E.; Hoffman, J. S.; Clark, P. U.; Mix, A. C.


    High-resolution records of deglacial paleoceanographic change along the Labrador shelf are scarce. However, they are required in order to characterize and understand possible ice-ocean interactions involving the eastern sector of the Laurentide Ice Sheet (LIS). We have generated a high-resolution stable isotope and detrital stratigraphic record for core HU2001043-008 (990m, 48° N, 45° W) from Flemish Pass, Labrador Sea, to better understand the role of LIS ice-rafting events in abrupt climate changes during the last glaciation. Samples at two-centimeter resolution were disaggregated, washed, and picked for Neogloboquandrina pachyderma (sinistral) for stable isotope and radiocarbon analysis. The δ18O signal in foraminiferal calcite allows us to examine surface-ocean changes that may indicate an influx of freshwater, which may or may not be related to an LIS ice-rafting event. Our results will help in developing a better understanding of the source of LIS ice-rafting events, precursory indicators of the events, and how these events are associated with changes in deep-water formation in the Labrador Sea.

  5. Percent Agriculture Adjacent to Streams

    U.S. Environmental Protection Agency — The type of vegetation along a stream influences the water quality in the stream. Intact buffer strips of natural vegetation along streams tend to intercept...

  6. Percent Forest Adjacent to Streams

    U.S. Environmental Protection Agency — The type of vegetation along a stream influences the water quality in the stream. Intact buffer strips of natural vegetation along streams tend to intercept...

  7. Evaluation of Metal Toxicity in Streams Affected by Abandoned Mine Lands, Upper Animas River Watershed, Colorado

    Besser, John M.; Allert, Ann L.; Hardesty, Douglas K.; Ingersoll, Christopher G.; May, Thomas W.; Wang, Ning; Leib, Kenneth J.


    Acid drainage from abandoned mines and from naturally-acidic rocks and soil in the upper Animas River watershed of Colorado generates elevated concentrations of acidity and dissolved metals in stream waters and deposition of metal-contaminated particulates in streambed sediments, resulting in both toxicity and habitat degradation for stream biota. High concentrations of iron (Fe), aluminum (Al), zinc (Zn), copper (Cu), cadmium (Cd), and lead (Pb) occur in acid streams draining headwaters of the upper Animas River watershed, and high concentrations of some metals, especially Zn, persist in circumneutral reaches of the Animas River and Mineral Creek, downstream of mixing zones of acid tributaries. Seasonal variation of metal concentrations is reflected in variation in toxicity of stream water. Loadings of dissolved metals to the upper Animas River and tributaries are greatest during summer, during periods of high stream discharge from snowmelt and monsoonal rains, but adverse effects on stream biota may be greater during winter low-flow periods, when stream flows are dominated by inputs of groundwater and contain greatest concentrations of dissolved metals. Fine stream-bed sediments of the upper Animas River watershed also contain elevated concentrations of potentially toxic metals. Greatest sediment metal concentrations occur in the Animas River upstream from Silverton, where there are extensive deposits of mine and mill tailings, and in mixing zones in the Animas River and lower Mineral Creek, where precipitates of Fe and Al oxides also contain high concentrations of other metals. This report summarizes the findings of a series of toxicity studies in streams of the upper Animas River watershed, conducted on-site and in the laboratory between 1998 and 2000. The objectives of these studies were: (1) to determine the relative toxicity of stream water and fine stream-bed sediments to fish and invertebrates; (2) to determine the seasonal range of toxicity in stream

  8. Trends in Children's Concepts of Vertebrate and Invertebrate.

    Braund, Martin


    Presents the results of a cross-age study of 7- to 15-year-old children on their thinking about vertebrate and invertebrate animals. Suggests experiences that could be included in the school science curriculum and argues for more classroom work relating structure with function in order to address students' conceptual difficulties. (Contains 18…

  9. An investigation into the chemical composition of alternative invertebrate prey

    Oonincx, D.G.A.B.; Dierenfeld, E.S.


    The aim of this study was to determine the chemical composition of eight invertebrate species and evaluate their suitability as alternative prey. The species selected were rusty red cockroaches (Blatta lateralis), six-spotted cockroaches (Eublaberus distanti), Madagascar hissing cockroaches (Grompha

  10. Bibliography of African inland water invertebrates (to 1980)

    Davies, BR


    Full Text Available This bibliography is a direct outcome of the SIL-UNEP Workshop on African Limnology held at the University of Nairobi, Kenya, between 16-23 December, 1979. Part 1 of the framework document for the A4 section of the Workshop - "Invertebrates...

  11. Invertebrates: Revealing a Hidden World in the Year of Biodiversity

    Sanders, Dawn


    Biodiversity means the variety of life in all its forms. It includes the variety of species and ecosystems in the world, and genetic variation. Invertebrates are one of the largest and most accessible groups of animals for primary children to study. In this article, the author explains why and how children should engage with the idea of…

  12. Invertebrates: Revealing a Hidden World in the Year of Biodiversity

    Sanders, Dawn


    Biodiversity means the variety of life in all its forms. It includes the variety of species and ecosystems in the world, and genetic variation. Invertebrates are one of the largest and most accessible groups of animals for primary children to study. In this article, the author explains why and how children should engage with the idea of…

  13. Marine invertebrate diversity in Aristotle’s zoology

    Voultsiadou, E.; Vafidis, D.


    The aim of this paper is to bring to light Aristotle’s knowledge of marine invertebrate diversity as this has been recorded in his works 25 centuries ago, and set it against current knowledge. The analysis of information derived from a thorough study of his zoological writings revealed 866 records r

  14. Invertebrate neurophylogeny: suggested terms and definitions for a neuroanatomical glossary

    Müller Carsten HG


    Full Text Available Abstract Background Invertebrate nervous systems are highly disparate between different taxa. This is reflected in the terminology used to describe them, which is very rich and often confusing. Even very general terms such as 'brain', 'nerve', and 'eye' have been used in various ways in the different animal groups, but no consensus on the exact meaning exists. This impedes our understanding of the architecture of the invertebrate nervous system in general and of evolutionary transformations of nervous system characters between different taxa. Results We provide a glossary of invertebrate neuroanatomical terms with a precise and consistent terminology, taxon-independent and free of homology assumptions. This terminology is intended to form a basis for new morphological descriptions. A total of 47 terms are defined. Each entry consists of a definition, discouraged terms, and a background/comment section. Conclusions The use of our revised neuroanatomical terminology in any new descriptions of the anatomy of invertebrate nervous systems will improve the comparability of this organ system and its substructures between the various taxa, and finally even lead to better and more robust homology hypotheses.

  15. Nanoparticle-protein corona in invertebrate in vitro testing

    Hayashi, Yuya; Miclaus, Teodora; Scavenius, Carsten;


    , and the primary cells were thus exposed to silver nanoparticles with pre-formed corona of serum albumin (a major serum protein). Here we have profiled proteins forming the hard corona around silver nanoparticles (OECD reference materials, 15 nm and 75 nm) using gel electrophoresis techniques to identify proteins...... for evaluation of the protein corona in invertebrate in vitro setting....

  16. Integrative neural networks models for stream assessment in restoration projects

    Gazendam, Ed; Gharabaghi, Bahram; Ackerman, Josef D.; Whiteley, Hugh


    Stream-habitat assessment for evaluation of restoration projects requires the examination of many parameters, both watershed-scale and reach-scale, to incorporate the complex non-linear effects of geomorphic, riparian, watershed and hydrologic factors on aquatic ecosystems. Rapid geomorphic assessment tools used by many jurisdictions to assess natural channel design projects seldom include watershed-level parameters, which have been shown to have a significant effect on benthic habitat in stream systems. In this study, Artificial Neural Network (ANN) models were developed to integrate complex non-linear relationships between the aquatic ecosystem health indices and key watershed-scale and reach-scale parameters. Physical stream parameters, based on QHEI parameters, and watershed characteristics data were collected at 112 sites on 62 stream systems located in Southern Ontario. Benthic data were collected separately and benthic invertebrate summary indices, specifically Hilsenhoff's Biotic Index (HBI) and Richness, were determined. The ANN models were trained on the randomly selected 3/4 of the dataset of 112 streams in Ontario, Canada and validated on the remaining 1/4. The R2 values for the developed ANN model predictions were 0.86 for HBI and 0.92 for Richness. Sensitivity analysis of the trained ANN models revealed that Richness was directly proportional to Erosion and Riparian Width and inversely proportional to Floodplain Quality and Substrate parameters. HBI was directly proportional to Velocity Types and Erosion and inversely proportional to Substrate, % Treed and 1:2 Year Flood Flow parameters. The ANN models can be useful tools for watershed managers in stream assessment and restoration projects by allowing consideration of watershed properties in the stream assessment.

  17. Invertebrate grazing during the regenerative phase affects the ultimate structure of macrophyte communities

    Elger, A.F.; Willby, N.; Cabello-Martinez, M.


    1. Although the biomass of freshwater macrophytes consumed by invertebrate herbivores (excluding crayfish) is usually low, there is growing evidence that invertebrates do exert a structuring effect on macrophyte communities. To explain this, we postulated that the effect of invertebrates may be conc

  18. Invertebrate community composition differs between invasive herb alligator weed and native sedges

    Bassett, Imogen E.; Paynter, Quentin; Beggs, Jacqueline R.


    Chemical and/or architectural differences between native and exotic plants may influence invertebrate community composition. According to the enemy release hypothesis, invasive weeds should host fewer and less specialised invertebrates than native vegetation. Invertebrate communities were compared on invasive Alternanthera philoxeroides (alligator weed) and native sedges (Isolepis prolifer and Schoenoplectus tabernaemontani) in a New Zealand lake. A. philoxeroides is more architecturally and chemically similar to I. prolifer than to S. tabernaemontani. Lower invertebrate abundance, richness and proportionally fewer specialists were predicted on A. philoxeroides compared to native sedges, but with greatest differences between A. philoxeroides and S. tabernaemontani. A. philoxeroides is more architecturally and chemically similar to I. prolifer than to S. tabernaemontani. Invertebrate abundance showed taxa-specific responses, rather than consistently lower abundance on A. philoxeroides. Nevertheless, as predicted, invertebrate fauna of A. philoxeroides was more similar to that of I. prolifer than to S. tabernaemontani. The prediction of a depauperate native fauna on A. philoxeroides received support from some but not all taxa. All vegetation types hosted generalist-dominated invertebrate communities with simple guild structures. The enemy release hypothesis thus had minimal ability to predict patterns in this system. Results suggest the extent of architectural and chemical differences between native and invasive vegetation may be useful in predicting the extent to which they will host different invertebrate communities. However, invertebrate ecology also affects whether invertebrate taxa respond positively or negatively to weed invasion. Thus, exotic vegetation may support distinct invertebrate communities despite similar overall invertebrate abundance to native vegetation.

  19. The overlooked biodiversity of flower-visiting invertebrates.

    Carl W Wardhaugh

    Full Text Available Estimates suggest that perhaps 40% of all invertebrate species are found in tropical rainforest canopies. Extrapolations of total diversity and food web analyses have been based almost exclusively on species inhabiting the foliage, under the assumption that foliage samples are representative of the entire canopy. We examined the validity of this assumption by comparing the density of invertebrates and the species richness of beetles across three canopy microhabitats (mature leaves, new leaves and flowers on a one hectare plot in an Australian tropical rainforest. Specifically, we tested two hypotheses: 1 canopy invertebrate density and species richness are directly proportional to the amount of resource available; and 2 canopy microhabitats represent discrete resources that are utilised by their own specialised invertebrate communities. We show that flowers in the canopy support invertebrate densities that are ten to ten thousand times greater than on the nearby foliage when expressed on a per-unit resource biomass basis. Furthermore, species-level analyses of the beetle fauna revealed that flowers support a unique and remarkably rich fauna compared to foliage, with very little species overlap between microhabitats. We reject the hypothesis that the insect fauna on mature foliage is representative of the greater canopy community even though mature foliage comprises a very large proportion of canopy plant biomass. Although the significance of the evolutionary relationship between flowers and insects is well known with respect to plant reproduction, less is known about the importance of flowers as resources for tropical insects. Consequently, we suggest that this constitutes a more important piece of the 'diversity jigsaw puzzle' than has been previously recognised and could alter our understanding of the evolution of plant-herbivore interactions and food web dynamics, and provide a better foundation for accurately estimating global species

  20. The complement C3 protein family in invertebrates

    M Nonaka


    Full Text Available Complement C3 plays a pivotal role in the innate immune system of mammals as the central component of the complement system essential for its activation mechanism and effecter function. C3 has a unique intra-chain thioester bond that is shared by some complement and non-complement proteins forming a thioester protein (TEP family. Phylogenetic analysis of TEP family genes of vertebrates and invertebrates revealed that the TEP family is divided into two subfamilies, the C3 subfamily and the alpha-2-macroglobulin (A2M subfamily. The establishment of the TEP genes and differentiation of them into the C3 and A2M subfamilies occurred prior to the divergence of Cnidaria and Bilateria, in a common ancestor of Eumetazoa more than 600 MYA. Since then the A2M subfamily has been retained by all metazoan lineages analyzed thus far. In contrast, the C3 subfamily has been retained only by deuterostomes and some protostomes, and has been lost in multiple protostome lineages. Although the direct functional analysis of the most invertebrate TEPs is still to be performed, conservation of the basic domain structure and functionally important residues for each molecule suggests that the basic function is also conserved. Functional analyses performed on a few invertebrate C3 support this conclusion. The gene duplication events that generated C4 and C5 from C3 occurred in a common ancestor of jawed vertebrates, indicating that invertebrate and cyclostome C3s represent the pre-duplication state. In addition to C3, complement Bf and MASP involved in the activation of C3 are also identified in Cnidaria and some invertebrates, indicating that the complement system is one of the most ancient innate immune systems of Eumetazoa.

  1. Crawling to collapse: ecologically unsound ornamental invertebrate fisheries.

    Andrew Rhyne

    Full Text Available BACKGROUND: Fishery management has historically been an inexact and reactionary discipline, often taking action only after a critical stock suffers overfishing or collapse. The invertebrate ornamental fishery in the State of Florida, with increasing catches over a more diverse array of species, is poised for collapse. Current management is static and the lack of an adaptive strategy will not allow for adequate responses associated with managing this multi-species fishery. The last decade has seen aquarium hobbyists shift their display preference from fish-only tanks to miniature reef ecosystems that include many invertebrate species, creating increased demand without proper oversight. The once small ornamental fishery has become an invertebrate-dominated major industry supplying five continents. METHODOLOGY/PRINCIPAL FINDINGS: Here, we analyzed the Florida Marine Life Fishery (FLML landing data from 1994 to 2007 for all invertebrate species. The data were organized to reflect both ecosystem purpose (in the wild and ecosystem services (commodities for each reported species to address the following question: Are ornamental invertebrates being exploited for their fundamental ecosystem services and economic value at the expense of reef resilience? We found that 9 million individuals were collected in 2007, 6 million of which were grazers. CONCLUSIONS/SIGNIFICANCE: The number of grazers now exceeds, by two-fold, the number of specimens collected for curio and ornamental purposes altogether, representing a major categorical shift. In general, landings have increased 10-fold since 1994, though the number of licenses has been dramatically reduced. Thus, despite current management strategies, the FLML Fishery appears to be crawling to collapse.

  2. Academic streaming in Europe

    Falaschi, Alessandro; Mønster, Dan; Doležal, Ivan;


    The TF-NETCAST task force was active from March 2003 to March 2004, and during this time the mem- bers worked on various aspects of streaming media related to the ultimate goal of setting up common services and infrastructures to enable netcasting of high quality content to the academic community...... in Europe. We report on a survey of the use of streaming media in the academic community in Europe, an open source content delivery network, and a portal for announcing live streaming events to the global academic community....

  3. Trout Stream Special Regulations

    Minnesota Department of Natural Resources — This layer shows Minnesota trout streams that have a special regulation as described in the 2006 Minnesota Fishing Regulations. Road crossings were determined using...

  4. Channelized Streams in Iowa

    Iowa State University GIS Support and Research Facility — This draft dataset consists of all ditches or channelized pieces of stream that could be identified using three input datasets; namely the1:24,000 National...

  5. Streaming tearing mode

    Shigeta, M.; Sato, T.; Dasgupta, B.


    The magnetohydrodynamic stability of streaming tearing mode is investigated numerically. A bulk plasma flow parallel to the antiparallel magnetic field lines and localized in the neutral sheet excites a streaming tearing mode more strongly than the usual tearing mode, particularly for the wavelength of the order of the neutral sheet width (or smaller), which is stable for the usual tearing mode. Interestingly, examination of the eigenfunctions of the velocity perturbation and the magnetic field perturbation indicates that the streaming tearing mode carries more energy in terms of the kinetic energy rather than the magnetic energy. This suggests that the streaming tearing mode instability can be a more feasible mechanism of plasma acceleration than the usual tearing mode instability.

  6. Streaming media bible

    Mack, Steve


    This book "tells you everything you need to know to produce professional-quality streaming media for the Internet, from an overview of the available systems and tools to high-end techniques for top quality results...

  7. Roads Near Streams

    U.S. Environmental Protection Agency — Roads are a source of auto related pollutants (e.g. gasoline, oil and other engine fluids). When roads are near streams, rain can wash these pollutants directly into...

  8. Future Roads Near Streams

    U.S. Environmental Protection Agency — Roads are a source of auto related pollutants (e.g. gasoline, oil and other engine fluids). When roads are near streams, rain can wash these pollutants directly into...

  9. DNR 24K Streams

    Minnesota Department of Natural Resources — 1:24,000 scale streams captured from USGS seven and one-half minute quadrangle maps, with perennial vs. intermittent classification, and connectivity through lakes,...

  10. Streaming tearing mode

    Shigeta, M.; Sato, T.; Dasgupta, B.


    The magnetohydrodynamic stability of streaming tearing mode is investigated numerically. A bulk plasma flow parallel to the antiparallel magnetic field lines and localized in the neutral sheet excites a streaming tearing mode more strongly than the usual tearing mode, particularly for the wavelength of the order of the neutral sheet width (or smaller), which is stable for the usual tearing mode. Interestingly, examination of the eigenfunctions of the velocity perturbation and the magnetic field perturbation indicates that the streaming tearing mode carries more energy in terms of the kinetic energy rather than the magnetic energy. This suggests that the streaming tearing mode instability can be a more feasible mechanism of plasma acceleration than the usual tearing mode instability.

  11. The leaf breakdown of Picramnia sellowii (Picramniales: Picramniaceae as index of anthropic disturbances in tropical streams

    M. P. Lopes

    Full Text Available Abstract There are few studies in tropical regions exploring the use of leaf breakdown process as a functional tool to assess anthropic disturbance on aquatic ecosystems. We assessed the effects of water pollution due to human activities on the leaf breakdown rate of Picramnia sellowii in streams of the southeastern Brazil. The experiment was carried out for 60 days in three reference streams and three streams impaired by organic pollution and absence of riparian vegetation. Three litter bags were incubated in each stream containing 3 ± 0.05 g of P. sellowii leaves. The reference streams presented higher values of dissolved oxygen and lower values of nutrients, turbidity, electrical conductivity, total impermeable area and water temperature. The leaf breakdown rate (k differed significantly between the reference (k = 0.014 ± 0.003 d–1 and impaired streams (k = 0.005 ± 0.001 d–1. The leaves incubated in the reference streams contained greater fungal biomass (measured as ergosterol concentration and abundance of invertebrates, as well as greater presence of shredders, with k values being related to the biomass of these organisms. Overall, there were clear differences between the leaf mass loss in the reference and impaired streams. These results reinforce the negative effect of urbanization on leaf breakdown and fungal and shredder biomass.

  12. The leaf breakdown of Picramnia sellowii (Picramniales: Picramniaceae) as index of anthropic disturbances in tropical streams.

    Lopes, M P; Martins, R T; Silveira, L S; Alves, R G


    There are few studies in tropical regions exploring the use of leaf breakdown process as a functional tool to assess anthropic disturbance on aquatic ecosystems. We assessed the effects of water pollution due to human activities on the leaf breakdown rate of Picramnia sellowii in streams of the southeastern Brazil. The experiment was carried out for 60 days in three reference streams and three streams impaired by organic pollution and absence of riparian vegetation. Three litter bags were incubated in each stream containing 3 ± 0.05 g of P. sellowii leaves. The reference streams presented higher values of dissolved oxygen and lower values of nutrients, turbidity, electrical conductivity, total impermeable area and water temperature. The leaf breakdown rate (k) differed significantly between the reference (k = 0.014 ± 0.003 d-1) and impaired streams (k = 0.005 ± 0.001 d-1). The leaves incubated in the reference streams contained greater fungal biomass (measured as ergosterol concentration) and abundance of invertebrates, as well as greater presence of shredders, with k values being related to the biomass of these organisms. Overall, there were clear differences between the leaf mass loss in the reference and impaired streams. These results reinforce the negative effect of urbanization on leaf breakdown and fungal and shredder biomass.

  13. Streaming Virtual Reality Content

    El-Ganainy, Tarek; Hefeeda, Mohamed


    The recent rise of interest in Virtual Reality (VR) came with the availability of commodity commercial VR prod- ucts, such as the Head Mounted Displays (HMD) created by Oculus and other vendors. To accelerate the user adoption of VR headsets, content providers should focus on producing high quality immersive content for these devices. Similarly, multimedia streaming service providers should enable the means to stream 360 VR content on their platforms. In this study, we try to cover different ...

  14. Reincarnation of Streaming Applications


    AFRL-RY-WP-TR-2009-1033 REINCARNATION OF STREAMING APPLICATIONS Saman Amarsinghe, Robert Miller, and Michael Ernst Massachusetts...2007 – 31 December 2008 4. TITLE AND SUBTITLE REINCARNATION OF STREAMING APPLICATIONS 5a. CONTRACT NUMBER 5b. GRANT NUMBER FA8650-07-C-7737 5c...Program Reincarnation , using a simple prototype. A Program Reincarnation tool will assist the programmer in replacing the program’s code (the body

  15. Detrital zircon evidence for Hf isotopic evolution of granitoid crust and continental growth

    Iizuka, Tsuyoshi; Komiya, Tsuyoshi; Rino, Shuji; Maruyama, Shigenori; Hirata, Takafumi


    We have determined U-Pb ages, trace element abundances and Hf isotopic compositions of approximately 1000 detrital zircon grains from the Mississippi, Congo, Yangtze and Amazon Rivers. The U-Pb isotopic data reveal the lack of >3.3 Ga zircons in the river sands, and distinct peaks at 2.7-2.5, 2.2-1.9, 1.7-1.6, 1.2-1.0, 0.9-0.4, and uniformitarian secular change in Hf isotopes of granitoid crusts; Hf isotopic compositions of granitoid crusts deviate from the mantle evolution line from about 3.3 to 2.0 Ga, the deviation declines between 2.0 and 1.3 Ga and again increases afterwards. Consideration of mantle-crust mixing models for granitoid genesis suggests that the noted isotopic trends are best explained if the rate of crust generation globally increased in two stages at around (or before) 3.3 and 1.3 Ga, whereas crustal differentiation was important in the evolution of the continental crust at 2.3-2.2 Ga and after 0.6 Ga. Reconciling the isotopic secular change in granitoid crust with that in sedimentary rocks suggests that sedimentary recycling has essentially taken place in continental settings rather than active margin settings and that the sedimentary mass significantly grew through addition of first-cycle sediments from young igneous basements, until after ˜1.3 Ga when sedimentary recycling became the dominant feature of sedimentary evolution. These findings, coupled with the lack of zircons older than 3.3 Ga in river sands, imply the emergence of large-scale continents at about 3.3 Ga with further rapid growth at around 1.3 Ga. This resulted in the major growth of the sedimentary mass between 3.3 and 1.3 Ga and the predominance of its cannibalistic recycling later.

  16. Geometry and structure of the andesitic volcano-detritic deposits: The Merapi case

    Selles, A.; Deffontaines, B.; Hendrayana, H.; Violette, S.


    Several geological studies have been performed on the volcano-detritic deposits but finally the global overview of the geometry of those is still poorly known. The quick alteration enhances the high heterogeneity of these formations, especially under tropical climate. Better knowledge of the structure of the volcano-sedimentary edifices is capital to understand:i) the geomorphological impacts, as landslides ii) or the hydrogeological processes. The Merapi Mount is an andesitic strato-volcano, located in Central Java and is one of the most active volcanoes in Indonesia. About 500,000 people live in the immediate vicinity of the volcano and are directly subject, not only to the volcanic eruptions but also to the landslide hazards. The East flank of the Merapi presents a complex history and has been relatively spared by the recent volcanic activity; thus, the geomorphology and the structure of the deposit have been driven by the erosion and remobilization processes under equatorial climate. This work contributes to understand the processes of construction, destruction and sedimentation of a complex active strato-volcano and shed light to its geological and geomorphological history. Based on field observations and literature, the specific deposits have been identified. The lithological facies have been described and several cross sections have been done to precise the distinct phases of building edifice, due to old eruptions. Recent field surveys allowed characterizing the dismantling steps and processes of the volcano by erosion and the local to distal sedimentation associated. The East flank has been split in four zones where each formation presents a lateral facies variation depending on the distance from the summit and the age of deposits. Based on the collected data, the size and the three dimensional extension of each deposits has been delimitated. The geological and geomorphological interpretation is proposed through a conceptual model.

  17. Detrital phosphorus as a proxy of flooding events in the Changjiang River Basin

    Meng, Jia [Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Qingdao 266100 (China); College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100 (China); Yao, Peng, E-mail: [Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Qingdao 266100 (China); Qingdao Collaborative Innovation Center of Marine Science and Technology, Qingdao 266100 (China); Institute of Marine Organic Geochemistry, Ocean University of China, Qingdao 266100 (China); Bianchi, Thomas S. [Department of Geological Sciences, University of Florida, Gainesville, FL 32611-2120 (United States); Li, Dong; Zhao, Bin; Xu, Bochao [Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Qingdao 266100 (China); College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100 (China); Yu, Zhigang [Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Qingdao 266100 (China); Institute of Marine Organic Geochemistry, Ocean University of China, Qingdao 266100 (China)


    In this study, sediment grain size (MGS), specific surface area (SSA), total organic carbon (TOC) contents, C/N molar ratios, stable carbon isotope, and P species in a sediment core, collected from the East China Sea (ECS) inner-shelf were measured to explore the applicability of detrital phosphorus (De-P) as a potential indicator of past flooding events in the Changjiang River Basin (CRB). In particular, we examined the linkages between the evolution of floods with regional climate changes and anthropogenic activities in the CRB. Peaks of De-P concentrations in sediments corresponded well with the worst flooding events of the CRB over the past two centuries (e.g., 1850s, 1860s, 1900s, 1920s, 1950s, 1980s, and 2000s). Moreover, De-P also corresponded well with the extreme hypoxic events in 1981 and 1998 in the Changjiang Estuary as indicated by Mo/Al ratios, indicating potential linkages between De-P as a flooding proxy to flood-induced hypoxia events in this region. In addition, a robust relationship was found among De-P, the floods in 1950s, 1980s, and 2000s of the CRB, the intensive El Niño-Southern Oscillation (ENSO), the abnormally weak East Asian Summer Monsoon (EASM) and the warm phase of Pacific Decadal Oscillation (PDO), suggesting that De-P also provided insights to linkages between regional climate change and flooding events in this region. - Highlights: • De-P was used to track past floods in the Changjiang River Basin (CRB). • De-P may serve as a proxy for flood-induced hypoxia events in the Changjiang Estuary. • De-P may be a proxy for examining linkages between floods and climatic drivers.

  18. Usbnd Pb detrital zircon ages from some Neoproterozoic successions of Uruguay: Provenance, stratigraphy and tectonic evolution

    Pecoits, Ernesto; Aubet, Natalie R.; Heaman, Larry M.; Philippot, Pascal; Rosière, Carlos A.; Veroslavsky, Gerardo; Konhauser, Kurt O.


