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Sample records for phytochemistry trophic interactions

  1. Network structure beyond food webs: mapping non-trophic and trophic interactions on Chilean rocky shores.

    Science.gov (United States)

    Sonia Kéfi; Berlow, Eric L; Wieters, Evie A; Joppa, Lucas N; Wood, Spencer A; Brose, Ulrich; Navarrete, Sergio A

    2015-01-01

    How multiple types of non-trophic interactions map onto trophic networks in real communities remains largely unknown. We present the first effort, to our knowledge, describing a comprehensive ecological network that includes all known trophic and diverse non-trophic links among >100 coexisting species for the marine rocky intertidal community of the central Chilean coast. Our results suggest that non-trophic interactions exhibit highly nonrandom structures both alone and with respect to food web structure. The occurrence of different types of interactions, relative to all possible links, was well predicted by trophic structure and simple traits of the source and target species. In this community, competition for space and positive interactions related to habitat/refuge provisioning by sessile and/or basal species were by far the most abundant non-trophic interactions. If these patterns are orroborated in other ecosystems, they may suggest potentially important dynamic constraints on the combined architecture of trophic and non-trophic interactions. The nonrandom patterning of non-trophic interactions suggests a path forward for developing a more comprehensive ecological network theory to predict the functioning and resilience of ecological communities.

  2. Complex trophic interactions in kelp forest ecosystems

    Science.gov (United States)

    Estes, J.A.; Danner, E.M.; Doak, D.F.; Konar, B.; Springer, A.M.; Steinberg, P.D.; Tinker, M. Tim; Williams, T.M.

    2004-01-01

    The distributions and abundances of species and populations change almost continuously. Understanding the processes responsible is perhaps ecology’s most fundamental challenge. Kelp-forest ecosystems in southwest Alaska have undergone several phase shifts between alga- and herbivore-dominated states in recent decades. Overhunting and recovery of sea otters caused the earlier shifts. Studies focusing on these changes demonstrate the importance of top-down forcing processes, a variety of indirect food-web interactions associated with the otter-urchin-kelp trophic cascade, and the role of food-chain length in the coevolution of defense and resistance in plants and their herbivores. This system unexpectedly shifted back to an herbivore-dominated state during the 1990s, because of a sea-otter population collapse that apparently was driven by increased predation by killer whales. Reasons for this change remain uncertain but seem to be linked to the whole-sale collapse of marine mammals in the North Pacific Ocean and southern Bering Sea. We hypothesize that killer whales sequentially "fished down" pinniped and sea-otter populations after their earlier prey, the great whales, were decimated by commercial whaling. The dynamics of kelp forests in southwest Alaska thus appears to have been influenced by an ecological chain reaction that encompassed numerous species and large scales of space and time.

  3. Trophic interaction modifications: an empirical and theoretical framework.

    Science.gov (United States)

    Terry, J Christopher D; Morris, Rebecca J; Bonsall, Michael B

    2017-10-01

    Consumer-resource interactions are often influenced by other species in the community. At present these 'trophic interaction modifications' are rarely included in ecological models despite demonstrations that they can drive system dynamics. Here, we advocate and extend an approach that has the potential to unite and represent this key group of non-trophic interactions by emphasising the change to trophic interactions induced by modifying species. We highlight the opportunities this approach brings in comparison to frameworks that coerce trophic interaction modifications into pairwise relationships. To establish common frames of reference and explore the value of the approach, we set out a range of metrics for the 'strength' of an interaction modification which incorporate increasing levels of contextual information about the system. Through demonstrations in three-species model systems, we establish that these metrics capture complimentary aspects of interaction modifications. We show how the approach can be used in a range of empirical contexts; we identify as specific gaps in current understanding experiments with multiple levels of modifier species and the distributions of modifications in networks. The trophic interaction modification approach we propose can motivate and unite empirical and theoretical studies of system dynamics, providing a route to confront ecological complexity. © 2017 The Authors. Ecology Letters published by CNRS and John Wiley & Sons Ltd.

  4. Trophic interactions in changing landscapes: responses of soil food webs.

    NARCIS (Netherlands)

    Hedlund, K.; Griffiths, B.; Christensen, S.; Scheu, S.; Setälä, H.; Tscharntke, T.; Verhoef, H.A.

    2004-01-01

    Soil communities in landscapes that are rapidly changing due to a range of anthropogenic processes can be regarded as highly transient systems where interactions between competing species or trophic levels may be seriously disrupted. In disturbed communities dispersal in space and time has a role in

  5. Trait-mediated trophic interactions: is foraging theory keeping up?

    Science.gov (United States)

    Steven F. Railsback; Bret C. Harvey

    2013-01-01

    Many ecologists believe that there is a lack of foraging theory that works in community contexts, for populations of unique individuals each making trade-offs between food and risk that are subject to feedbacks from behavior of others. Such theory is necessary to reproduce the trait-mediated trophic interactions now recognized as widespread and strong. Game theory can...

  6. Trait-mediated trophic interactions: is foraging theory keeping up?

    Science.gov (United States)

    Railsback, Steven F; Harvey, Bret C

    2013-02-01

    Many ecologists believe that there is a lack of foraging theory that works in community contexts, for populations of unique individuals each making trade-offs between food and risk that are subject to feedbacks from behavior of others. Such theory is necessary to reproduce the trait-mediated trophic interactions now recognized as widespread and strong. Game theory can address feedbacks but does not provide foraging theory for unique individuals in variable environments. 'State- and prediction-based theory' (SPT) is a new approach that combines existing trade-off methods with routine updating: individuals regularly predict future food availability and risk from current conditions to optimize a fitness measure. SPT can reproduce a variety of realistic foraging behaviors and trait-mediated trophic interactions with feedbacks, even when the environment is unpredictable. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Analysis of trophic interactions reveals highly plastic response to climate change in a tri-trophic High-Arctic ecosystem

    DEFF Research Database (Denmark)

    Mortensen, Lars O.; Schmidt, Niels Martin; Hoye, Toke T.

    2016-01-01

    As a response to current climate changes, individual species have changed various biological traits, illustrating an inherent phenotypic plasticity. However, as species are embedded in an ecological network characterised by multiple consumer-resource interactions, ecological mismatches are likely...... to arise when interacting species do not respond homogeneously. The approach of biological networks analysis calls for the use of structural equation modelling (SEM), a multidimensional analytical setup that has proven particularly useful for analysing multiple interactions across trophic levels. Here we...

  8. Thiacloprid affects trophic interaction between gammarids and mayflies

    International Nuclear Information System (INIS)

    Englert, D.; Bundschuh, M.; Schulz, R.

    2012-01-01

    Neonicotinoid insecticides like thiacloprid enter agricultural surface waters, where they may affect predator–prey-interactions, which are of central importance for ecosystems as well as the functions these systems provide. The effects of field relevant thiacloprid concentrations on the leaf consumption of Gammarus fossarum (Amphipoda) were assessed over 96 h (n = 13–17) in conjunction with its predation on Baetis rhodani (Ephemeroptera) nymphs. The predation by Gammarus increased significantly at 0.50–1.00 μg/L. Simultaneously, its leaf consumption decreased with increasing thiacloprid concentration. As a consequence of the increased predation at 1.00 μg/L, gammarids' dry weight rose significantly by 15% compared to the control. At 4.00 μg/L, the reduced leaf consumption was not compensated by an increase in predation causing a significantly reduced dry weight of Gammarus (∼20%). These results may finally suggest that thiacloprid adversely affects trophic interactions, potentially translating into alterations in ecosystem functions, like leaf litter breakdown and aquatic-terrestrial subsidies. - Highlights: ► Field relevant thiacloprid concentrations affected gammarid and mayfly interaction. ► Gammarus leaf consumption and predation success is adversely affected. ► Gammarus growth increased due to higher predation at 1.0 μg thiacloprid/L. ► The study's results are discussed in the context of ecosystem functions. - Field relevant thiacloprid concentrations affect species interactions, which may translate to alterations in ecosystem functions.

  9. Species co-occurrence networks: Can they reveal trophic and non-trophic interactions in ecological communities?

    Science.gov (United States)

    Freilich, Mara A; Wieters, Evie; Broitman, Bernardo R; Marquet, Pablo A; Navarrete, Sergio A

    2018-03-01

    Co-occurrence methods are increasingly utilized in ecology to infer networks of species interactions where detailed knowledge based on empirical studies is difficult to obtain. Their use is particularly common, but not restricted to, microbial networks constructed from metagenomic analyses. In this study, we test the efficacy of this procedure by comparing an inferred network constructed using spatially intensive co-occurrence data from the rocky intertidal zone in central Chile to a well-resolved, empirically based, species interaction network from the same region. We evaluated the overlap in the information provided by each network and the extent to which there is a bias for co-occurrence data to better detect known trophic or non-trophic, positive or negative interactions. We found a poor correspondence between the co-occurrence network and the known species interactions with overall sensitivity (probability of true link detection) equal to 0.469, and specificity (true non-interaction) equal to 0.527. The ability to detect interactions varied with interaction type. Positive non-trophic interactions such as commensalism and facilitation were detected at the highest rates. These results demonstrate that co-occurrence networks do not represent classical ecological networks in which interactions are defined by direct observations or experimental manipulations. Co-occurrence networks provide information about the joint spatial effects of environmental conditions, recruitment, and, to some extent, biotic interactions, and among the latter, they tend to better detect niche-expanding positive non-trophic interactions. Detection of links (sensitivity or specificity) was not higher for well-known intertidal keystone species than for the rest of consumers in the community. Thus, as observed in previous empirical and theoretical studies, patterns of interactions in co-occurrence networks must be interpreted with caution, especially when extending interaction

  10. Invasive plant architecture alters trophic interactions by changing predator abundance and behavior

    Science.gov (United States)

    Dean E. Pearson

    2009-01-01

    As primary producers, plants are known to influence higher trophic interactions by initiating food chains. However, as architects, plants may bypass consumers to directly affect predators with important but underappreciated trophic ramifications. Invasion of western North American grasslands by the perennial forb, spotted knapweed (Centaurea maculosa...

  11. Multispecies interactions across trophic levels at macroscales: retrospective and future directions

    NARCIS (Netherlands)

    Kissling, W.D.; Schleuning, M.

    2015-01-01

    Trophic interactions among multiple species are ubiquitous in nature and their importance for structuring ecological communities has been extensively demonstrated at local spatial scales. However, how local species interactions scale-up to large spatial scales and how they contribute to shape

  12. Trophic interactions, ecosystem structure and function in the southern Yellow Sea

    Science.gov (United States)

    Lin, Qun; Jin, Xianshi; Zhang, Bo

    2013-01-01

    The southern Yellow Sea is an important fishing ground, providing abundant fishery resources. However, overfishing and climate change have caused a decline in the resource and damaged the ecosystem. We developed an ecosystem model to analyze the trophic interactions and ecosystem structure and function to guide sustainable development of the ecosystem. A trophic mass-balance model of the southern Yellow Sea during 2000-2001 was constructed using Ecopath with Ecosim software. We defined 22 important functional groups and studied their diet composition. The trophic levels of fish, shrimp, crabs, and cephalopods were between 2.78 and 4.39, and the mean trophic level of the fisheries was 3.24. The trophic flows within the food web occurred primarily in the lower trophic levels. The mean trophic transfer efficiency was 8.1%, of which 7.1% was from primary producers and 9.3% was from detritus within the ecosystem. The transfer efficiency between trophic levels II to III to IV to V to >V was 5.0%, 5.7%, 18.5%, and 19.7%-20.4%, respectively. Of the total flow, phytoplankton contributed 61% and detritus contributed 39%. Fishing is defined as a top predator within the ecosystem, and has a negative impact on most commercial species. Moreover, the ecosystem had a high gross efficiency of the fishery and a high value of primary production required to sustain the fishery. Together, our data suggest there is high fishing pressure in the southern Yellow Sea. Based on analysis of Odum's ecological parameters, this ecosystem was at an immature stage. Our results provide some insights into the structure and development of this ecosystem.

  13. Simulated tri-trophic networks reveal complex relationships between species diversity and interaction diversity.

    Science.gov (United States)

    Pardikes, Nicholas A; Lumpkin, Will; Hurtado, Paul J; Dyer, Lee A

    2018-01-01

    Most of earth's biodiversity is comprised of interactions among species, yet it is unclear what causes variation in interaction diversity across space and time. We define interaction diversity as the richness and relative abundance of interactions linking species together at scales from localized, measurable webs to entire ecosystems. Large-scale patterns suggest that two basic components of interaction diversity differ substantially and predictably between different ecosystems: overall taxonomic diversity and host specificity of consumers. Understanding how these factors influence interaction diversity, and quantifying the causes and effects of variation in interaction diversity are important goals for community ecology. While previous studies have examined the effects of sampling bias and consumer specialization on determining patterns of ecological networks, these studies were restricted to two trophic levels and did not incorporate realistic variation in species diversity and consumer diet breadth. Here, we developed a food web model to generate tri-trophic ecological networks, and evaluated specific hypotheses about how the diversity of trophic interactions and species diversity are related under different scenarios of species richness, taxonomic abundance, and consumer diet breadth. We investigated the accumulation of species and interactions and found that interactions accumulate more quickly; thus, the accumulation of novel interactions may require less sampling effort than sampling species in order to get reliable estimates of either type of diversity. Mean consumer diet breadth influenced the correlation between species and interaction diversity significantly more than variation in both species richness and taxonomic abundance. However, this effect of diet breadth on interaction diversity is conditional on the number of observed interactions included in the models. The results presented here will help develop realistic predictions of the relationships

  14. Quantifying Trophic Interactions and Carbon Flow in Louisiana Salt Marshes Using Multiple Biomarkers

    Science.gov (United States)

    Polito, M. J.; Lopez-Duarte, P. C.; Olin, J.; Johnson, J. J.; Able, K.; Martin, C. W.; Fodrie, J.; Hooper-Bui, L. M.; Taylor, S.; Stouffer, P.; Roberts, B. J.; Rabalais, N. N.; Jensen, O.