    The Neoproterozoic volcano-sedimentary successions of Uruguay have been the subject of several sedimentologic, chrono-stratigraphic and tectonic interpretation studies. Recent studies have shown, however, that the stratigraphy, age and tectonic evolution of these units remain uncertain. Here we use new Usbnd Pb detrital zircon ages, combined with previously published geochronologic and stratigraphic data in order to provide more precise temporal constraints on their depositional age and to establish a more solid framework for the stratigraphic and tectonic evolution of these units. The sequence of events begins with a period of tectonic quiescence and deposition of extensive mixed siliciclastic-carbonate sedimentary successions. This is followed by the development of small fault-bounded siliciclastic and volcaniclastic basins and the emplacement of voluminous granites associated with episodic terrane accretion. According to our model, the Arroyo del Soldado Group and the Piedras de Afilar Formation were deposited sometime between ∼1000 and 650 Ma, and represent passive continental margin deposits of the Nico Pérez and Piedra Alta terranes, respectively. In contrast, the Ediacaran San Carlos (Dionisio terranes, and the herein defined Edén Terrane. The Edén and the Nico Pérez terranes likely accreted at ∼650-620 Ma (Edén Accretionary Event), followed by their accretion to the Piedra Alta Terrane at ∼620-600 Ma (Piedra Alta Accretionary Event), and culminating with the accretion of the Cuchilla Dionisio Terrane at ∼600-560 Ma (Cuchilla Dionisio Accretionary Event). Although existing models consider all the Ediacaran granites as a result of a single orogenic event, recently published age constraints point to the existence of at least two distinct stages of granite generation, which are spatially and temporally associated with the Edén and Cuchilla Dionisio accretionary events.

  19. Gulf stream separation dynamics

    Schoonover, Joseph

    Climate models currently struggle with the more traditional, coarse ( O(100 km) ) representation of the ocean. In these coarse ocean simulations, western boundary currents are notoriously difficult to model accurately. The modeled Gulf Stream is typically seen exhibiting a mean pathway that is north of observations, and is linked to a warm sea-surface temperature bias in the Mid-Atlantic Bight. Although increased resolution ( O(10 km) ) improves the modeled Gulf Stream position, there is no clean recipe for obtaining the proper pathway. The 70 year history of literature on the Gulf Stream separation suggests that we have not reached a resolution on the dynamics that control the current's pathway just south of the Mid-Atlantic Bight. Without a concrete knowledge on the separation dynamics, we cannot provide a clean recipe for accurately modeling the Gulf Stream at increased resolutions. Further, any reliable parameterization that yields a realistic Gulf Stream path must express the proper physics of separation. The goal of this dissertation is to determine what controls the Gulf Stream separation. To do so, we examine the results of a model intercomparison study and a set of numerical regional terraforming experiments. It is argued that the separation is governed by local dynamics that are most sensitive to the steepening of the continental shelf, consistent with the topographic wave arrest hypothesis of Stern (1998). A linear extension of Stern's theory is provided, which illustrates that wave arrest is possible for a continuously stratified fluid.

  20. Closure of Tethys and early stages of Himalayan evolution: constraints from the detrital record, Ladakh, India

    Jenks, D.; Najman, Y.; Godin, L.; Parrish, R.; Horstwood, M.; Green, O.; Bown, P.; Garzanti, E.; Willems, H.


    Closure of Tethys marks initiation of collision between India and Asia, and the start of Himalayan orogenesis. A clear understanding of when this occurred is paramount to understanding the tectonic and denudational processes that have occurred since collision. A number of methods and datasets have been used to constrain the initiation of collision, from faunal mixing at 65 Ma [1] to the timing at which Indian rocks reached UHP depths at 57 Ma [2], to a reduction in northward drift of the Indian plate at 55 Ma [3]. New interpretations have placed collision as late as 38 Ma [4]. The extent of diachroneity is also disputed, varying from slight [5] to substantial [6]. Two approaches are used here to determine collision, 1) the timing of closure of the Tethys Ocean [7], based on stratigraphic succession, 2) first evidence of Asian derived material deposited on the Indian plate [8], using U-Pb ages of detrital zircon to assess provenance. In Ladakh, Indian plate passive margin limestones of the Mid-Late Paleocene Dibling Formation [9] are overlain by the youngest marine facies of the region, the marine siltstones of the Kong Fm. and the fluvio-deltaic facies of the Chulung La Fm. [8]. The age of the Kong and Chulung La formations is disputed, ranging from P5/6 (56 Ma) [10] to P8 (50.5 Ma) [8]. The provenance is also debated, considered either to be eroded from ophiolitic material from the Indian plate [10] or containing detritus from the Trans-Himalayan arc of the Asian plate [8,11]. We applied biostratigraphy, and U-Pb dating on detrital zircon, to samples from the Kong and Chulung La Formations to define depositional age and provenance. Biostratigraphy identified Asselines A. placentula grande and A. pomeroli, from the SBZ 10 (50.5 to 52.5 Ma) and SBZ 9 (53 Ma) zones respectively, thereby defining a minimum age of collision at 50.5 Ma, based on cessation of marine facies. However, the possibility that these fossils are reworked will be discussed. U-Pb dating of

  1. Raman spectroscopy of detrital garnet from the (U)HP terrane of eastern Papua New Guinea

    Andò, Sergio; Baldwin, Suzanne L.; Fitzgerald, Paul G.; Malusà, Marco G.; Aliatis, Irene; Vezzoli, Giovanni; Garzanti, Eduardo


    Garnet is one of the most widespread heavy minerals in sediments derived from orogenic systems. Its chemical composition varies systematically with temperature and pressure conditions, and thus provides information on the metamorphic evolution of source areas that is crucial in tectonic and geodynamic reconstructions. Garnet is easily identified in mineral grain mounts and is relatively stable during burial diagenesis. Raman spectroscopy allows rapid determination of garnet compositions in grain mounts or thin sections of sand and sandstone samples, and can be used to assess their density and chemical composition quite accurately ("MIRAGEM" method of Bersani et al., 2009; Andò et al., 2009). In the D'Entrecastreaux Islands of southeastern Papua New Guinea, the world's youngest (U)HP rocks are exposed. There, mafic rocks and their felsic host gneisses were metamorphosed under eclogite facies conditions from late Miocene to Pliocene, before being exhumed from depths of ~90 km (Baldwin et al., 2004, 2008). The eclogite preserves a peak assemblage of garnet, omphacite, rutile, phengite and Si02 (Hill and Baldwin, 1993). A coesite-eclogite has been found in one small island outcrop. In order to sample garnet populations representative of a larger geographical area, we sampled and studied a heavy-mineral-dominated placer sand (HMC 80) from a beach from SE Goodenough Island. Garnet grains in beach sand are associated with blue-green to subordinately green-brown amphibole and minor epidote, omphacitic clinopyroxene, titanite, apatite and rutile. The subordinate low-density fraction is feldspatho-quartzose with high-rank metamorphic rock fragments and biotite (Q62 F35 Lm2; MI 360). Detrital garnets are mostly classified as almandine with relatively high Mg and Ca and lacking Mn, typical of the eclogite facies (Win et al., 2007; type Ci garnets of Mange and Morton 2007; Andò et al., 2013). In well-described stratigraphic sequences within syn-and post-tectonic basins

  2. Streaming Pool: reuse, combine and create reactive streams with pleasure

    CERN. Geneva


    When connecting together heterogeneous and complex systems, it is not easy to exchange data between components. Streams of data are successfully used in industry in order to overcome this problem, especially in the case of "live" data. Streams are a specialization of the Observer design pattern and they provide asynchronous and non-blocking data flow. The ongoing effort of the ReactiveX initiative is one example that demonstrates how demanding this technology is even for big companies. Bridging the discrepancies of different technologies with common interfaces is already done by the Reactive Streams initiative and, in the JVM world, via reactive-streams-jvm interfaces. Streaming Pool is a framework for providing and discovering reactive streams. Through the mechanism of dependency injection provided by the Spring Framework, Streaming Pool provides a so called Discovery Service. This object can discover and chain streams of data that are technologically agnostic, through the use of Stream IDs. The stream to ...

  3. D- and L-lactate dehydrogenases during invertebrate evolution

    Stillman Jonathon H


    Full Text Available Abstract Background The L-lactate and D-lactate dehydrogenases, which are involved in the reduction of pyruvate to L(--lactate and D(+-lactate, belong to evolutionarily unrelated enzyme families. The genes encoding L-LDH have been used as a model for gene duplication due to the multiple paralogs found in eubacteria, archaebacteria, and eukaryotes. Phylogenetic studies have suggested that several gene duplication events led to the main isozymes of this gene family in chordates, but little is known about the evolution of L-Ldh in invertebrates. While most invertebrates preferentially oxidize L-lactic acid, several species of mollusks, a few arthropods and polychaetes were found to have exclusively D-LDH enzymatic activity. Therefore, it has been suggested that L-LDH and D-LDH are mutually exclusive. However, recent characterization of putative mammalian D-LDH with significant similarity to yeast proteins showing D-LDH activity suggests that at least mammals have the two naturally occurring forms of LDH specific to L- and D-lactate. This study describes the phylogenetic relationships of invertebrate L-LDH and D-LDH with special emphasis on crustaceans, and discusses gene duplication events during the evolution of L-Ldh. Results Our phylogenetic analyses of L-LDH in vertebrates are consistent with the general view that the main isozymes (LDH-A, LDH-B and LDH-C evolved through a series of gene duplications after the vertebrates diverged from tunicates. We report several gene duplication events in the crustacean, Daphnia pulex, and the leech, Helobdella robusta. Several amino acid sequences with strong similarity to putative mammalian D-LDH and to yeast DLD1 with D-LDH activity were found in both vertebrates and invertebrates. Conclusion The presence of both L-Ldh and D-Ldh genes in several chordates and invertebrates suggests that the two enzymatic forms are not necessarily mutually exclusive. Although, the evolution of L-Ldh has been punctuated by

  4. Streams and their future inhabitants

    Sand-Jensen, K.; Friberg, N.


    In this fi nal chapter we look ahead and address four questions: How do we improve stream management? What are the likely developments in the biological quality of streams? In which areas is knowledge on stream ecology insuffi cient? What can streams offer children of today and adults of tomorrow?...

  5. The involvement of metallothionein in the development of aquatic invertebrate

    Mao Huan; Wang Dahui [Sperm Laboratory, College of Life Sciences, Zhejiang University, Hangzhou 310058 (China); Yang Wanxi, E-mail: [Sperm Laboratory, College of Life Sciences, Zhejiang University, Hangzhou 310058 (China)


    The many documents on metallothioneins (MTs) in aquatic organisms focus especially on their use as biomarkers in environmental monitoring programs, but there are a few papers that summarize the physiological role of MTs in aquatic organisms especially in their development. The multifaceted role of MTs include involvement in homeostasis, protection against heavy metals and oxidant damage, metabolic regulation, sequestration and/or redox control. MTs could be induced by heavy metals which are able to hinder gametogenesis, suppress embryogenesis, and hamper development. Here we pay more attention on the non-essential metal cadmium, which is the most studied heavy metal regarding MTs, and its effects on the development of aquatic invertebrates. In this paper, we have collected published information on MTs in aquatic organisms - mollusks, crustaceans, etc., and summarize its functions in aquatic invertebrates, especially those related to their development.

  6. Innate immunity against moulds: lessons learned from invertebrate models.

    Ben-Ami, Ronen


    The emergence over the past two decades of invasive mycoses as a significant problem in immunocompromised patients underscores the importance of deciphering innate immunity against filamentous fungi. However, the complexity and cost of traditionally used mammalian model hosts presents a bottleneck that has limited the rate of advances in this field. In contrast, invertebrate model hosts have several important advantages, including simple immune systems, genetic tractability, and amenity to high-throughput experiments. The application of these models to studies of host-pathogen interactions is contingent on two tenets: (1) host innate defenses are preserved across widely disparate taxa, and (2) similar fungal virulence factors are operative in insects and in mammals. Validation of these principles paved the way for the use of invertebrates as facile models for studying invasive mould infections. These studies have helped shape our understanding of human pattern recognition receptors, phagocytic cell function and antimicrobial proteins, and their roles in host defense against filamentous fungi.

  7. Nutraceutical Interventions for Promoting Healthy Aging in Invertebrate Models

    Yuqing Dong


    Full Text Available Aging is a complex and inevitable biological process that is associated with numerous chronically debilitating health effects. Development of effective interventions for promoting healthy aging is an active but challenging area of research. Mechanistic studies in various model organisms, noticeably two invertebrates, Caenorhabditis elegans and Drosophila melanogaster, have identified many genes and pathways as well as dietary interventions that modulate lifespan and healthspan. These studies have shed light on some of the mechanisms involved in aging processes and provide valuable guidance for developing efficacious aging interventions. Nutraceuticals made from various plants contain a significant amount of phytochemicals with diverse biological activities. Phytochemicals can modulate many signaling pathways that exert numerous health benefits, such as reducing cancer incidence and inflammation, and promoting healthy aging. In this paper, we outline the current progress in aging intervention studies using nutraceuticals from an evolutionary perspective in invertebrate models.

  8. New assemly model of Jiangnan Orogen: insight from detrital zircon geochronology of pre-Cretaceous strata, South China

    Su, J.; Dong, S.


    The Jiangnan Orogen separates the Yangtze and Cathaysian Blocks in South China and provokes a longstanding debate on the amalgamation history between the two Blocks. The assembly of the two Blocks is termed Sibao orogeny marked by undeformed Late Neoproterozoic strata (Banxi Group) overlying on the deformed Early Neoproterozoic strata (Lengjiaxi Group) in China. Detrital zircons can provide critical links in recognizing the source history of a deposit, sedimentary dispersal systems and tectonic reconstructions. Therefore, fifteen sandstone samples taken from pre-Cretaceous strata of Yangtze Block are analyzed to constrain the evolution of the South China Block (SCB), especially the assembly between Yangtze and Cathaysia Blocks. The results show that the detrital zircons from the Neoproterozoic Lengjiaxi Group (ca. 830 Ma) near the boundary of large detachment fault of Hengshan have similar age populations with that in the other sites of the Jiangnan Orogen, different from that of the Kunyang and Dahongshan Groups (>960 Ma) in the southwestern margin of the Yangtze Block. The detrital zircons from Paleozoic samples have similar age populations with that in the Cathaysia Block. We infer that they originate from the Cathaysia Block, together with paleogeography, paleocurrent and former research. The detrital zircons of middle-late Jurassic sandstones in southwestern and central Yangtze yield dominant populations at 2.0-1.7 Ga and subordinate Groups of 2.6-2.4Ga, 0.7-0.8Ga and 0.6-0.4Ga. The provenance of late Triassic strata may be derived from southern Yangtze and North China Block due to the collisions among the Indosina, South China and North China Blocks, whereas the Jurassic sediments may be partly derived from uplift erosion of Jiangnan Orogen due to intra-continental orogeny induced by pacific subduction towards Eurasia Plate. The tectothermal event occurred at ca. 1.1-0.8 Ga has long been attributed to the assembly or breakup of Yangtze and Cathaysia Blocks

  9. Direct Comparison of Detrital Garnet, Monazite, and Zircon Ages from a Southern Appalachian Tributary System for the French Broad River, North Carolina, USA

    Maneiro, K. A.; Baxter, E. F.; Samson, S. D.; Marschall, H.


    Nineteen detrital garnet ages from a tributary draining into the French Broad River of North Carolina represent the first full-scale deployment of a new detrital garnet geochronometer. Under the new geochronometer, inclusions within the garnet serve as a proxy for the original source rock and eliminate required assumption of a single source for detritus. Additionally, method development has advanced techniques for small sample Nd and Sm analysis by thermal ionization mass spectrometry (TIMS), allowing for Sm-Nd analysis of single detrital garnet grains for the first time. This is also the first dataset allowing direct comparison of detrital garnet, monazite, and zircon. The three proximate tributaries sampled drain a limited source lithology, and prior studies provide detrital monazite and zircon ages (e.g. Hietpas et al., 2010, Geology; Moecher et al., 2011, Geosphere). The weighted average age for tributary detrital monazite is 460.9 ± 2.5 Ma (95% confidence). Zircon cores failed to record Paleozoic metamorphism, while zircon rims gave a weighted average age of 443.5 ± 8.7 Ma (95% confidence). The tributary system is garnet-bearing, with garnet grains exceeding the current minimum volume required for single grain analysis (≥ 0.4 mm max. diameter). Previously reported initial ages from the garnet grains (Maneiro-Eccles, 2015, Goldschmidt) have been updated to include blank correction accounting for extremely small Nd loads; clean garnet analyses contain 17-445 pg Nd and repeat blanks indicate contribution of 4.31 ± 0.59 pg Nd. The resulting weighted average age for garnet is 438.8 ± 8.1 Ma (95% confidence). The weighted average ages for zircon rims and garnet overlap within error, while the monazite age is older (22.1 ± 8.5 Myr older than garnet, 17.4 ± 9.1 Myr older than zircon). Age variance between minerals could be attributed to monazite sampling bias, limited sample size, and either influence by a secondary tectonic event (e.g. the Cherokee Orogeny

  10. Effects of Electromagnetic Fields on Fish and Invertebrates

    Schultz, Irvin R.; Woodruff, Dana L.; Marshall, Kathryn E.; Pratt, William J.; Roesijadi, Guritno


    In this progress report, we describe the preliminary experiments conducted with three fish and one invertebrate species to determine the effects of exposure to electromagnetic fields. During fiscal year 2010, experiments were conducted with coho salmon (Onchrohychus kisutch), California halibut (Paralicthys californicus), Atlantic halibut (Hippoglossus hippoglossus), and Dungeness crab (Cancer magister). The work described supports Task 2.1.3: Effects on Aquatic Organisms, Subtask Electromagnetic Fields.

  11. Effects of Electromagnetic Fields on Fish and Invertebrates

    Schultz, Irvin R.; Woodruff, Dana L.; Marshall, Kathryn E.; Pratt, William J.; Roesijadi, Guritno


    In this progress report, we describe the preliminary experiments conducted with three fish and one invertebrate species to determine the effects of exposure to electromagnetic fields. During fiscal year 2010, experiments were conducted with coho salmon (Onchrohychus kisutch), California halibut (Paralicthys californicus), Atlantic halibut (Hippoglossus hippoglossus), and Dungeness crab (Cancer magister). The work described supports Task 2.1.3: Effects on Aquatic Organisms, Subtask Electromagnetic Fields.

  12. Nutraceutical Interventions for Promoting Healthy Aging in Invertebrate Models


    Aging is a complex and inevitable biological process that is associated with numerous chronically debilitating health effects. Development of effective interventions for promoting healthy aging is an active but challenging area of research. Mechanistic studies in various model organisms, noticeably two invertebrates, Caenorhabditis elegans and Drosophila melanogaster, have identified many genes and pathways as well as dietary interventions that modulate lifespan and healthspan. These studies ...

  13. First U-Pb detrital zircon ages from Numidian sandstones in Southern Apennines (Italy): Evidences of African provenance

    Fornelli, Annamaria; Micheletti, Francesca; Langone, Antonio; Perrone, Vincenzo


    Two samples of quartz-rich sandstones collected in the Numidian Flysch of Southern Apennines (Italy) have been studied to highlight the provenance of detritus using radiometric dating by LA-ICP-MS of detrital zircons and to compare the obtained ages with those of the Betic and Maghrebian Chains. The provenance of quartzose detritus from European or African Plates is still debated in these Chains, accordingly the ages of the detrital zircons can contribute significantly to discriminate the origin of the quartzose supply. The U-Pb zircon ages (n = 47) vary from 3047 ± 13 Ma (Mesoarchean) to 516 ± 19 Ma (Cambrian). The predominance of Paleo-Proteozoic ages (2500-1600 Ma) and the lack of Hercynian and Alpine ones suggest a provenance of the Numidian supply from North-African cratonic areas during the early-middle Langhian, when the Numidian successions of Southern Apennines were deposited. In addition, a cluster of ages at 773 ± 24 Ma and 668 ± 12 Ma in one sample and at 664 ± 17 Ma in the other sample, calculated on zircon domains with magmatic zoning, testify to an important contribution from Neo-proterozoic "granitic" rocks widely outcropping in the North-African Craton. The age data on detrital zircons from Numidian sandstones in Southern Apennines overlap those found in the Numidian sandstones widespread in the Betic Cordillera and in the Maghrebian Chain from south Spain to Sicily. This suggests that the entire depositional zone in which Numidian Flysch deposited, was fed from a southerly source represented by the African Craton where Archean, Proterozoic and Cambrian rocks widely crop out from the Atlantic coast to the Hoggar and Tibesti Massifs. Finally, it must be outlined that a Meso-Archean zircon age (3047 Ma) has been found in the Numidian Flysch of the Southern Apennines whereas in the Numidian Flysch of the Maghrebian Chain, zircons older than Paleo-proterozoic (1840 Ma) have not yet been found.

  14. Sandstone provenance and detrital zircon geochronology record changes in Plio-Pleistocene tectonism of the Southern Cascadia forearc

    Garcia, M. J.; Michalak, M.; Hourigan, J. K.


    The Cascadia Subduction Zone (CSZ) in the Pacific NW is defined by subducting oceanic lithosphere (Juan de Fuca-Gorda) beneath the North American Plate, from British Colombia to Northern California. In the Southern CSZ, the forearc is characterized by high topography of the Klamath Mountain Province west of the volcanic arc, the lower lying Northern Coast Ranges, comprising Cretaceous through Miocene Franciscan Formation, and structurally controlled coastal basins of Pliocene-Pleistocene fluvial-marine sedimentary rocks. The southernmost CSZ is affected by northward migration of the Mendocino Triple Junction; high rates of rock uplift and tectonically controlled drainage patterns are evident of its passage spatially and temporally. While provenance sources for early-to-mid Tertiary sedimentary units of the Franciscan are well-described, less is known about provenance sources in Plio-Pleistocene time, and how changes in regional tectonics, such as the migration of the MTJ, and uplift of the Klamath Mountains, may have affected sediment dispersal. Previous work and our preliminary results indicate that the Plio-Pleistocene Wildcat Group of the Eel River basin is characterized by distant sources. Aalto et al., (1998) and Moley (1997) use detrital mica Ar/Ar ages and petrofacies analyses of the Wildcat to hypothesize provenance from the distant Idaho Batholith. We test this hypothesis using detrital zircon U-Pb geochronology, and present eight new detrital sample ages from Plio-Pleistocene sedimentary basins along the coastal margin north of the MTJ. These results are used to inform paleographic reconstructions of Pliocene-Pleistocene regional topography associated with the dynamic tectonics of Southern Cascadia.

  15. Mucin-Type O-Glycosylation in Invertebrates

    Erika Staudacher


    Full Text Available O-Glycosylation is one of the most important posttranslational modifications of proteins. It takes part in protein conformation, protein sorting, developmental processes and the modulation of enzymatic activities. In vertebrates, the basics of the biosynthetic pathway of O-glycans are already well understood. However, the regulation of the processes and the molecular aspects of defects, especially in correlation with cancer or developmental abnormalities, are still under investigation. The knowledge of the correlating invertebrate systems and evolutionary aspects of these highly conserved biosynthetic events may help improve the understanding of the regulatory factors of this pathway. Invertebrates display a broad spectrum of glycosylation varieties, providing an enormous potential for glycan modifications which may be used for the design of new pharmaceutically active substances. Here, overviews of the present knowledge of invertebrate mucin-type O-glycan structures and the currently identified enzymes responsible for the biosynthesis of these oligosaccharides are presented, and the few data dealing with functional aspects of O-glycans are summarised.

  16. Lessons in modularity: the evolutionary ecology of colonial invertebrates

    Roger N. Hughes


    Full Text Available Benthic colonial invertebrates share with higher plants a modular construction and a sessile adult life. Both types of organism show parallel evolutionary responses to common selective forces, but in contrast to the long-established focus on plants, comparable study of colonial invertebrates has developed relatively recently, largely owing to the application of new techniques in image processing and molecular biology. Species whose life cycles are readily completed under laboratory conditions and whose colonies are easily propagated from cuttings provide powerful models for experimentally investigating fundamental evolutionary problems, including metabolic allometry, the manifestation of ageing and the origin of allorecognition systems. Free of the confounding influences of behavioural manipulation and costs of copulation, colonial invertebrates whose water-borne sperm fertilize retained eggs lend themselves well to the experimental study of cryptic female choice, sperm competition and sexual conflict. In these respects, it will be productive to adopt and extend theoretical frameworks developed for flowering plants to guide experimental investigation of modular animals. Since mate choice occurs at the cellular level in modular animals, reproductive isolation is uncorrelated with morphology and cryptic speciation is likely to be widespread.

  17. Integration of ESCA index through the use of sessile invertebrates

    Luigi Piazzi


    Full Text Available The ESCA (Ecological Status of Coralligenous Assemblages index was developed to assess the ecological quality of coralligenous habitat using macroalgae as a biological indicator. The aim of this study was to evaluate the response to human-induced pressures of macroalgae and sessile macro-invertebrates shaping the coralligenous habitat and to integrate their sensitivity into the ESCA index. Coralligenous assemblages were sampled at 15 locations of the NW Mediterranean Sea classified into three groups: i marine protected areas; ii low urbanized locations; and iii highly urbanized locations. A sensitivity level value was assigned to each taxon/group on the basis of its abundance in each environmental condition, the data available in the literature and the results of an expert judgement survey. The index that includes the totality of the assemblages (named ESCA-TA, calculated using both macroalgae and sessile macro-invertebrates, detected the levels of human pressure more precisely than the index calculated with only macroalgae or with only invertebrates. The potential for assessing the ecological quality of marine coastal areas was thus increased with the ESCA-TA index thanks to the use of a higher variety of descriptors.

  18. Toxicity of abamectin and doramectin to soil invertebrates

    Kolar, Lucija [Laboratory of Forensic Toxicology and Ecotoxicology, Veterinary Faculty, University of Ljubljana, Gerbiceva 60, SI-1000 Ljubljana (Slovenia); Institute of Ecological Science, Vrije Universiteit, De Boelelaan 1085, 1081 HV Amsterdam (Netherlands)], E-mail:; Kozuh Erzen, Nevenka [Laboratory of Forensic Toxicology and Ecotoxicology, Veterinary Faculty, University of Ljubljana, Gerbiceva 60, SI-1000 Ljubljana (Slovenia)], E-mail:; Hogerwerf, Lenny [Institute of Ecological Science, Vrije Universiteit, De Boelelaan 1085, 1081 HV Amsterdam (Netherlands)], E-mail:; Gestel, Cornelis A.M. van [Institute of Ecological Science, Vrije Universiteit, De Boelelaan 1085, 1081 HV Amsterdam (Netherlands)], E-mail:


    This study aimed at determining the toxicity of avermectins to soil invertebrates in soil and in faeces from recently treated sheep. Abamectin was more toxic than doramectin. In soil, earthworms (Eisenia andrei) were most affected with LC50s of 18 and 228 mg/kg dry soil, respectively, while LC50s were 67-111 and >300 mg/kg for springtails (Folsomia candida), isopods (Porcellio scaber) and enchytraeids (Enchytraeus crypticus). EC50s for the effect on reproduction of springtails and enchytraeids were 13 and 38 mg/kg, respectively for abamectin, and 42 and 170 mg/kg for doramectin. For earthworms, NOEC was 10 and 8.4 mg/kg for abamectin and doramectin effects on body weight. When exposed in faeces, springtails and enchytraeids gave LC50s and EC50s of 1.0-1.4 and 0.94-1.1 mg/kg dry faeces for abamectin and 2.2->2.4 mg/kg for doramectin. Earthworm reproduction was not affected. This study indicates a potential risk of avermectins for soil invertebrates colonizing faeces from recently treated sheep. - Avermectins may pose a risk to soil invertebrates colonizing faeces from recently treated sheep.

  19. Soil macrofauna (invertebrates of Kazakhstanian Stipa lessingiana dry steppe

    Bragina Tatyana М.


    Full Text Available Stipa lessingiana steppes used to be prevalent on the dry Trans-Ural denudation plains, particularly, on the Sub-Ural and the Turgay Plateau. But, most of them have been lost because they were plowed up during the Virgin Land campaign in the second part of 20th century. This paper presents a detailed study of the faunistic composition and the structure of soil-dwelling invertebrate communities (macrofauna of a temperate-dry bunch feather grass steppe in the Turgai Plateau (Northern-Turgai physical-geographical province of steppe Kazakhstan, Kostanay Oblast. The study site is located in the territory of the Naurzum State Nature Reserve, a part of the UNESCO World Heritage site “Saryarka Steppe and Lakes of Northern Kazakhstan”, where remnants of Virgin S. lessingiana steppes have been preserved to the present day. This region is the driest and most continental in climate of all the dry steppes of Kazakhstan. The total abundance and biomass of soil invertebrate communities in the investigated site were lower than in the northern and western steppe areas. Soil invertebrates are among the major components that determine the functioning of terrestrial natural ecosystems.

  20. Zebra mussel effects on benthic invertebrates: physical or biotic?

    Botts, P. Silver; Patterson, Benjamin A.; Schloesser, Don W.


    In soft sediments, Dreissena spp. create firm substrate in the form of aggregates of living mussels (druses) that roll free on the sediments. Druses provide physical structure which increases habitat heterogeneity, and the mussels increase benthic organic matter through the production of pseudofeces and feces. Descriptive and experimental studies were used to determine: 1) whether the density of benthic invertebrates in soft sediments increased in the presence of druses, and 2) whether the invertebrate assemblage responded to the physical structure provided by a druse or to some biotic effect associated with the presence of living mussels. In core samples collected biweekly during summer in Presque Isle Bay, Erie, Pennsylvania, amphipods, chironomids, oligochaetes, turbellarians, and hydrozoans were significantly more abundant in sand with druses than in bare sand. When mesh bags containing either a living druse, non-living druse, or no druse were incubated in the bay for 33 d, we found that chironomids were significantly more abundant in treatments with living druses than with non-living druses, and in treatments with non-living druses than with no druse; turbellarians, amphipods, and hydrozoans were significantly more abundant in treatments with living or non-living druses than with no druse; oligochaetes showed no significant differences among treatments. This study demonstrates that most taxa of benthic invertebrates in soft substrate respond specifically to the physical structure associated with aggregates of mussel shells, but further study is needed to examine chironomid responses to some biotic effect dependent on the presence of living mussels.

  1. Improved ultrastructure of marine invertebrates using non-toxic buffers

    Jacqueline Montanaro


    Full Text Available Many marine biology studies depend on field work on ships or remote sampling locations where sophisticated sample preservation techniques (e.g., high-pressure freezing are often limited or unavailable. Our aim was to optimize the ultrastructural preservation of marine invertebrates, especially when working in the field. To achieve chemically-fixed material of the highest quality, we compared the resulting ultrastructure of gill tissue of the mussel Mytilus edulis when fixed with differently buffered EM fixatives for marine specimens (seawater, cacodylate and phosphate buffer and a new fixative formulation with the non-toxic PHEM buffer (PIPES, HEPES, EGTA and MgCl2. All buffers were adapted for immersion fixation to form an isotonic fixative in combination with 2.5% glutaraldehyde. We showed that PHEM buffer based fixatives resulted in equal or better ultrastructure preservation when directly compared to routine standard fixatives. These results were also reproducible when extending the PHEM buffered fixative to the fixation of additional different marine invertebrate species, which also displayed excellent ultrastructural detail. We highly recommend the usage of PHEM-buffered fixation for the fixation of marine invertebrates.

  2. Biometry of neotropical invertebrates inhabiting floodplain rivers: unraveling bionomy

    Florencia Zilli

    Full Text Available ABSTRACT Currently, it is widely recognized that invertebrates play key roles in neotropical floodplains and in many other environments worldwide. However, little information has been published concerning their biometry, in spite that it represents an essential tool for many different studies. Here, we provided length-mass and length-length relationships by fitting the linearized model (log10 Y = log10a + b log10 X and several mean biomass ratios ± SE for bivalves, gastropods, quironomids, ephemeropterans, oligochaetes and hirudineans. We measured, weighed, oven dried and incinerated to ashes specimens collected from 2005 to 2014 in the Paraná River, Argentina. The lineal equations had fit levels higher than 75% in most of the significant regressions. Hence, when slopes were compared, differences raised from ontogeny and phylogeny of taxa. Additionally, slopes resulted different from constants of other regions, types of environments and climates. In addition, organic matter ratios resulted significantly different among invertebrates according to their feeding types. The equations and ratios that we provided will facilitate future research on life history, productivity and energy transference in the food webs of invertebrates inhabiting floodplain wetlands and can be used as tools for planning management strategies and in restoration projects of aquatic environments.

  3. Toll-like receptors in invertebrate innate immunity

    L Zheng


    Full Text Available Among invertebrates, innate immunity is the only defense mechanism against harmful non-self agents.In response to recognition of microbial pattern molecules, Drosophila melanogaster activates either theToll or Imd pathway, leading to the translocation of NF-kB (or Rel transcription factors from the cytoplasmto the nucleus and the subsequent production of antimicrobial peptides, which provide systemic innateimmunity. Toll-like receptors (TLRs are characterized by an extracellular leucine rich repeat (LRRdomain and an intracellular Toll/interleukin-1 receptor (TIR domain. TLRs are found from cnidarians tomammals. Here we argue that TLR mediated innate immunity developed during an early stage ofevolution when organisms acquired a body cavity. This is supported by the distributions of TLR and Relgenes in the animal kingdom. Further, TLR mediated immunity appears to have developed independentlyin invertebrates and vertebrates. Recent studies have shown that microbial molecules, with the potentialto signal through TLR, can be beneficial to host survival. Studies on this signaling pathway could opendoors to a better understanding of the origins of innate immunity in invertebrates and potentialtransmission blocking strategies aimed at ameliorating vector-borne diseases.

  4. Montana StreamStats


    About this volumeMontana StreamStats is a Web-based geographic information system ( application that provides users with access to basin and streamflow characteristics for gaged and ungaged streams in Montana. Montana StreamStats was developed by the U.S. Geological Survey (USGS) in cooperation with the Montana Departments of Transportation, Environmental Quality, and Natural Resources and Conservation. The USGS Scientific Investigations Report consists of seven independent but complementary chapters dealing with various aspects of this effort.Chapter A describes the Montana StreamStats application, the basin and streamflow datasets, and provides a brief overview of the streamflow characteristics and regression equations used in the study. Chapters B through E document the datasets, methods, and results of analyses to determine streamflow characteristics, such as peak-flow frequencies, low-flow frequencies, and monthly and annual characteristics, for USGS streamflow-gaging stations in and near Montana. The StreamStats analytical toolsets that allow users to delineate drainage basins and solve regression equations to estimate streamflow characteristics at ungaged sites in Montana are described in Chapters F and G.

  5. Isotopic studies on detrital zircons of Silurian-Devonian siliciclastic sequences from Argentinean North Patagonia and Sierra de la Ventana regions: comparative provenance

    Uriz, Norberto J.; Cingolani, Carlos A.; Chemale, Farid; Macambira, Moacir B.; Armstrong, Richard


    The Silurian-Devonian siliciclastic sedimentary units known as Sierra Grande Formation and the upper part of the Ventana Group crop out in the eastern area of the North Patagonian Massif and in the Ventania system, toward the Atlantic border of Argentina. Both sequences show similar stratigraphical characteristics and were deposited in a shallow marine platform paleoenvironment. Previous contributions have provided evidence of an allochthonous Patagonia terrane that amalgamate to Gondwana during the Permian-Triassic. However, other lines of research support a crustal continuity southward, where the Pampean and Famatinian events extend into the northern Patagonia. In either case, the detrital input to the Eo-Mesopaleozoic basins generated along the passive margin tectonic setting should reflect the sedimentary sources. In this contribution, new age data on the sedimentary provenance of these units is provided by U-Pb and Lu-Hf isotopic studies on detrital zircons, using LA-ICP-MS and SHRIMP methodologies. The main sedimentary sources of detrital zircons for both regions are of Cambrian-Ordovician and Neoproterozoic age, while a secondary mode is Mesoproterozoic. Zircons from older cratonic sources (Mesoarchean-Paleoproterozoic ages) are scarcely recorded. The sample from the upper section of the Devonian Lolén Formation (Ventana Group) shows an important change in the sedimentary provenance, with a main mode of Mesoproterozoic detrital zircons. Detrital source areas considering the orogenic cycles known for southwest South America (Famatinian, Pampean-Brasiliano, Mesoproterozoic-`Grenvillian' and Paleoproterozoic-`Transamazonian') are proposed.

  6. Using Detrital Geochronologic and Thermochronologic "Double-Dating" to Constrain Depositional Age, Provenance, and Exhumation Signals in Ancient Forearc Basins

    Orme, D. A.


    The application of coupled detrital zircon U-Pb geochronology and (U-Th)/He thermochronology to sedimentary basins has the potential for unprecedented details about grain provenance, depositional age and source and basin exhumation signals. Although several studies have implored this technique, it is underutilized and may prove useful in geologic settings that are traditionally difficult to explore. For example, constraining the depositional age of strata in ancient forearc basins is challenging as many horizons are devoid of fossils and post-burial diagenesis of limestone beds limits biostratigraphic age control. This study applies U-Pb detrital zircon geochronology to clastic rocks from the Cretaceous-Eocene Xigaze forearc basin in southern Tibet to (1) to determine the provenance of forearc basin strata and (2) to constrain a maximum depositional age of stratigraphic horizons using the youngest distinct age group from a sample. In addition, (U-Th)/He thermochronology was applied to a subset of the detrital zircons on which U-Pb ages were previously determined in order to determine the timing of exhumation of Xigaze forearc strata and its source region. The use of young populations of zircons is a good method for age control in the Xigaze forearc basin because magmatism in the source area was more-or-less continuous and the lag time between the youngest zircons in a sample and the time of that samples deposition is likely relatively small. A total of 2,330 zircon grains yielded ages with acceptable precision and concordance for geochronologic interpretation. Together with sandstone petrography, the detrital zircons indicate that the primary source of detritus in the basin from ~113 to 54 Ma was the Gangdese magmatic arc. Analysis of the youngest age component of individual samples reveals a decrease in the youngest ages upsection, consistent with maximum depositional ages that are close to the likely true depositional age based on intervening tuff layers. Double

  7. Detrital Mineral Record of the Central Myanmar Basin and implications for the evolution of the eastern Himalayan margin

    Brezina, C. A.; Robinson, R. A. J.; Barfod, D. N.; Carter, A.; Parrish, R. R.; Horstwood, M. S.; Thein, M.; Win Oo, N.


    Single grain detrital thermochronology (40Ar/39Ar white mica, zircon fission track and Lu-Hf analysis) of Eocene, Oligocene and Miocene sedimentary rocks from the Central Myanmar Basin permits the identification of tectonothermal events in the source areas, and an understanding of how exhumation histories and changing provenance are related to the palaeogeography of the West Burma block during India-Asia collision. Robinson et al. (2014) used detrital zircon U-Pb and Lu-Hf isotopic analysis to show that Eocene and Oligocene sedimentary rocks were primarily sourced from the Gangdese magmatic arc that lies exclusively within the southern Lhasa terrane, and that the Yarlung Tsangpo and Irrawaddy River were connected at this time. Detrital thermochronology reveal these Paleogene deposits contain broadly distributed, mainly pre-Himalayan 40Ar/39Ar white mica cooling ages, reflecting the contribution from multiple source areas with a cooling history that is similar to the Lhasa terrane. A distinct change in provenance to a single, sustained source area during deposition of the Miocene units is recorded by a white mica 40Ar/39Ar cooling age peak of 37 Ma and a lesser peak of 17 - 21 Ma that is also observed in detrital zircon fission track age data. These two age peaks, 37 Ma and 17 - 21 Ma, likely reflect an initial period of crustal thickening, metamorphism and exhumation in the southern Mogok Metamorphic Belt, and a later phase of exhumation associated with deformation in the eastern syntaxis and the onset of extension in Myanmar and other parts of SE Asia. The latter events are also associated with the disconnection of the Yarlung Tsangpo from the Irrawaddy River around 18 Ma (Robinson et al., 2014). The combined dataset provides constraints on the position and movement of the West Burma block from the Late Eocene to Early Miocene, supports an Oligocene (~37 Ma) age for the timing of India-West Burma-Sibumasu coupling, and an Early Miocene age for extension

  8. Paleocene Turbidite Deposition in the Central American Seaway (NW Costa Rica): Geochemical Analysis and Provenance of Detrital Spinel and Clinopyroxene

    Giblin, A. C.


    The Central American Land Bridge is the crucial connection between North and South America, and the Miocene closure of the Panama seaway led to a change in global oceanic circulation patterns. Modern Costa Rica is part of the island arc that formed over the western Caribbean subduction zone, and the Santa Elena peninsula is on the northwest coast of Costa Rica next to the Sandino forearc basin. This study focuses on the origin and provenance of the Paleocene deep-water Rivas and Descartes turbidites that crop out on the northern part of the Santa Elena peninsula in northwestern Costa Rica. Understanding the sedimentary fill of the Sandino Basin that contributed to the closing of the seaway may lead to a better understanding of the Late Cretaceous-Paleogene arcs. Provenance studies of the Santa Elena Peninsula turbidite sandstone bodies constrain the history of the paleogeography and tectonics of the region. Petrographic analyses of rock thin sections constrain source areas; geochemical analysis of individual detrital heavy minerals from rock samples give indications of sediment sources and tectonic setting during deposition. This study is a provenance analysis based on (i) semi-quantitative energy-dispersive spectrometry analysis of heavy minerals, (ii) quantitative wavelength-dispersive spectrometry for major elements of detrital clinopyroxene and spinel grains, (iii) trace element analysis through laser ablation of single detrital clinopyroxene grains, and (iv) comparative analysis of the different potential source rocks to clearly identify the most likely sediment sources. The detrital spinel and clinopyroxene are possibly sourced from: mantle ophiolites, mid-ocean ridge gabbros, or volcanic arc tholeiitic basalts or calc-alkaline andesites. Spinel and clinopyroxne geochemistry suggests a possible peridotitic source, linked to mantle rocks that are now covered by Tertiary volcanics or have completely eroded. The character of the crustal minerals indicates

  9. Detrital thermochronology of Rhine, Elbe and Meuse river sediment (Central Europe): implications for provenance, erosion and mineral fertility

    Glotzbach, C.; Busschers, F. S.; Winsemann, J.


    Here we present detrital apatite fission track (AFT), zircon fission track (ZFT) and a few apatite (U-Th)/He (AHe) data of Middle Pleistocene to modern Rhine, Meuse and Elbe river sediments in order to resolve processes that control detrital age distributions (provenance, erosion and mineral fertility). We used a modelling approach to compare observed with theoretically predicted age distributions from an interpolated in situ AFT and ZFT age map. In situ cooling ages do show large differences in the Rhine drainage basin, facilitating the differentiation between different source regions. Inconsistencies between observed and theoretical age distributions of the Meuse and Elbe samples can be explained by mixing and reworking of sediments with different provenances (Meuse Middle Pleistocene terrace sediment) and a yet unexplored source region with old AFT ages (Elbe samples). Overall, the results show that detrital thermochronology is capable of identifying the provenance of Middle Pleistocene to modern sediments. The AFT age distributions of Rhine sediments are dominated ( 70%) by AFT ages representing the Alps. A possible explanation is higher erosion rates in the Alps as compared to areas outside the Alps. A Late Pleistocene sample from the Upper Rhine Graben contains apatite grains from the Molasse and Hegau volcanics, which we explain with a shift of the headwaters of the Rhine to the north as a result of intense Middle Pleistocene Riss glaciation. Contrary to the observed dominance of Alpine-derived AFT ages in Rhine sediments, the relative contribution of zircon ages with sources in the Alps is lower and significantly decreases downstream, suggesting a major source of zircons outside the Alps. This can be explained by increased zircon fertility of sediments derived from the Rhenish massif. Therefore, we conclude that erosion and mineral fertility are the main processes controlling detrital AFT and ZFT age distributions of the sampled river sediment. In case of

  10. Do Variations in Detrital Inputs Influence Stable Soil Organic Matter? - An Experimental Approach

    Lajtha, K.; Townsend, K.; Brewer, E.; Caldwell, B.; Kalbitz, K.; Plante, A.


    because aboveground, labile litter adds very little to stabilized SOM in grasslands, and that root-derived C is the dominant control on SOM stabilization in grasslands. These results were confirmed with analysis of labile C (short -term respiration measurements) and acid hydrolysis resistant C across treatments. The relative contribution of aboveground vs. belowground litter was analyzed through the analysis of cutin and suberin acids, and we found that the detrital source of litter was retained in soils and could be fingerprinted through this analysis. Thermal analysis, including thermogravimetry (TG) and differential scanning calorimetry (DSC) performed simultaneously is currently being applied to explore both SOM quality and stability.

  11. Global Age Distribution of Detrital Zircons, the Supercontinent Cycle, and Subduction Flux Through Time

    Bradley, D. C.


    The global age distribution of detrital zircons (DZ) tracks the supercontinent cycle. Abundance of zircon ages in modern sands fluctuates through an order of magnitude, with maxima at ca. 2.7, 1.9, 1.0, and 0.45 Ga and minima at ca. 2.3, 1.6, 0.9, 0.7, 0.40, and 0.21 Ga. The age distribution is shaped by differences in zircon production at rifts, arcs, and collisional orogens; by preservation, exhumation, destruction, and recycling of zircons; and by methodological and regional sampling biases. The first-order age maxima and minima have been explained by two largely incompatible models. Model 1 holds that global subduction flux (area subducted per unit time) is constant, that DZ minima reflect destruction of intraoceanic arcs by subduction erosion, and that maxima correspond to times of greater preservation of zircon sources leading up to and during collision. In contrast, Model 2 holds that stepwise changes in global subduction flux—and thus in zircon production at convergent boundaries—are intrinsic to supercontinent cycles. This follows because convergent boundaries are extinguished during collision; hence supercontinent tenures correspond to zircon minima. Examination of >80 geologic secular trends reveals little empirical evidence bearing on these alternatives. The most telling evidence is provided by reconstructed sea levels. Model 1 implies no particular changes in sea level during supercontinent assembly. If plate motion were to cease across a collisional orogen, the same amount of convergence would begin elsewhere and the world population of ridges and ridge volume would be unaffected. In contrast, Model 2 predicts a drop in sea level triggered by supercontinent assembly because death of a collisional plate boundary would mean death of the corresponding ridge and consequent increase in room for seawater in the ocean basins. Reconstructions of global sea level show a major low centered in the Triassic, one that is not linked to glaciation. The sea level

  12. Detrital and delayed CRM acquisition in redbeds: the Lower Cretaceous Zicapa Formation, southern Mexico

    Sierra-Rojas, M. I.; Molina-Garza, R. S.


    The Lower Cretaceous Zicapa Formation is characterized by hematite-cemented clastic rocks interbeded with limestone and volcanic rocks, deposited in continental to transitional-marine environments. The paleomagnetic data presented here correspond to exposures in the San Juan de las Joyas locality, in the Mixteca terrain of southern Mexico. Hematite cement is derived from an important input of primary volcanic material contemporaneous with deposition and from mafic to intermediate metavolcanic sources. We sampled 17 sites in a 110 m segment of continuous depositation of fine to coarse, red to purple, lithic sandstone and siltstone. The natural magnetization is multivectorial, and AF demagnetization suggests that it resides primarily in hematite. One magnetization component is unblocked below 200C is north-directed and positive. A low-unblocking temperature magnetization (LT) is unblocked between 250-500C, and a high-unblocking-temperature component (HT) is defined between about 600-650C. Both, the LT and HT components are dual-polarity and form nearly antipodal groups of WNW (ESE) directions. NRM demagnetization and rock magnetic data suggest the presence of two kinds of particles carrying the LT and HT components. Polarity changes in the section sampled are characterized by sites that register in the HT component the magnetic field previous to the transition of polarity (which is detrital magnetization residing in specular hematite), whilst the LT registers the magnetic field after the polarity transition. Typically, in the overlying (post-transition) site the LT and HT components are of the same polarity. This suggests that the LT component is a late (or delayed) CRM that resides in small particles of pigmentary hematite. The accepted sites yield a tilt corrected mean of declination Dec= 273 degrees, inclination Inc= 33.1 degrees (α95=11.7 y k=18).The mean directions are discordant with respect to expected North America reference for Early Cretaceous indicating a

  13. Spatial analysis of climatic cycles of a detrital aquifer by mean of Indicator Kriging

    Luque-Espinar, Juan Antonio; Pardo-Igúzquiza, Eulogio; Pulido-Velazquez, David; Fernández-Chacón, Francisca; Jiménez-Sánchez, Jorge; Chica-Olmo, Mario


    In a previous work, spectral analysis was carried out to investigate the climate cycles in a detrital aquifer located in southern Spain. The Vega de Granada aquifer is located in an alluvial plain surrounded by mountains. The aquifer has a superposition of Quaternary sedimentary materials showing a broad range of permeabilities. This aquifer is the receptor of a drainage basin of 2900 km2 and has a surface of around 200 km2. Its alluvial sediments attain a thickness of 250 m in the middle. The sediment sizes are mainly gravel, sands, silts and clay, with frequent spatial changes. The transmissivity of the range from 40000 m2/day to 100 m2/day and the effective porosity ranging between 1% and 10%. The main inputs into the aquifer come from the infiltration of surface runoff and the infiltration of rainfall water. More than 50 piezometric data series were studied with monthly temporal unit. The studied period has a span of more than 30 years. The main climatic cycles are annual, NAO, ENSO and semiannual. For this study, confidence levels of <90%, 90%, 95%, and 99% were established. The spatial distribution in the aquifer of climate cycles and their confidence levels were studied by mean Indicator Kriging. This methodology is based on geostatistical non-parametric methods. For this purpose, the confidence levels were codified in indicator variables. Overall, eleven experimental variograms were calculated and it fitted to a spherical model. In this sense, the spatial behavior of the climate cycles is quite similar in all cases. The estimation results are presented as binary maps that show areas where every cycle appears with a maximum spatial probability. Basically, the interpretation of these maps indicates a close connection to main recharge areas of the aquifer. On the other hand, the changes in permeability in the aquifer are considerable, which may explain in some cases the spatial variations in the spectra calculated. Acknowledgments: This research has been

  14. South China connected to north India in Gondwana: sedimentary basin and detrital provenance analyses

    Yao, W.; Li, Z. X.; Li, W. X.; Li, X. H.; Yang, J. H.


    The paleoposition of South China during the Ediacaran-Silurian is important for understanding the assembly of Gondwana. We report here the tectonostratigraphic evolution of the Ediacaran-Silurian Nanhua foreland basin in South China, and discuss South China's connection with Gondwana and potential tectonic triggers for both the Wuyi-Yunkai orogeny in South China and the Bhimphedian orogeny in north India. The Nanhua basin was involved in a three-stage evolution, which are: Stage 1 (the Ediacaran-Cambrian) recording the start of tectonic subsidence with turbiditic marine clastic deposition, fed by exotic orogens outboard South China; Stage 2 (the Ordovician to earliest-Silurian) featured by migrating depocentres with dominant shallow marine to deltaic clastic deposition, fed by the local Wuyi-Yunkai orogen; and Stage 3 (the Silurian) showing the arrival of depocentre in the Yangtze Block during the waning stage of the Wuyi-Yunkai orogeny with deltaic deposition in the remanent foreland basin. Detrital zircon analyses of the Ediacaran-Silurian sandstones across the Nanhua basin reveal a prominent age population of 1100-900 Ma (with a peak age at ~980 Ma) and moderate populations of Archean-Paleozoic ages, grossly matching that of crystalline and sedimentary rocks in northern India. Zircon isotopes of the Stage 1 samples suggest three Precambrian episodes of juvenile crustal growth at 3.0 Ga, 2.5 Ga and 1.0 Ga, and a major crustal reworking at 580-500 Ma for the source areas, which are constraint to be northwestern India and its surrounding orogens. Together with other evidence, we propose that South China likely collided with northwestern India during the Gondwana assembly, generated the Bhimphedian orogeny in north India and formed two foreland basins on both the north India and South China sides. Far-field stress of the collision triggered the Ordovician-Silurian Wuyi-Yunkai orogeny in South China. The Stage 2-3 samples in the Nanhua basin of South China were shed

  15. Introduction to Tidal Streams

    Newberg, Heidi Jo

    Dwarf galaxies that come too close to larger galaxies suffer tidal disruption; the differential gravitational force between one side of the galaxy and the other serves to rip the stars from the dwarf galaxy so that they instead orbit the larger galaxy. This process produces "tidal streams" of stars, which can be found in the stellar halo of the Milky Way, as well as in halos of other galaxies. This chapter provides a general introduction to tidal streams, including the mechanism through which the streams are created, the history of how they were discovered, and the observational techniques by which they can be detected. In addition, their use in unraveling galaxy formation histories and the distribution of dark matter in galaxies is discussed, as is the interaction between these dwarf galaxy satellites and the disk of the larger galaxy.

  16. Effect of oil palm on the Plecoptera and Trichoptera (Insecta) assemblages in streams of eastern Amazon.

    de Paiva, Carina Kaory Sasahara; de Faria, Ana Paula Justino; Calvão, Lenize Batista; Juen, Leandro


    The production of oil palm is expected to increase in the Amazon region. However, expansion of oil palm plantation leads to significant changes in the physical structure of aquatic ecosystems, mainly through the reduction of riparian vegetation that is essential for aquatic biodiversity. Here, we evaluated the effects of oil palm on the physical habitat structure of Amazonian stream environments and assemblages of Plecoptera and Trichoptera (PT), ​both found in these streams. We compared streams sampled in oil palm plantations (n = 13) with natural forest areas ("reference" streams, n = 8), located in the eastern Amazon, Brazil. Our results showed that oil palm streams were more likely to be in close proximity to roads, had higher pH values, and higher amounts of fine substrate deposited in the channel than reference streams. Further, these environmental changes had important effects on the aquatic invertebrate assemblages, reducing the abundance and richness of PT. Nevertheless, the genera composition of the assemblages did not differ between reference and oil palm (PERMANOVA, pseudo-F (1,19) = 1.891; p = 0.111). We conclude that oil palm production has clear negative impacts on aquatic environments and PT assemblages in Amazonian streams. We recommend that oil palm producers invest more in planning of road networks to avoid the construction of roads near to the riparian vegetation. This planning can minimize impacts of oil palm production on aquatic systems in the Amazon.

  17. Effect of land use on the composition, diversity and abundance of insects drifting in neotropical streams.

    Gimenez, B C G; Lansac-Tôha, F A; Higuti, J


    Streams may exhibit differences in community structure of invertebrate drift, which may be a reflex of variation in environmental factors, able to change in conditions of anthropogenic interventions. The aim of this study was to analyze the composition, diversity and abundance of insects drifting in two neotropical streams under different land use and to identify the environmental factors involved in determining such patterns. 54 taxa of aquatic insects were identified in urban and rural streams. The results indicated significant differences in species composition due to the replacement of specialist species by generalist species in the urban stream. Higher diversity of taxa was recorded in the rural stream, with high levels of dissolved oxygen and high water flow, which favored the occurrence of sensitive groups to environmental disturbances, such as Ephemeroptera, Plecoptera, Trichoptera and Coleoptera taxa, that living mainly in clean and well oxygenated waters. On the other hand, a higher density of insects drifting, especially Chironomidae, was observed in the urban stream, where high values of pH, electrical conductivity and nitrogen were observed. These larvae are able to explore a wide range of environmental conditions, owing to their great capacity for physiological adaptation. Despite observing the expected patterns, there were no significant differences between streams for the diversity and abundance of species. Thus, the species composition can be considered as the best predictor of impacts on the drifting insect community.