    2017-12-01

    Salt marshes are critical habitats for many species in the northern Gulf of Mexico. However, given their complex nature, quantifying trophic linkages and the flow of carbon through salt marsh food webs is challenging. This gap in our understanding of food web structure and function limits our ability to evaluate the impacts of natural and anthropogenic stressors on salt marsh ecosystems. For example, 2010 Deepwater Horizon (DWH) oil spill had the potential to alter trophic and energy pathways. Even so, our ability to evaluate its effects on Louisiana salt marsh food webs was limited by a poor basis for comparison of the pre-spill baseline food web. To be better equipped to measure significant alterations in salt marsh ecosystems in the future, we quantified trophic interactions at two marsh sites in Barataria Bay, LA in May and October of 2015. Trophic structure and carbon flow across 52 species of saltmarsh primary producers and consumers were examined through a combination of three approaches: bulk tissue stable isotope analysis (δ13C, δ15N, δ34S), dietary fatty acid analysis (FAA), and compound-specific stable isotope analysis of essential amino acids (δ13C EAA). Bulk stable isotope analysis indicated similar trophic diversity between sites and seasons with the use of aquatic resources increasing concomitantly with trophic level. FAA and δ13C EAA biomarkers revealed that marsh organisms were largely divided into two groups: those that primarily derive carbon from terrestrial C4 grasses, and those that predominately derive carbon from a combination of phytoplankton and benthic microalgal sources. Differences in trophic structure and carbon flow were minimal between seasons and sites that were variably impacted by the DWH spill. These data on salt marsh ecosystem structure will be useful to inform future injury assessments and restoration initiatives.

  15. The interacting effects of temperature and food chain length on trophic abundance and ecosystem function.

    Science.gov (United States)

    Beveridge, Oliver S; Humphries, Stuart; Petchey, Owen L

    2010-05-01

    1. While much is known about the independent effects of trophic structure and temperature on density and ecosystem processes, less is known about the interaction(s) between the two. 2. We manipulated the temperature of laboratory-based bacteria-protist communities that contained communities with one, two, or three trophic levels, and recorded species' densities and bacterial decomposition. 3. Temperature, food chain length and their interaction produced significant responses in microbial density and bacterial decomposition. Prey and resource density expressed different patterns of temperature dependency during different phases of population dynamics. The addition of a predator altered the temperature-density relationship of prey, from a unimodal trend to a negative one. Bacterial decomposition was greatest in the presence of consumers at higher temperatures. 4. These results are qualitatively consistent with a recent model of direct and indirect temperature effects on resource-consumer population dynamics. Results highlight and reinforce the importance of indirect effects of temperature mediated through trophic interactions. Understanding and predicting the consequences of environmental change will require that indirect effects, trophic structure, and individual species' tolerances be incorporated into theory and models.

  16. Predicting Trophic Interactions and Habitat Utilization in the California Current Ecosystem

    Science.gov (United States)

    2015-09-30

    Foraging patterns: model-data comparison . Simulated (colored circles) and observed (black circles) foraging locations for male sea lion individuals off...focusing on trophic interactions affecting habitat utilization and foraging patterns of California sea lions (CSL) in the California Current Large Marine...by considering patterns of covariability between environmental variables (e.g., temperature, primary production) and foraging patterns and success of

  17. Trophic interactions between native and introduced fish species in a littoral fish community.

    Science.gov (United States)

    Monroy, M; Maceda-Veiga, A; Caiola, N; De Sostoa, A

    2014-11-01

    The trophic interactions between 15 native and two introduced fish species, silverside Odontesthes bonariensis and rainbow trout Oncorhynchus mykiss, collected in a major fishery area at Lake Titicaca were explored by integrating traditional ecological knowledge and stable-isotope analyses (SIA). SIA suggested the existence of six trophic groups in this fish community based on δ(13)C and δ(15)N signatures. This was supported by ecological evidence illustrating marked spatial segregation between groups, but a similar trophic level for most of the native groups. Based on Bayesian ellipse analyses, niche overlap appeared to occur between small O. bonariensis (<90 mm) and benthopelagic native species (31.6%), and between the native pelagic killifish Orestias ispi and large O. bonariensis (39%) or O. mykiss (19.7%). In addition, Bayesian mixing models suggested that O. ispi and epipelagic species are likely to be the main prey items for the two introduced fish species. This study reveals a trophic link between native and introduced fish species, and demonstrates the utility of combining both SIA and traditional ecological knowledge to understand trophic relationships between fish species with similar feeding habits. © 2014 The Fisheries Society of the British Isles.

  18. Reciprocal Trophic Interactions and Transmission of Blood Parasites between Mosquitoes and Frogs

    Directory of Open Access Journals (Sweden)

    Todd G. Smith

    2012-04-01

    Full Text Available The relationship between mosquitoes and their amphibian hosts is a unique, reciprocal trophic interaction. Instead of a one-way, predator-prey relationship, there is a cyclical dance of avoidance and attraction. This has prompted spatial and temporal synchrony between organisms, reflected in emergence time of mosquitoes in the spring and choice of habitat for oviposition. Frog-feeding mosquitoes also possess different sensory apparatuses than do their mammal-feeding counterparts. The reciprocal nature of this relationship is exploited by various blood parasites that use mechanical, salivary or trophic transmission to pass from mosquitoes to frogs. It is important to investigate the involvement of mosquitoes, frogs and parasites in this interaction in order to understand the consequences of anthropogenic actions, such as implementing biocontrol efforts against mosquitoes, and to determine potential causes of the global decline of amphibian species.

  19. The Ecology of Shallow Lakes - Trophic Interactions in the Pelagial

    DEFF Research Database (Denmark)

    Jeppesen, E.

    publications. The thesis was in June 1998 approved by The Faculty of Natural Sciences at the University of Copenhagen for defence for the doctor´s degree in Natural Sciences (D.sc). This thesis describes how biological interactions in the pelagial of lakes change across both nutrients and depth gradients......The defence took place on December 11, 1998 at The Freshwater Centre, Silkeborg, Denmark. Officiel opponents was Prof. Jürgen Benndorf, University of Technology, Dresden,Germany and Prof. Dag Hessen, University of Oslo, Norway . The defence was led by Lektor Leif Lau Jeppesen, Zoological Institute...

  20. Interactions to the fifth trophic level: secondary and tertiary parasitoid wasps show extraordinary efficiency in utilizing host resources

    NARCIS (Netherlands)

    Harvey, J.A.; Wagenaar, R.; Bezemer, T.M.

    2009-01-01

    1. Parasitoid wasps are highly efficient organisms at utilizing and assimilating limited resources from their hosts. This study explores interactions over three trophic levels, from the third (primary parasitoid) to the fourth (secondary parasitoid) and terminating in the fifth (tertiary

  1. Artificial light at night alters trophic interactions of intertidal invertebrates.

    Science.gov (United States)

    Underwood, Charlotte N; Davies, Thomas W; Queirós, Ana M

    2017-07-01

    balance of interspecific interactions involved in community structuring may be affected. © 2017 The Authors. Journal of Animal Ecology © 2017 British Ecological Society.

  2. Incorporating anthropogenic effects into trophic ecology: predator–prey interactions in a human-dominated landscape

    Science.gov (United States)

    Dorresteijn, Ine; Schultner, Jannik; Nimmo, Dale G.; Fischer, Joern; Hanspach, Jan; Kuemmerle, Tobias; Kehoe, Laura; Ritchie, Euan G.

    2015-01-01

    Apex predators perform important functions that regulate ecosystems worldwide. However, little is known about how ecosystem regulation by predators is influenced by human activities. In particular, how important are top-down effects of predators relative to direct and indirect human-mediated bottom-up and top-down processes? Combining data on species' occurrence from camera traps and hunting records, we aimed to quantify the relative effects of top-down and bottom-up processes in shaping predator and prey distributions in a human-dominated landscape in Transylvania, Romania. By global standards this system is diverse, including apex predators (brown bear and wolf), mesopredators (red fox) and large herbivores (roe and red deer). Humans and free-ranging dogs represent additional predators in the system. Using structural equation modelling, we found that apex predators suppress lower trophic levels, especially herbivores. However, direct and indirect top-down effects of humans affected the ecosystem more strongly, influencing species at all trophic levels. Our study highlights the need to explicitly embed humans and their influences within trophic cascade theory. This will greatly expand our understanding of species interactions in human-modified landscapes, which compose the majority of the Earth's terrestrial surface. PMID:26336169

  3. Understanding trophic interactions of Orius spp. (Hemiptera: Anthocoridae) in lettuce crops by molecular methods.

    Science.gov (United States)

    Gomez-Polo, Priscila; Alomar, Oscar; Castañé, Cristina; Aznar-Fernández, Thaïs; Lundgren, Jonathan G; Piñol, Josep; Agustí, Nuria

    2016-02-01

    The aphid Nasonovia ribisnigri (Mosley) (Hemiptera: Aphididae) and the thrips Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) are common pests in Mediterranean lettuce crops, where Orius spp. are common generalist predators. Predation by Orius spp. was studied in a lettuce plot by conventional polymerase chain reaction (PCR) and real-time PCR analyses using specific primers of both main pests. Also, high-throughput sequencing was used to have a wider approach of the diet of these predators in natural field conditions. Molecular analyses indicated a higher predation on N. ribisnigri in spring and on F. occidentalis in summer. Predation on alternative prey, like Collembola, was also found in both seasons. Real-time PCR was more sensitive than conventional PCR in showing the target trophic links, whereas high-throughput sequencing revealed predation on other natural enemies - intraguild predation (IGP), showing other trophic interactions of Orius majusculus within the studied ecosystem. This study gives important information about the trophic relationships present in Mediterranean lettuce crops in different periods of the year. The detected predation by Orius spp. on alternative prey, as well as on other natural enemies, should be further investigated to clarify whether it adds or detracts to the biological control of N. ribisnigri and F. occidentalis. © 2015 Society of Chemical Industry.

  4. Benthic Trophic Interactions in an Antarctic Shallow Water Ecosystem Affected by Recent Glacier Retreat.

    Directory of Open Access Journals (Sweden)

    Francesca Pasotti

    Full Text Available The western Antarctic Peninsula is experiencing strong environmental changes as a consequence of ongoing regional warming. Glaciers in the area are retreating rapidly and increased sediment-laden meltwater runoff threatens the benthic biodiversity at shallow depths. We identified three sites with a distinct glacier-retreat related history and different levels of glacial influence in the inner part of Potter Cove (King George Island, South Shetland Islands, a fjord-like embayment impacted since the 1950s by a tidewater glacier retreat. We compared the soft sediment meio- and macrofauna isotopic niche widths (δ13C and δ15N stable isotope analysis at the three sites to investigate possible glacier retreat-related influences on benthic trophic interactions. The isotopic niches were locally shaped by the different degrees of glacier retreat-related disturbance within the Cove. Wider isotopic niche widths were found at the site that has become ice-free most recently, and narrower niches at the older ice-free sites. At an intermediate state of glacier retreat-related disturbance (e.g. via ice-growler scouring species with different strategies could settle. The site at the earliest stage of post-retreat development was characterized by an assemblage with lower trophic redundancy. Generally, the isotopic niche widths increased with increasing size spectra of organisms within the community, excepting the youngest assemblage, where the pioneer colonizer meiofauna size class displayed the highest isotopic niche width. Meiofauna at all sites generally occupied positions in the isotopic space that suggested a detrital-pool food source and/or the presence of predatory taxa. In general ice scour and glacial impact appeared to play a two-fold role within the Cove: i either stimulating trophic diversity by allowing continuous re-colonization of meiofaunal species or, ii over time driving the benthic assemblages into a more compact trophic structure with

  5. Benthic Trophic Interactions in an Antarctic Shallow Water Ecosystem Affected by Recent Glacier Retreat.

    Science.gov (United States)

    Pasotti, Francesca; Saravia, Leonardo Ariel; De Troch, Marleen; Tarantelli, Maria Soledad; Sahade, Ricardo; Vanreusel, Ann

    2015-01-01

    The western Antarctic Peninsula is experiencing strong environmental changes as a consequence of ongoing regional warming. Glaciers in the area are retreating rapidly and increased sediment-laden meltwater runoff threatens the benthic biodiversity at shallow depths. We identified three sites with a distinct glacier-retreat related history and different levels of glacial influence in the inner part of Potter Cove (King George Island, South Shetland Islands), a fjord-like embayment impacted since the 1950s by a tidewater glacier retreat. We compared the soft sediment meio- and macrofauna isotopic niche widths (δ13C and δ15N stable isotope analysis) at the three sites to investigate possible glacier retreat-related influences on benthic trophic interactions. The isotopic niches were locally shaped by the different degrees of glacier retreat-related disturbance within the Cove. Wider isotopic niche widths were found at the site that has become ice-free most recently, and narrower niches at the older ice-free sites. At an intermediate state of glacier retreat-related disturbance (e.g. via ice-growler scouring) species with different strategies could settle. The site at the earliest stage of post-retreat development was characterized by an assemblage with lower trophic redundancy. Generally, the isotopic niche widths increased with increasing size spectra of organisms within the community, excepting the youngest assemblage, where the pioneer colonizer meiofauna size class displayed the highest isotopic niche width. Meiofauna at all sites generally occupied positions in the isotopic space that suggested a detrital-pool food source and/or the presence of predatory taxa. In general ice scour and glacial impact appeared to play a two-fold role within the Cove: i) either stimulating trophic diversity by allowing continuous re-colonization of meiofaunal species or, ii) over time driving the benthic assemblages into a more compact trophic structure with increased

  6. Trophic interactions among grouper (Epinephelus marginatus), octopus (Octopus vulgaris) and red lobster (Palinurus elephas) in the Western Mediterranean

    OpenAIRE

    Quetglas, A. (Antoni); Reñones, O. (Olga); Goñi, R. (Raquel)

    2001-01-01

    In the present paper a first evaluation of the trophic interactions between grouper, octopus and spiny red lobster in the western Mediterranean is presented. The efficiency of octopus preying on lobsters is also estimated from trap catches. Grouper and octopus base their diet on the same major taxonomic groups and this is reflected in the values of diet overlap. Trophic diversity of grouper and octopus is also very similar. The estimation of the octopus efficiency preying on lobsters shows th...

  7. Ecological and evolutionary consequences of tri-trophic interactions: Spatial variation and effects of plant density.

    Science.gov (United States)

    Abdala-Roberts, Luis; Parra-Tabla, Víctor; Moreira, Xoaquín; Ramos-Zapata, José

    2017-02-01

    The factors driving variation in species interactions are often unknown, and few studies have made a link between changes in interactions and the strength of selection. We report on spatial variation in functional responses by a seed predator (SP) and its parasitic wasps associated with the herb Ruellia nudiflora . We assessed the influence of plant density on consumer responses and determined whether density effects and spatial variation in functional responses altered natural selection by these consumers on the plant. We established common gardens at two sites in Yucatan, Mexico, and planted R. nudiflora at two densities in each garden. We recorded fruit output and SP and parasitoid attack; calculated relative fitness (seed number) under scenarios of three trophic levels (accounting for SP and parasitoid effects), two trophic levels (accounting for SP but not parasitoid effects), and one trophic level (no consumer effects); and compared selection strength on fruit number under these scenarios across sites and densities. There was spatial variation in SP recruitment, whereby the SP functional response was negatively density-dependent at one site but density-independent at the other; parasitoid responses were density-independent and invariant across sites. Site variation in SP attack led, in turn, to differences in SP selection on fruit output, and parasitoids did not alter SP selection. There were no significant effects of density at either site. Our results provide a link between consumer functional responses and consumer selection on plants, which deepens our understanding of geographic variation in the evolutionary outcomes of multitrophic interactions. © 2017 Botanical Society of America.

  8. Unintended consequences of management actions in salt pond restoration: cascading effects in trophic interactions.

    Directory of Open Access Journals (Sweden)

    John Y Takekawa

    Full Text Available Salt evaporation ponds have played an important role as habitat for migratory waterbirds across the world, however, efforts to restore and manage these habitats to maximize their conservation value has proven to be challenging. For example, salinity reduction has been a goal for restoring and managing former salt evaporation ponds to support waterbirds in the South Bay Salt Pond Restoration Project in San Francisco Bay, California, USA. Here, we describe a case study of unexpected consequences of a low-dissolved oxygen (DO event on trophic interactions in a salt pond system following management actions to reduce salinity concentrations. We document the ramifications of an anoxic event in water quality including salinity, DO, and temperature, and in the response of the biota including prey fish biomass, numerical response by California Gulls (Larus californicus, and chick survival of Forster's Tern (Sterna forsteri. Management actions intended to protect receiving waters resulted in decreased DO concentrations that collapsed to zero for ≥ 4 consecutive days, resulting in an extensive fish kill. DO depletion likely resulted from an algal bloom that arose following transition of the pond system from high to low salinity as respiration and decomposition outpaced photosynthetic production. We measured a ≥ 6-fold increase in biomass of fish dropped on the levee by foraging avian predators compared with weeks prior to and following the low-DO event. California Gulls rapidly responded to the availability of aerobically-stressed and vulnerable fish and increased in abundance by two orders of magnitude. Mark-recapture analysis of 254 Forster's Tern chicks indicated that their survival declined substantially following the increase in gull abundance. Thus, management actions to reduce salinity concentrations resulted in cascading effects in trophic interactions that serves as a cautionary tale illustrating the importance of understanding the interaction

  9. Unintended consequences of management actions in salt pond restoration: cascading effects in trophic interactions

    Science.gov (United States)

    Takekawa, John Y.; Ackerman, Joshua T.; Brand, Arriana; Graham, Tanya R.; Eagles-Smith, Collin A.; Herzog, Mark; Topping, Brent R.; Shellenbarger, Gregory; Kuwabara, James S.; Mruz, Eric; Piotter, Sara L.; Athearn, Nicole D.

    2015-01-01

    Salt evaporation ponds have played an important role as habitat for migratory waterbirds across the world, however, efforts to restore and manage these habitats to maximize their conservation value has proven to be challenging. For example, salinity reduction has been a goal for restoring and managing former salt evaporation ponds to support waterbirds in the South Bay Salt Pond Restoration Project in San Francisco Bay, California, USA. Here, we describe a case study of unexpected consequences of a low-dissolved oxygen (DO) event on trophic interactions in a salt pond system following management actions to reduce salinity concentrations. We document the ramifications of an anoxic event in water quality including salinity, DO, and temperature, and in the response of the biota including prey fish biomass, numerical response by California Gulls (Larus californicus), and chick survival of Forster's Tern (Sterna forsteri). Management actions intended to protect receiving waters resulted in decreased DO concentrations that collapsed to zero for ≥ 4 consecutive days, resulting in an extensive fish kill. DO depletion likely resulted from an algal bloom that arose following transition of the pond system from high to low salinity as respiration and decomposition outpaced photosynthetic production. We measured a ≥ 6-fold increase in biomass of fish dropped on the levee by foraging avian predators compared with weeks prior to and following the low-DO event. California Gulls rapidly responded to the availability of aerobically-stressed and vulnerable fish and increased in abundance by two orders of magnitude. Mark-recapture analysis of 254 Forster's Tern chicks indicated that their survival declined substantially following the increase in gull abundance. Thus, management actions to reduce salinity concentrations resulted in cascading effects in trophic interactions that serves as a cautionary tale illustrating the importance of understanding the interaction of water quality

  10. Unintended consequences of management actions in salt pond restoration: cascading effects in trophic interactions.

    Science.gov (United States)

    Takekawa, John Y; Ackerman, Joshua T; Brand, L Arriana; Graham, Tanya R; Eagles-Smith, Collin A; Herzog, Mark P; Topping, Brent R; Shellenbarger, Gregory G; Kuwabara, James S; Mruz, Eric; Piotter, Sara L; Athearn, Nicole D

    2015-01-01

    Salt evaporation ponds have played an important role as habitat for migratory waterbirds across the world, however, efforts to restore and manage these habitats to maximize their conservation value has proven to be challenging. For example, salinity reduction has been a goal for restoring and managing former salt evaporation ponds to support waterbirds in the South Bay Salt Pond Restoration Project in San Francisco Bay, California, USA. Here, we describe a case study of unexpected consequences of a low-dissolved oxygen (DO) event on trophic interactions in a salt pond system following management actions to reduce salinity concentrations. We document the ramifications of an anoxic event in water quality including salinity, DO, and temperature, and in the response of the biota including prey fish biomass, numerical response by California Gulls (Larus californicus), and chick survival of Forster's Tern (Sterna forsteri). Management actions intended to protect receiving waters resulted in decreased DO concentrations that collapsed to zero for ≥ 4 consecutive days, resulting in an extensive fish kill. DO depletion likely resulted from an algal bloom that arose following transition of the pond system from high to low salinity as respiration and decomposition outpaced photosynthetic production. We measured a ≥ 6-fold increase in biomass of fish dropped on the levee by foraging avian predators compared with weeks prior to and following the low-DO event. California Gulls rapidly responded to the availability of aerobically-stressed and vulnerable fish and increased in abundance by two orders of magnitude. Mark-recapture analysis of 254 Forster's Tern chicks indicated that their survival declined substantially following the increase in gull abundance. Thus, management actions to reduce salinity concentrations resulted in cascading effects in trophic interactions that serves as a cautionary tale illustrating the importance of understanding the interaction of water quality

  11. Cascading trophic interactions in the littoral zone: an enclosure experiment in shallow Lake Stigsholm, Denmark

    DEFF Research Database (Denmark)

    Jeppesen, E.; Søndergaard, M.; Søndergaard, M.

    2002-01-01

    The importance of grazer versus resource control has been extensively studied in the pelagic zone of lakes. In contrast, comparatively little is known about trophic interactions within the littoral zone. We conducted an experiment in the littoral zone of a eutrophic shallow lake using six 20 m2......, zooplankton grazing was equivalent to production in M+, but amounted to littoral zones do not alone feed on particles produced in the water, but also exploit alternative sources such as periphyton...... hypothesize that the strong cascading effects of zooplankton on chlorophyll-a and microorganisms in the littoral zone at natural fish densities are restricted to eutrophic lakes with high plant densities....

  12. Successional changes in trophic interactions support a mechanistic model of post-fire population dynamics.

    Science.gov (United States)

    Smith, Annabel L

    2018-01-01

    Models based on functional traits have limited power in predicting how animal populations respond to disturbance because they do not capture the range of demographic and biological factors that drive population dynamics, including variation in trophic interactions. I tested the hypothesis that successional changes in vegetation structure, which affected invertebrate abundance, would influence growth rates and body condition in the early-successional, insectivorous gecko Nephrurus stellatus. I captured geckos at 17 woodland sites spanning a succession gradient from 2 to 48 years post-fire. Body condition and growth rates were analysed as a function of the best-fitting fire-related predictor (invertebrate abundance or time since fire) with different combinations of the co-variates age, sex and location. Body condition in the whole population was positively affected by increasing invertebrate abundance and, in the adult population, this effect was most pronounced for females. There was strong support for a decline in growth rates in weight with time since fire. The results suggest that increased early-successional invertebrate abundance has filtered through to a higher trophic level with physiological benefits for insectivorous geckos. I integrated the new findings about trophic interactions into a general conceptual model of mechanisms underlying post-fire population dynamics based on a long-term research programme. The model highlights how greater food availability during early succession could drive rapid population growth by contributing to previously reported enhanced reproduction and dispersal. This study provides a framework to understand links between ecological and physiological traits underlying post-fire population dynamics.

  13. Microbial trophic interactions and mcrA gene expression in monitoring of anaerobic digesters

    Directory of Open Access Journals (Sweden)

    Alejandra eAlvarado

    2014-11-01

    Full Text Available Anaerobic digestion (AD is a biological process where different trophic groups of microorganisms break down biodegradable organic materials in the absence of oxygen. A wide range of anaerobic digestion technologies is being used to convert livestock manure, municipal and industrial wastewaters, and solid organic wastes into biogas. AD gains importance not only because of its relevance in waste treatment but also because of the recovery of carbon in the form of methane, which is a renewable energy and is used to generate electricity and heat. Despite the advances on the engineering and design of new bioreactors for anaerobic digestion, the microbiology component always poses challenges. Microbiology of AD processes is complicated as the efficiency of the process depends on the interactions of various trophic groups involved. Due to the complex interdependence of microbial activities for the functionality of the anaerobic bioreactors, the genetic expression of mcrA, which encodes a key enzyme in methane formation, is proposed as a parameter to monitor the process performance in real time. This review evaluates the current knowledge on microbial groups, their interactions and their relationship to the performance of anaerobic biodigesters with a focus on using mcrA gene expression as a tool to monitor the process.

  14. Microbial trophic interactions and mcrA gene expression in monitoring of anaerobic digesters

    Science.gov (United States)

    Alvarado, Alejandra; Montañez-Hernández, Lilia E.; Palacio-Molina, Sandra L.; Oropeza-Navarro, Ricardo; Luévanos-Escareño, Miriam P.; Balagurusamy, Nagamani

    2014-01-01

    Anaerobic digestion (AD) is a biological process where different trophic groups of microorganisms break down biodegradable organic materials in the absence of oxygen. A wide range of AD technologies is being used to convert livestock manure, municipal and industrial wastewaters, and solid organic wastes into biogas. AD gains importance not only because of its relevance in waste treatment but also because of the recovery of carbon in the form of methane, which is a renewable energy and is used to generate electricity and heat. Despite the advances on the engineering and design of new bioreactors for AD, the microbiology component always poses challenges. Microbiology of AD processes is complicated as the efficiency of the process depends on the interactions of various trophic groups involved. Due to the complex interdependence of microbial activities for the functionality of the anaerobic bioreactors, the genetic expression of mcrA, which encodes a key enzyme in methane formation, is proposed as a parameter to monitor the process performance in real time. This review evaluates the current knowledge on microbial groups, their interactions, and their relationship to the performance of anaerobic biodigesters with a focus on using mcrA gene expression as a tool to monitor the process. PMID:25429286

  15. Complexity of plant volatile-mediated interactions beyond the third trophic level

    NARCIS (Netherlands)

    Poelman, E.H.; Kos, M.

    2016-01-01

    Food chains of plant-associated communities typically reach beyond three trophic levels. The predators and parasitoids in the third trophic level are under attack by top predators or parasitised by hyperparasitoids. These higher trophic level organisms respond to plant volatiles in search of their

  16. Feeding behavior and trophic interaction of three shark species in the Galapagos Marine Reserve

    Directory of Open Access Journals (Sweden)

    Diego Páez-Rosas

    2018-05-01

    Full Text Available There is great concern about the future of sharks in Ecuador because of the lack of biological knowledge of most species that inhabit the region. This paper analyzes the feeding behavior of the pelagic thresher shark (Alopias pelagicus, the blue shark (Prionace glauca and the silky shark (Carcharhinus falciformis through the use of stable isotopes of carbon and nitrogen (δ13C and δ15N, with the aim of determining the degree of interaction between these species in the Galapagos Marine Reserve. No interspecific differences were found in use of oceanic vs. inshore feeding areas (δ13C: Kruskal–Wallis test, p = 0.09. The position in the hierarchy of the food web where A. pelagicus feeds differed from that of the other species (δ15N: Kruskal–Wallis test, p = 0.01. There were no significant differences in δ13C and δ15N values between males and females of the three species (Student’s t-test, p > 0.05, which suggests that both sexes have a similar feeding behavior. A specialist strategy was observed in P. glauca (trophic niche breadth TNB = 0.69, while the other species were found to be generalist (A. pelagicus TNB = 1.50 and C. falciformis TNB = 1.09. The estimated trophic level (TL varied between the three species. C. falciformis occupied the highest trophic level (TL = 4.4, making it a quaternary predator in the region. The results of this study coincide with the identified behavior in these predators in other areas of the tropical Pacific (Colombia and Mexico, and suggest a pelagic foraging strategy with differential consumption of prey between the three species. These ecological aspects can provide timely information when implementing in conservation measures for these shark species in the Tropical Pacific and Galapagos Marine Reserve.