  18. Effect of land use on the composition, diversity and abundance of insects drifting in neotropical streams

    B. C. G. Gimenez

    Full Text Available Abstract Streams may exhibit differences in community structure of invertebrate drift, which may be a reflex of variation in environmental factors, able to change in conditions of anthropogenic interventions. The aim of this study was to analyze the composition, diversity and abundance of insects drifting in two neotropical streams under different land use and to identify the environmental factors involved in determining such patterns. 54 taxa of aquatic insects were identified in urban and rural streams. The results indicated significant differences in species composition due to the replacement of specialist species by generalist species in the urban stream. Higher diversity of taxa was recorded in the rural stream, with high levels of dissolved oxygen and high water flow, which favored the occurrence of sensitive groups to environmental disturbances, such as Ephemeroptera, Plecoptera, Trichoptera and Coleoptera taxa, that living mainly in clean and well oxygenated waters. On the other hand, a higher density of insects drifting, especially Chironomidae, was observed in the urban stream, where high values of pH, electrical conductivity and nitrogen were observed. These larvae are able to explore a wide range of environmental conditions, owing to their great capacity for physiological adaptation. Despite observing the expected patterns, there were no significant differences between streams for the diversity and abundance of species. Thus, the species composition can be considered as the best predictor of impacts on the drifting insect community.

  19. Use of an integrated flow model to estimate ecologically relevant hydrologic characteristics at stream biomonitoring sites

    Kennen, J.G.; Kauffman, L.J.; Ayers, M.A.; Wolock, D.M.; Colarullo, S.J.


    We developed an integrated hydroecological model to provide a comprehensive set of hydrologic variables representing five major components of the flow regime at 856 aquatic-invertebrate monitoring sites in New Jersey. The hydroecological model simulates streamflow by routing water that moves overland and through the subsurface from atmospheric delivery to the watershed outlet. Snow accumulation and melt, evapotranspiration, precipitation, withdrawals, discharges, pervious- and impervious-area runoff, and lake storage were accounted for in the water balance. We generated more than 78 flow variables, which describe the frequency, magnitude, duration, rate of change, and timing of flow events. Highly correlated variables were filtered by principal component analysis to obtain a non-redundant subset of variables that explain the majority of the variation in the complete set. This subset of variables was used to evaluate the effect of changes in the flow regime on aquatic-invertebrate assemblage structure at 856 biomonitoring sites. We used non-metric multidimensional scaling (NMS) to evaluate variation in aquatic-invertebrate assemblage structure across a disturbance gradient. We employed multiple linear regression (MLR) analysis to build a series of MLR models that identify the most important environmental and hydrologic variables driving the differences in the aquatic-invertebrate assemblages across the disturbance gradient. The first axis of NMS ordination was significantly related to many hydrologic, habitat, and land-use/land-cover variables, including the average number of annual storms producing runoff, ratio of 25-75% exceedance flow (flashiness), diversity of natural stream substrate, and the percentage of forested land near the stream channel (forest buffer). Modifications in the hydrologic regime as the result of changes in watershed land use appear to promote the retention of highly tolerant aquatic species; in contrast, species that are sensitive to

  20. Crustal growth history of the Korean Peninsula:Constraints from detrital zircon ages in modern river sediments

    Taejin Choi; Yong Il Lee; Yuji Orihashi


    U-Pb analyses were carried out on detrital zircon grains from major river-mouth sediments draining South Korea to infer provenance characteristics and the crustal growth history of the southern Korean Peninsula, using a laser ablation inductively coupled plasma mass spectrometer (LA-ICP-MS). The Korean Peninsula is located in the East Asian continental margin and mainly comprises three Precambrian massifs and two metamorphic belts in between them. We obtained 515 concordant to slightly discordant zircon ages ranging from ca. 3566 to ca. 48 Ma. Regardless of river-mouth location, predominance of Mesozoic (249e79 Ma) and Paleoproterozoic (2491e1691 Ma) ages with subordinate Archean ages in-dicates that the zircon ages reflect present exposures of plutonic/metamorphic rocks in the drainage basins of the South Korean rivers and the crustal growth of the southern Korean Peninsula was focused in these two periods. Comparison of detrital zircon-age data between the North and South Korean river sediments reveals that the Paleoproterozoic zircon age distributions of both regions are nearly identical, while the NeoproterozoicePaleozoic ages exist and the Mesozoic ages are dominant in southern Korean Peninsula. This result suggests that Precambrian terrains in Korea record the similar pre-Mesozoic magmatic history and that the influence of Mesozoic magmatism was mainly focused in South Korea.

  1. Trace elements and cathodoluminescence of detrital quartz in Arctic marine sediments – a new ice-rafted debris provenance proxy

    A. Müller


    Full Text Available The records of ice-rafted debris (IRD provenance in the North Atlantic – Barents Sea allow the reconstruction of the spatial and temporal changes of ice-flow drainage patterns during glacial and deglacial periods. In this study a new approach to characterisation of the provenance of detrital quartz grains in the fraction > 500 μm of marine sediments offshore of Spitsbergen is introduced, utilizing scanning electron microscope backscattered electron and cathodoluminescence (CL imaging, combined with laser ablation inductively-coupled plasma mass spectrometry. Based on their micro-inclusions, CL and trace element characteristics the investigated IRD grains can be classified into five distinct populations. Three of the populations are indicative of potential IRD provenance provinces in the Storfjord area including Barentsøya and Egdeøya. The results imply that under modern (interglacial conditions IRD deposition along the western Spitsbergen margin is mainly governed by the East Svalbard Current controlling the ice-drift pattern. The presence of detrital quartz from local provinces, however, indicates that variations in IRD supply from western Spitsbergen may be quantified as well. In this pilot study it is demonstrated that this new approach applied on Arctic continental margin sediments, bears a considerable potential for the definition of the sources of IRD and thus of spatial/temporal changes in ice-flow drainage patterns during glacial/interglacial cycles.

  2. U-Pb ages of detrital zircon and provenances of Red Clay in the Chinese Loess Plateau

    Gong, Hujun; Xie, Wenbin; Zhang, Rui; Zhang, Yunxiang


    The Chinese Loess Plateau (CLP), which is located in the central part of China, mainly contains two sequences: the Quaternary loess-paleosol sequence and the late Miocene-Pliocene Red Clay sequence. U-Pb ages of detrital zircon from the Quaternary loess-paleosol sequences indicate that the current spatial pattern of central Asian aridification was largely established during the early Quaternary. U-Pb ages of detrital zircon from the underlying Red Clay sequences demonstrate that the northern source regions were important contributors for the dust since the late Miocene, except for the periods of ∼8 Ma and ∼5.5 to ∼4 Ma. These two periods correspond to increased and decreased dust deposition in the North Pacific, respectively, ascribed to the late Miocene aridification of the Qaidam Basin (in the west of the CLP) and the early Pliocene aridification of the Tarim Basin (in the west of the CLP). We attribute the increase of the Qaidam Basin-derived North Pacific dust fluxes to the uplift of the NE Tibetan Plateau. Such uplift also controlled the climatic and environmental changes in central Asian during the late Miocene. This study highlights the dynamical process of the central Asian aridification during the late Miocene-Pliocene.

  3. Multiple stressors in agricultural streams: a mesocosm study of interactions among raised water temperature, sediment addition and nutrient enrichment.

    Jeremy J Piggott

    Full Text Available Changes to land use affect streams through nutrient enrichment, increased inputs of sediment and, where riparian vegetation has been removed, raised water temperature. We manipulated all three stressors in experimental streamside channels for 30 days and determined the individual and pair-wise combined effects on benthic invertebrate and algal communities and on leaf decay, a measure of ecosystem functioning. We added nutrients (phosphorus+nitrogen; high, intermediate, natural and/or sediment (grain size 0.2 mm; high, intermediate, natural to 18 channels supplied with water from a nearby stream. Temperature was increased by 1.4°C in half the channels, simulating the loss of upstream and adjacent riparian shade. Sediment affected 93% of all biological response variables (either as an individual effect or via an interaction with another stressor generally in a negative manner, while nutrient enrichment affected 59% (mostly positive and raised temperature 59% (mostly positive. More of the algal components of the community responded to stressors acting individually than did invertebrate components, whereas pair-wise stressor interactions were more common in the invertebrate community. Stressors interacted often and in a complex manner, with interactions between sediment and temperature most common. Thus, the negative impact of high sediment on taxon richness of both algae and invertebrates was stronger at raised temperature, further reducing biodiversity. In addition, the decay rate of leaf material (strength loss accelerated with nutrient enrichment at ambient but not at raised temperature. A key implication of our findings for resource managers is that the removal of riparian shading from streams already subjected to high sediment inputs, or land-use changes that increase erosion or nutrient runoff in a landscape without riparian buffers, may have unexpected effects on stream health. We highlight the likely importance of intact or restored buffer

  4. The early Paleozoic sedimentary-tectonic evolution of the circum-Mangar areas, Tarim block, NW China: Constraints from integrated detrital records

    Dong, Shunli; Li, Zhong; Jiang, Lei


    The Mangar depression, located in the eastern part of the Tarim basin, had deposited extremely-thick lower Paleozoic sediments, which yields great scientific value and hydrocarbon resource potential. Due to the lack of enough outcrop and core studies, many issues, e.g., early Paleozoic geographical evolution, basin nature and tectonic affinity, are still poorly understood. In this study, we selected circum-Mangar areas (i.e., the South Quruqtagh, Tabei and Tazhong areas), and carried out comprehensive detrital provenance analysis including detrital modal analysis, heavy mineral and trace element analysis, and detrital zircon U-Pb dating on the Middle-Upper Ordovician and Silurian sandstones. The results show that Upper Ordovician-Lower Silurian detrital provenances of the South Quruqtagh and Tabei areas were primarily derived from the intracontinental uplifts in Tarim. Meanwhile, Upper Silurian detrital provenances of the above two areas were mainly derived from the mix of intracontinental uplifts and continental-margin arcs. Dramatic Late Silurian provenance-change suggests the evident tectonic transition of the northern Tarim margin, which is the opening of the South Tianshan back-arc oceanic basin. Combining the previous studies, an integral redefinition model for the Mangar depression has been made. The evolution process of the Mangar depression could be divided into four stages: graben stage (late Neoproterozoic), transitional stage (Cambrian to Middle Ordovician), downwarp stage (Late Ordovician to Early Silurian) and extinction stage (Late Silurian). Hence, the Mangar depression evolved as an aulacogen. Significantly, the evolutional scenario of the Mangar aulacogen was consistent with that of the North Altyn Tagh and the North Qilian, suggesting that the Mangar aulacogen was involved mainly in the Proto-Tethys tectonic realm south to the Tarim block. However, the Late Silurian tectonic activity in the northern Tarim margin did produce massive detrital

  5. Numerical Modelling of Streams

    Vestergaard, Kristian

    In recent years there has been a sharp increase in the use of numerical water quality models. Numeric water quality modeling can be divided into three steps: Hydrodynamic modeling for the determination of stream flow and water levels. Modelling of transport and dispersion of a conservative...

  6. Academic streaming in Europe

    Falaschi, Alessandro; Mønster, Dan; Doležal, Ivan


    The TF-NETCAST task force was active from March 2003 to March 2004, and during this time the mem- bers worked on various aspects of streaming media related to the ultimate goal of setting up common services and infrastructures to enable netcasting of high quality content to the academic community...

  7. Music Streaming in Denmark

    Pedersen, Rasmus Rex

    This report analyses how a ’per user’ settlement model differs from the ‘pro rata’ model currently used. The analysis is based on data for all streams by WiMP users in Denmark during August 2013. The analysis has been conducted in collaboration with Christian Schlelein from Koda on the basis...

  8. The Rabbit Stream Cipher

    Boesgaard, Martin; Vesterager, Mette; Zenner, Erik


    The stream cipher Rabbit was first presented at FSE 2003, and no attacks against it have been published until now. With a measured encryption/decryption speed of 3.7 clock cycles per byte on a Pentium III processor, Rabbit does also provide very high performance. This paper gives a concise...... description of the Rabbit design and some of the cryptanalytic results available....

  9. Stream Automata Are Coalgebras

    Ciancia, V.; Venema, Y.


    Stream automata (also called ω-automata) and ω-regular languages are of paramount importance in Computer Science and Logic. A coalgebraic treatment of these structures has not been given yet. We study a simple two-sorted setting where deterministic Muller automata can be cast as coalgebras, so that

  10. Stream Water Quality Model

    U.S. Environmental Protection Agency — QUAL2K (or Q2K) is a river and stream water quality model that is intended to represent a modernized version of the QUAL2E (or Q2E) model (Brown and Barnwell 1987).

  11. Clustering Text Data Streams

    Yu-Bao Liu; Jia-Rong Cai; Jian Yin; Ada Wai-Chee Fu


    Clustering text data streams is an important issue in data mining community and has a number of applications such as news group filtering, text crawling, document organization and topic detection and tracing etc. However, most methods are similarity-based approaches and only use the TF*IDF scheme to represent the semantics of text data and often lead to poor clustering quality. Recently, researchers argue that semantic smoothing model is more efficient than the existing TF.IDF scheme for improving text clustering quality. However, the existing semantic smoothing model is not suitable for dynamic text data context. In this paper, we extend the semantic smoothing model into text data streams context firstly. Based on the extended model, we then present two online clustering algorithms OCTS and OCTSM for the clustering of massive text data streams. In both algorithms, we also present a new cluster statistics structure named cluster profile which can capture the semantics of text data streams dynamically and at the same time speed up the clustering process. Some efficient implementations for our algorithms are also given. Finally, we present a series of experimental results illustrating the effectiveness of our technique.

  12. Streaming-video produktion

    Grønkjær, Poul


     E-learning Lab på Aalborg Universitet har i forbindelse med forskningsprojektet Virtuelle Læringsformer og Læringsmiljøer foretaget en række praktiske eksperimenter med streaming-video produktioner. Hensigten med denne artikel er at formidle disse erfaringer. Artiklen beskriver hele produktionsf...... E-learning Lab på Aalborg Universitet har i forbindelse med forskningsprojektet Virtuelle Læringsformer og Læringsmiljøer foretaget en række praktiske eksperimenter med streaming-video produktioner. Hensigten med denne artikel er at formidle disse erfaringer. Artiklen beskriver hele...... produktionsforløbet: fra ide til færdigt produkt, forskellige typer af præsentationer, dramaturgiske overvejelser samt en konceptskitse. Streaming-video teknologien er nu så udviklet med et så tilfredsstillende audiovisuelt udtryk at vi kan begynde at fokusere på, hvilket indhold der er velegnet til at blive gjort...... tilgængeligt uafhængigt af tid og sted. Afslutningsvis er der en række kildehenvisninger, blandt andet en oversigt over de streaming-video produktioner, som denne artikel bygger på....

  13. On Meteoroid Streams Identification

    Klacka, J


    Criterion for the membership of individual meteors to meteoroid streams presented by Valsecchi {\\it et. al.} (1999) and Jopek {\\it et. al.} (1999) is discussed. The authors characterize and use their criterion as a distance function. However, it is not a distance function. Some practical aspects are also discussed. Correct criterion is presented.

  14. Endocrine Function in Aquatic Invertebrates and Evidence for Disruption by Environmental Pollutants

    Pinder, L.C.V.; Pottinger, T.G.; Billinghurst, Z.; Depledge, M.H.


    EXECUTIVE SUMMARY Objectives 1. This report addresses five primary objectives:- (i) to summarize the key elements of invertebrate endocrine systems; (ii) to assess whether existing test systems are adequate for the detection of endocrine disruption in invertebrates, what new tests might be required, which species of invertebrates are most appropriate for such tests, what end-points should be measured and whether the same organisms can be used for both laboratory and environme...

  15. The implications of climate change for positive contributions of invertebrates to world agriculture


    [EN] Terrestrial invertebrate species play a dominant role in the trophic dynamics of agricultural ecosystems. Subtle changes in the composition of communities and species interactions at different trophic levels, and role of ecosystem engineers can dramatically modify the effects of invertebrates on plant productivity in agricultural systems. The effect of climate change on relevant invertebrates in agricultural systems, and their potential to adapt or move is discussed. All terrestrial syst...

  16. The implications of climate change for positive contributions of invertebrates to world agriculture

    Cock, M.J.W.; Biesmeijer, Jacobus C.; Cannon, R.J.C.; Gerard, Philippa J.; Gillespie, Dave; Jiménez, Juan J.; Lavelle, Patrick; Suresh K. Raina


    [EN] Terrestrial invertebrate species play a dominant role in the trophic dynamics of agricultural ecosystems. Subtle changes in the composition of communities and species interactions at different trophic levels, and role of ecosystem engineers can dramatically modify the effects of invertebrates on plant productivity in agricultural systems. The effect of climate change on relevant invertebrates in agricultural systems, and their potential to adapt or move is discussed. All terrestrial syst...

  17. Recovery of a mining-damaged stream ecosystem

    Christopher A. Mebane


    Full Text Available Abstract This paper presents a 30+ year record of changes in benthic macroinvertebrate communities and fish populations associated with improving water quality in mining-influenced streams. Panther Creek, a tributary to the Salmon River in central Idaho, USA suffered intensive damage from mining and milling operations at the Blackbird Mine that released copper (Cu, arsenic (As, and cobalt (Co into tributaries. From the 1960s through the 1980s, no fish and few aquatic invertebrates could be found in 40 km of mine-affected reaches of Panther Creek downstream of the metals contaminated tributaries, Blackbird and Big Deer Creeks. Efforts to restore water quality began in 1995, and by 2002 Cu levels had been reduced by about 90%, with incremental declines since. Rainbow Trout (Oncorhynchus mykiss were early colonizers, quickly expanding their range as areas became habitable when Cu concentrations dropped below about 3X the U.S. Environmental Protection Agency’s biotic ligand model (BLM based chronic aquatic life criterion. Anadromous Chinook Salmon (O. tshawytscha and steelhead (O. mykiss have also reoccupied Panther Creek. Full recovery of salmonid populations occurred within about 12-years after the onset of restoration efforts and about 4-years after the Cu chronic criteria had mostly been met, with recovery interpreted as similarity in densities, biomass, year class strength, and condition factors between reference sites and mining-influenced sites. Shorthead Sculpin (Cottus confusus were slower than salmonids to disperse and colonize. While benthic macroinvertebrate biomass has increased, species richness has plateaued at about 70 to 90% of reference despite the Cu criterion having been met for several years. Different invertebrate taxa had distinctly different recovery trajectories. Among the slowest taxa to recover were Ephemerella, Cinygmula and Rhithrogena mayflies, Enchytraeidae oligochaetes, and Heterlimnius aquatic beetles. Potential

  18. Biodiversity of Insect Larvae in Streams at Jobolarangan Forest



    Full Text Available Insect larvae are macro-invertebrate that becomes the most perfect indicator of aquatic-environmental health. Natural streams usually determined by its insect-larvae community in a good condition, in which their taxonomic diversity and richness are high. The objective of the research was to know the taxonomic diversity and richness of insect-larvae family in streams at Jobolarangan forest. The larvae were sampled using net-surber (dip-net in three location of streams, i.e.: Parkiran (1773 m asl., Mrutu (1875 m asl., and Air Terjun (1600 m asl.. The screened insect-larvae were grouped its family and counted their individual number. The diversity was counted using Shanon-Weiner diversity indices. In this research was found 12 families of insect-larvae consisted of two families of Odonata order, 3 families of Coleopteran order, and a family of Lepidoptera. Nine families identified, while the three insect-larvae i.e. 2 of Coleoptera and 1 of Lepidoptera were not identified yet. The Parkiran station indicated the highest diversity index of 0.1436.

  19. Feeding live invertebrate prey in zoos and aquaria: Are there welfare concerns?

    Keller, Martha


    Invertebrates constitute more than 90% of all species on earth, however, as a rule, humans do not regard invertebrates as creatures that can suffer and they are generally seen as creatures that should be eliminated. As a result, the importance of their welfare may be grossly unappreciated. For instance, the feeding of live food is often viewed as a good method of enrichment and invertebrates are commonly used as live prey in many zoological facilities. As a result, zoos may send mixed messages to their patrons in that welfare is considered only for the invertebrates that are part of their zoological collection and not necessarily for the invertebrates used as feed. Research indicates that many invertebrates possess nociceptors, opioid receptors, and demonstrate behavioral responses indicative of pain sensation. In addition, in some taxa, there may be evidence of higher cognitive functions such as emotions and learning, although studies in this area of research are preliminary and sparse. Therefore, the possibility for suffering exists in many invertebrate species and as such, zoological facilities have an ethical responsibility to take their welfare into consideration. This paper discusses the current research regarding invertebrates' capacity for suffering and discusses methods facilities can use to improve the welfare of their invertebrate live prey. © 2017 Wiley Periodicals, Inc.

  20. Chemical Screening Method for the Rapid Identification of Microbial Sources of Marine Invertebrate-Associated Metabolites

    Russell G. Kerr


    Full Text Available Marine invertebrates have proven to be a rich source of secondary metabolites. The growing recognition that marine microorganisms associated with invertebrate hosts are involved in the biosynthesis of secondary metabolites offers new alternatives for the discovery and development of marine natural products. However, the discovery of microorganisms producing secondary metabolites previously attributed to an invertebrate host poses a significant challenge. This study describes an efficient chemical screening method utilizing a 96-well plate-based bacterial cultivation strategy to identify and isolate microbial producers of marine invertebrate-associated metabolites.

  1. Lightweight query authentication on streams


    We consider a stream outsourcing setting, where a data owner delegates the management of a set of disjoint data streams to an untrusted server. The owner authenticates his streams via signatures. The server processes continuous queries on the union of the streams for clients trusted by the owner. Along with the results, the server sends proofs of result correctness derived from the owner's signatures, which are easily verifiable by the clients. We design novel constructions for a collection o...

  2. Transport distance of invertebrate environmental DNA in a natural river.

    Kristy Deiner

    Full Text Available Environmental DNA (eDNA monitoring is a novel molecular technique to detect species in natural habitats. Many eDNA studies in aquatic systems have focused on lake or ponds, and/or on large vertebrate species, but applications to invertebrates in river systems are emerging. A challenge in applying eDNA monitoring in flowing waters is that a species' DNA can be transported downstream. Whether and how far eDNA can be detected due to downstream transport remains largely unknown. In this study we tested for downstream detection of eDNA for two invertebrate species, Daphnia longispina and Unio tumidus, which are lake dwelling species in our study area. The goal was to determine how far away from the source population in a lake their eDNA could be detected in an outflowing river. We sampled water from eleven river sites in regular intervals up to 12.3 km downstream of the lake, developed new eDNA probes for both species, and used a standard PCR and Sanger sequencing detection method to confirm presence of each species' eDNA in the river. We detected D. longispina at all locations and across two time points (July and October; whereas with U. tumidus, we observed a decreased detection rate and did not detect its eDNA after 9.1 km. We also observed a difference in detection for this species at different times of year. The observed movement of eDNA from the source amounting to nearly 10 km for these species indicates that the resolution of an eDNA sample can be large in river systems. Our results indicate that there may be species' specific transport distances for eDNA and demonstrate for the first time that invertebrate eDNA can persist over relatively large distances in a natural river system.

  3. Macro-invertebrate decline in surface water polluted with imidacloprid.

    Tessa C Van Dijk

    Full Text Available Imidacloprid is one of the most widely used insecticides in the world. Its concentration in surface water exceeds the water quality norms in many parts of the Netherlands. Several studies have demonstrated harmful effects of this neonicotinoid to a wide range of non-target species. Therefore we expected that surface water pollution with imidacloprid would negatively impact aquatic ecosystems. Availability of extensive monitoring data on the abundance of aquatic macro-invertebrate species, and on imidacloprid concentrations in surface water in the Netherlands enabled us to test this hypothesis. Our regression analysis showed a significant negative relationship (P<0.001 between macro-invertebrate abundance and imidacloprid concentration for all species pooled. A significant negative relationship was also found for the orders Amphipoda, Basommatophora, Diptera, Ephemeroptera and Isopoda, and for several species separately. The order Odonata had a negative relationship very close to the significance threshold of 0.05 (P = 0.051. However, in accordance with previous research, a positive relationship was found for the order Actinedida. We used the monitoring field data to test whether the existing three water quality norms for imidacloprid in the Netherlands are protective in real conditions. Our data show that macrofauna abundance drops sharply between 13 and 67 ng l(-1. For aquatic ecosystem protection, two of the norms are not protective at all while the strictest norm of 13 ng l(-1 (MTR seems somewhat protective. In addition to the existing experimental evidence on the negative effects of imidacloprid on invertebrate life, our study, based on data from large-scale field monitoring during multiple years, shows that serious concern about the far-reaching consequences of the abundant use of imidacloprid for aquatic ecosystems is justified.

  4. Scientometric trends of freshwater benthic invertebrates studies in Brazil

    Ana Lúcia Brandimarte

    Full Text Available Abstract: Aim The aim of this paper is to analyze trends in the literature concerning benthic invertebrates in Brazil, mainly the number of published papers and approaches used. Methods The Ph.D. database of the Lattes Platform (CNPq was used as the source of information for the period 1970-2014. We searched for the terms “benthos”, “macroinvertebrates”, and “zoobenthos” in the titles and keywords of the papers listed on the platform. Papers were classified into the following categories: Systematics, Life History, Ecology, and Divulgation. These categories were further divided into subcategories. The percentage of papers in every major category and subcategory was calculated. Results The search introduced 1,573 papers, which were mainly related to Ecology and Systematics. From 1970 to 2009, the number of papers published per decade increased exponentially, and the upward trend continues. The number of papers concerning Systematics, especially in Taxonomy, is increasing. Of the papers in Ecology category, those about Structure, Dynamics, and Distribution of the fauna have been increasing since the 1980s, and there has been an evident increase in the production of papers related to environmental damage in the last decade. The rate of production of papers concerning the role of invertebrates in ecosystems and the effects of different Spatial Scales has been increasing since the 2000s. Conclusion There is a clear tendency towards the increased continuity of paper production concerning freshwater benthic invertebrates, and relatively new approaches as Conservation and Exotic Species are becoming relevant.

  5. Fish odour triggers conspecific attraction behaviour in an aquatic invertebrate.

    Kullmann, Harald; Thünken, Timo; Baldauf, Sebastian A; Bakker, Theo C M; Frommen, Joachim G


    Group living has evolved as an adaptation to predation in many animal species. In a multitude of vertebrates, the tendency to aggregate varies with the risk of predation, but experimental evidence for this is less well known in invertebrates. Here, we examine the tendency to aggregate in the freshwater amphipod Gammarus pulex in the absence and presence of predator fish odour. Without fish odour, the gammarids showed no significant tendency to aggregate. In contrast to this, in fish-conditioned water, they significantly preferred to stay close to conspecifics. Predation risk can, thus, influence gammarids social behaviour.

  6. The phylogeny of invertebrates and the evolution of myelin.

    Roots, Betty I


    Current concepts of invertebrate phylogeny are reviewed. Annelida and Arthropoda, previously regarded as closely related, are now placed in separate clades. Myelin, a sheath of multiple layers of membranes around nerve axons, is found in members of the Annelida, Arthropoda and Chordata. The structure, composition and function of the sheaths in Annelida and Arthropoda are examined and evidence for the separate evolutionary origins of myelin in the three clades is presented. That myelin has arisen independently at least three times, namely in Annelids, Arthropodas and Chordates, provides a remarkable example of convergent evolution.

  7. [Venomous and poisonous animals. V. Envenomations by venomous marine invertebrates].

    Bédry, R; de Haro, L


    Epidemiological information about marine envenomation is generally less extensive in Europe than in tropical countries where this type of injury is more severe and the need for medical attention is more frequent. For this reason use of the regional poison control centers in the areas where envenomation occurs must be encouraged. The purpose of this review is to describe envenomation by poisonous marine invertebrates (cephalopods, sea urchins, cone shells, jellyfish, anemones, star-fish, corals, and worms). Understanding of these envenomation syndromes is important not only in tropical areas but also in Europe where importation of dangerous species has increased in recent years.

  8. Nitrous oxide production associated with coastal marine invertebrates

    Heisterkamp, Ines Maria; Schramm, Andreas; de Beer, Dirk


    , excluding the aquacultured shrimp Litopenaeus vannamei, which showed the highest rate of N2O emission measured so far for any marine species (3.569 nmol ind.–1 h–1), probably due to very high nitrate concentrations in the rearing tanks. The N2O emitted by L. vannamei was almost exclusively produced in its...... with an experimentally cleaned shell. Thus, the N2O production associated with marine invertebrates is apparently not due to gut denitrification in every species, but may also result from microbial activity on the external surfaces of animals. The high abundance and potential N2O emission rates of many marine...