  17. Feeding behavior and trophic interaction of three shark species in the Galapagos Marine Reserve.

    Science.gov (United States)

    Páez-Rosas, Diego; Insuasti-Zarate, Paul; Riofrío-Lazo, Marjorie; Galván-Magaña, Felipe

    2018-01-01

    There is great concern about the future of sharks in Ecuador because of the lack of biological knowledge of most species that inhabit the region. This paper analyzes the feeding behavior of the pelagic thresher shark ( Alopias pelagicus ), the blue shark ( Prionace glauca ) and the silky shark ( Carcharhinus falciformis ) through the use of stable isotopes of carbon and nitrogen ( δ 13 C and δ 15 N), with the aim of determining the degree of interaction between these species in the Galapagos Marine Reserve. No interspecific differences were found in use of oceanic vs. inshore feeding areas ( δ 13 C: Kruskal-Wallis test, p = 0.09). The position in the hierarchy of the food web where A. pelagicus feeds differed from that of the other species ( δ 15 N: Kruskal-Wallis test, p = 0.01). There were no significant differences in δ 13 C and δ 15 N values between males and females of the three species (Student's t -test, p  > 0.05), which suggests that both sexes have a similar feeding behavior. A specialist strategy was observed in P. glauca (trophic niche breadth TNB = 0.69), while the other species were found to be generalist ( A. pelagicus TNB = 1.50 and C. falciformis TNB = 1.09). The estimated trophic level (TL) varied between the three species. C. falciformis occupied the highest trophic level (TL = 4.4), making it a quaternary predator in the region. The results of this study coincide with the identified behavior in these predators in other areas of the tropical Pacific (Colombia and Mexico), and suggest a pelagic foraging strategy with differential consumption of prey between the three species. These ecological aspects can provide timely information when implementing in conservation measures for these shark species in the Tropical Pacific and Galapagos Marine Reserve.

  18. Trophic Interactions between Generalist Predators and the Two Spotted Spide Mite, Tetranychus urticae in, Strawberry

    DEFF Research Database (Denmark)

    Jacobsen, Stine Kramer

    The two spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), is a major cause of pest damage worldwide. Its host range includes among many the strawberry crop, a high value crop in Denmark as well as in many other temperate and subtropical regions. Chemical control of T. urticae...... occurrence and diversity of predatory insects and predatory mites in Danish strawberry fields and surrounding vegetation is lacking, as is the knowledge of the potential of generalist insect predators to control T. urticae. The overall objective of this PhD thesis was to investigate the trophic interactions...... between natural enemies, in particular generalist predators and the two spotted spider mite, T. urticae, in strawberry. This was done by investigating interactions of T. urticae and its natural enemies as influenced by cropping practice and the surrounding vegetation (Manuscript I) as well as more...

  19. Food-web dynamics and trophic-level interactions in a multispecies community of freshwater unionids

    Science.gov (United States)

    Nichols, S.J.; Garling, D.

    2000-01-01

    We compared feeding habits and trophic-level relationships of unionid species in a detritus-dominated river and an alga-dominated lake using biochemical analyses, gut contents, and stable-isotope ratios. The δ13C ratios for algae and other food-web components show that all unionids from both the river and the lake used bacterial carbons, not algal carbons, as their main dietary source, in spite of positive selection and concentration of diatoms and green algae from the water column in the gut and mantle cavity. Algae did provide key nutrients such as vitamins A and D and phytosterols that were bioaccumulated in the tissues of all species. The δ15N ratios for the multispecies unionid community in the Huron River indicated some differences in nitrogen enrichment between species, the greatest enrichment being found in Pyganadon grandis. These δ15N ratios indicate that unionids may not always feed as primary consumers or omnivores. Stable-isotope data were critical for delineating diets and trophic-level interactions of this group of filter-feeders. Further refinements in identifying bacterial and picoplankton components of the fine particulate organic matter are needed to complete our understanding of resource partitioning between multispecies unionid populations.

  20. Trophic interactions in the St. Lawrence Estuary (Canada): Must the blue whale compete for krill?

    Science.gov (United States)

    Savenkoff, C.; Comtois, S.; Chabot, D.

    2013-09-01

    Inverse methodology was used to construct a mass-balance model of the Lower St. Lawrence Estuary (LSLE) for the 2008-2010 time period. Our first objective was to make an overall description of community structure, trophic interactions, and the effects of fishing and predation on the vertebrate and invertebrate communities of the ecosystem. A second objective was to identify other important predators of krill, and to assess if these compete with blue whales, listed as endangered under the Canadian Species at Risk Act in 2005 (northwest Atlantic population). The Estuary and the Gulf of St. Lawrence are summer feeding grounds for blue whales and other marine mammals. Blue whales eat only euphausiids (krill) and require dense concentrations of prey to meet their energy requirements, which makes them particularly vulnerable to changes in prey availability. In the LSLE, many species from secondary producers (hyperiid amphipods, other macrozooplankton) to top predators (fish, birds, and marine mammals) consumed euphausiids. Consequently, krill predators were found at all consumer trophic levels. However, our results showed that only about 35% of the estimated euphausiid production was consumed by all predator species combined. Euphausiid did not seem to be a restricted resource in the LSLE ecosystem, at least during the study period. The blue whale did not appear to have to compete for krill in the LSLE.

  1. Hydration status and diurnal trophic interactions shape microbial community function in desert biocrusts

    Science.gov (United States)

    Kim, Minsu; Or, Dani

    2017-12-01

    Biological soil crusts (biocrusts) are self-organised thin assemblies of microbes, lichens, and mosses that are ubiquitous in arid regions and serve as important ecological and biogeochemical hotspots. Biocrust ecological function is intricately shaped by strong gradients of water, light, oxygen, and dynamics in the abundance and spatial organisation of the microbial community within a few millimetres of the soil surface. We report a mechanistic model that links the biophysical and chemical processes that shape the functioning of biocrust representative microbial communities that interact trophically and respond dynamically to cycles of hydration, light, and temperature. The model captures key features of carbon and nitrogen cycling within biocrusts, such as microbial activity and distribution (during early stages of biocrust establishment) under diurnal cycles and the associated dynamics of biogeochemical fluxes at different hydration conditions. The study offers new insights into the highly dynamic and localised processes performed by microbial communities within thin desert biocrusts.

  2. Hydration status and diurnal trophic interactions shape microbial community function in desert biocrusts

    Directory of Open Access Journals (Sweden)

    M. Kim

    2017-12-01

    Full Text Available Biological soil crusts (biocrusts are self-organised thin assemblies of microbes, lichens, and mosses that are ubiquitous in arid regions and serve as important ecological and biogeochemical hotspots. Biocrust ecological function is intricately shaped by strong gradients of water, light, oxygen, and dynamics in the abundance and spatial organisation of the microbial community within a few millimetres of the soil surface. We report a mechanistic model that links the biophysical and chemical processes that shape the functioning of biocrust representative microbial communities that interact trophically and respond dynamically to cycles of hydration, light, and temperature. The model captures key features of carbon and nitrogen cycling within biocrusts, such as microbial activity and distribution (during early stages of biocrust establishment under diurnal cycles and the associated dynamics of biogeochemical fluxes at different hydration conditions. The study offers new insights into the highly dynamic and localised processes performed by microbial communities within thin desert biocrusts.

  3. Rain forest promotes trophic interactions and diversity of trap-nesting Hymenoptera in adjacent agroforestry.

    Science.gov (United States)

    Klein, Alexandra-Maria; Steffan-Dewenter, Ingolf; Tscharntke, Teja

    2006-03-01

    1. Human alteration of natural ecosystems to agroecosystems continues to accelerate in tropical countries. The resulting world-wide decline of rain forest causes a mosaic landscape, comprising simple and complex agroecosystems and patchily distributed rain forest fragments of different quality. Landscape context and agricultural management can be expected to affect both species diversity and ecosystem services by trophic interactions. 2. In Central Sulawesi, Indonesia, 24 agroforestry systems, differing in the distance to the nearest natural forest (0-1415 m), light intensity (37.5-899.6 W/m(-2)) and number of vascular plant species (7-40 species) were studied. Ten standardized trap nests for bees and wasps, made from reed and knotweed internodes, were exposed in each study site. Occupied nests were collected every month, over a period totalling 15 months. 3. A total of 13,617 brood cells were reared to produce adults of 14 trap-nesting species and 25 natural enemy species, which were mostly parasitoids. The total number of species was affected negatively by increasing distance from forest and increased with light intensity of agroforestry systems. The parasitoids in particular appeared to benefit from nearby forests. Over a 500-m distance, the number of parasitoid species decreased from eight to five, and parasitism rates from 12% to 4%. 4. The results show that diversity and parasitism, as a higher trophic interaction and ecosystem service, are enhanced by (i) improved connectivity of agroecosystems with natural habitats such as agroforestry adjacent to rain forest and (ii) management practices to increase light availability in agroforestry, which also enhances richness of flowering plants in the understorey.

  4. Study of a tri-trophic prey-dependent food chain model of interacting populations.

    Science.gov (United States)

    Haque, Mainul; Ali, Nijamuddin; Chakravarty, Santabrata

    2013-11-01

    The current paper accounts for the influence of intra-specific competition among predators in a prey dependent tri-trophic food chain model of interacting populations. We offer a detailed mathematical analysis of the proposed food chain model to illustrate some of the significant results that has arisen from the interplay of deterministic ecological phenomena and processes. Biologically feasible equilibria of the system are observed and the behaviours of the system around each of them are described. In particular, persistence, stability (local and global) and bifurcation (saddle-node, transcritical, Hopf-Andronov) analysis of this model are obtained. Relevant results from previous well known food chain models are compared with the current findings. Global stability analysis is also carried out by constructing appropriate Lyapunov functions. Numerical simulations show that the present system is capable enough to produce chaotic dynamics when the rate of self-interaction is very low. On the other hand such chaotic behaviour disappears for a certain value of the rate of self interaction. In addition, numerical simulations with experimented parameters values confirm the analytical results and shows that intra-specific competitions bears a potential role in controlling the chaotic dynamics of the system; and thus the role of self interactions in food chain model is illustrated first time. Finally, a discussion of the ecological applications of the analytical and numerical findings concludes the paper. Copyright © 2013 Elsevier Inc. All rights reserved.

  5. Invasive plant architecture alters trophic interactions by changing predator abundance and behavior.

    Science.gov (United States)

    Pearson, Dean E

    2009-03-01

    As primary producers, plants are known to influence higher trophic interactions by initiating food chains. However, as architects, plants may bypass consumers to directly affect predators with important but underappreciated trophic ramifications. Invasion of western North American grasslands by the perennial forb, spotted knapweed (Centaurea maculosa), has fundamentally altered the architecture of native grassland vegetation. Here, I use long-term monitoring, observational studies, and field experiments to document how changes in vegetation architecture have affected native web spider populations and predation rates. Native spiders that use vegetation as web substrates were collectively 38 times more abundant in C. maculosa-invaded grasslands than in uninvaded grasslands. This increase in spider abundance was accompanied by a large shift in web spider community structure, driven primarily by the strong response of Dictyna spiders to C. maculosa invasion. Dictyna densities were 46-74 times higher in C. maculosa-invaded than native grasslands, a pattern that persisted over 6 years of monitoring. C. maculosa also altered Dictyna web building behavior and foraging success. Dictyna webs on C. maculosa were 2.9-4.0 times larger and generated 2.0-2.3 times higher total prey captures than webs on Achillea millefolium, their primary native substrate. Dictyna webs on C. maculosa also captured 4.2 times more large prey items, which are crucial for reproduction. As a result, Dictyna were nearly twice as likely to reproduce on C. maculosa substrates compared to native substrates. The overall outcome of C. maculosa invasion and its transformative effects on vegetation architecture on Dictyna density and web building behavior were to increase Dictyna predation on invertebrate prey >/=89 fold. These results indicate that invasive plants that change the architecture of native vegetation can substantially impact native food webs via nontraditional plant --> predator --> consumer

  6. NanoSIMS study of trophic interactions in the coral-dinoflagellate endosymbiosis

    Science.gov (United States)

    Kopp, Christophe; Mathieu, Pernice; Domart-Coulon, Isabelle; Djediat, Chakib; Spangenberg, Jorge; Alexander, Duncan; Hignette, Michel; Meziane, Tarik; Meibom, Anders

    2013-04-01

    Tropical and subtropical reef-building corals generally form a stable endosymbiotic association with autotrophic single-celled dinoflagellate algae, commonly known as "zooxanthellae", which is crucial for the development of coral reef ecosystems. In the present work, the spatial and temporal dynamics of trophic interactions between corals and their dinoflagellates was investigated in situ and at a subcellular level in the reef-building coral Pocillopora damicornis. Transmission electron microscopy (TEM) and quantitative NanoSIMS isotopic imaging of tissue ultra-thin sections (70 nm) were combined to precisely track the assimilation and the fate of 15N-labeled compounds (ammonium, nitrate and aspartic acid) within each symbiotic partner of the coral-dinoflagellate association. Among our main results, we found that (i) both dinoflagellate algae and coral tissue rapidly assimilate ammonium and aspartic acid from the environment, (ii) however only the dinoflagellates assimilate nitrate, (ii) nitrogen is rapidly and temporary stored within the dinoflagellate cells into uric acid crystals, and (iii) the dinoflagellate endosymbionts translocate nitrogenous compounds to their coral host. This study paves the way for exploring in details the wide range of metabolic interactions between partners of any symbiosis in the biosphere.

  7. Genetic variation in foundation species governs the dynamics of trophic interactions

    Science.gov (United States)

    Valencia-Cuevas, Leticia; Mussali-Galante, Patricia; Cano-Santana, Zenón; Pujade-Villar, Juli; Equihua-Martínez, Armando

    2018-01-01

    Abstract Various studies have demonstrated that the foundation species genetic diversity can have direct effects that extend beyond the individual or population level, affecting the dependent communities. Additionally, these effects may be indirectly extended to higher trophic levels throughout the entire community. Quercus castanea is an oak species with characteristics of foundation species beyond presenting a wide geographical distribution and being a dominant element of Mexican temperate forests. In this study, we analyzed the influence of population (He) and individual (HL) genetic diversity of Q. castanea on its canopy endophagous insect community and associated parasitoids. Specifically, we studied the composition, richness (S) and density of leaf-mining moths (Lepidoptera: Tischeridae, Citheraniidae), gall-forming wasps (Hymenoptera: Cynipidae), and canopy parasitoids of Q. castanea. We sampled 120 trees belonging to six populations (20/site) through the previously recognized gradient of genetic diversity. In total, 22 endophagous insect species belonging to three orders (Hymenoptera, Lepidoptera, and Diptera) and 20 parasitoid species belonging to 13 families were identified. In general, we observed that the individual genetic diversity of the host plant (HL) has a significant positive effect on the S and density of the canopy endophagous insect communities. In contrast, He has a significant negative effect on the S of endophagous insects. Additionally, indirect effects of HL were observed, affecting the S and density of parasitoid insects. Our results suggest that genetic variation in foundation species can be one of the most important factors governing the dynamics of tritrophic interactions that involve oaks, herbivores, and parasitoids. PMID:29492034

  8. Shark-Cetacean trophic interaction, Duinefontein, Koeberg, (5 Ma, South Africa

    Directory of Open Access Journals (Sweden)

    Romala Govender

    2015-11-01

    Full Text Available This study forms part of a larger project to reconstruct the Mio-Pliocene marine palaeoenvironment along South Africa’s west coast. It documents the shark–cetacean trophic interaction during the Zanclean (5 Ma at Duinefontein (Koeberg. The damage described on the fragmentary cetacean bones was compared with similar damage observed on fossils from Langebaanweg, a Mio-Pliocene site on the west coast of South Africa, and data present in the literature. This comparison showed that the damage was the result of shark bites. The state of preservation makes it difficult to determine if the shark bite marks were the cause of death or as a result of scavenging. The presence of the bite marks on the bone would, however, indicate some degree of skeletonisation. Bite marks on some cranial fragments would suggest that the cetacean’s body was in an inverted position typical of a floating carcass. The preservation of the material suggests that the bones were exposed to wave action resulting in their fragmentation as well as abrasion, polishing and rolling. It also suggests that the cetacean skeletons were exposed for a long time prior to burial. The morphology of the bites suggests that the damage was inflicted by sharks with serrated and unserrated teeth. Shark teeth collected from the deposit include megalodon (Carcharodon megalodon, white (Carcharodon carcharias as well as mako (Isurus sp. and Cosmopolitodus hastalis sharks, making these sharks the most likely predators/scavengers.

  9. Local ecological knowledge of artisanal fishermen in southern Bahia, Brazil, about trophic interactions of sharks

    Directory of Open Access Journals (Sweden)

    Márcio Luiz Vargas Barbosa Filho

    2016-09-01

    Full Text Available Despite the serious threats that affect shark species living along the central coast of Brazil, knowledge about the life history of these animals is still scarce. The present study describes the knowledge and perceptions of fishermen from southern Bahia, Brazil, on the trophic interactions of sharks. The objective of this work was to generate information that contributes to a better understanding of the life history of sharks from this poorly known region. In 2012, semi-structured interviews were conducted with 65 fishermen, with over 15 years of experience, about fisheries and aspects of shark feeding behavior. The study found that the participants have comprehensive ethno-ecological knowledge about shark feeding habits, describing 39 types of items as components of the diets of these animals. They are also able to recognize the favored items in the diet of each ethnospecies of shark. Similar studies about shark feeding habits along the Brazilian coast should be developed. This will generate more detailed knowledge and/or new scientific hypotheses about the interspecific relationships of these predators and their prey.

  10. Coupling auto trophic in vitro plant cultivation system to scanning electron microscope to study plant-fungal interactions

    Energy Technology Data Exchange (ETDEWEB)

    Jaeger, N. de; Decock, C.; Declereck, S.; Providencia, I. E. de la

    2010-07-01

    The interactions of plants with pathogens and beneficial micro-organisms have been seldom compared on the same host and under strict controlled auto trophic in vitro culture conditions. Here, the life cycle of two plant beneficial (Glomus sp. MUCL 41833 and Trichoderma harzianum) and one plant pathogen (Rhizoctonia solani) fungi were described on potato (Solanum tuberosum) plantlets under auto trophic in vitro culture conditions using video camera imaging and the scanning electron microscope (SEM). (i) The colony developmental pattern of the extraradical mycelium within the substrate, (ii) the reproduction structures and (iii) the three-dimensional spatial arrangements of the fungal hyphae within the potato root cells were successfully visualized, monitored and described. The combination of the autotrophic in vitro culture system and SEM represent a powerful tool for improving our knowledge on the dynamics of plant-fungal interactions. (Author) 41 refs.

  11. The tri-trophic interactions hypothesis: interactive effects of host plant quality, diet breadth and natural enemies on herbivores.

    Directory of Open Access Journals (Sweden)

    Kailen A Mooney

    Full Text Available Several influential hypotheses in plant-herbivore and herbivore-predator interactions consider the interactive effects of plant quality, herbivore diet breadth, and predation on herbivore performance. Yet individually and collectively, these hypotheses fail to address the simultaneous influence of all three factors. Here we review existing hypotheses, and propose the tri-trophic interactions (TTI hypothesis to consolidate and integrate their predictions. The TTI hypothesis predicts that dietary specialist herbivores (as compared to generalists should escape predators and be competitively dominant due to faster growth rates, and that such differences should be greater on low quality (as compared to high quality host plants. To provide a preliminary test of these predictions, we conducted an empirical study comparing the effects of plant (Baccharis salicifolia quality and predators between a specialist (Uroleucon macolai and a generalist (Aphis gossypii aphid herbivore. Consistent with predictions, these three factors interactively determine herbivore performance in ways not addressed by existing hypotheses. Compared to the specialist, the generalist was less fecund, competitively inferior, and more sensitive to low plant quality. Correspondingly, predator effects were contingent upon plant quality only for the generalist. Contrary to predictions, predator effects were weaker for the generalist and on low-quality plants, likely due to density-dependent benefits provided to the generalist by mutualist ants. Because the TTI hypothesis predicts the superior performance of specialists, mutualist ants may be critical to A. gossypii persistence under competition from U. macolai. In summary, the integrative nature of the TTI hypothesis offers novel insight into the determinants of plant-herbivore and herbivore-predator interactions and the coexistence of specialist and generalist herbivores.

  12. Trophic interactions among the heterotrophic components of plankton in man-made peat pools

    Directory of Open Access Journals (Sweden)

    Michał Niedźwiecki

    2017-03-01

    Full Text Available Man-made peat pools are permanent freshwater habitats developed due to non-commercial man-made peat extraction. Yet, they have not been widely surveyed in terms of ecosystem functioning, mainly regarding the complexity of heterotrophic components of the plankton. In this study we analysed distribution and trophic interrelations among heterotrophic plankton in man-made peat pools located in different types of peatbogs. We found that peat pools showed extreme differences in environmental conditions that occurred to be important drivers of distribution of microplankton and metazooplankton. Abundance of bacteria and protozoa showed significant differences, whereas metazooplankton was less differentiated in density among peat pools. In all peat pools stress-tolerant species of protozoa and metazoa were dominant. In each peat pool five trophic functional groups were distinguished. The abundance of lower functional trophic groups (bacteria, heterotrophic nanoflagellates (HNF and ciliates feeding on bacteria and HNF was weakly influenced by environmental drivers and was highly stable in all peat pool types. Higher functional trophic groups (naupli, omnivorous and carnivorous ciliates, cladocerans, adult copepods and copepodites were strongly influenced by environmental variables and exhibited lower stability. Our study contributes to comprehensive knowledge of the functioning of peat bogs, as our results have shown that peat pools are characterized by high stability of the lowest trophic levels, which can be crucial for energy transfer and carbon flux through food webs.

  13. Microbial plankton communities in the coastal southeastern Black Sea: biomass, composition and trophic interactions

    Directory of Open Access Journals (Sweden)

    Ulgen Aytan

    2018-04-01

    Full Text Available Summary: We investigated biomass and composition of the pico-, nano- and microplankton communities in a coastal station of the southeastern Black Sea during 2011. We also examined trophic interactions within these communities from size-fractionated dilution experiments in February, June and December. Autotrophic and heterotrophic biomasses showed similar seasonal trends, with a peak in June, but heterotrophs dominated throughout the year. Autotrophic biomass was mainly comprised by nanoflagellates and diatoms in the first half of the year, and by dinoflagellates and Synechococcus spp. in the second half. Heterotrophic biomass was mostly dominated by heterotrophic bacteria, followed by nanoflagellates and microzooplankton. Dilution experiments suggest that nano- and microzooplankton were significant consumers of autotrophs and heterotrophic bacteria. More than 100% of bacterial production was consumed by grazers in all experiments, while 46%, 21% and 30% of daily primary production were consumed in February, June and December, respectively. In February, autotrophs were the main carbon source, but in December, it was heterotrophic bacteria. An intermediate situation was observed in June, with similar carbon flows from autotrophs and heterotrophic bacteria. Size-fraction dilution experiments suggested that heterotrophic nanoflagellates are an important link between the high heterotrophic bacterial biomass and microzooplankton. In summary, these results indicate that nano- and microzooplankton were responsible for comprising a significant fraction of total microbial plankton biomass, standing stocks, growth and grazing processes. This suggests that in 2011, the microbial food web was an important compartment of the planktonic food web in the coastal southeastern Black Sea. Keywords: Phytoplankton, Microzooplankton, Carbon biomass, Microbial food web, Grazing, Black Sea

  14. Trophic dynamics in a simple experimental ecosystem: Interactions among centipedes, Collembola and introduced earthworms

    Science.gov (United States)

    Meixiang Gao; Melanie K. Taylor; Mac A. Callaham

    2017-01-01

    Invasive earthworms in North America are known to have dramatic influences on soil ecosystems, including negative effects on other soil fauna. In general, studies examining this phenomenon have focused on invasive earthworm impacts on organisms at the same or lower trophic level as the earthworms themselves (i.e., detritivores and decomposers). In contrast, there have...

  15. Trophic Interactions of Infant Bifidobacteria and Eubacterium hallii during L-Fucose and Fucosyllactose Degradation.

    Science.gov (United States)

    Schwab, Clarissa; Ruscheweyh, Hans-Joachim; Bunesova, Vera; Pham, Van Thanh; Beerenwinkel, Niko; Lacroix, Christophe

    2017-01-01

    subsp. suis were able to utilize L-fucose. This study identified a trophic interaction of infant bifidobacteria and E. hallii during L-fucose degradation, and pointed at E. hallii as a metabolically versatile species that occurs in infants and utilizes intermediates of bifidobacterial HMO fermentation.

  16. Impact of conservation areas on trophic interactions between apex predators and herbivores on coral reefs.

    Science.gov (United States)

    Rizzari, Justin R; Bergseth, Brock J; Frisch, Ashley J

    2015-04-01

    Apex predators are declining at alarming rates due to exploitation by humans, but we have yet to fully discern the impacts of apex predator loss on ecosystem function. In a management context, it is critically important to clarify the role apex predators play in structuring populations of lower trophic levels. Thus, we examined the top-down influence of reef sharks (an apex predator on coral reefs) and mesopredators on large-bodied herbivores. We measured the abundance, size structure, and biomass of apex predators, mesopredators, and herbivores across fished, no-take, and no-entry management zones in the Great Barrier Reef Marine Park, Australia. Shark abundance and mesopredator size and biomass were higher in no-entry zones than in fished and no-take zones, which indicates the viability of strictly enforced human exclusion areas as tools for the conservation of predator communities. Changes in predator populations due to protection in no-entry zones did not have a discernible influence on the density, size, or biomass of different functional groups of herbivorous fishes. The lack of a relationship between predators and herbivores suggests that top-down forces may not play a strong role in regulating large-bodied herbivorous coral reef fish populations. Given this inconsistency with traditional ecological theories of trophic cascades, trophic structures on coral reefs may need to be reassessed to enable the establishment of appropriate and effective management regimes. © 2014 Society for Conservation Biology.