  9. Biobanking of a Marine Invertebrate Model Organism: The Sea Urchin

    Estefania Paredes


    Full Text Available The sea urchin has long been used as an invertebrate model organism in developmental biology, membrane transport and sperm oocyte interactions, and for the assessment of marine pollution. This review explores the effects of cryopreservation and biobanking in the biology and development of sea urchins, all the way from germaplasm through to juveniles. This review will provide an integral view of the process and all that is known so far about the biology of cryopreserved sea urchins, as well as provide an insight on the applications of the biobanking of these model organisms.

  10. Distribution pattern of benthic invertebrates in Danish estuaries

    Kristensen, Erik; Delefosse, Matthieu; Quintana, Cintia Organo


    factors such as behavior and intraspecific interactions. Thus, at the examined spatial scale, the more intense intraspecific interactions (e.g. territoriality) cause less aggregated distribution patterns among large- than small-bodied invertebrates. The species-specific interactions seem sufficiently...... strong to override environmental influences (e.g. water depth and sediment type). The strong linear relationship between the slope b and intercept log(a) from the power relationship is remarkably similar for all surveys providing a common slope of−1.63 with the present sampling approach.We suggest...

  11. Analysis of hydraulic characteristics for stream diversion in small stream

    Ahn, Sang-Jin; Jun, Kye-Won [Chungbuk National University, Cheongju(Korea)


    This study is the analysis of hydraulic characteristics for stream diversion reach by numerical model test. Through it we can provide the basis data in flood, and in grasping stream flow characteristics. Analysis of hydraulic characteristics in Seoknam stream were implemented by using computer model HEC-RAS(one-dimensional model) and RMA2(two-dimensional finite element model). As a result we became to know that RMA2 to simulate left, main channel, right in stream is more effective method in analysing flow in channel bends, steep slope, complex bed form effect stream flow characteristics, than HEC-RAS. (author). 13 refs., 3 tabs., 5 figs.

  12. Meteor Stream Membership Criteria

    Klacka, J


    Criteria for the membership of individual meteors in meteor streams are discussed from the point of view of their mathematical and also physical properties. Discussion is also devoted to the motivation. It is shown that standardly used criteria (mainly D-criterion of Southworth and Hawkins, 1963) have unusual mathematical properties in the sense of a term ``distance'', between points in a phase space, and, physical motivation and realization for the purpose of obtaining their final form is not natural and correct, and, moreover, they lead also to at least surprising astrophysical results. General properties of possible criteria are discussed. A new criterion for the membership in meteor streams is suggested. It is based on probability theory. Finally, a problem of meteor orbit determination for known parent body is discussed.

  13. Detrital chrome spinel evidence for a Neotethyan intra-oceanic island arc collision with India in the Paleocene

    Baxter, Alan T.; Aitchison, Jonathan C.; Ali, Jason R.; Chan, Jacky Sik-Lap; Chan, Gavin Heung Ngai


    Models that support a single collision scenario for India and Eurasia are incompatible with the evidence that an intra-oceanic island arc (IOIA) existed within the Neotethyan Ocean. Understanding the spatial and temporal extent of any IOIA is crucial for India-Eurasia collision studies as the entire ocean, including any intra-oceanic features, must have been consumed or emplaced prior to continental collision. Here, we review what is known about the Neotethyan IOIA and report evidence from sedimentary successions in NW India and southern Tibet to constrain when and where it was emplaced. We use detrital mineral geochemistry and supporting provenance and age data to identify the source of the sediments and compare the timing of erosion of IOIA-derived material in both regions. Detrital chrome spinels, extracted from distinct sedimentary horizons in southern Tibet (Sangdanlin) and NW India (Ladakh), exhibit similar average geochemical values (TiO2 = 0.09 and 0.24%, Cr# = 0.66 and 0.68 and Mg# = 0.45 and 0.53, respectively) and supra-subduction zone (SSZ), forearc peridotite signatures. Furthermore, they overlap with in-situ chrome spinels reported from the Spongtang Ophiolite in NW India and the Sangsang Ophiolite in southern Tibet. As with many of the ophiolitic remnants that crop out in and adjacent to the Yarlung-Tsangpo and Indus suture zones (YTSZ and ISZ respectively), the Spongtang and Sangsang ophiolites formed in an IOIA setting. Linking the source of the detrital chrome spinels to those analysed from remnant IOIA massifs in the YTSZ and ISZ is strong evidence for the emplacement of the IOIA onto the Indian margin. The timing of the IOIA collision with India is constrained by the depositional ages of the chrome spinel-bearing sediments to the end of the Paleocene (Thanetian) in southern Tibet and the Early Eocene in NW India. This indirectly provides a maximum age constraint of Late Paleocene-Early Eocene for intercontinental collision between India and

  14. Permafrost thaw and intense thermokarst activity decreases abundance of stream benthic macroinvertebrates.

    Chin, Krista S; Lento, Jennifer; Culp, Joseph M; Lacelle, Denis; Kokelj, Steven V


    Intensification of permafrost thaw has increased the frequency and magnitude of large permafrost slope disturbances (mega slumps) in glaciated terrain of northwestern Canada. Individual thermokarst disturbances up to 40 ha in area have made large volumes of previously frozen sediments available for leaching and transport to adjacent streams, significantly increasing sediment and solute loads in these systems. To test the effects of this climate-sensitive disturbance regime on the ecology of Arctic streams, we explored the relationship between physical and chemical variables and benthic macroinvertebrate communities in disturbed and undisturbed stream reaches in the Peel Plateau, Northwest Territories, Canada. Highly disturbed and undisturbed stream reaches differed with respect to taxonomic composition and invertebrate abundance. Minimally disturbed reaches were not differentiated by these variables but rather were distributed along a disturbance gradient between highly disturbed and undisturbed sites. In particular, there was evidence of a strong negative relationship between macroinvertebrate abundance and total suspended solids, and a positive relationship between abundance and the distance from the disturbance. Increases in both sediments and nutrients appear to be the proximate cause of community differences in highly disturbed streams. Declines in macroinvertebrate abundance in response to slump activity have implications for the food webs of these systems, potentially leading to negative impacts on higher trophic levels, such as fish. Furthermore, the disturbance impacts on stream health can be expected to intensify as climate change increases the frequency and magnitude of thermokarst.

  15. The LHCb Turbo stream

    Puig, A.


    The LHCb experiment will record an unprecedented dataset of beauty and charm hadron decays during Run II of the LHC, set to take place between 2015 and 2018. A key computing challenge is to store and process this data, which limits the maximum output rate of the LHCb trigger. So far, LHCb has written out a few kHz of events containing the full raw sub-detector data, which are passed through a full offline event reconstruction before being considered for physics analysis. Charm physics in particular is limited by trigger output rate constraints. A new streaming strategy includes the possibility to perform the physics analysis with candidates reconstructed in the trigger, thus bypassing the offline reconstruction. In the Turbo stream the trigger will write out a compact summary of physics objects containing all information necessary for analyses. This will allow an increased output rate and thus higher average efficiencies and smaller selection biases. This idea will be commissioned and developed during 2015 with a selection of physics analyses. It is anticipated that the turbo stream will be adopted by an increasing number of analyses during the remainder of LHC Run II (2015-2018) and ultimately in Run III (starting in 2020) with the upgraded LHCb detector.

  16. Gas stream cleanup

    Bossart, S.J.; Cicero, D.C.; Zeh, C.M.; Bedick, R.C.


    This report describes the current status and recent accomplishments of gas stream cleanup (GSCU) projects sponsored by the Morgantown Energy Technology Center (METC) of the US Department of Energy (DOE). The primary goal of the Gas Stream Cleanup Program is to develop contaminant control strategies that meet environmental regulations and protect equipment in advanced coal conversion systems. Contaminant control systems are being developed for integration into seven advanced coal conversion processes: Pressurized fludized-bed combustion (PFBC), Direct coal-fueled turbine (DCFT), Intergrated gasification combined-cycle (IGCC), Gasification/molten carbonate fuel cell (MCFC), Gasification/solid oxide fuel cell (SOFC), Coal-fueled diesel (CFD), and Mild gasification (MG). These advanced coal conversion systems present a significant challenge for development of contaminant control systems because they generate multi-contaminant gas streams at high-pressures and high temperatures. Each of the seven advanced coal conversion systems incorporates distinct contaminant control strategies because each has different contaminant tolerance limits and operating conditions. 59 refs., 17 figs., 5 tabs.

  17. Gas stream cleanup

    Bossart, S.J.; Cicero, D.C.; Zeh, C.M.; Bedick, R.C.


    This report describes the current status and recent accomplishments of gas stream cleanup (GSCU) projects sponsored by the Morgantown Energy Technology Center (METC) of the US Department of Energy (DOE). The primary goal of the Gas Stream Cleanup Program is to develop contaminant control strategies that meet environmental regulations and protect equipment in advanced coal conversion systems. Contaminant control systems are being developed for integration into seven advanced coal conversion processes: Pressurized fludized-bed combustion (PFBC), Direct coal-fueled turbine (DCFT), Intergrated gasification combined-cycle (IGCC), Gasification/molten carbonate fuel cell (MCFC), Gasification/solid oxide fuel cell (SOFC), Coal-fueled diesel (CFD), and Mild gasification (MG). These advanced coal conversion systems present a significant challenge for development of contaminant control systems because they generate multi-contaminant gas streams at high-pressures and high temperatures. Each of the seven advanced coal conversion systems incorporates distinct contaminant control strategies because each has different contaminant tolerance limits and operating conditions. 59 refs., 17 figs., 5 tabs.

  18. The LHCb Turbo stream

    Puig, A., E-mail:


    The LHCb experiment will record an unprecedented dataset of beauty and charm hadron decays during Run II of the LHC, set to take place between 2015 and 2018. A key computing challenge is to store and process this data, which limits the maximum output rate of the LHCb trigger. So far, LHCb has written out a few kHz of events containing the full raw sub-detector data, which are passed through a full offline event reconstruction before being considered for physics analysis. Charm physics in particular is limited by trigger output rate constraints. A new streaming strategy includes the possibility to perform the physics analysis with candidates reconstructed in the trigger, thus bypassing the offline reconstruction. In the Turbo stream the trigger will write out a compact summary of physics objects containing all information necessary for analyses. This will allow an increased output rate and thus higher average efficiencies and smaller selection biases. This idea will be commissioned and developed during 2015 with a selection of physics analyses. It is anticipated that the turbo stream will be adopted by an increasing number of analyses during the remainder of LHC Run II (2015–2018) and ultimately in Run III (starting in 2020) with the upgraded LHCb detector.

  19. Streaming-video produktion

    Poul Grønkjær


    Full Text Available

    Første gang publiceret i UNEV nr. 3: Internet Video: Teknik og pædagogik mødes på nettet, april - juni 2004, red. Jens Dørup. ISSN 1603-5518.

    E-learning Lab på Aalborg Universitet har i forbindelse med forskningsprojektet Virtuelle Læringsformer og Læringsmiljøer foretaget en række praktiske eksperimenter med streaming-video produktioner. Hensigten med denne artikel er at formidle disse erfaringer. Artiklen beskriver hele produktionsforløbet: fra ide til færdigt produkt, forskellige typer af præsentationer, dramaturgiske overvejelser samt en konceptskitse. Streaming-video teknologien er nu så udviklet med et så tilfredsstillende audiovisuelt udtryk at vi kan begynde at fokusere på, hvilket indhold der er velegnet til at blive gjort tilgængeligt uafhængigt af tid og sted. Afslutningsvis er der en række kildehenvisninger, blandt andet en oversigt over de streaming-video produktioner, som denne artikel bygger på.

  20. Lichen physiological traits and growth forms affect communities of associated invertebrates.

    Bokhorst, Stef; Asplund, Johan; Kardol, Paul; Wardle, David A


    While there has been much interest in the relationships between traits of primary producers and composition of associated invertebrate consumer communities, our knowledge is largely based on studies from vascular plants, while other types of functionally important producers, such as lichens, have rarely been considered. To address how physiological traits of lichens drive community composition of invertebrates, we collected thalli from 27 lichen species from southern Norway and quantified the communities of associated springtails, mites, and nematodes. For each lichen species, we measured key physiological thallus traits and determined whether invertebrate communities were correlated with these traits. We also explored whether invertebrate communities differed among lichen groups, categorized according to nitrogen-fixing ability, growth form, and substratum. Lichen traits explained up to 39% of the variation in abundances of major invertebrate groups. For many invertebrate groups, abundance was positively correlated with lichen N and P concentrations, N:P ratio, and the percentage of water content on saturation (WC), but had few relationships with concentrations of carbon-based secondary compounds. Diversity and taxonomic richness of invertebrate groups were sometimes also correlated with lichen N and N:P ratios. Nitrogen-fixing lichens showed higher abundance and diversity of some invertebrate groups than did non-N-fixing lichens. However, this emerged in part because most N-fixing lichens have a foliose growth form that benefits invertebrates, through, improving the microclimate, independently of N concentration. Furthermore, invertebrate communities associated with terricolous lichens were determined more by their close proximity to the soil invertebrate pool than by lichen traits. Overall, our results reveal that differences between lichen species have a large impact on the invertebrate communities that live among the thalli. Different invertebrate groups show

  1. Can color vision variation explain sex differences in invertebrate foraging by capuchin monkeys?

    Amanda D. MELIN, Linda M. FEDIGAN, Hilary C. YOUNG, Shoji KAWAMURA


    Full Text Available Invertebrates are the main source of protein for many small-bodied monkeys. Prey vary in size, mobility, degree of protective covering, and use of the forest, i.e. canopy height, and whether they are exposed or embed themselves in substrates. Sex-differentiation in foraging patterns is well documented for some monkey species and recent studies find that color vision phenotype can also affect invertebrate foraging. Since vision phenotype is polymorphic and sex-linked in most New World monkeys - males have dichromatic vision and females have either dichromatic or trichromatic vision - this raises the possibility that sex differences are linked to visual ecology. We tested predicted sex differences for invertebrate foraging in white-faced capuchins Cebus capucinus and conducted 12 months of study on four free-ranging groups between January 2007 and September 2008. We found both sex and color vision effects. Sex: Males spent more time foraging for invertebrates on the ground. Females spent more time consuming embedded, colonial invertebrates, ate relatively more “soft” sedentary invertebrates, and devoted more of their activity budget to invertebrate foraging. Color Vision: Dichromatic monkeys had a higher capture efficiency of exposed invertebrates and spent less time visually foraging. Trichromats ate relatively more “hard” sedentary invertebrates. We conclude that some variation in invertebrate foraging reflects differences between the sexes that may be due to disparities in size, strength, reproductive demands or niche preferences. However, other intraspecific variation in invertebrate foraging that might be mistakenly attributed to sex differences actually reflects differences in color vision [Current Zoology 56 (3: 300–312, 2010].

  2. Seasonal changes in the invertebrate community of granular activated carbon filters and control technologies.

    Wang, Qing; You, Wei; Li, Xiaowei; Yang, Yufeng; Liu, Lijun


    Invertebrate colonization of granular activated carbon (GAC) filters in the waterworks is one of the most frequently occurring and least studied biological problems of water processing in China. A survey of invertebrate colonization of GAC filters was carried out weekly from October 2010 to December 2011 at a reservoir water treatment works in South China. Twenty-six kinds of invertebrates were observed. The abundance was as high as 5600ind.m(-3) with a mean of 860ind.m(-3). Large variations in abundance were observed among different seasons and before and after GAC filtration. The dominant organisms were rotifers and copepods. The average invertebrate abundance in the filtrate was 12-18.7 times of that in the pre-filtered water. Results showed that the GAC filters were colonized by invertebrates which may lead to a higher output of organisms in the filtrate than in the pre-filtered water. The invertebrate abundance in the GAC filters was statistically correlated with the water temperature. Seasonal patterns were observed. The invertebrate abundance grew faster in the spring and summer. Copepods were dominant in the summer while rotifers dominated in all other seasons of the year. There was a transition of small invertebrates (rotifers) gradually being substituted by larger invertebrates (copepods) from spring to summer. Control measures such as backwashing with chloric water, drying filter beds and soaking with saliferous water were implemented in the waterworks to reduce invertebrate abundances in the GAC filters. The results showed that soaking with saliferous water (99%, reduction in percent) was best but drying the filter beds (84%) was more economical. Soaking filter beds with 20g/L saliferous water for one day can be implemented in case of emergency. In order to keep invertebrate abundance in the acceptable range, some of these measures should be adopted.

  3. Fertilization success in marine invertebrates: the influence of gamete age.

    Williams, Mark Elliott; Bentley, Matthew Graeme


    Gamete age has been postulated to be unimportant to the fertilization ecology of marine invertebrates. However, recent research suggests that, for some species at least, it may have a direct impact upon fertilization success. We present comparative data on the influence of gamete age on fertilization and development success in several marine invertebrates: the polychaetes Arenicola marina and Nereis virens and the asteroid echinoderm Asterias rubens. Oocytes are much longer lived in the polychaetes than in the echinoderm, with A. marina oocytes still capable of fertilizing and developing normally 96 h post-spawning. Developmental abnormalities and failure to reach blastula tend to occur well before the fertilizable life of the oocytes has expired. Sperm are similarly longer lived in the polychaetes; however, fertilizing capacity is markedly reduced following incubation in conspecific egg-conditioned seawater. These results are discussed in terms of the fertilization strategies of the three species. We further suggest that, for A. marina at least, longer-lived sperm and eggs are central to the fertilization strategy of this species.

  4. Role of hemocytes in invertebrate adult neurogenesis and brain repair

    PG Chaves da Silva


    Full Text Available The repair of lesions of the central nervous system (CNS varies widely throughout the animal kingdom. At the level of neuronal replacement lie the major differences in CNS regeneration. At one extreme are the amniote vertebrates (reptile, avian and mammalian groups, which have very limited capacity for neuronal replacement, and therefore for neural regeneration; at the other extreme, animals such as planarians (flatworms and colonial tunicates can repair their entire CNS after major injuries. These differences can be attributed to the abundance of multipotent and/or pluripotent stem cells and/or undifferentiated precursors among the general cell population. In this review we discuss recent advancements in knowledge of regeneration of the CNS of invertebrates. We focus on ascidians, which are a sister group of vertebrates, but we also address other invertebrate groups. Because neurogenesis is central to the events that allow regeneration of the adult CNS, we address this issue focusing on crustaceans, which have provided a paradigm to study the mechanisms underlying this phenomenon. The attraction of hemocytes toward a neurogenic niche and respecification of these cells toward a neural fate has been strongly suggested. Based on recent and emerging research, we suggest that cells of the blood lineage are not only associated with the roles that are generally attributed to them, but are the cells that either signal other cell types to differentiate into neural cells, or even eventually themselves transdifferentiate into neural cells.

  5. Patterns of genetic connectivity in invertebrates of temperate MPA networks

    Patricia Marti-Puig


    Full Text Available Temperate reefs are among the most threatened marine habitats due to impacts caused by high density of human settlements, coastal development, pollution, fisheries and tourism. Networks of marine protected areas (MPAs are an important tool for ensuring long-term health and conservation of ecological processes in the marine environment. Design of the MPA network has to be based on deep understanding of spatial patterns of species distribution, and on the make-up of connectivity among populations. Most benthic invertebrates are sessile and/or sedentary in the adult phase, and their dispersal relies mainly on the gametes and/or larval behaviours. Genetic markers allow us to quantify gene flow and structuring among populations, and to infer patterns of genetic connectivity. Based on the information available in the peer reviewed literature on genetic connectivity in benthic invertebrates of temperate MPAs, we provide a comment about the gaps and the needs. Moreover, we propose a rationale to plan and optimise future studies on this topic. A conceptual framework for planning effective studies on genetic connectivity in an MPAs network is provided, including general recommendations on sampling design, key species and molecular markers to use.

  6. Tropical seaweed beds are important habitats for mobile invertebrate epifauna

    Tano, Stina; Eggertsen, M.; Wikström, S. A.; Berkström, C.; Buriyo, A. S.; Halling, C.


    Marine macrophyte habitats in temperate regions provide productive habitats for numerous organisms, with their abundant and diverse invertebrate epifaunal assemblages constituting important linkages between benthic primary production and higher trophic levels. While it is commonly also recognized that certain vegetated habitats in the tropics, such as seagrass meadows, can harbour diverse epifaunal assemblages and may constitute important feeding grounds to fish, little is known about the epifaunal assemblages associated with tropical seaweed beds. We investigated the abundance, biomass and taxon richness of the mobile epifaunal community (≥1 mm) of tropical East African seaweed beds, as well as the abundance of invertivorous fishes, and compared it with that of closely situated seagrass meadows, to establish the ecological role of seaweed beds as habitat for epifauna as well as potential feeding grounds for fish. The results showed that seaweed beds had a higher abundance of mobile epifauna (mean ± SD: 10,600 ± 6000 vs 3700 ± 2800 per m2) than seagrass meadows, as well as a higher invertebrate biomass (35.9 ± 46.8 vs 1.9 ± 2.1 g per m2) and taxon richness (32.7 ± 11.8 vs 19.1 ± 6.3 taxa per sample), despite having a lower macrophyte biomass. Additionally, the high abundance of invertivorous fishes found in seaweed beds indicates that they act as important feeding grounds to several fish species in the region.

  7. Toxicity of carbon nanotubes to freshwater aquatic invertebrates

    Mwangi, Joseph N.; Wang, Ning; Ingersoll, Christopher G.; Hardesty, Doug K.; Brunson, Eric L.; Li, Hao; Deng, Baolin


    Carbon nanotubes (CNTs) are hydrophobic in nature and thus tend to accumulate in sediments if released into aquatic environments. As part of our overall effort to examine the toxicity of carbon-based nanomaterials to sediment-dwelling invertebrates, we have evaluated the toxicity of different types of CNTs in 14-d water-only exposures to an amphipod (Hyalella azteca), a midge (Chironomus dilutus), an oligochaete (Lumbriculus variegatus), and a mussel (Villosa iris) in advance of conducting whole-sediment toxicity tests with CNTs. The results of these toxicity tests conducted with CNTs added to water showed that 1.00g/L (dry wt) of commercial sources of CNTs significantly reduced the survival or growth of the invertebrates. Toxicity was influenced by the type and source of the CNTs, by whether the materials were precleaned by acid, by whether sonication was used to disperse the materials, and by species of the test organisms. Light and electron microscope imaging of the surviving test organisms showed the presence of CNTs in the gut as well as on the outer surface of the test organisms, although no evidence was observed to show penetration of CNTs through cell membranes. The present study demonstrated that both the metals solubilized from CNTs such as nickel and the "metal-free" CNTs contributed to the toxicity.

  8. Many roads to resistance: how invertebrates adapt to Bt toxins.

    Griffitts, Joel S; Aroian, Raffi V


    The Cry family of Bacillus thuringiensis insecticidal and nematicidal proteins constitutes a valuable source of environmentally benign compounds for the control of insect pests and disease agents. An understanding of Cry toxin resistance at a molecular level will be critical to the long-term utility of this technology; it may also shed light on basic mechanisms used by other bacterial toxins that target specific organisms or cell types. Selection and cross-resistance studies have confirmed that genetic adaptation can elicit varying patterns of Cry toxin resistance, which has been associated with deficient protoxin activation by host proteases, and defective Cry toxin-binding cell surface molecules, such as cadherins, aminopeptidases and glycolipids. Recent work also suggests Cry toxin resistance may be induced in invertebrates as an active immune response. The use of model invertebrates, such as Caenorhabditis elegans and Drosophila melanogaster, as well as advances in insect genomics, are likely to accelerate efforts to clone Cry toxin resistance genes and come to a detailed and broad understanding of Cry toxin resistance.

  9. Comparative ecotoxicity of chlorantraniliprole to non-target soil invertebrates.

    Lavtižar, Vesna; Berggren, Kristina; Trebše, Polonca; Kraak, Michiel H S; Verweij, Rudo A; van Gestel, Cornelis A M


    The insecticide chlorantraniliprole (CAP) is gaining importance in agricultural practice, but data on its possible negative effects on non-target organisms is severely deficient. This study therefore determined CAP toxicity to non-target soil invertebrates playing a crucial role in ecosystem functioning, including springtails (Folsomia candida), isopods (Porcellio scaber), enchytraeids (Enchytraeus crypticus) and oribatid mites (Oppia nitens). In sublethal toxicity tests in Lufa 2.2 soil, chronic exposure to CAP concentrations up to 1000 mg/kgdw did not affect the survival and reproduction of E. crypticus and O. nitens nor the survival, body weight and consumption of P. scaber. In contrast, the survival and reproduction of F. candida was severely affected, with an EC50 for effects on reproduction of 0.14 mg CAP/kgdw. The toxicity of CAP to the reproduction of F. candida was tested in four different soils following OECD guideline 232, and additionally in an avoidance test according to ISO guideline 17512-2. A significantly lower toxicity in soils rich in organic matter was observed, compared to low organic soils. Observations in the avoidance test with F. candida suggest that CAP acted in a prompt way, by affecting collembolan locomotor abilities thus preventing them from escaping contaminated soil. This study shows that CAP may especially pose a risk to non-target soil arthropods closely related to insects, while other soil invertebrates seem rather insensitive.

  10. Detrital zircon without detritus: a result of 496-Ma-old fluid-rock interaction during the gold-lode formation of Passagem, Minas Gerais, Brazil

    Cabral, Alexandre Raphael; Zeh, Armin


    Zircon and xenotime occur in tourmaline-rich hydrothermal pockets in the auriferous lode of Passagem de Mariana, a world-class gold deposit. Zircon grains show pristine oscillatory zoning, but many of them are altered, exhibiting porous domains filled with graphite. Uranium-Pb dating of zircon, using in-situ laser ablation-inductively coupled plasma-mass spectrometry, yields ages between 3.2 and 2.65 Ga, which match those for detrital zircon of the footwall quartzite of the > 2.65-Ga-old Moeda Formation. Discordant analyses point to zircon-age resetting during the Brasiliano orogeny at ca. 500 Ma. This interpretation is supported by U-Pb dating of euhedral xenotime immediately adjacent to altered zircon within the same tourmaline pocket. The xenotime grains give a Concordia age of 496.3 ± 2.0 Ma, which is identical to that determined for monazite of a quartz-hematite vein-type deposit (i.e., jacutinga lode) in the region (Itabira), another important mineralisation style of gold. The occurrence of relatively abundant inherited detrital zircon, but absence of rock fragments in the tourmaline pocket investigated here, implies that detrital material was completely replaced by tourmaline. The graphite overprint on the altered detrital zircon attests to a reducing fluid, which was likely formed by fluid-rock interaction with carbonaceous phyllite of the Batatal Formation, the host rock of the Passagem lode.

  11. Differences in water depth determine leaf-litter decomposition in streams: implications on impact assessment reliability

    Martínez A.


    Full Text Available Leaf-litter decomposition is a widespread functional indicator to assess the stream ecosystem status. However, the spatial location of leaf-bags could distort the impact assessment since intrinsic features of a given site have an important role in the spatial distribution of macroinvertebrates, which could affect decomposition rate. A source of variability that can be easily controlled is the water depth at which bags are incubated in stream bed. Therefore, we tested if water depth within a same mesohabitat (riffles can determine decomposition rates. Due to the seasonal variability of macroinvertebrate assemblages in temperate regions, the study was performed in autumn-winter and spring to test the consistency of the findings. In three streams from North of Spain 15 mesh bags with alder leaves were placed in riffles covering a gradient of depths. Depth had a positive effect on decomposition rates and biomass of associated total invertebrates and shredders in autumn-winter, fauna variables helping to explain the differences in rates. In spring, depth affected negatively rates, the observed variability being weakly explained by invertebrates, which did not show differences along depth. Despite the opposite trend between seasons, water depth influences the decomposition rates, which may reduce or increase differences among systems if the water depth distribution is greatly biased. Our study highlights the importance of covering a similar range of water depths in the different systems being compared.