  17. Establishment and metabolic analysis of a model microbial community for understanding trophic and electron accepting interactions of subsurface anaerobic environments

    Directory of Open Access Journals (Sweden)

    Yang Zamin K

    2010-05-01

    Full Text Available Abstract Background Communities of microorganisms control the rates of key biogeochemical cycles, and are important for biotechnology, bioremediation, and industrial microbiological processes. For this reason, we constructed a model microbial community comprised of three species dependent on trophic interactions. The three species microbial community was comprised of Clostridium cellulolyticum, Desulfovibrio vulgaris Hildenborough, and Geobacter sulfurreducens and was grown under continuous culture conditions. Cellobiose served as the carbon and energy source for C. cellulolyticum, whereas D. vulgaris and G. sulfurreducens derived carbon and energy from the metabolic products of cellobiose fermentation and were provided with sulfate and fumarate respectively as electron acceptors. Results qPCR monitoring of the culture revealed C. cellulolyticum to be dominant as expected and confirmed the presence of D. vulgaris and G. sulfurreducens. Proposed metabolic modeling of carbon and electron flow of the three-species community indicated that the growth of C. cellulolyticum and D. vulgaris were electron donor limited whereas G. sulfurreducens was electron acceptor limited. Conclusions The results demonstrate that C. cellulolyticum, D. vulgaris, and G. sulfurreducens can be grown in coculture in a continuous culture system in which D. vulgaris and G. sulfurreducens are dependent upon the metabolic byproducts of C. cellulolyticum for nutrients. This represents a step towards developing a tractable model ecosystem comprised of members representing the functional groups of a trophic network.

  18. Predicting species distribution and abundance responses to climate change: why it is essential to include biotic interactions across trophic levels.

    Science.gov (United States)

    Van der Putten, Wim H; Macel, Mirka; Visser, Marcel E

    2010-07-12

    Current predictions on species responses to climate change strongly rely on projecting altered environmental conditions on species distributions. However, it is increasingly acknowledged that climate change also influences species interactions. We review and synthesize literature information on biotic interactions and use it to argue that the abundance of species and the direction of selection during climate change vary depending on how their trophic interactions become disrupted. Plant abundance can be controlled by aboveground and belowground multitrophic level interactions with herbivores, pathogens, symbionts and their enemies. We discuss how these interactions may alter during climate change and the resulting species range shifts. We suggest conceptual analogies between species responses to climate warming and exotic species introduced in new ranges. There are also important differences: the herbivores, pathogens and mutualistic symbionts of range-expanding species and their enemies may co-migrate, and the continuous gene flow under climate warming can make adaptation in the expansion zone of range expanders different from that of cross-continental exotic species. We conclude that under climate change, results of altered species interactions may vary, ranging from species becoming rare to disproportionately abundant. Taking these possibilities into account will provide a new perspective on predicting species distribution under climate change.

  19. The role of life histories and trophic interactions in population recovery.

    Science.gov (United States)

    Audzijonyte, Asta; Kuparinen, Anna

    2016-08-01

    Factors affecting population recovery from depletion are at the focus of wildlife management. Particularly, it has been debated how life-history characteristics might affect population recovery ability and productivity. Many exploited fish stocks have shown temporal changes towards earlier maturation and reduced adult body size, potentially owing to evolutionary responses to fishing. Whereas such life-history changes have been widely documented, their potential role on stock's ability to recover from exploitation often remains ignored by traditional fisheries management. We used a marine ecosystem model parameterized for Southeastern Australian ecosystem to explore how changes towards "faster" life histories might affect population per capita growth rate r. We show that for most species changes towards earlier maturation during fishing have a negative effect (3-40% decrease) on r during the recovery phase. Faster juvenile growth and earlier maturation were beneficial early in life, but smaller adult body sizes reduced the lifetime reproductive output and increased adult natural mortality. However, both at intra- and inter-specific level natural mortality and trophic position of the species were as important in determining r as species longevity and age of maturation, suggesting that r cannot be predicted from life-history traits alone. Our study highlights that factors affecting population recovery ability and productivity should be explored in a multi-species context, where both age-specific fecundity and survival schedules are addressed simultaneously. It also suggests that contemporary life-history changes in harvested species are unlikely to increase their resilience and recovery ability. © 2016 Society for Conservation Biology.

  20. Phytochemistry of Cannabis sativa L.

    Science.gov (United States)

    ElSohly, Mahmoud A; Radwan, Mohamed M; Gul, Waseem; Chandra, Suman; Galal, Ahmed

    Cannabis (Cannabis sativa, or hemp) and its constituents-in particular the cannabinoids-have been the focus of extensive chemical and biological research for almost half a century since the discovery of the chemical structure of its major active constituent, Δ 9 -tetrahydrocannabinol (Δ 9 -THC). The plant's behavioral and psychotropic effects are attributed to its content of this class of compounds, the cannabinoids, primarily Δ 9 -THC, which is produced mainly in the leaves and flower buds of the plant. Besides Δ 9 -THC, there are also non-psychoactive cannabinoids with several medicinal functions, such as cannabidiol (CBD), cannabichromene (CBC), and cannabigerol (CBG), along with other non-cannabinoid constituents belonging to diverse classes of natural products. Today, more than 560 constituents have been identified in cannabis. The recent discoveries of the medicinal properties of cannabis and the cannabinoids in addition to their potential applications in the treatment of a number of serious illnesses, such as glaucoma, depression, neuralgia, multiple sclerosis, Alzheimer's, and alleviation of symptoms of HIV/AIDS and cancer, have given momentum to the quest for further understanding the chemistry, biology, and medicinal properties of this plant.This contribution presents an overview of the botany, cultivation aspects, and the phytochemistry of cannabis and its chemical constituents. Particular emphasis is placed on the newly-identified/isolated compounds. In addition, techniques for isolation of cannabis constituents and analytical methods used for qualitative and quantitative analysis of cannabis and its products are also reviewed.

  1. Jatropha Tanjorensis - Review of Phytochemistry, Pharmacology ...

    African Journals Online (AJOL)

    Based on the findings of this work, future study on the phytochemistry and chemical constituents in relation to certain other biological activities are required to fully understand the phytochemical and complex pharmacological effect of the plant specie. Further work to isolate active compounds from the plant is also necessary.

  2. Trophic interactions within the microbial food web in a tropical floodplain lake (Laguna Bufeos,Bolivia

    Directory of Open Access Journals (Sweden)

    Danny Rejas

    2005-06-01

    Full Text Available Whether the primary role of bacterioplankton is to act as "remineralizers" of nutrients or as direct nutritional source for higher trophic levels will depend on factors controlling their production and abundance. In tropical lakes, low nutrient concentration is probably the main factor limiting bacterial growth, while grazing by microzooplankton is generally assumed to be the main loss factor for bacteria. Bottom-up and top-down regulation of microbial abundance was studied in six nutrient limitation and dilution gradient-size fractionation in situ experiments. Bacteria, heterotrophic nanoflagellates (HNF, ciliates and rotifers showed relatively low densities. Predation losses of HNF and ciliates accounted for a major part of their daily production, suggesting a top-down regulation of protistan populations by rotifers. Phosphorus was found to be strongly limiting for bacterial growth, whereas no response to enrichment with Nitrogen or DOC was detected. HNF were the major grazers on bacteria (g=0.43 d-1 , the grazing coefficient increased when ciliates were added (g=0.80 d-1 but decreased when rotifers were added (g=0.23 d-1 probably due to nutrient recycling or top-down control of HNF and ciliates by rotifers. Rev. Biol. Trop. 53 (1-2:85-96. Epub 2005 Jun 24Que el bacterioplancton juegue básicamente un papel de reciclaje de nutrientes, o sea una fuente directa de nutrientes, depende de varios factores que afectan su producción y abundancia. En los lagos tropicales, la baja concentración de nutrientes es posiblemente el principal factor limitante del crecimiento bacteriano, y suele suponerse que la mayor pérdida poblacional de bacterias se debe a depredación por parte del microzooplancton. Estudiamos la regulación ascendente ("de abajo hacia arriba" y descendente ("de arriba hacia abajo" de abundancia bacteriana mediante seis experimentos in situ de limitación de nutrientes y de fraccionamiento de la dilución tamaño- gradiente. Bacterias

  3. Interactions among species in a tri-trophic system: the influence of ...

    African Journals Online (AJOL)

    BioMAP

    persistence/abundance are affected by more than two interacting species (Begon ... importance of methodology in revealing why an endangered population is ..... closely related butterfly which also oviposits on thyme buds) failed because the ...

  4. Interactions between trophic levels in upwelling and non-upwelling regions during summer monsoon

    Digital Repository Service at National Institute of Oceanography (India)

    Malik, A; Fernandes, C.E.G.; Gonsalves, M.J.B.D.; Subina, N.S.; Mamatha, S.S.; Krishna, K.S.; Varik, S.; RituKumari; Gauns, M.; Cejoice, R.P.; Pandey, S.S.; Jineesh, V.K.; Kamaleson, A; Vijayan, V.; Mukherjee, I.; Subramanyan, S.; Nair, S.; Ingole, B.S.; LokaBharathi, P.A

    Coastal upwelling is a regular phenomenon occurring along the southwest coast of India during summer monsoon (May–September). We hypothesize that there could be a shift in environmental parameters along with changes in the network of interactions...

  5. Sweet Tetra-Trophic Interactions: Multiple Evolution of Nectar Secretion, a Defensive Extended Phenotype in Cynipid Gall Wasps.

    Science.gov (United States)

    Nicholls, James A; Melika, George; Stone, Graham N

    2017-01-01

    Many herbivores employ reward-based mutualisms with ants to gain protection from natural enemies. We examine the evolutionary dynamics of a tetra-trophic interaction in which gall wasp herbivores induce their host oaks to produce nectar-secreting galls, which attract ants that provide protection from parasitoids. We show that, consistent with other gall defensive traits, nectar secretion has evolved repeatedly across the oak gall wasp tribe and also within a single genus (Disholcaspis) that includes many nectar-inducing species. Once evolved, nectar secretion is never lost in Disholcaspis, consistent with high defensive value of this trait. We also show that evolution of nectar secretion is correlated with a transition from solitary to aggregated oviposition, resulting in clustered nectar-secreting galls, which produce a resource that ants can more easily monopolize. Such clustering is commonly seen in ant guard mutualisms. We suggest that correlated evolution between maternal oviposition and larval nectar induction traits has enhanced the effectiveness of this gall defense strategy.

  6. The comparative uptake and interaction of several radionuclides in the trophic levels surrounding the Los Alamos Meson Physics Facility (LAMPF) waste water ponds

    Energy Technology Data Exchange (ETDEWEB)

    Brooks, G.H. Jr.

    1989-08-01

    A study was undertaken to examine the uptake, distribution, and interaction of five activation products (Co-57, Be-7, Cs-134, Rb-83, and Mn-54) within the biotic and abiotic components surrounding the waste treatment lagoons of the Los Alamos Meson Physics Facility (LAMPF). The study attempted to ascertain where, and what specific interactions were taking place among the isotopes and the biotic/abiotic components. A statistical approach, utilizing Multivariate Analysis of Variance (MANOVA), was conducted testing the radioisotopic concentrations by (1) the trophic levels (TROPLVL) in each position sampled on the grid, (2) where sampled on the grid (TRAN), (3) where sampled with-in each grid line (PLOT), and (4) the side with which sampled (SIDE). This provided both the dependent and independent variables that would be tested. The Null Hypothesis (Ho) tested the difference in the mean values of the isotopes within/between each of the four independent variables. The Rb-83 statistic indicated an accumulation within the TRAN and PLOT variables within the sampled area. The Co-57 test statistic provided a value which indicated that accumulation of this isotope within TROPLVL was taking place. Mn-54 test values indicated that accumulation was also taking place at the higher trophic levels within the PLOT, TRAN, and SIDE positions. Cs-134 was found to accumulate to third level in this trophic level structure (TROPLVL-(vegetation)), and then decrease from there. The Be-7 component provided no variance from known compartmental transfers. 210 refs., 17 figs., 4 tabs.

  7. The comparative uptake and interaction of several radionuclides in the trophic levels surrounding the Los Alamos Meson Physics Facility (LAMPF) waste water ponds

    International Nuclear Information System (INIS)

    Brooks, G.H. Jr.

    1989-08-01

    A study was undertaken to examine the uptake, distribution, and interaction of five activation products (Co-57, Be-7, Cs-134, Rb-83, and Mn-54) within the biotic and abiotic components surrounding the waste treatment lagoons of the Los Alamos Meson Physics Facility (LAMPF). The study attempted to ascertain where, and what specific interactions were taking place among the isotopes and the biotic/abiotic components. A statistical approach, utilizing Multivariate Analysis of Variance (MANOVA), was conducted testing the radioisotopic concentrations by (1) the trophic levels (TROPLVL) in each position sampled on the grid, (2) where sampled on the grid (TRAN), (3) where sampled with-in each grid line (PLOT), and (4) the side with which sampled (SIDE). This provided both the dependent and independent variables that would be tested. The Null Hypothesis (Ho) tested the difference in the mean values of the isotopes within/between each of the four independent variables. The Rb-83 statistic indicated an accumulation within the TRAN and PLOT variables within the sampled area. The Co-57 test statistic provided a value which indicated that accumulation of this isotope within TROPLVL was taking place. Mn-54 test values indicated that accumulation was also taking place at the higher trophic levels within the PLOT, TRAN, and SIDE positions. Cs-134 was found to accumulate to third level in this trophic level structure [TROPLVL-(vegetation)], and then decrease from there. The Be-7 component provided no variance from known compartmental transfers. 210 refs., 17 figs., 4 tabs

  8. Species co-occurrence affects the trophic interactions of two juvenile reef shark species in tropical lagoon nurseries in Moorea (French Polynesia).