  12. Quantifying spatial scaling patterns and their local and regional correlates in headwater streams: implications for resilience

    Emma Göthe


    Full Text Available The distribution of functional traits within and across spatiotemporal scales has been used to quantify and infer the relative resilience across ecosystems. We use explicit spatial modeling to evaluate within- and cross-scale redundancy in headwater streams, an ecosystem type with a hierarchical and dendritic network structure. We assessed the cross-scale distribution of functional feeding groups of benthic invertebrates in Swedish headwater streams during two seasons. We evaluated functional metrics, i.e., Shannon diversity, richness, and evenness, and the degree of redundancy within and across modeled spatial scales for individual feeding groups. We also estimated the correlates of environmental versus spatial factors of both functional composition and the taxonomic composition of functional groups for each spatial scale identified. Measures of functional diversity and within-scale redundancy of functions were similar during both seasons, but both within- and cross-scale redundancy were low. This apparent low redundancy was partly attributable to a few dominant taxa explaining the spatial models. However, rare taxa with stochastic spatial distributions might provide additional information and should therefore be considered explicitly for complementing future resilience assessments. Otherwise, resilience may be underestimated. Finally, both environmental and spatial factors correlated with the scale-specific functional and taxonomic composition. This finding suggests that resilience in stream networks emerges as a function of not only local conditions but also regional factors such as habitat connectivity and invertebrate dispersal.

  13. Selected biological characteristics of streams in the southeastern Uinta Basin, Utah and Colorado

    Naten, Ronald W.; Fuller, Richard H.


    Biological sampling was carried out during 1976-78 in five streams in the southeastern Uinta Basin, Utah and Colorado, in order to provide baseline water-quality data for an area of potential oil-shale development. The biological activity in the streams sampled generally is limited by physical factors more so than by chemical constituents and plant nutrients. Characteristics of streamflow, such as high turbidity, fluctuating water levels, and moderate to high salinity, limit production of flora and fauna biomass. Samples were collected for the determination of bacterial and periphyton concentrations and benthic-invertebrate communities. Bacterial concentrations were generally small, with some fecal contamination, primarily from livestock and wildlife. Members of the order Chlorophyta (green algae) were the major periphytic algae present in three of the streams sampled. Bitter Creek was dominated by members of the order Cyanophyta (blue-green algae), and pennate diatoms were the predominant algae in Willow Creek. The benthic-invertebrate communities generally reflect a nonpolluted environment. Shannon-Weiner diversity indices ranged from 1.14 to 3.08. (USGS)

  14. Leaf litter breakdown, microbial respiration and shredder production in metal-polluted streams

    Carlisle, D.M.; Clements, W.H.


    1. If species disproportionately influence ecosystem functioning and also differ in their sensitivities to environmental conditions, the selective removal of species by anthropogenic stressors may lead to strong effects on ecosystem processes. We evaluated whether these circumstances held for several Colorado, U.S.A. streams stressed by Zn. 2. Benthic invertebrates and chemistry were sampled in five second-third order streams for 1 year. Study streams differed in dissolved metal concentrations, but were otherwise similar in chemical and physical characteristics. Secondary production of leaf-shredding insects was estimated using the increment summation and size-frequency methods. Leaf litter breakdown rates were estimated by retrieving litter-bags over a 171 day period. Microbial activity on leaf litter was measured in the laboratory using changes in oxygen concentration over a 48 h incubation period. 3. Dissolved Zn concentrations varied eightfold among two reference and three polluted streams. Total secondary production of shredders was negatively associated with metal contamination. Secondary production in reference streams was dominated by Taenionema pallidum. Results of previous studies and the current investigation demonstrate that this shredder is highly sensitive to metals in Colorado headwater streams. Leaf litter breakdown rates were similar between reference streams and declined significantly in the polluted streams. Microbial respiration at the most contaminated site was significantly lower than at reference sites. 4. Our results supported the hypothesis that some shredder species contribute disproportionately to leaf litter breakdown. Furthermore, the functionally dominant taxon was also the most sensitive to metal contamination. We conclude that leaf litter breakdown in our study streams lacked functional redundancy and was therefore highly sensitive to contaminant-induced alterations in community structure. We argue for the necessity of simultaneously

  15. Shifts in leaf litter breakdown along a forest-pasture-urban gradient in Andean streams.

    Iñiguez-Armijos, Carlos; Rausche, Sirkka; Cueva, Augusta; Sánchez-Rodríguez, Aminael; Espinosa, Carlos; Breuer, Lutz


    Tropical montane ecosystems of the Andes are critically threatened by a rapid land-use change which can potentially affect stream variables, aquatic communities, and ecosystem processes such as leaf litter breakdown. However, these effects have not been sufficiently investigated in the Andean region and at high altitude locations in general. Here, we studied the influence of land use (forest-pasture-urban) on stream physico-chemical variables (e.g., water temperature, nutrient concentration, and pH), aquatic communities (macroinvertebrates and aquatic fungi) and leaf litter breakdown rates in Andean streams (southern Ecuador), and how variation in those stream physico-chemical variables affect macroinvertebrates and fungi related to leaf litter breakdown. We found that pH, water temperature, and nutrient concentration increased along the land-use gradient. Macroinvertebrate communities were significantly different between land uses. Shredder richness and abundance were lower in pasture than forest sites and totally absent in urban sites, and fungal richness and biomass were higher in forest sites than in pasture and urban sites. Leaf litter breakdown rates became slower as riparian land use changed from natural to anthropogenically disturbed conditions and were largely determined by pH, water temperature, phosphate concentration, fungal activity, and single species of leaf-shredding invertebrates. Our findings provide evidence that leaf litter breakdown in Andean streams is sensitive to riparian land-use change, with urban streams being the most affected. In addition, this study highlights the role of fungal biomass and shredder species (Phylloicus; Trichoptera and Anchytarsus; Coleoptera) on leaf litter breakdown in Andean streams and the contribution of aquatic fungi in supporting this ecosystem process when shredders are absent or present low abundance in streams affected by urbanization. Finally, we summarize important implications in terms of managing of

  16. Using a C4 Invasive Grass to Isolate the Role of Detrital Carbon versus Rhizodeposit Carbon in Supplying Soil Carbon Pools

    Sokol, N.; Bradford, M.


    Plant inputs are the primary sources of carbon (C) to soil organic carbon (SOC) pools. Historically, detrital plant sources were thought to dominate C supply to SOC pools. An emerging body of research highlights the previously underestimated role of root exudates and other rhizodeposits. However, few experimental field studies have directly tracked the relative contributions of rhizodeposits versus detritial C inputs into different SOC pools, due to how methodologically challenging they are to measure in a field setting. Here, I present the first 3 years of data from an experimental field study of the prolific, C4 invasive grass species Microstegium vimineum. I use its unique isotopic signature in plots manipulated to contain detrital-only and rhizodeposit-only inputs, to track their relative contributions into microbial biomass C, particulate organic C (POC; >53 um) and mineral-associated organic C (MIN C; <53 um) soil pools. After 3 years, the presence of M. vimineum significantly affected both total SOC and the proportion of M. vimineum-derived C in POC pools. Both detrital inputs and rhizodeposit inputs from M. vimineum caused an increase in total SOC. Total SOC was 38% greater in detrital-only plots compared to control plots, and 39% greater in rhizodeposit-only plots compared to control plots. The proportion of M. vimineum-derived C in the POC was pool was 32% greater in rhizodeposit-only plots compared to detrital-only plots. The proportion of M.vimineum-derived C in the MIN C pool was not significantly different between treatments (at p<0.05). Microbial biomass was highest in rhizodeposit-only plots (p=0.03). Overall, plots containing rhizodeposit-only inputs contributed more Microstegium-derived C than did plots containing detrital-only inputs. While this observation is consistent with emerging theory on the primacy of the belowground, root-associated pathway in supplying C to soil C pools, this increase is generally assumed to be through the MIN C pool

  17. Significance of detrital zircons in upper Devonian ocean-basin strata of the Sonora allochthon and Lower Permian synorogenic strata of the Mina Mexico foredeep, central Sonora, Mexico

    Poole, F.G.; Gehrels, G.E.; Stewart, John H.


    U-Pb isotopic dating of detrital zircons from a conglomeratic barite sandstone in the Sonora allochthon and a calciclastic sandstone in the Mina Mexico foredeep of the Minas de Barita area reveals two main age groups in the Upper Devonian part of the Los Pozos Formation, 1.73-1.65 Ga and 1.44-1.42 Ga; and three main age groups in the Lower Permian part of the Mina Mexico Formation, 1.93-1.91 Ga, 1.45-1.42 Ga, and 1.1-1.0 Ga. Small numbers of zircons with ages of 2.72-2.65 Ga, 1.30-1.24 Ga, ca. 2.46 Ga, ca. 1.83 Ga, and ca. 0.53 Ga are also present in the Los Pozos sandstone. Detrital zircons ranging in age from 1.73 to 1.65 Ga are considered to have been derived from the Yavapai, Mojave, and Mazatzal Provinces and their transition zones of the southwestern United States and northwestern Mexico. The 1.45-1.30 Ga detrital zircons were probably derived from scattered granite bodies within the Mojave and Mazatzal basement rocks in the southwestern United States and northwestern Mexico, and possibly from the Southern and Eastern Granite-Rhyolite Provinces of the southern United States. The 1.24-1.0 Ga detrital zircons are believed to have been derived from the Grenville (Llano) Province to the east and northeast or from Grenvilleage intrusions or anatectites to the north. Several detrital zircon ages ranging from 2.72 to 1.91 Ga were probably derived originally from the Archean Wyoming Province and Early Paleoproterozoic rocks of the Lake Superior region. These older detrital zircons most likely have been recycled one or more times into the Paleozoic sandstones of central Sonora. The 0.53 Ga zircon is believed to have been derived from a Lower Cambrian granitoid or meta-morphic rock northeast of central Sonora, possibly in New Mexico and Colorado, or Oklahoma. Detrital zircon geochronology suggests that most of the detritus in both samples was derived from Laurentia to the north, whereas some detritus in the Permian synorogenic foredeep sequence was derived from the

  18. High-resolution detrital flux and provenance records from the Lake Suigetsu (SG06/12 cores) and climate changes in Central Japan during the last deglaciation

    Nagashima, K.; Nakagawa, T.; Suzuki, Y.; Tada, R.; Sugisaki, S.; Bronk Ramsey, C.; Bryant, C. L.; Staff, R.; Brauer, A.; Lamb, H.; Schlolaut, G.; Tarasov, P. E.; Gotanda, K.; Haraguchi, T.; Yonenobu, H.; Yokoyama, Y.


    Stalagmites in Chinese caves (e.g., Wang et al., 2001, 2005), loess/paleosol sequence of the Chinese Loess Plateau, and lacustrine sediments in Asian countries are favorable to monitor the past changes in East Asian monsoon and the path and intensity of the Westerly Jet. However, not much is known about these changes during the last deglaciation mostly due to the large uncertainty in the chronologies of the lacustrine and loess/paleosol sediments. Lake Suigetsu in Central Japan is known for the varved sediments which cover at least last 70 kyr. Recently, precise Age-Model is established for SG06 core based on varve counting and more than 800 radiocarbon dates (e.g., Ramsey et al., 2012; Staff et al., 2013). Here we examine the precipitation and wind-system changes in Central Japan during the last deglaciation from the flux and provenance changes of the detrital materials in the sediments of SG06 core. We reconstructed flux of detrital materials for the last glacial part of the SG06 core (1402-1810 cm interval of the SG06 composite depth) with 1 cm resolution (corresponded to 7-13 yrs) and estimated provenance of the detrital materials using color, chemical compositions (please see a poster presented by Suzuki et al), grain sizes, and electron spin resonance intensity and crystallinity of the quartz (these methods were detailed in Nagashima et al., 2007, 2011). The reconstructed flux of detrital materials are characterized by the millennial-scale increases exceeding 12 mg/cm2/yr at 16,600-14,800 and 13,700-12,800 SG062012 yr BP and short-lived (centennial to decadal) episodes of higher flux repeated more than thirty times throughout the deglaciation. The grain sizes, color, and crystallinity of quartz suggest that the content of the detrital materials increased during 16,600-14,800 SG062012 yr BP, which was mostly due to suspended particles supplied from Hasu river through Lake Mikata, that is located immediately upstream of Lake Suigetsu and trapping most of coarse

  19. Geochemistry and U-Pb geochronology of detrital zircons in the Brujas beach sands, Campeche, Southwestern Gulf of Mexico, Mexico

    Tapia-Fernandez, Hector J.; Armstrong-Altrin, John S.; Selvaraj, Kandasamy


    This study investigated the bulk sediment geochemistry, U-Pb ages and rare earth element (REE) geochemistry of one hundred detrital zircons recovered from the Brujas beach sands in southwestern Gulf of Mexico to understand the provenance and age spectra. The bulk sediments are high in Zr and Hf contents (∼1400-3773 ppm and ∼33-90 ppm, respectively) suggested the abundance of resistant mineral zircon. The chondrite normalized REE patterns of the bulk sediments are less fractionated with enriched low REE (LREE; LaCN/SmCN = ∼491-693), depleted heavy REE (HREE; GdCN/YbCN = ∼44-69) and a negative Eu anomaly (Eu/Eu∗ = ∼0.44-0.67) suggested that the source rock is felsic type. The results of this study revealed highly varied contents of Th (∼4.2-321 ppm), U (∼20.7-1680 ppm), and Hf (∼6970-14,200 ppm) in detrital zircons compared to bulk sands. The total REE content (∼75 and 1600 ppm) and its chondrite-normalized pattern with positive Ce and negative Eu anomalies as well as low Th/U ratio of zircon grains indicated that they were dominantly of magmatic origin. U-Pb data of zircons indicated two age populations, with predominance of Permian-Triassic (∼216-286 Ma) and Neoproterozoic (∼551-996 Ma). The Permian-Triassic zircons were contributed by the granitoids and recycled metasedimentary rocks of the Chiapas Massif Complex. The major contribution of Neoproterozoic zircons was from the Chaucus, Oaxacan, and Chiapas Massif Complexes in Grenville Province, southern Mexico. U-Pb ages of zircons from the Brujas beach are consistent to the reported zircon ages from the drainage basins of Usumacinta, Coatzacoalcos, and Grijalva Rivers in southern Mexico, suggesting that the sediments delivered by the rivers to the beach area are vital in defining the provenance of placers.

  20. Provenance shift in Cambrian mid-Baltica: detrital zircon chronology of Ediacaran–Cambrian sandstones in Estonia

    Yukio Isozaki


    Full Text Available In order to clarify the tectono-sedimentary history of Paleozoic Baltica, age spectra of detrital zircon grains from the Ediacaran (Kotlin Regional Stage and Lower Cambrian sandstones (lowermost Lontova and Lükati formations in western Estonia in central Baltica were analyzed by LA-ICPMS. The abundant occurrence of Archean to Mesoproterozoic (2800–1000 Ma zircon grains was confirmed in all samples. The new data provided the following information on the provenance of siliciclastic material as well as a major change in the sedimentary regime of the Paleo-Baltic basin during the Early Cambrian: (1 the Ediacaran–Lower Cambrian Paleo-Baltic basin received abundant terrigenous clastics from the core of Baltica underlain by the Archean–Mesoproterozoic crystalline crust, (2 the exposed surface area of the 1600 Ma Rapakivi granites apparently was more extensive during the Ediacaran–Early Cambrian than at present, (3 a major re-organization of the basin geometry occurred in the middle Early Cambrian (ca 530–515 Ma in central Baltica, inducing a change in the sediment supply system, (4 in contrast to the total absence of Neoproterozoic detrital zircon grains before the middle Early Cambrian, their sudden appearance at this time, together with consistent occurrence at least until the mid-Devonian, suggests a significant uplift event located in southeast Baltica and/or in a more easterly land domain (e.g., in Sarmatia, (5 possible sources for the Neoproterozoic zircon grains include the peripheral mobile belts with pan-African signatures around Baltica, e.g., the so-called Gondwanan fragments along the Tornquist margin to the southwest and the Timanian belt along the northeastern margin.

  1. Facilitation and predation structure a grassland detrital food web: the responses of soil nematodes to isopod processing of litter.

    Bastow, Justin L


    1. Detritus can support successive consumers, whose interactions may be structured by changes in the condition of their shared resource. One model of such species interactions is a processing chain, in which consumers feeding on the resource in a less processed state change the resource condition for subsequent consumers. 2. In a series of experiments, the hypothesis was tested that a common detritivore, the terrestrial isopod Porcellio scaber, affects soil nematodes through the processing of plant litter. Different detrital resources were added to soil from a California coastal prairie in order to simulate litter processing by the detritivore. Treatments that included only whole grass litter corresponded to detrital food webs lacking detritivores, while treatments that included mixtures of P. scaber faeces and grass litter corresponded to different densities or feeding rates of P. scaber. 3. Simulated litter processing by P. scaber increased the abundance of bacterivorous nematodes by between 32% and 202% after 24-44 days in laboratory experiments, but had no effect on fungivorous or predaceous nematodes. 4. In a subsequent field experiment, however, fungivorous nematodes were suppressed by isopod litter processing while bacterivores showed no response. Instead, P. scaber processing of litter increased the abundance of predaceous nematodes in the field experiment by 176%. 5. When simulated litter processing of litter was crossed in laboratory experiments with predaceous nematode addition (comparable to the response of predators in the field experiment), the abundance of bacterivores was increased by isopod processing of litter (by an average of 122%), but suppressed by elevated densities of predaceous nematodes (by an average of 41%). 6. This suggests that litter processing by P. scaber facilitates the bacterial channel of the soil food web, but that predaceous nematodes suppress the response of bacterivores in the field. Processing chain interactions may

  2. Detrital zircon provenance and paleogeography implications for Furnas Formation in the northwest of Paraná Basin

    Thais Borba Santos


    Full Text Available In the northwest of the Paraná Basin, between the states of Mato Grosso and Goiás, there are exposures of the Furnas Formation, where the Transbrasiliano Lineament is also recognized. From the analysis of magnetic maps, the geological and geophysical framework of the study area was defined, with six main domains separated by 5 lineaments. The contact between Paraguay Belt and the Goiás Magmatic Arc is marked by the main direction of the Transbrasiliano Lineament in the study area. Other lineaments that occur associated with the deformation direction of the Paraguay Belt have been identified as a minor component of Transbrasiliano Lineament. The description of outcrops along the northwest border of the Paraná Basin allowed the recognition of units I, II and III of the Furnas Formation. The U-Pb data from detrital zircon from the Furnas Formation showed predominance of grain with Neoproterozoic ages (560 - 800 Ma, with a minimum age of 526 Ma, and the occurrence of grain with Paleoproterozoic (≈1750/2100 Ma and Archean (≈2700/2800/3100 Ma ages. The study of detrital zircons provenance of the Furnas Formation using U-Pb age determination, associated with the structural framework of the foundation of the basin, and the comparison with paleoenvironmental data were the basis for assessing the paleogeography of the northwestern portion of the Paraná Basin during the aggradation of the Furnas Formation. Ages indicate an important Neoproterozoic contribution similar to the ages of the rocks found in the Goias Magmatic Arc, which associated with data of paleocurrents towards northwest allow us to infer that the arc rocks constituted high terrain, oriented in the NE-SW direction.

  3. Changing exhumation patterns during Cenozoic growth and glaciation of the Alaska Range: Insights from detrital thermochronology and geochronology

    Lease, Richard O.; Haeussler, Peter J.; O'Sullivan, Paul


    Cenozoic growth of the Alaska Range created the highest topography in North America, but the space-time pattern and drivers of exhumation are poorly constrained. We analyzed U/Pb and fission-track double dates of detrital zircon and apatite grains from 12 catchments that span a 450 km length of the Alaska Range to illuminate the timing and extent of exhumation during different periods. U/Pb ages indicate a dominant Late Cretaceous to Oligocene plutonic provenance for the detrital grains, with only a small percentage of grains recycled from the Mesozoic and Paleozoic sedimentary cover. Fission-track ages record exhumation during Alaska Range growth and incision and reveal three distinctive patterns. First, initial Oligocene exhumation was focused in the central Alaska Range at ~30 Ma and expanded outward along the entire length of the range until 18 Ma. Oligocene exhumation, coeval with initial Yakutat microplate collision >600 km to the southeast, suggests a far-field response to collision that was localized by the Denali Fault within a weak Mesozoic suture zone. Second, the variable timing of middle to late Miocene exhumation suggests independently evolving histories influenced by local structures. Time-transgressive cooling ages suggest successive rock uplift and erosion of Mounts Foraker (12 Ma) through Denali (6 Ma) as crust was advected through a restraining bend in the Denali Fault and indicate a long-term slip rate ~4 mm/yr. Third, Pliocene exhumation is synchronous (3.7-2.7 Ma) along the length of the Alaska Range but only occurs in high-relief, glacier-covered catchments. Pliocene exhumation may record an acceleration in glacial incision that was coincident with the onset of Northern Hemisphere glaciation.

  4. Faulting and erosion in the Argentine Precordillera during changes in subduction regime: Reconciling bedrock cooling and detrital records

    Fosdick, Julie C.; Carrapa, Barbara; Ortíz, Gustavo


    The Argentine Precordillera is an archetypal retroarc fold-and-thrust belt that records tectonics associated with changing subduction regimes. The interactions between exhumation and faulting in the Precordillera were investigated using apatite and zircon (U-Th-Sm)/He and apatite fission track thermochronometry from the Precordillera and adjacent geologic domains. Inverse modeling of thermal histories constrains eastward in-sequence rock cooling associated with deformation and erosion from 18 to 2 Ma across the Central Precordillera tracking thrusting during this time. The youngest AHe ages (5-2 Ma) and highest erosion rates are located in the eastern and western extremities of the Precordillera and indicate that recent denudation is concentrated at its structural boundaries. Moreover, synchronous rapid Pliocene cooling of the Frontal Cordillera, Eastern Precordillera, and Sierra del Valle Fértil was coeval with initiation of basement-involved faulting in the foreland. Detrital zircon U-Pb geochronology from the ca. 16-8.1 Ma Bermejo foreland basin strata suggests fluvial connectivity westward beyond the Frontal Cordillera to the Main Cordillera and Coast Range followed by an important shift in sediment provenance at ca. 10 Ma. At this time, we suggest that a substantial decrease in Permo-Triassic igneous sources in the Frontal Cordillera and concurrent increase in recycled zircons signatures of Paleozoic strata are best explained by uplift and erosion of the Precordillera during widening of the thrust-belt. Bedrock thermochronology and modeling indicate a 2-6 Myr lag time between faulting-related cooling in the hinterland and the detrital record of deformation in the foreland basin, suggesting that for tectonically active semi-arid settings, bedrock cooling may be more sensitive to onset of faulting. We suggest that high erosion rates in the Frontal Cordillera and Eastern Precordillera are associated with increased interplate coupling during shallowing of the

  5. Ecological Status of Wyoming Streams, 2000-2003

    Peterson, David A.; Hargett, Eric G.; Wright, Peter R.; Zumberge, Jeremy R.


    The ecological status of perennial streams in Wyoming was determined and compared with the status of perennial streams throughout 12 States in the western United States, using data collected as part of the Western Pilot Environmental Monitoring and Assessment Program (EMAP-West). Results for Wyoming are compared and contrasted in the context of the entire EMAP-West study area (west-wide) and climatic regions (based on aggregated ecoregions) within Wyoming. In Wyoming, ecological status, estimated as the proportion of the perennial stream length in least disturbed, most disturbed, and intermediate disturbance condition, based on ecological indicators of vertebrate and invertebrate assemblages was similar, in many cases, to the status of those assemblages determined for EMAP-West. Ecological status based on chemical and physical habitat stressors also was similar in Wyoming to west-wide proportions in many cases. Riparian disturbance was one of the most common physical stressors west-wide and in Wyoming. The estimates of riparian disturbance indicated about 90 percent of the stream length in the xeric climatic region in Wyoming was rated most disturbed, compared to about 30 percent rated most disturbed in the mountain climatic region in Wyoming. Results from analyses using a macroinvertebrate multi-metric index (MMI) and macroinvertebrate ratio of observed to expected taxa (O/E) developed specifically for the west-wide EMAP study were compared to results using a macroinvertebrate MMI and O/E developed for Wyoming. Proportions of perennial stream length in various condition categories determined from macroinvertebrate MMIs often were similar in Wyoming to proportions observed west-wide. Differences were larger, but not extreme, between west-wide and Wyoming O/E models. An aquatic life use support decision matrix developed for interpreting the Wyoming MMI and O/E model data indicated about one-half of the stream length statewide achieves the State's narrative aquatic

  6. Aboveground vertebrate and invertebrate herbivore impacts on net N mineralization in subalpine grasslands

    Anita C. Risch; Martin Schutz; Martijn L. Vandegehuchte; Wim H. van der Putten; Henk Duyts; Ursina Raschein; Dariusz J. Gwiazdowicz; Matt D. Busse; Deborah S. Page-Dumroese; Stephan Zimmerman


    Aboveground herbivores have strong effects on grassland nitrogen (N) cycling. They can accelerate or slow down soil net N mineralization depending on ecosystem productivity and grazing intensity. Yet, most studies only consider either ungulates or invertebrate herbivores, but not the combined effect of several functionally different vertebrate and invertebrate...

  7. Evidence for multi-cycle sedimentation and provenance constraints from detrital zircon U-Pb ages: Triassic strata of the Lusitanian basin (western Iberia)

    Pereira, M. F.; Gama, C.; Chichorro, M.; Silva, J. B.; Gutiérrez-Alonso, G.; Hofmann, M.; Linnemann, U.; Gärtner, A.


    Laser ablation ICP-MS U-Pb analyses were conducted on detrital zircons of Triassic sandstone and conglomerate from the Lusitanian basin in order to: i) document the age spectra of detrital zircon; ii) compare U-Pb detrital zircon ages with previous published data obtained from Upper Carboniferous, Ordovician, Cambrian and Ediacaran sedimentary rocks of the pre-Mesozoic basement of western Iberia; iii) discuss potential sources; and iv) test the hypothesis of sedimentary recycling. U-Pb dating of zircons established a maximum depositional age for this deposit as Permian (ca. 296 Ma), which is about sixty million years older compared to the fossil content recognized in previous studies (Upper Triassic). The distribution of detrital zircon ages obtained points to common source areas: the Ossa-Morena and Central Iberian zones that outcrop in and close to the Porto-Tomar fault zone. The high degree of immaturity and evidence of little transport of the Triassic sediment suggests that granite may constitute primary crystalline sources. The Carboniferous age of ca. 330 Ma for the best estimate of crystallization for a granite pebble in a Triassic conglomerate and the Permian-Carboniferous ages (< ca. 315 Ma) found in detrital zircons provide evidence of the denudation of Variscan and Cimmerian granites during the infilling of continental rift basins in western Iberia. The zircon age spectra found in Triassic strata are also the result of recycling from the Upper Carboniferous Buçaco basin, which probably acted as an intermediate sediment repository. U-Pb data in this study suggest that the detritus from the Triassic sandstone and conglomerate of the Lusitanian basin is derived from local source areas with features typical of Gondwana, with no sediment from external sources from Laurussia or southwestern Iberia.

  8. Exposure and nontarget effects of transgenic Bt corn debris in streams.

    Jensen, Peter D; Dively, Galen P; Swan, Christopher M; Lamp, William O


    Corn (Zea mays L.) transformed with a gene from the bacterium Bacillus thuringiensis (Bt) comprises 49% of all corn in the United States. The input of senesced corn tissue expressing the Bt gene may impact stream-inhabiting invertebrates that process plant debris, especially trichopteran species related to the target group of lepidopteran pests. Our goal was to assess risk associated with transgenic corn debris entering streams. First, we show the input of corn tissue after harvest was extended over months in a stream. Second, using laboratory bioassays based on European corn borer [Ostrinia nubilalis (Hübner)], we found no bioactivity of Cry1Ab protein in senesced corn tissue after 2 wk of exposure to terrestrial or aquatic environments. Third, we show that Bt near-isolines modify growth and survivorship of some species of invertebrates. Of the four nontarget invertebrate species fed Bt near-isolines, growth of two closely related trichopterans was not negatively affected, whereas a tipulid crane fly exhibited reduced growth rates, and an isopod exhibited reduced growth and survivorship on the Cry1Ab near-isoline but not on the stacked Cry1Ab + Cry3Bb1 near-isoline. Because of lack of evidence of bioactivity of Bt after 2 wk and because of lack of nontarget effects on the stacked near-isoline, we suggest that tissue-mediated differences, and not the presence of the Cry1Ab protein, caused the different responses among the species. Overall, our results provide evidence that adverse effects to aquatic nontarget shredders involve complex interactions arising from plant genetics and environment that cannot be ascribed to the presence of Cry1Ab proteins.

  9. An invertebrate stomach's view on vertebrate ecology: certain invertebrates could be used as "vertebrate samplers" and deliver DNA-based information on many aspects of vertebrate ecology.

    Calvignac-Spencer, Sébastien; Leendertz, Fabian H; Gilbert, M Thomas P; Schubert, Grit


    Recent studies suggest that vertebrate genetic material ingested by invertebrates (iDNA) can be used to investigate vertebrate ecology. Given the ubiquity of invertebrates that feed on vertebrates across the globe, iDNA might qualify as a very powerful tool for 21st century population and conservation biologists. Here, we identify some invertebrate characteristics that will likely influence iDNA retrieval and elaborate on the potential uses of invertebrate-derived information. We hypothesize that beyond inventorying local faunal diversity, iDNA should allow for more profound insights into wildlife population density, size, mortality, and infectious agents. Based on the similarities of iDNA with other low-quality sources of DNA, a general technical framework for iDNA analyses is proposed. As it is likely that no such thing as a single ideal iDNA sampler exists, forthcoming research efforts should aim at cataloguing invertebrate properties relevant to iDNA retrieval so as to guide future usage of the invertebrate tool box.

  10. NODC Standard Format Pathology Data Sets (1973-1980): Marine Invertebrate Pathology (F063) (NODC Accession 0014191)

    National Oceanic and Atmospheric Administration, Department of Commerce — Marine Invertebrate Pathology (F063) contains data from examinations of diseased marine invertebrates. Although these data maybe from field observations, they derive...

  11. STREAM2016: Streaming Requirements, Experience, Applications and Middleware Workshop

    Fox, Geoffrey [Indiana Univ., Bloomington, IN (United States); Jha, Shantenu [Rutgers Univ., New Brunswick, NJ (United States); Ramakrishnan, Lavanya [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)


    The Department of Energy (DOE) Office of Science (SC) facilities including accelerators, light sources and neutron sources and sensors that study, the environment, and the atmosphere, are producing streaming data that needs to be analyzed for next-generation scientific discoveries. There has been an explosion of new research and technologies for stream analytics arising from the academic and private sectors. However, there has been no corresponding effort in either documenting the critical research opportunities or building a community that can create and foster productive collaborations. The two-part workshop series, STREAM: Streaming Requirements, Experience, Applications and Middleware Workshop (STREAM2015 and STREAM2016), were conducted to bring the community together and identify gaps and future efforts needed by both NSF and DOE. This report describes the discussions, outcomes and conclusions from STREAM2016: Streaming Requirements, Experience, Applications and Middleware Workshop, the second of these workshops held on March 22-23, 2016 in Tysons, VA. STREAM2016 focused on the Department of Energy (DOE) applications, computational and experimental facilities, as well software systems. Thus, the role of “streaming and steering” as a critical mode of connecting the experimental and computing facilities was pervasive through the workshop. Given the overlap in interests and challenges with industry, the workshop had significant presence from several innovative companies and major contributors. The requirements that drive the proposed research directions, identified in this report, show an important opportunity for building competitive research and development program around streaming data. These findings and recommendations are consistent with vision outlined in NRC Frontiers of Data and National Strategic Computing Initiative (NCSI) [1, 2]. The discussions from the workshop are captured as topic areas covered in this report's sections. The report

  12. Environmental hazards of aluminum to plants, invertebrates, fish, and wildlife

    Sparling, D.W.; Lowe, T.P.


    Aluminum is extremely common throughout the world and is innocuous under circumneutral or alkaline conditions. However, in acidic environments, it can be a maJor limiting factor to many plants and aquatic organisms. The greatest concern for toxicity in North America occurs in areas that are affected by wet and dry acid deposition, such as eastern Canada and the northeastern U.S. Acid mine drainage, logging, and water treatment plant effluents containing alum can be other maJor sources of Al. In solution, the metal can combine with several different agents to affect toxicity. In general, Al hydroxides and monomeric Al are the most toxic forms. Dissolved organic carbons, F, PO(3)3- and SO(4)2- ameliorate toxicity by reducing bioavailability. Elevated metal levels in water and soil can cause serious problems for some plants. Algae tend to be both acid- and Al tolerant and, although some species may disappear with reduced pH, overall algae productivity and biomass are seldom affected if pH is above 3.0. Aluminum and acid toxicity tend to be additive to some algae when pH is less than 4.5. Because the metal binds with inorganic P, it may reduce P availability and reduce productivity. Forest die-backs in North America involving red spruce, Fraser fir, balsam fir, loblolly pine, slash pine, and sugar maples have been ascribed to Al toxicity, and extensive areas of European forests have died because of the combination of high soil Al and low pH. Extensive research on crops has produced Al-resistant cultivars and considerable knowledge about mechanisms of and defenses against toxicity. Very low Al levels may benefit some plants, although the metal is not recognized as an essential nutrient. Hyperaccumulator species of plants may concentrate Al to levels that are toxic to herbivores. Toxicity in aquatic invertebrates is also acid dependent. Taxa such as Ephemeroptera, Plecoptera, and Cladocera are sensitive and may perish when Al is less than 1 mg.L-1 whereas dipterans

  13. Herbivory and growth in terrestrial and aquatic populations of amphibious stream plants

    Sand-Jensen, Kaj; Jacobsen, Dean


    to evaluate advantages and disadvantages of aerial and submerged life. 2. Terrestrial populations had higher area shoot density, biomass and leaf production than aquatic populations, while leaf turnover rate and longevity were the same. Terrestrial populations experienced lower percentage grazing loss of leaf......1. Many amphibious plant species grow in the transition between terrestrial and submerged vegetation in small lowland streams. We determined biomass development, leaf turnover rate and invertebrate herbivory during summer in terrestrial and aquatic populations of three amphibious species...

  14. Distinguishing the effects of habitat degradation and pesticide stress on benthic invertebrates using stressor-specific metrics.

    von der Ohe, Peter Carsten; Goedkoop, Willem


    Hydromorphological degradation is a well known stressor for running waters, while the effects of elevated levels of pesticides are widely ignored. Hence, distinguishing between the effects of these two stressors is an urgent task for water managers that aim at appropriate remediation measures. We used a large monitoring data set on benthic invertebrates, habitat descriptors, and physico-chemical variables to develop the SPEAR[%](habitat) metric that indicates the effects of in-stream habitat degradation. SPEAR[%](habitat) correlated significantly with the habitat degradation score (HDS; based on substratum and vegetation coverage), while it did not respond to any physico-chemical variables (r(2)=0.20). This relationship improved for streams with low modeled pesticide inputs (r(2)=0.33), and improved even further for a subset of streams dominated by soft-bottom substrata, i.e. for similar stream-types (r(2)=0.65). These relationships were confirmed for an independent dataset that was not used in the derivation of the HDS (r(2)=0.57 and r(2)=0.65, respectively). These findings show that the SPEAR[%](habitat) had a high degree of specificity for the effects of habitat degradation. Conversely, neither the commonly used EPT and ASPT metrics, nor the German Fauna Index or SPEAR[%](pesticides) showed significant relationships with HDS. These metrics instead correlated significantly with the run-off potential (RP), a proxy of pesticide contamination of streams. Similarly, RP was also the most important explanatory variable for SPEAR[%](pesticides), followed by alkalinity and the number of forested upstream stretches (r(2)=0.61). The latter are expected to alleviate pesticide effects, as indicated by higher SPEAR[%](pesticides) values. These findings show that an integrated analysis of the two stressor-specific SPEAR-metrics in combination with the metrics of general ecological degradation can help water managers to distinguish between the effects of habitat degradation and

  15. Terrestrial Invertebrate Arsenic Accumulation Associated With an Arsenic Hyperaccumulating Fern, Pteris vittata (Polypodiales: Pteridaceae).

    Jaffe, B D; Ketterer, M E; Hofstetter, R W


    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 4,000 mg 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. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email:

  16. Evolutionary Transition of Promoter and Gene Body DNA Methylation across Invertebrate-Vertebrate Boundary.

    Keller, Thomas E; Han, Priscilla; Yi, Soojin V


    Genomes of invertebrates and vertebrates exhibit highly divergent patterns of DNA methylation. Invertebrate genomes tend to be sparsely methylated, and DNA methylation is mostly targeted to a subset of transcription units (gene bodies). In a drastic contrast, vertebrate genomes are generally globally and heavily methylated, punctuated by the limited local hypo-methylation of putative regulatory regions such as promoters. These genomic differences also translate into functional differences in DNA methylation and gene regulation. Although promoter DNA methylation is an important regulatory component of vertebrate gene expression, its role in invertebrate gene regulation has been little explored. Instead, gene body DNA methylation is associated with expression of invertebrate genes. However, the evolutionary steps leading to the differentiation of invertebrate and vertebrate genomic DNA methylation remain unresolved. Here we analyzed experimentally determined DNA methylation maps of several species across the invertebrate-vertebrate boundary, to elucidate how vertebrate gene methylation has evolved. We show that, in contrast to the prevailing idea, a substantial number of promoters in an invertebrate basal chordate Ciona intestinalis are methylated. Moreover, gene expression data indicate significant, epigenomic context-dependent associations between promoter methylation and expression in C. intestinalis. However, there is no evidence that promoter methylation in invertebrate chordate has been evolutionarily maintained across the invertebrate-vertebrate boundary. Rather, body-methylated invertebrate genes preferentially obtain hypo-methylated promoters among vertebrates. Conversely, promoter methylation is preferentially found in lineage- and tissue-specific vertebrate genes. These results provide important insights into the evolutionary origin of epigenetic regulation of vertebrate gene expression. © The Author(s) 2015. Published by Oxford University Press on behalf

  17. The California stream quality assessment

    Van Metre, Peter C.; Egler, Amanda L.; May, Jason T.


    In 2017, the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) project is assessing stream quality in coastal California, United States. The USGS California Stream Quality Assessment (CSQA) will sample streams over most of the Central California Foothills and Coastal Mountains ecoregion (modified from Griffith and others, 2016), where rapid urban growth and intensive agriculture in the larger river valleys are raising concerns that stream health is being degraded. Findings will provide the public and policy-makers with information regarding which human and natural factors are the most critical in affecting stream quality and, thus, provide insights about possible approaches to protect the health of streams in the region.

  18. The Southeast Stream Quality Assessment

    Van Metre, Peter C.; Journey, Celeste


    In 2014, the U.S. Geological Survey (USGS) National Water-Quality Assessment Program (NAWQA) is assessing stream quality across the Piedmont and southern Appalachian Mountains in the southeastern United States. The goal of the Southeast Stream Quality Assessment (SESQA) is to characterize multiple water-quality factors that are stressors to aquatic life—contaminants, nutrients, sediment, and streamflow alteration—and the relation of these stressors to ecological conditions in streams throughout the region. Findings will provide communities and policymakers with information on which human and environmental factors are the most critical in controlling stream quality and, thus, provide insights about possible approaches to protect or improve stream quality. The SESQA study will be the second regional study by the NAWQA program, and it will be of similar design and scope as the Midwest Stream Quality Assessment conducted in 2013 (Van Metre and others, 2012).

  19. The structure and host entry of an invertebrate parvovirus.

    Meng, Geng; Zhang, Xinzheng; Plevka, Pavel; Yu, Qian; Tijssen, Peter; Rossmann, Michael G


    The 3.5-Å resolution X-ray crystal structure of mature cricket parvovirus (Acheta domesticus densovirus [AdDNV]) has been determined. Structural comparisons show that vertebrate and invertebrate parvoviruses have evolved independently, although there are common structural features among all parvovirus capsid proteins. It was shown that raising the temperature of the AdDNV particles caused a loss of their genomes. The structure of these emptied particles was determined by cryo-electron microscopy to 5.5-Å resolution, and the capsid structure was found to be the same as that for the full, mature virus except for the absence of the three ordered nucleotides observed in the crystal structure. The viral protein 1 (VP1) amino termini could be externalized without significant damage to the capsid. In vitro, this externalization of the VP1 amino termini is accompanied by the release of the viral genome.

  20. Effects of Microgravity and Hypergravity on Invertebrate Development

    Miquel, J.


    Data suggest that abnormal gravity loads do not increase the rate of mutations in lower animals. Insects such as Drosophila melanogaster and Tribolium confusum have been able to reproduce aboard unmanned and manned space satellites, though no precise quantitative data have been obtained on mating competence and various aspects of development. Research with Drosophila flown on Cosmos spacecraft suggests that flight behavior is seriously disturbed in insects exposed to microgravity, which is reflected in increased oxygen utilization and concomitant life shortening. The decrease in longevity was less striking when the flies were enclosed in space, which suggests that they could adapt to the altered gravitational environment when maturation of flight behavior took place in microgravity. The reviewed data suggest that further research on the development of invertebrates in space is in order for clarification of the metabolic and behavioral effects of microgravity and of the development and function of the orientation and gravity sensing mechanisms of lower animals.

  1. [Food poisoning with marine animal toxins of invertebrate origin].

    Orlando, E; Legnani, P; Boari, C; Forni, M C; Gennari, P


    The consumption of seafood is increasing and hence the risk of poisoning. For this reason, the study of food poisoning caused by zootoxins from marine invertebrates has become of signal importance. These toxins come from bivalve molluscs and other species. Depending on the type of toxin concerned, poisoning attributable to molluscs may give rise to paralysis, caused by saxitossin, neurotoxic effects (gimbretoxin), or haemolysis (venerupin). Poisoning caused by coelenterates, echinoderms, cephalopods, Neptunea, abalone, crabs and lobsters is less common, and its clinical pictures and pathogenesis have not been fully established. In some instances, toxins presented in the phytoplankton ingested by these animals appear to be responsible, whereas in others its would seem that they themselves elaborate the active principles directly.

  2. The Dicistroviridae: An Emerging Family of Invertebrate Viruses

    Bryony C. Bonning


    Dicistroviruses comprise a newly characterized and rapidly expanding family of small RNA viruses of invertebrates. Several features of this virus group have attracted considerable research interest in recent years. In this review I provide an overview of the Dicistroviridae and describe progress made toward the understanding and practical application of dicistroviruses, including (i) construction of the first infectious clone of a dicistrovirus, (ii) use of the baculovirus expression system for production of an infectious dicistrovirus, (iii) the use of Drosophila C virus for analysis of host response to virus infection, and (iv) correlation of the presence of Israeli acute paralysis virus with honey bee colony collapse disorder. The potential use of dicistroviruses for insect pest management is also discussed. The structure, mechanism and practical use of the internal ribosome entry site (IRES) elements has recently been reviewed elsewhere.

  3. Ecotoxicology of nanomaterials: the role of invertebrate testing

    AG Cattaneo


    Full Text Available Engineered nanomaterials represent a new and expanding class of chemicals whose environmental hazard is actually poorly determined. The peculiar behavior of nanomaterials makes them much more similar to new chemicals than to the corresponding bulk materials; this feature imposes reliable and standardized evaluation protocols for toxicity and ecotoxicity assessments. General rules for assessing nanotoxicity and the state of the art are periodically published in reports by control agencies. This review highlights the role of invertebrates as valuable and validated test organisms for assessing ecotoxicity of new and/or untested chemicals. The general scarcity of experimental data, their unequal distribution among the different nanomaterials and environmental conditions, the difficulties in manipulating nanomaterials and obtaining stable and homogeneous suspensions, the confusion arising from a not well defined metrics are discussed

  4. The Physics of Broadcast Spawning in Benthic Invertebrates

    Crimaldi, John P.; Zimmer, Richard K.


    Most benthic invertebrates broadcast their gametes into the sea, whereupon successful fertilization relies on the complex interaction between the physics of the surrounding fluid flow and the biological properties and behavior of eggs and sperm. We present a holistic overview of the impact of instantaneous flow processes on fertilization across a range of scales. At large scales, transport and stirring by the flow control the distribution of gametes. Although mean dilution of gametes by turbulence is deleterious to fertilization, a variety of instantaneous flow phenomena can aggregate gametes before dilution occurs. We argue that these instantaneous flow processes are key to fertilization efficiency. At small scales, sperm motility and taxis enhance contact rates between sperm and chemoattractant-releasing eggs. We argue that sperm motility is a biological adaptation that replaces molecular diffusion in conventional mixing processes and enables gametes to bridge the gap that remains after aggregation by the flow.

  5. Sensitivity ranking for freshwater invertebrates towards hydrocarbon contaminants.

    Gerner, Nadine V; Cailleaud, Kevin; Bassères, Anne; Liess, Matthias; Beketov, Mikhail A


    Hydrocarbons have an utmost economical importance but may also cause substantial ecological impacts due to accidents or inadequate transportation and use. Currently, freshwater biomonitoring methods lack an indicator that can unequivocally reflect the impacts caused by hydrocarbons while being independent from effects of other stressors. The aim of the present study was to develop a sensitivity ranking for freshwater invertebrates towards hydrocarbon contaminants, which can be used in hydrocarbon-specific bioindicators. We employed the Relative Sensitivity method and developed the sensitivity ranking S hydrocarbons based on literature ecotoxicological data supplemented with rapid and mesocosm test results. A first validation of the sensitivity ranking based on an earlier field study has been conducted and revealed the S hydrocarbons ranking to be promising for application in sensitivity based indicators. Thus, the first results indicate that the ranking can serve as the core component of future hydrocarbon-specific and sensitivity trait based bioindicators.

  6. Terrestrial cave invertebrates of the Vrachanska Planina Mountains



    Full Text Available The modern biospeleological research in Bulgaria started in 1921 in the Ledenika Cave. From 65 caves of “Vrachanski Balkan” Nature Park and its surroundings have been recorded a total of 218 species of terrestrial invertebrates, including 32 species of troglobionts, most of them endemic to Vrachanska Planina Mts. (including the caves near Lakatnik: Isopoda Oniscoidea – 4, Chilopoda – 1, Diplopoda – 5, Opiliones – 2, Pseudoscorpiones – 3, Araneae – 3, Collembola – 2, Diplura – 2, Coleoptera, Carabidae – 7, Coleoptera, Leiodidae – 3. Troglobites are known from 51 caves, the richest being the caves near Lakatnik (Temnata dupka - 10, Zidanka - 7, Razhishkata dupka - 5, Svinskata dupka - 6, Kozarskata peshtera - 5, near Vratsa (Ledenika - 11, Barkite 8 - 5, Belyar - 6, Toshova dupka near Glavatsi - 6 and others.

  7. DMPD: Infectious non-self recognition in invertebrates: lessons from Drosophila andother insect models. [Dynamic Macrophage Pathway CSML Database

    Full Text Available 15476918 Infectious non-self recognition in invertebrates: lessons from Drosophila ...fectious non-self recognition in invertebrates: lessons from Drosophila andother insect models. PubmedID 154...76918 Title Infectious non-self recognition in invertebrates: lessons from Drosop

  8. The LHCb Turbo stream

    Puig Navarro, Albert


    The LHCb experiment will record an unprecedented dataset of beauty and charm hadron decays during Run II of the LHC, set to take place between 2015 and 2018. A key computing challenge is to store and process this data, which limits the maximum output rate of the LHCb trigger. So far, LHCb has written out a few kHz of events containing the full raw sub-detector data, which are passed through a full offline event reconstruction before being considered for physics analysis. Charm physics in particular is limited by trigger output rate constraints. A new streaming strategy includes the possibility to perform the physics analysis with candidates reconstructed in the trigger, thus bypassing the offline reconstruction. In the Turbo stream the trigger will write out a compact summary of physics objects containing all information necessary for analyses. This will allow an increased output rate and thus higher average efficiencies and smaller selection biases. This idea will be commissioned and developed during 2015 wi...

  9. The LHCb Turbo Stream

    Benson, Sean; Vesterinen, Mika Anton; Williams, John Michael


    The LHCb experiment will record an unprecedented dataset of beauty and charm hadron decays during Run II of the LHC, set to take place between 2015 and 2018. A key computing challenge is to store and process this data, which limits the maximum output rate of the LHCb trigger. So far, LHCb has written out a few kHz of events containing the full raw sub-detector data, which are passed through a full offline event reconstruction before being considered for physics analysis. Charm physics in particular is limited by trigger output rate constraints. A new streaming strategy includes the possibility to perform the physics analysis with candidates reconstructed in the trigger, thus bypassing the offline reconstruction and discarding the raw event. In the Turbo stream the trigger will write out a compact summary of physics objects containing all information necessary for analyses, and this will allow an increased output rate and thus higher average efficiencies and smaller selection biases. This idea will be commissi...

  10. The LHCb Turbo Stream

    Benson, Sean


    The LHCb experiment will record an unprecedented dataset of beauty and charm hadron decays during Run II of the LHC, set to take place between 2015 and 2018. A key computing challenge is to store and process this data, which limits the maximum output rate of the LHCb trigger. So far, LHCb has written out a few kHz of events containing the full raw sub-detector data, which are passed through a full offline event reconstruction before being considered for physics analysis. Charm physics in particular is limited by trigger output rate constraints. A new streaming strategy includes the possibility to perform the physics analysis with candidates reconstructed in the trigger, thus bypassing the offline reconstruction. In the "turbo stream" the trigger will write out a compact summary of "physics" objects containing all information necessary for analyses, and this will allow an increased output rate and thus higher average efficiencies and smaller selection biases. This idea will be commissioned and developed during...

  11. Iron isotope fractionation in marine invertebrates in near shore environments

    Emmanuel, S.; Schuessler, J. A.; Vinther, J.; Matthews, A.; von Blanckenburg, F.


    Chitons (Mollusca) are marine invertebrates that produce radula (teeth or rasping tongue) containing high concentrations of biomineralized magnetite and other iron bearing minerals. As Fe isotope signatures are influenced by redox processes and biological fractionation, Fe isotopes in chiton radula might be expected to provide an effective tracer of ambient oceanic conditions and biogeochemical cycling. Here, in a pilot study to measure Fe isotopes in marine invertebrates, we examine Fe isotopes in modern marine chiton radula collected from different locations in the Atlantic and Pacific oceans to assess the range of isotopic values, and to test whether or not the isotopic signatures reflect seawater values. Furthermore, by comparing two species that have very different feeding habits but collected from the same location, we infer a possible link between diet and Fe isotopic signatures. Values of δ56Fe (relative to IRMM-014) in chiton teeth range from -1.90 to 0.00‰ (±0.05‰ (2σ) uncertainty in δ56Fe), probably reflecting a combination of geographical control and biological fractionation processes. Comparison with published local surface seawater Fe isotope data shows a consistent negative offset of chiton teeth Fe isotope compositions relative to seawater. Strikingly, two different species from the same locality in the North Pacific (Puget Sound, Washington, USA) have distinct isotopic signatures. Tonicella lineata, which feeds on red algae, has a mean δ56Fe of -0.65 ± 0.26‰ (2σ, 3 specimens), while Mopalia muscosa, which feeds primarily on green algae, shows lighter isotopic values with a mean δ56Fe of -1.47 ± 0.98‰ (2σ, 5 specimens). Although chitons are not simple recorders of the ambient seawater Fe isotopic signature, these preliminary results suggest that Fe isotopes provide information concerning Fe biogeochemical cycling in near shore environments, and might be used to probe sources of Fe in the diets of different organisms.

  12. Leaf degradation of Salix humboldtiana Willd: (Salicaceae and invertebrate colonization in a subtropical lake (Brazil Degradação foliar de Salix humboldtiana Willd: (Salicaceae e colonização por invertebrados em um lago subtropical (Brasil

    Franko Telöken


    Full Text Available AIM: To evaluate leaf degradation and invertebrate colonization of Salix humboldtiana Willd. in a subtropical shallow lake on the coastal plain of Rio Grande do Sul, Brazil; METHODS: Litter bags containing 6.85 g of leaves were incubated in the superficial layer of sediment in the littoral region for 1, 4, 7, 14, 32, 47 and 71 days; RESULTS: After 71 days, a loss of 51% of the initial leaf weight was observed (k = 0.0100 d-1. We estimated that it would take 300 days to lose 95% of the initial weight. A total of 16040 organisms and 35 taxa were identified. Caenidae (25.9%, Oligochaeta (19%, Ostracoda (13.8%, Hydracarina (9.8%, Tanypodinae (9.7% and Coenagrionidae (7.7% were the most highly represented taxa. We observed increases in density, richness and diversity of taxa over time, with a stabilizing trend noted in the taxa diversity. Regarding the functional trophic groups (FTGs, gathering-collectors accounted for 57.6% of the community, while predators (25%, scrapers (15.8%, filtering-collectors (0.88% and shredders (0.73% were also represented. The diversity and evenness of the FTGs had stabilized by day 14; CONCLUSIONS: S. humboldtiana detritus provides a favorable habitat for a sufficient duration to support a high density and diversity of aquatic invertebrates. The small percentage of shredders indicates the minor influence of the invertebrate community on the rate of detrital degradation. The main contribution of invertebrates to detrital processing comes from the consumption of fine particulate organic matter by gathering-collectors.OBJETIVOS: Avaliar a degradação foliar de Salix humboldtiana Willd. e a colonização pela comunidade de invertebrados aquáticos em um lago raso subtropical, planície costeira do Rio Grande do Sul, Brasil; MÉTODOS: Bolsas de decomposição contendo 6,85 g de folhas foram incubadas na região litorânea, na superfície do sedimento, e retiradas após 1, 4, 7, 14, 32, 47 e 71 dias de decomposi

  13. Mining developer communication data streams

    Connor, Andy M.; Jacqui Finlay; Russel Pears


    This paper explores the concepts of modelling a sof tware development project as a process that results in the creation of a continuous stream of d ata. In terms of the Jazz repository used in this research, one aspect of that stream of data would b e developer communication. Such data can be used to create an evolving social network charac terized by a range of metrics. This paper presents the application of data stream mining tech ni...

  14. Acoustic streaming with heat exchange

    Gubaidullin, A. A.; Pyatkova, A. V.


    Acoustic streaming in a cylindrical cavity with heat exchange is numerically investigated. The cavity is filled with air. The boundaries of the cavity are maintained at constant temperature. The features of acoustic streaming manifesting with the decrease in the frequency of vibration in comparison with the resonant frequency are determined. The influence of the nonlinearity of process on acoustic streaming is shown. The nonlinearity is caused by the increase of the vibration amplitude.

  15. The Phoenix Stream: A Cold Stream in the Southern Hemisphere

    Balbinot, E.; Yanny, B.; Li, T. S.; Santiago, B.; Marshall, J. L.; Finley, D. A.; Pieres, A.; Abbott, T. M. C.; Abdalla, F. B.; Allam, S.; Benoit-Lévy, A.; Bernstein, G. M.; Bertin, E.; Brooks, D.; Burke, D. L.; Carnero Rosell, A.; Carrasco Kind, M.; Carretero, J.; Cunha, C. E.; da Costa, L. N.; DePoy, D. L.; Desai, S.; Diehl, H. T.; Doel, P.; Estrada, J.; Flaugher, B.; Frieman, J.; Gerdes, D. W.; Gruen, D.; Gruendl, R. A.; Honscheid, K.; James, D. J.; Kuehn, K.; Kuropatkin, N.; Lahav, O.; March, M.; Martini, P.; Miquel, R.; Nichol, R. C.; Ogando, R.; Romer, A. K.; Sanchez, E.; Schubnell, M.; Sevilla-Noarbe, I.; Smith, R. C.; Soares-Santos, M.; Sobreira, F.; Suchyta, E.; Tarle, G.; Thomas, D.; Tucker, D.; Walker, A. R.; DES Collaboration


    We report the discovery of a stellar stream in the Dark Energy Survey Year 1 (Y1A1) data. The discovery was made through simple color-magnitude filters and visual inspection of the Y1A1 data. We refer to this new object as the Phoenix stream, after its resident constellation. After subtraction of the background stellar population we detect a clear signal of a simple stellar population. By fitting the ridge line of the stream in color-magnitude space, we find that a stellar population with age τ = 11.5 ± 0.5 Gyr and [Fe/H] < -1.6, located 17.5 ± 0.9 kpc from the Sun, gives an adequate description of the stream stellar population. The stream is detected over an extension of 8.°1 (2.5 kpc) and has a width of ˜54 pc assuming a Gaussian profile, indicating that a globular cluster (GC) is a probable progenitor. There is no known GC within 5 kpc that is compatible with being the progenitor of the stream, assuming that the stream traces its orbit. We examined overdensities (ODs) along the stream, however, no obvious counterpart-bound stellar system is visible in the coadded images. We also find ODs along the stream that appear to be symmetrically distributed—consistent with the epicyclic OD scenario for the formation of cold streams—as well as a misalignment between the northern and southern part of stream. Despite the close proximity we find no evidence that this stream and the halo cluster NGC 1261 have a common accretion origin linked to the recently found EriPhe OD.