    Science.gov (United States)

    Matich, Philip; Kiszka, Jeremy J; Mourier, Johann; Planes, Serge; Heithaus, Michael R

    2017-06-01

    Food web structure is shaped by interactions within and across trophic levels. As such, understanding how the presence and absence of predators, prey, and competitors affect species foraging patterns is important for predicting the consequences of changes in species abundances, distributions, and behaviors. Here, we used plasma δ 13 C and δ 15 N values from juvenile blacktip reef sharks (Carcharhinus melanopterus) and juvenile sicklefin lemon sharks (Negaprion acutidens) to investigate how species co-occurrence affects their trophic interactions in littoral waters of Moorea, French Polynesia. Co-occurrence led to isotopic niche partitioning among sharks within nurseries, with significant increases in δ 15 N values among sicklefin lemon sharks, and significant decreases in δ 15 N among blacktip reef sharks. Niche segregation likely promotes coexistence of these two predators during early years of growth and development, but data do not suggest coexistence affects life history traits, such as body size, body condition, and ontogenetic niche shifts. Plasticity in trophic niches among juvenile blacktip reef sharks and sicklefin lemon sharks also suggests these predators are able to account for changes in community structure, resource availability, and intra-guild competition, and may fill similar functional roles in the absence of the other species, which is important as environmental change and human impacts persist in coral reef ecosystems. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Identification of trophic interactions within an estuarine food web (northern New Zealand) using fatty acid biomarkers and stable isotopes

    Science.gov (United States)

    Alfaro, Andrea C.; Thomas, François; Sergent, Luce; Duxbury, Mark

    2006-10-01

    Fatty acid biomarkers and stable isotope signatures were used to identify the trophic dynamics of a mangrove/seagrass estuarine food web at Matapouri, northern New Zealand. Specific fatty acids were used to identify the preferred food sources (i.e., mangroves, seagrass, phytoplankton, macroalgae, bacteria, and zooplankton) of dominant fauna (i.e., filter feeders, grazing snails, scavenger/predatory snails, shrimp, crabs, and fish), and their presence in water and sediment samples throughout the estuary. The diets of filter feeders were found to be dominated by dinoflagellates, whereas grazers showed a higher diatom contribution. Bacteria associated with organic debris on surface sediments and brown algal ( Hormosira banksii) material in the form of suspended organic matter also accounted for a high proportion of most animal diets. Animals within higher trophic levels had diverse fatty acid profiles, revealing their varied feeding strategies and carbon sources. The stable isotope (δ 13C and δ 15N) analyses of major primary producers and consumers/predators revealed a trend of 15N enrichment with increasing trophic level, while δ 13C values provided a generally good description of carbon flow through the food web. Overall results from both fatty acid profiles and stable isotopes indicate that a variety of carbon sources with a range of trophic pathways typify this food web. Moreover, none of the animals studied was dependent on a single food source. This study is the first to use a comprehensive fatty acid biomarker and stable isotope approach to investigate the food web dynamics within a New Zealand temperate mangrove/seagrass estuary. This quantitative research may contribute to the currently developing management strategies for estuaries in northern New Zealand, especially for those perceived to have expanding mangrove fringes.

  10. Spring diet and trophic partitioning in an alpine lizard community ...

    African Journals Online (AJOL)

    The influences of species interactions on habitat use, restrictions in trophic availability and evolutionary history as determinant factors are discussed. Keywords: trophic ecology, communities, pseudocommunity analysis, Lacerta perspicillata, Lacerta andreanszkyi, Podarcis vaucheri, Quedenfeldtia trachyblepharus, Morocco ...

  11. Trophic interactions of the pelagic ecosystem over the Reykjanes Ridge as evaluated by fatty acid and stable isotope analyses

    Science.gov (United States)

    Petursdottir, H.; Gislason, A.; Falk-Petersen, S.; Hop, H.; Svavarsson, J.

    2008-01-01

    Trophic relationships of the important oceanic crustacean species Calanus finmarchicus, Meganyctiphanes norvegica and Sergestes arcticus, as well as the mesopelagic fishes Maurolicus muelleri, Benthosema glaciale and Sebastes mentella, were investigated over the Reykjanes Ridge in June 2003 and in June 2004. Measurements were performed of length, wet weight, dry weight, total lipid, lipid class, fatty acid and fatty alcohol profiles and stable isotopes (δ 13C and δ 15N). High amounts of the Calanus lipid markers, 20:1(n-9) and 22:1(n-11) in these species confirm the importance of Calanus spp. in this ecosystem. Comparisons of fatty acid/alcohol profiles by multivariate analysis revealed two main trophic pathways over the Reykjanes Ridge. In one pathway, Calanus spp. was an important part of the diet for the small mesopelagic fish species M. muelleri and B. glaciale and the shrimp S. arcticus, whereas in the other pathway, the euphausiid M. norvegica was the dominant food for the redfish S. mentella, and Calanus spp. were of less importance. M. muelleri and the smaller B. glaciale feed on C. finmarchicus, whereas the larger B. glaciale and S. arcticus select the larger, deeper-living C. hyperboreus. All investigated species are true pelagic species except for the shrimp S. arcticus, which seems to have a benthic feeding habit as well. The δ 15N levels show that of the species investigated, C. finmarchicus occupies the lowest trophic level (2.0) and the redfish, S. mentella, the highest (4.2). All the species were lipid rich, typical for subarctic pelagic ecosystem. Calanus finmarchicus, S. arcticus and B. glaciale store wax esters as their lipid stores, while M. norvegica, M. muelleri and S. mentella store triacylglycerols.

  12. Plasticity of trophic interactions among sharks from the oceanic south-western Indian Ocean revealed by stable isotope and mercury analyses

    Science.gov (United States)

    Kiszka, Jeremy J.; Aubail, Aurore; Hussey, Nigel E.; Heithaus, Michael R.; Caurant, Florence; Bustamante, Paco

    2015-02-01

    Sharks are a major component of the top predator guild in oceanic ecosystems, but the trophic relationships of many populations remain poorly understood. We examined chemical tracers of diet and habitat (δ15N and δ13C, respectively) and total mercury (Hg) concentrations in muscle tissue of seven pelagic sharks: blue shark (Prionace glauca), short-fin mako shark (Isurus oxyrinchus), oceanic whitetip shark (Carcharhinus longimanus), scalloped hammerhead shark (Sphyrna lewini), pelagic thresher shark (Alopias pelagicus), crocodile shark (Pseudocarcharias kamoharai) and silky shark (Carcharhinus falciformis), from the data poor south-western tropical Indian Ocean. Minimal interspecific variation in mean δ15N values and a large degree of isotopic niche overlap - driven by high intraspecific variation in δ15N values - was observed among pelagic sharks. Similarly, δ13C values of sharks overlapped considerably for all species with the exception of P. glauca, which had more 13C-depleted values indicating possibly longer residence times in purely pelagic waters. Geographic variation in δ13C, δ15N and Hg were observed for P. glauca and I. oxyrinchus. Mean Hg levels were similar among species with the exception of P. kamoharai which had significantly higher Hg concentrations likely related to mesopelagic feeding. Hg concentrations increased with body size in I. oxyrinchus, P. glauca and C. longimanus. Values of δ15N and δ13C varied with size only in P. glauca, suggesting ontogenetic shifts in diets or habitats. Together, isotopic data indicate that - with few exceptions - variance within species in trophic interactions or foraging habitats is greater than differentiation among pelagic sharks in the south-western Indian Ocean. Therefore, it is possible that this group exhibits some level of trophic redundancy, but further studies of diets and fine-scale habitat use are needed to fully test this hypothesis.

  13. Trophic interactions and distribution of some Squaliforme sharks, including new diet descriptions for Deania calcea and Squalus acanthias.

    Directory of Open Access Journals (Sweden)

    Matthew R Dunn

    Full Text Available Squaliforme sharks are a common but relatively vulnerable bycatch in many deep water fisheries. Eleven species of squaliforme shark are commonly caught at depths of 200-1200 m on Chatham Rise, New Zealand, and their diversity suggests they might occupy different niches. The diets of 133 Deania calcea and 295 Squalus acanthias were determined from examination of stomach contents. The diet of D. calcea was characterised by mesopelagic fishes, and S. acanthias by benthic to pelagic fishes, but was more adaptive and included likely scavenging. Multivariate analyses found the most important predictors of diet variability in S. acanthias were year, bottom temperature, longitude, and fish weight. The diet of the nine other commonly caught squaliforme sharks was reviewed, and the spatial and depth distribution of all species on Chatham Rise described from research bottom trawl survey catches. The eleven species had a variety of different diets, and depth and location preferences, consistent with niche separation to reduce interspecific competition. Four trophic groups were identified, characterised by: mesopelagic fishes and invertebrates (Centroselachus crepidater, D. calcea, and Etmopterus lucifer; mesopelagic and benthopelagic fishes and invertebrates (Centroscymnus owstoni, Etmopterus baxteri; demersal and benthic fishes (Centrophorus squamosus, Dalatias licha, Proscymnodon plunketi; and a generalist diet of fishes and invertebrates (S. acanthias. The trophic levels of the species in each of the four groups were estimated as 4.18-4.24, 4.20-4.23, 4.24-4.48, and 3.84 respectively. The diet of Oxynotus bruniensis and Squalus griffini are unknown. The different niches occupied by different species are likely to influence their vulnerability to bottom trawl fisheries. Some species may benefit from fisheries through an increased availability of scavenged prey.

  14. Trophic interactions and distribution of some Squaliforme sharks, including new diet descriptions for Deania calcea and Squalus acanthias.

    Science.gov (United States)

    Dunn, Matthew R; Stevens, Darren W; Forman, Jeffrey S; Connell, Amelia

    2013-01-01

    Squaliforme sharks are a common but relatively vulnerable bycatch in many deep water fisheries. Eleven species of squaliforme shark are commonly caught at depths of 200-1200 m on Chatham Rise, New Zealand, and their diversity suggests they might occupy different niches. The diets of 133 Deania calcea and 295 Squalus acanthias were determined from examination of stomach contents. The diet of D. calcea was characterised by mesopelagic fishes, and S. acanthias by benthic to pelagic fishes, but was more adaptive and included likely scavenging. Multivariate analyses found the most important predictors of diet variability in S. acanthias were year, bottom temperature, longitude, and fish weight. The diet of the nine other commonly caught squaliforme sharks was reviewed, and the spatial and depth distribution of all species on Chatham Rise described from research bottom trawl survey catches. The eleven species had a variety of different diets, and depth and location preferences, consistent with niche separation to reduce interspecific competition. Four trophic groups were identified, characterised by: mesopelagic fishes and invertebrates (Centroselachus crepidater, D. calcea, and Etmopterus lucifer); mesopelagic and benthopelagic fishes and invertebrates (Centroscymnus owstoni, Etmopterus baxteri); demersal and benthic fishes (Centrophorus squamosus, Dalatias licha, Proscymnodon plunketi); and a generalist diet of fishes and invertebrates (S. acanthias). The trophic levels of the species in each of the four groups were estimated as 4.18-4.24, 4.20-4.23, 4.24-4.48, and 3.84 respectively. The diet of Oxynotus bruniensis and Squalus griffini are unknown. The different niches occupied by different species are likely to influence their vulnerability to bottom trawl fisheries. Some species may benefit from fisheries through an increased availability of scavenged prey.

  15. Trophic interaction between topmouth gudgeon (Pseudorasbora parva and the co-occurring species during summer in the Dniprodzerzhynsk reservoir

    Directory of Open Access Journals (Sweden)

    Didenko A.V.

    2015-01-01

    Full Text Available Topmouth gudgeon, Pseudorasbora parva is the most common invasive fish in Europe, which can compete with the juveniles of valuable commercial fishes. The goal of this work is to study the diet of topmouth gudgeon and trophic relationships with some native fishes inhabiting the littoral zone of the Dniprodzerzhynsk reservoir. The obtained relatively low values of diet overlaps between topmouth gudgeon and other co-occurring cyprinids such as juvenile roach, Rutilus rutilus; silver bream, Blicca bjoerkna; rudd, Scardinius erythrophthalmus; Prussian carp, Carassius gibelio and bleak, Abramis brama, indicate that it is not a serious food competitor for them, especially commercially valuable ones. On the contrary, high diet overlaps were observed among some native cyprinids such as juvenile roach, silver bream, rudd, and bleak. The major prey items of topmouth gudgeon were Chydorus sphaericus and chironomids, whereas other cyprinids selected Bosmina spp. This peculiarity may be due to different vertical distributions of these fish in the littoral zone of the reservoir, where topmouth gudgeon inhabit near-bottom water layers, where they preyed on near-bottom and benthic zooplankters and chironomids, while juvenile roach, silver bream, rudd, and juvenile and adult bleak live in higher water layers, where they preyed on pelagic zooplankton.

  16. Competitive Interactions between Invasive Nile Tilapia and Native Fish: The Potential for Altered Trophic Exchange and Modification of Food Webs

    Science.gov (United States)

    Martin, Charles W.; Valentine, Marla M.; Valentine, John F.

    2010-01-01

    Recent studies have highlighted both the positive and negative impacts of species invasions. Most of these studies have been conducted on either immobile invasive plants or sessile fauna found at the base of food webs. Fewer studies have examined the impacts of vagile invasive consumers on native competitors. This is an issue of some importance given the controlling influence that consumers have on lower order plants and animals. Here, we present results of laboratory experiments designed to assess the impacts of unintended aquaculture releases of the Nile tilapia (Oreochromis niloticus), in estuaries of the Gulf of Mexico, on the functionally similar redspotted sunfish (Lepomis miniatus). Laboratory choice tests showed that tilapia prefer the same structured habitat that native sunfish prefer. In subsequent interspecific competition experiments, agonistic tilapia displaced sunfish from their preferred structured habitats. When a piscivore (largemouth bass) was present in the tank with both species, the survival of sunfish decreased. Based on these findings, if left unchecked, we predict that the proliferation of tilapia (and perhaps other aggressive aquaculture fishes) will have important detrimental effects on the structure of native food webs in shallow, structured coastal habitats. While it is likely that the impacts of higher trophic level invasive competitors will vary among species, these results show that consequences of unintended releases of invasive higher order consumers can be important. PMID:21200433

  17. Competitive interactions between invasive Nile tilapia and native fish: the potential for altered trophic exchange and modification of food webs.