  16. Interactions among forest age, valley and channel morphology, and log jams regulate animal production in mountain streams

    Walters, D. M.; Venarsky, M. P.; Hall, R. O., Jr.; Herdrich, A.; Livers, B.; Winkelman, D.; Wohl, E.


    Forest age and local valley morphometry strongly influence the form and function of mountain streams in Colorado. Streams in valleys with old growth forest (>350 years) have extensive log jam complexes that create multi-thread channel reaches with extensive pool habitat and large depositional areas. Streams in younger unmanaged forests (e.g., 120 years old) and intensively managed forests have much fewer log jams and lower wood loads. These are single-thread streams dominated by riffles and with little depositional habitat. We hypothesized that log jam streams would retain more organic matter and have higher metabolism, leading to greater production of stream macroinvertebrates and trout. Log jam reaches should also have greater emergence of adult aquatic insects, and consequently have higher densities of riparian spiders taking advantage of these prey. Surficial organic matter was 3-fold higher in old-growth streams, and these streams had much higher ecosystem respiration. Insect production (g m2 y-1) was similar among forest types, but fish density was four times higher in old-growth streams with copious log jams. However, at the valley scale, insect production (g m-1 valley-1) and trout density (number m-1 valley-1) was 2-fold and 10-fold higher, respectively, in old growth streams. This finding is because multi-thread reaches created by log jams have much greater stream area and stream length per meter of valley than single-thread channels. The more limited response of macroinvertebrates may be related to fish predation. Trout in old growth streams had similar growth rates and higher fat content than fish in other streams in spite of occurring at higher densities and higher elevation/colder temperatures. This suggests that the positive fish effect observed in old growth streams is related to greater availability of invertebrate prey, which is consistent with our original hypothesis. Preliminary analyses suggest that spider densities do not respond strongly to

  17. Data streams algorithms and applications

    Muthukrishnan, S


    Data stream algorithms as an active research agenda emerged only over the past few years, even though the concept of making few passes over the data for performing computations has been around since the early days of Automata Theory. The data stream agenda now pervades many branches of Computer Science including databases, networking, knowledge discovery and data mining, and hardware systems. Industry is in synch too, with Data Stream Management Systems (DSMSs) and special hardware to deal with data speeds. Even beyond Computer Science, data stream concerns are emerging in physics, atmospheric

  18. Stream Productivity by Outermost Termination

    Zantema, Hans; 10.4204/EPTCS.15.7


    Streams are infinite sequences over a given data type. A stream specification is a set of equations intended to define a stream. A core property is productivity: unfolding the equations produces the intended stream in the limit. In this paper we show that productivity is equivalent to termination with respect to the balanced outermost strategy of a TRS obtained by adding an additional rule. For specifications not involving branching symbols balancedness is obtained for free, by which tools for proving outermost termination can be used to prove productivity fully automatically.

  19. Stream Productivity by Outermost Termination

    Hans Zantema


    Full Text Available Streams are infinite sequences over a given data type. A stream specification is a set of equations intended to define a stream. A core property is productivity: unfolding the equations produces the intended stream in the limit. In this paper we show that productivity is equivalent to termination with respect to the balanced outermost strategy of a TRS obtained by adding an additional rule. For specifications not involving branching symbols balancedness is obtained for free, by which tools for proving outermost termination can be used to prove productivity fully automatically.

  20. Relation between Streaming Potential and Streaming Electrification Generated by Streaming of Water through a Sandwich-type Cell

    Maruyama, Kazunori; NIKAIDO, Mitsuru; Hara, Yoshinori; Tanizaki, Yoshie


    Both streaming potential and accumulated charge of water flowed out were measured simultaneously using a sandwich-type cell. The voltages generated in divided sections along flow direction satisfied additivity. The sign of streaming potential agreed with that of streaming electrification. The relation between streaming potential and streaming electrification was explained from a viewpoint of electrical double layer in glass-water interface.

  1. Relation between Streaming Potential and Streaming Electrification Generated by Streaming of Water through a Sandwich-type Cell

    Maruyama, Kazunori; NIKAIDO, Mitsuru; Hara, Yoshinori; Tanizaki, Yoshie


    Both streaming potential and accumulated charge of water flowed out were measured simultaneously using a sandwich-type cell. The voltages generated in divided sections along flow direction satisfied additivity. The sign of streaming potential agreed with that of streaming electrification. The relation between streaming potential and streaming electrification was explained from a viewpoint of electrical double layer in glass-water interface.

  2. Analyzing indicators of stream health for Minnesota streams

    Singh, U.; Kocian, M.; Wilson, B.; Bolton, A.; Nieber, J.; Vondracek, B.; Perry, J.; Magner, J.


    Recent research has emphasized the importance of using physical, chemical, and biological indicators of stream health for diagnosing impaired watersheds and their receiving water bodies. A multidisciplinary team at the University of Minnesota is carrying out research to develop a stream classification system for Total Maximum Daily Load (TMDL) assessment. Funding for this research is provided by the United States Environmental Protection Agency and the Minnesota Pollution Control Agency. One objective of the research study involves investigating the relationships between indicators of stream health and localized stream characteristics. Measured data from Minnesota streams collected by various government and non-government agencies and research institutions have been obtained for the research study. Innovative Geographic Information Systems tools developed by the Environmental Science Research Institute and the University of Texas are being utilized to combine and organize the data. Simple linear relationships between index of biological integrity (IBI) and channel slope, two-year stream flow, and drainage area are presented for the Redwood River and the Snake River Basins. Results suggest that more rigorous techniques are needed to successfully capture trends in IBI scores. Additional analyses will be done using multiple regression, principal component analysis, and clustering techniques. Uncovering key independent variables and understanding how they fit together to influence stream health are critical in the development of a stream classification for TMDL assessment.


    I Made Oka Widyantara


    Full Text Available This paper aims to analyze Internet-based streaming video service in the communication media with variable bit rates. The proposed scheme on Dynamic Adaptive Streaming over HTTP (DASH using the internet network that adapts to the protocol Hyper Text Transfer Protocol (HTTP. DASH technology allows a video in the video segmentation into several packages that will distreamingkan. DASH initial stage is to compress the video source to lower the bit rate video codec uses H.26. Video compressed further in the segmentation using MP4Box generates streaming packets with the specified duration. These packages are assembled into packets in a streaming media format Presentation Description (MPD or known as MPEG-DASH. Streaming video format MPEG-DASH run on a platform with the player bitdash teritegrasi bitcoin. With this scheme, the video will have several variants of the bit rates that gave rise to the concept of scalability of streaming video services on the client side. The main target of the mechanism is smooth the MPEG-DASH streaming video display on the client. The simulation results show that the scheme based scalable video streaming MPEG-DASH able to improve the quality of image display on the client side, where the procedure bufering videos can be made constant and fine for the duration of video views

  4. 40Ar- 39Ar dating of detrital muscovite in provenance investigations: a case study from the Adelaide Rift Complex, South Australia

    Haines, Peter W.; Turner, Simon P.; Kelley, Simon P.; Wartho, Jo-Anne; Sherlock, Sarah C.


    Detrital zircon ages are commonly used to investigate sediment provenance and supply routes. Here, we explore the advantages of employing multiple, complimentary techniques via a case study of the Neoproterozoic and Cambrian of the Adelaide Rift Complex, South Australia. Detrital muscovite Ar-Ar ages are presented from stratigraphic units, or equivalents, that have previously been the subject of U-Pb detrital zircon dating, and, in some cases, whole-rock Sm-Nd isotope studies. The zircon age ranges and whole-rock Sm-Nd isotope data suggest that early Neoproterozoic sediments from near the base of the Adelaide Rift Complex comprise a mixture of detritus derived from the adjacent Gawler Craton (Palaeoproterozoic to earliest Mesoproterozoic) and overlying Gairdner flood basalts. In contrast, detrital muscovites from this level have a broad scatter of Mesoproterozoic infrared (IR) laser total fusion Ar-Ar ages, while UV laser traverses indicate that the age spread reflects partial resetting by multiple heating events, rather than a mixture of sources. Younger Neoproterozoic sediments document replacement of the Gawler Craton by the more distant Musgrave and/or Albany-Fraser Orogens as the main provenance. The Cambrian Kanmantoo Group marks an abrupt change in depositional style and a new sediment source. The Kanmantoo Group have older Nd model ages than underlying strata, yet are dominated by near to deposition-aged (˜500-650 Ma) detrital zircons and muscovites, suggesting rapid cooling and exhumation of a tectonically active provenance region. Although this source remains uncertain, evidence points towards the distant Pan-African orogenic belts. Deposition in the Adelaide Rift Complex was terminated in the late Early Cambrian by the Delamerian Orogeny, and the results of previous detrital mineral dating studies from the Lachlan Fold Belt to the east are consistent with at least partial derivation of these sediments from reworked upper Adelaide Rift Complex (Kanmantoo

  5. Aquatic and terrestrial organic matter in the diet of stream consumers: implications for mercury bioaccumulation.

    Jardine, Timothy D; Kidd, Karen A; Rasmussen, Joseph B


    The relative contribution of aquatic vs. terrestrial organic matter to the diet of consumers in fluvial environments and its effects on bioaccumulation of contaminants such as mercury (Hg) remain poorly understood. We used stable isotopes of carbon and nitrogen in a gradient approach (consumer isotope ratio vs. periphyton isotope ratio) across temperate streams that range in their pH to assess consumer reliance on aquatic (periphyton) vs. terrestrial (riparian vegetation) organic matter, and whether Hg concentrations in fish and their prey were related to these energy sources. Taxa varied in their use of the two sources, with grazing mayflies (Heptageniidae), predatory stoneflies (Perlidae), one species of water strider (Metrobates hesperius), and the fish blacknose dace (Rhinichthys atratulus) showing strong connections to aquatic sources, while Aquarius remigis water striders and brook trout (Salvelinus fontinalis) showed a weak link to in-stream production. The aquatic food source for consumers, periphyton, had higher Hg concentrations in low-pH waters, and pH was a much better predictor of Hg in predatory invertebrates that relied mainly on this food source vs. those that used terrestrial C. These findings suggest that stream biota relying mainly on dietary inputs from the riparian zone will be partially insulated from the effects of water chemistry on Hg availability. This has implications for the development of a whole-system understanding of nutrient and material cycling in streams, the choice of taxa in contaminant monitoring studies, and in understanding the fate of Hg in stream food webs.

  6. Comparative biology of pain: What invertebrates can tell us about how nociception works.

    Burrell, Brian D


    The inability to adequately treat chronic pain is a worldwide health care crisis. Pain has both an emotional and a sensory component, and this latter component, nociception, refers specifically to the detection of damaging or potentially damaging stimuli. Nociception represents a critical interaction between an animal and its environment and exhibits considerable evolutionary conservation across species. Using comparative approaches to understand the basic biology of nociception could promote the development of novel therapeutic strategies to treat pain, and studies of nociception in invertebrates can provide especially useful insights toward this goal. Both vertebrates and invertebrates exhibit segregated sensory pathways for nociceptive and nonnociceptive information, injury-induced sensitization to nociceptive and nonnociceptive stimuli, and even similar antinociceptive modulatory processes. In a number of invertebrate species, the central nervous system is understood in considerable detail, and it is often possible to record from and/or manipulate single identifiable neurons through either molecular genetic or physiological approaches. Invertebrates also provide an opportunity to study nociception in an ethologically relevant context that can provide novel insights into the nature of how injury-inducing stimuli produce persistent changes in behavior. Despite these advantages, invertebrates have been underutilized in nociception research. In this review, findings from invertebrate nociception studies are summarized, and proposals for how research using invertebrates can address questions about the fundamental mechanisms of nociception are presented.

  7. Biodiversity loss in seagrass meadows due to local invertebrate fisheries and harbour activities

    Nordlund, Lina Mtwana; Gullström, Martin


    Seagrass meadows provide a wide variety of ecosystem services, but their distribution and health are adversely affected by man. In the present study, we examined the influence of coastal exploitation in terms of invertebrate harvesting and harbour activity on invertebrate community composition in subtropical seagrass meadows at Inhaca Island, Mozambique, in the Western Indian Ocean. There was a fivefold higher invertebrate density and biomass, and clearly higher invertebrate species richness, in the protected (control) site compared to the two exploited sites. The causes for the clear differences between protected and exploited sites were probably a result of (1) the directional outtake of large edible or saleable invertebrates (mostly molluscs) and the absence of boat traffic in the harvested site, and (2) harbour activities. Invertebrate community composition in the two exploited sites also differed (although less clear), which was likely due to inherent distinction in type of disturbance. Our findings revealed that protection of seagrass habitat is necessary and that disturbances of different origin might require different forms of management and conservation. Designing protected areas is however a complex process due to competition for use and space with activities such as invertebrate harvesting and harbours.

  8. Human impacts to mountain streams

    Wohl, Ellen


    Mountain streams are here defined as channel networks within mountainous regions of the world. This definition encompasses tremendous diversity of physical and biological conditions, as well as history of land use. Human effects on mountain streams may result from activities undertaken within the stream channel that directly alter channel geometry, the dynamics of water and sediment movement, contaminants in the stream, or aquatic and riparian communities. Examples include channelization, construction of grade-control structures or check dams, removal of beavers, and placer mining. Human effects can also result from activities within the watershed that indirectly affect streams by altering the movement of water, sediment, and contaminants into the channel. Deforestation, cropping, grazing, land drainage, and urbanization are among the land uses that indirectly alter stream processes. An overview of the relative intensity of human impacts to mountain streams is provided by a table summarizing human effects on each of the major mountainous regions with respect to five categories: flow regulation, biotic integrity, water pollution, channel alteration, and land use. This table indicates that very few mountains have streams not at least moderately affected by land use. The least affected mountainous regions are those at very high or very low latitudes, although our scientific ignorance of conditions in low-latitude mountains in particular means that streams in these mountains might be more altered than is widely recognized. Four case studies from northern Sweden (arctic region), Colorado Front Range (semiarid temperate region), Swiss Alps (humid temperate region), and Papua New Guinea (humid tropics) are also used to explore in detail the history and effects on rivers of human activities in mountainous regions. The overview and case studies indicate that mountain streams must be managed with particular attention to upstream/downstream connections, hillslope

  9. Extreme Uplift and Erosion Rates in Eastern Himalayas (Siang-Brahmaputra Basin) Revealed by Detrital (U-Th)/He Termochronology

    Tibari, B.; Pik, R.; France-Lanord, C.; Carignan, J.; Lave, J.


    The distribution of erosion intensity in a major mountain range such as the Himalaya is a fundamental clue to investigate the interaction between climatic, tectonic and erosion processes that govern the morphology and evolution of an orogen. At the first order, the sediment flux measured on the two major rivers - Ganga and Brahmaputra - suggest higher mean denudation rates for the Eastern Himalaya than Western Himalaya (Galy and France-Lanord, 2001). However, the distribution of erosion in the Brahmaputra basin is not uniform and the Namche Barwa area, drained by the Siang-Tsangpo, appears to supply up to 50 % of the total sediment flux of the Brahmaputra (Singh and France-Lanord, 2002). In order to further constrain the relationships between such localized erosion and the associated exhumation rate of basement, we measured (U-Th)/He ages in detrital zircons from river sediments in the Brahmaputra basin. This thermochronological system (Z-He) is particularly interesting for detrital material because: (i) zircon is preserved during weathering and erosion processes, (ii) its closure temperature (150-180°C, Reiners et al., 2004) corresponds to a depth which is close to the surface but deep enough to avoid perturbations by topography variations, and (iii) the error associated to single grain measurement (8-10 %) allows a good definition of population ages. Z-He ages from the Brahmaputra river in Bangladesh range from 0.4 to 77 Ma. 40 % of the zircon population exhibit Z-He ages between 0.4 and 1 Ma defining the major distribution peak centred at 0.5 Ma. These very young ages correspond to extreme denudation rates of 5 to 7 mm/yr. Dispersed Z-He ages from 12 to 77 Ma do not define any population groups, whereas the remaining 40 % of the zircons have ages distributed between 2.5 and 7 Ma, which correspond to the pool of ages recorded by preliminary Z-He ages on the other Himalayan rivers of the basin. Therefore, such very high denudation rates (5-7 mm/yr) seems to

  10. Petrography and U-Pb detrital zircon geochronology of metasedimentary strata dredged from the Chukchi Borderland, Amerasia Basin, Arctic Ocean

    Brumley, K.; Miller, E. L.; Mayer, L. A.; Andronikov, A.; Wooden, J. L.; Dumitru, T. A.; Elliott, B.; Gehrels, G. E.; Mukasa, S. B.


    In 2008-2009, twelve dredges were taken aboard the USCGC Healy from outcrops along the Alpha Ridge, Northern Chukchi Borderland, Northwind Ridge and the Chukchi Plateau in the Arctic Ocean as part of the U.S. Extended Continental Shelf Project. To ensure sampling of outcrop, steep bathymetric slopes (>40°) with little mud cover were identified with multibeam sonar and targeted for dredging. The first dredge from Alpha Ridge yielded volcaniclastic sedimentary rocks deposited from a phreatomagmatic eruption in shallow water (<200m). This is inconsistent with tectonic reconstructions suggesting that the Alpha Ridge was created as an oceanic plateau on deep oceanic crust of the Canada Basin. Another dredge, taken from the northern tip of Northwind Ridge, yielded metasedimentary rocks deformed under greenschist facies conditions (chlorite+white mica). These rocks are intruded and/or overlain by mid-Cretaceous alkalic basalts, also taken in this dredge, and dated by 40Ar/39Ar (plagioclase separate) to be 112±1 Ma. The metasedimentary rocks, from this single dredge, range in grain size from mud to coarse sandstone and grit which all contain grains and sub-angular clasts of volcanic, plutonic, metamorphic and fine grained sedimentary rocks as well as monocrystalline quartz, potassium feldspar, and plagioclase. All of these samples display the same bedding to foliation angle and lithology, which further indicates that they were dredged from in situ outcrop and are not random samples of ice rafted debris. Based on grain size variations and graded beds, they are interpreted as Silurian gravity flow deposits fed by proximal syn-orogenic and/or magmatic arc sources. Detrital zircons were separated from four sandstone samples of the Northwind Ridge dredge, and their U-Pb single grain ages determined by LA-MC-ICPMS and SHRIMP, (N= 393). Their detrital zircon populations are dominated by euhedral first-cycle zircon ca. 430 and 980 Ma with lesser older recycled zircons between

  11. The mass of the Geminid meteoroid stream

    Ryabova, G. O.


    This paper describes a method for calculation of the mass of a meteoroid stream. The idea of the proposed method is simple: comparing observed meteor showers of the stream with their model. If we have a mathematical model for the stream, we know the total number of particles in the model stream and the number of particles registered at the Earth. We also know the mass distributions in the model stream and the model shower. Assuming that relations for the model stream are valid for the real stream, we calculate the real stream mass. The Geminid stream mass estimated on radar and visual observations is found to be 1016-1018 g.

  12. The evolutionary ecology of offspring size in marine invertebrates.

    Marshall, Dustin J; Keough, Michael J


    Intraspecific variation in offspring size is of fundamental ecological and evolutionary importance. The level of provisioning an organism receives from its mother can have far reaching consequences for subsequent survival and performance. In marine systems, the traditional focus was on the remarkable variation in offspring size among species but there is increasing focus on variation in offspring size within species. Here we review the incidence and consequences of intraspecific offspring-size variation for marine invertebrates. Offspring size is remarkably variable within and among marine invertebrate populations. We examined patterns of variation in offspring size within populations using a meta-analysis of the available data for 102 species across 7 phyla. The average coefficient of variation in offspring size within populations is 9%, while some groups (e.g., direct developers) showed much more variation (15%), reflecting a fourfold difference between the largest and smallest offspring in any population. Offspring-size variation can have for reaching consequences. Offspring size affects every stage of a marine invertebrate's life history, even in species in which maternal provisioning accounts for only a small proportion of larval nutrition (i.e., planktotrophs). In species with external fertilization, larger eggs are larger targets for sperm and as such, the sperm environment may select for different egg sizes although debate continues over the evolutionary importance of such effects. Offspring size affects the planktonic period in many species with planktotrophic and lecithotrophic development, but we found that this effect is not universal. Indeed, much of the evidence for the effects of offspring size on the planktonic period is limited to the echinoids and in this group and other taxa there is variable evidence, suggesting further work is necessary. Post-metamorphic effects of offspring size were strong in species with non-feeding larvae and direct

  13. Pre-Devonian tectonic evolution of the eastern South China Block:Geochronological evidence from detrital zircons


    Using the U-Pb LA-ICP-MS analysis technique we analyzed geochronological features of detrital zircons from Devonian and Ordovician coarse sandstone in southern Jiangxi Province,northern Cathaysia Block.Abundant ancient crustal information was obtained.The 350 groups of U-Pb age center on five ranges:2600-2300 Ma(peak at 2470 Ma),1100-900 Ma(peak at 980 Ma),900-700 Ma(peak at 800 Ma),650-520 Ma(peak at 600 Ma) and 450-400 Ma(peak at 440 Ma).We also found a detrital zircon of ~3.5 Ga.This is the oldest age in northern Cathaysia Block obtained so far.From the analysis we concluded that:(1) the 2600-2300 Ma period,characterized by a global continent-building,records late Neoarchean magmatism that did not occur in the neighboring area of Cathaysia;(2) the marked peak at 1100-900 Ma corresponds with the assembly time of the Neoproterozoic supercontinent,Rodinia,suggesting that the Cathaysia Block was once a part of Rodinia,and numerous euhedral zircons with similar ages likely resulted from the Grenville event;(3) the peak at 900-700 Ma corresponds to the breakup of Rodinia,as evidenced by wide occurrence of Neoproterozoic granite,basic dyke swarms and continental rift-type deposition;(4) the 650-520 Ma period is the typical time of the Pan-African event,but as yet no associated magmatic rock has been reported in this area;and(5) the peak at 450-400 Ma,representing the early Paleozoic orogeny,was recorded in various igneous rocks.Abundant Silurian-Lower Devonian granitic plutons,orthogneisses and their zircon U-Pb dating ages(450-400 Ma) are important evidence of an early Paleozoic orogenic event.Geological data support the interpretation of an Early Paleozoic tectonic heat event in Cathaysia,which was likely to be caused by intracontinental collision.

  14. Recovery of invertebrate and vertebrate populations in a coal ash stressed drainage system

    Cherry, D.S.; Larrick, S.R.; Guthrie, R.K.; Davis, E.M.; Sherberger, F.F.


    The influence of coal ash effluent on the densities of macrobenthic invertebrate and mosquitofish populations in a swamp drainage system was studied. Samples were collected during a period of 50 mo. Three perturbations in the swamp systemash siltation, low pH, and toxic elementscaused changes in population densities. Siltation from inefficient effluent management caused the greatest drop in invertebrate populations, and pH declines from flyash addition caused the greatest mosquitofish population reductions. Dipterans and odonates were most tolerant to coal ash stress. Invertebrate population recovery was observed on completion of an efficient ash retaining basin. (13 graphs, 28 references, 3 tables)

  15. Molecular architecture and biomedical leads of terpenes from red sea marine invertebrates.

    Hegazy, Mohamed Elamir F; Mohamed, Tarik A; Alhammady, Montaser A; Shaheen, Alaa M; Reda, Eman H; Elshamy, Abdelsamed I; Aziz, Mina; Paré, Paul W


    Marine invertebrates including sponges, soft coral, tunicates, mollusks and bryozoan have proved to be a prolific source of bioactive natural products. Among marine-derived metabolites, terpenoids have provided a vast array of molecular architectures. These isoprenoid-derived metabolites also exhibit highly specialized biological activities ranging from nerve regeneration to blood-sugar regulation. As a result, intense research activity has been devoted to characterizing invertebrate terpenes from both a chemical and biological standpoint. This review focuses on the chemistry and biology of terpene metabolites isolated from the Red Sea ecosystem, a unique marine biome with one of the highest levels of biodiversity and specifically rich in invertebrate species.

  16. Save Our Streams and Waterways.

    Indiana State Dept. of Education, Indianapolis. Center for School Improvement and Performance.

    Protection of existing water supplies is critical to ensuring good health for people and animals alike. This program is aligned with the Izaak Walton League of American's Save Our Streams program which is based on the concept that students can greatly improve the quality of a nearby stream, pond, or river by regular visits and monitoring. The…

  17. We All Stream for Video

    Technology & Learning, 2008


    More than ever, teachers are using digital video to enhance their lessons. In fact, the number of schools using video streaming increased from 30 percent to 45 percent between 2004 and 2006, according to Market Data Retrieval. Why the popularity? For starters, video-streaming products are easy to use. They allow teachers to punctuate lessons with…

  18. Longitudinal zonation of macroinvertebrates in an Ecuadorian glacier-fed stream: do tropical glacial systems fit the temperate model?

    Jacobsen, D.; Dangles, O.; Andino, P.


    of the equator in the Ecuadorian Andes. Our goal was to study the longitudinal distribution of the fauna in relation to environmental factors and to compare this with the conceptual model based on temperate-arctic glacier-fed streams. 3. Total density of invertebrates differed considerably at the two highest...... of the Diamesinae, and its replacement by Podonominae, is different from the pattern typically observed in north-temperate glacier-fed streams. This could be because of the fact that the genus Diamesa is missing from the Neotropics. 5. Stream temperature and channel stability explained most of the variability...... altitude sites; 4600 m-2 at a pro-glacial lake outlet and only 4 m-2 at a site originating directly from the glacier snout. Otherwise, there was a downstream decrease in density to about 825 m-2 at the three lowest sites. Taxon richness increased with distance from the glacier, very similar to the pattern...

  19. Stream Deniable-Encryption Algorithms

    N.A. Moldovyan


    Full Text Available A method for stream deniable encryption of secret message is proposed, which is computationally indistinguishable from the probabilistic encryption of some fake message. The method uses generation of two key streams with some secure block cipher. One of the key streams is generated depending on the secret key and the other one is generated depending on the fake key. The key streams are mixed with the secret and fake data streams so that the output ciphertext looks like the ciphertext produced by some probabilistic encryption algorithm applied to the fake message, while using the fake key. When the receiver or/and sender of the ciphertext are coerced to open the encryption key and the source message, they open the fake key and the fake message. To disclose their lie the coercer should demonstrate possibility of the alternative decryption of the ciphertext, however this is a computationally hard problem.

  20. Identification of 3.5 Ga detrital zircons from Yangtze craton in south China and the implication for Archean crust evolution

    LIU Xiaoming; GAO Shan; LING Wenli; YUAN Honglin; HU Zhaochu


    The LA-ICP-MS U-Pb dating of hundreds of detrital zircon grains from the Sinian sandstones of Liantuo formation and tillites of Nantuo formation at Sanxia area in Yichang identified 3319-3508 Ma zircon grains. Their 207pb/206pb and 206pb/238U ages show excellent agreement (concordia degree 99 %-100 % ). Their CL images exhibit well-developed oscillatory zoning and the Th/U ratios are within 0. 46-0. 76, implying that they are igneous zircons which formed during middle-early Archean. These zircons are the oldest ones discovered in Yangtze craton until now. However, the detrital zircons with ages older than 3.3 Ga in the metamorphic rocks of Kongling group were not found by further investigation, which suggests the presence of crust older than high-grade metamorphic Kongling terrain in Yangtze craton.