    Directory of Open Access Journals (Sweden)

    Charles W Martin

    2010-12-01

    Full Text Available Recent studies have highlighted both the positive and negative impacts of species invasions. Most of these studies have been conducted on either immobile invasive plants or sessile fauna found at the base of food webs. Fewer studies have examined the impacts of vagile invasive consumers on native competitors. This is an issue of some importance given the controlling influence that consumers have on lower order plants and animals. Here, we present results of laboratory experiments designed to assess the impacts of unintended aquaculture releases of the Nile tilapia (Oreochromis niloticus, in estuaries of the Gulf of Mexico, on the functionally similar redspotted sunfish (Lepomis miniatus. Laboratory choice tests showed that tilapia prefer the same structured habitat that native sunfish prefer. In subsequent interspecific competition experiments, agonistic tilapia displaced sunfish from their preferred structured habitats. When a piscivore (largemouth bass was present in the tank with both species, the survival of sunfish decreased. Based on these findings, if left unchecked, we predict that the proliferation of tilapia (and perhaps other aggressive aquaculture fishes will have important detrimental effects on the structure of native food webs in shallow, structured coastal habitats. While it is likely that the impacts of higher trophic level invasive competitors will vary among species, these results show that consequences of unintended releases of invasive higher order consumers can be important.

  18. Importance of interactions between food quality, quantity, and gut transit time on consumer feeding, growth, and trophic dynamics.

    Science.gov (United States)

    Mitra, Aditee; Flynn, Kevin J

    2007-05-01

    Ingestion kinetics of animals are controlled by both external food availability and feedback from the quantity of material already within the gut. The latter varies with gut transit time (GTT) and digestion of the food. Ingestion, assimilation efficiency, and thus, growth dynamics are not related in a simple fashion. For the first time, the important linkage between these processes and GTT is demonstrated; this is achieved using a biomass-based, mechanistic multinutrient model fitted to experimental data for zooplankton growth dynamics when presented with food items of varying quality (stoichiometric composition) or quantity. The results show that trophic transfer dynamics will vary greatly between the extremes of feeding on low-quantity/high-quality versus high-quantity/low-quality food; these conditions are likely to occur in nature. Descriptions of consumer behavior that assume a constant relationship between the kinetics of grazing and growth irrespective of food quality and/or quantity, with little or no recognition of the combined importance of these factors on consumer behavior, may seriously misrepresent consumer activity in dynamic situations.

  19. Trophic interactions of the endangered Southern river otter ( Lontra provocax) in a Chilean Ramsar wetland inferred from prey sampling, fecal analysis, and stable isotopes

    Science.gov (United States)

    Franco, Marcela; Guevara, Giovany; Correa, Loreto; Soto-Gamboa, Mauricio

    2013-04-01

    Non-invasive methodological approaches are highly recommended and commonly used to study the feeding ecology of elusive and threatened mammals. In this study, we use multiple lines of evidence to assess the feeding strategies of the endangered Southern river otter, by determining seasonal prey availability (electrofishing), analysis of undigested prey remains (spraints), and the use of stable isotopes (δ15N and δ13C) in otter spraints ( n = 262) and prey in a wetland ecosystem of southern Chile (39°49'S, 73°15'W). Fecal and isotopic analyses suggest that the otter diet is restricted to a few prey items, particularly the less-mobile, bottom-living, and larger prey such as crayfish ( Samastacus spinifrons, 86.11 %) and crabs ( Aegla spp., 32.45 %), supplemented opportunistically by cyprinids ( Cyprinus carpio, 9.55 %) and catfish ( Diplomystes camposensis, 5.66 %). The results suggest that the river otter is highly specialized in bottom foraging. Isotopic signatures of food sources and feces revealed a mid-upper trophic position for the Southern river otter, with either higher or lower δ15N values than their potential prey items. δ13C values for river otters were less enriched than their potential food resources. We suggest that due to their narrow trophic niche and possible dependence on only a few food items, this species may be highly vulnerable to the reduction in its prey populations. Finally, maintaining the ecological interactions between Southern river otters and their prey is considered a central priority for the survival of this endangered carnivore mammal.

  20. Phytochemistry and anti-microbial evaluation of Thaumatococcus ...

    African Journals Online (AJOL)

    Leaves of T. danielli are mostly used as food wrappers, and for thatching roofs in the rural and sub-urban areas of south-western Nigeria. Phytochemistry of the leaf extracts revealed the presence of alkaloids, tannins, saponins, anthraquinones, cardenolides and steroidal nucleus compounds. Thin layer chromatography of ...

  1. Proximate composition and phytochemistry of seed oil five cultivars ...

    African Journals Online (AJOL)

    Proximate composition and phytochemistry of seed oil five cultivars of Cajanus cajan in Nigeria. BA Iwalokun, OJ Adeyemi, TI Adeleke, EO Abayomi. Abstract. No Abstract. Nigerian Food Journal Vol. 24(1) 2006: 50-60. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

  2. Preliminary studies on the phytochemistry and efficacy of extracts of ...

    African Journals Online (AJOL)

    Phytochemistry of Spondias mombin bark, a known anti –tumour plant used traditionally, revealed the presence of alkaloids, saponins, tannins, phenolic compound and eugenol. The efficacy of the plant material tested on induced cancer in rats showed significant recovery using water extract treatment when compared with ...

  3. Green Turtle Trophic Ecology

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — SWFSC is currently conducting a study of green sea turtle (Chelonia mydas) trophic ecology in the eastern Pacific. Tissue samples and stable carbon and stable...

  4. Trophic interactions between larger crocodylians and giant tortoises on Aldabra Atoll, Western Indian Ocean, during the Late Pleistocene.

    Science.gov (United States)

    Scheyer, Torsten M; Delfino, Massimo; Klein, Nicole; Bunbury, Nancy; Fleischer-Dogley, Frauke; Hansen, Dennis M

    2018-01-01

    Today, the UNESCO World Heritage Site of Aldabra Atoll is home to about 100 000 giant tortoises, Aldabrachelys gigantea , whose fossil record goes back to the Late Pleistocene. New Late Pleistocene fossils (age ca . 90-125 000 years) from the atoll revealed some appendicular bones and numerous shell fragments of giant tortoises and cranial and postcranial elements of crocodylians. Several tortoise bones show circular holes, pits and scratch marks that are interpreted as bite marks of crocodylians. The presence of a Late Pleistocene crocodylian species, Aldabrachampsus dilophus , has been known for some time, but the recently found crocodylian remains presented herein are distinctly larger than those previously described. This indicates the presence of at least some larger crocodylians, either of the same or of a different species, on the atoll. These larger crocodylians, likely the apex predators in the Aldabra ecosystem at the time, were well capable of inflicting damage on even very large giant tortoises. We thus propose an extinct predator-prey interaction between crocodylians and giant tortoises during the Late Pleistocene, when both groups were living sympatrically on Aldabra, and we discuss scenarios for the crocodylians directly attacking the tortoises or scavenging on recently deceased animals.

  5. Radioactive tracers as a tool for the study of in situ meiofaunal-microbial trophic interactions in marine sediments

    International Nuclear Information System (INIS)

    Carman, K.R.

    1989-01-01

    Three methods of delivering labeled substrates to natural cores of sediments were compared. Slurried sediments disrupted the sedimentary structure and significantly altered uptake of labeled substrates by copepod species. Thus, disruption of sedimentary structure can significantly alter microbial-meiofaunal interactions and influence the results of grazing studies. The [ 3 H]-thymidine technique for measuring bacterial production was evaluated. The metabolic fate of labeled thymidine in a coastal marine sediment was not consistent with assumptions necessary for measuring bacterial production or its consumption by meiofauna. Microautoradiography was used to demonstrate the sedimentary microalgae and heterotrophic bacteria can be selectively labeled with [ 14 C]bicarbonate and labeled organic substrates, respectively. A study was performed to determine if radioactivity measured in copepods from grazing experiments was the result of ingestion of labeled microorganisms or the result of uptake by non-feeding processes. Uptake of label by copepods from [ 14 C]-bicarbonate was due almost exclusively to grazing on microalgae. Uptake of label by copepods from [ 14 C]-acetate, however, resulted from activity by epicuticular bacteria and was not due to ingestion of labeled bacteria

  6. Multi-tissue stable isotope analysis and acoustic telemetry reveal seasonal variability in the trophic interactions of juvenile bull sharks in a coastal estuary.

    Science.gov (United States)

    Matich, Philip; Heithaus, Michael R

    2014-01-01

    Understanding how natural and anthropogenic drivers affect extant food webs is critical to predicting the impacts of climate change and habitat alterations on ecosystem dynamics. In the Florida Everglades, seasonal reductions in freshwater flow and precipitation lead to annual migrations of aquatic taxa from marsh habitats to deep-water refugia in estuaries. The timing and intensity of freshwater reductions, however, will be modified by ongoing ecosystem restoration and predicted climate change. Understanding the importance of seasonally pulsed resources to predators is critical to predicting the impacts of management and climate change on their populations. As with many large predators, however, it is difficult to determine to what extent predators like bull sharks (Carcharhinus leucas) in the coastal Everglades make use of prey pulses currently. We used passive acoustic telemetry to determine whether shark movements responded to the pulse of marsh prey. To investigate the possibility that sharks fed on marsh prey, we modelled the predicted dynamics of stable isotope values in bull shark blood and plasma under different assumptions of temporal variability in shark diets and physiological dynamics of tissue turnover and isotopic discrimination. Bull sharks increased their use of upstream channels during the late dry season, and although our previous work shows long-term specialization in the diets of sharks, stable isotope values suggested that some individuals adjusted their diets to take advantage of prey entering the system from the marsh, and as such this may be an important resource for the nursery. Restoration efforts are predicted to increase hydroperiods and marsh water levels, likely shifting the timing, duration and intensity of prey pulses, which could have negative consequences for the bull shark population and/or induce shifts in behaviour. Understanding the factors influencing the propensity to specialize or adopt more flexible trophic interactions

  7. Dilution of 210Pb by organic sedimentation in lakes of different trophic states, and application to studies of sediment-water interactions

    International Nuclear Information System (INIS)

    Binford, M.W.; Brenner, M.

    1986-01-01

    Lake sediments reflect conditions in the water column and can be used for rapid, integrative measurements of limnological variables. Examination of 210 Pb-dated cores from 12 Florida lakes of widely differing trophic state (expressed as Carlson's trophic state index: TSI) shows that net accumulation rate of organic matter is related to primary productivity in the water column. In 26 other lakes the activity of unsupported 210 Pb g -1 organic matter in surficial sediments is inversely related to trophic state and, therefore, to organic accumulation rate. From this observation, the authors develop a new method that uses fallout 210 Pb as a dilution tracer to calculate net sedimentary accumulation rates of any material in surface mud. They demonstrate strong relationships between net loss rate of biologically important materials (C, N, P, and pigments) and their respective water concentrations (expressed as TSI). Multiple regression models incorporating net sediment accumulation rates of all four variables explain up to 70% of the lake-to-lake variation of TSI. The 210 Pb-dilution method has application for studies for material cycling, paleolimnology, and sediment accumulation processes

  8. Phytochemistry and biological activities of Heracleum persicum: a review.

    Science.gov (United States)

    Majidi, Zahra; Sadati Lamardi, S N

    2018-05-24

    Heracleum persicum Desf. ex Fisch is used in Iranian traditional medicines, for the treatment of various diseases including neurological, gastrointestinal, respiratory, rheumatological and urinary tract diseases. In phytochemical analysis of H. persicum, several classes of natural chemicals including volatile (aliphatic esters, carbonyls, phenyl propenes and terpenes) and nonvolatile (flavonoids, furanocoumarins, tannins and alkaloids) constituents as well as different minerals have been identified. Scientific studies on H. persicum proved that it has a wide range of biological and pharmacological activities. This article has provided comprehensive information on Iranian traditional uses, phytochemistry and pharmacological activities of H. persicum. Copyright © 2018 Shanghai Changhai Hospital. Published by Elsevier B.V. All rights reserved.

  9. Trophic assimilation efficiency markedly increases at higher trophic levels in four-level host-parasitoid food chain.

    Science.gov (United States)

    Sanders, Dirk; Moser, Andrea; Newton, Jason; van Veen, F J Frank

    2016-03-16

    Trophic assimilation efficiency (conversion of resource biomass into consumer biomass) is thought to be a limiting factor for food chain length in natural communities. In host-parasitoid systems, which account for the majority of terrestrial consumer interactions, a high trophic assimilation efficiency may be expected at higher trophic levels because of the close match of resource composition of host tissue and the consumer's resource requirements, which would allow for longer food chains. We measured efficiency of biomass transfer along an aphid-primary-secondary-tertiary parasitoid food chain and used stable isotope analysis to confirm trophic levels. We show high efficiency in biomass transfer along the food chain. From the third to the fourth trophic level, the proportion of host biomass transferred was 45%, 65% and 73%, respectively, for three secondary parasitoid species. For two parasitoid species that can act at the fourth and fifth trophic levels, we show markedly increased trophic assimilation efficiencies at the higher trophic level, which increased from 45 to 63% and 73 to 93%, respectively. In common with other food chains, δ(15)N increased with trophic level, with trophic discrimination factors (Δ(15)N) 1.34 and 1.49‰ from primary parasitoids to endoparasitic and ectoparasitic secondary parasitoids, respectively, and 0.78‰ from secondary to tertiary parasitoids. Owing to the extraordinarily high efficiency of hyperparasitoids, cryptic higher trophic levels may exist in host-parasitoid communities, which could alter our understanding of the dynamics and drivers of community structure of these important systems. © 2016 The Authors.

  10. Lippia citrodora: a review on its phytochemistry and pharmacological activities

    Directory of Open Access Journals (Sweden)

    2017-11-01

    Full Text Available Background and objectives: Lippia citrodora commonly known as lemon verbena is a species of flowering plant in the verbena family, native to western South America. With its antioxidant effects, it is mostly used in folk medicine to treat anti-inflammatory diseases, and diseases associated with oxidative stress. This review has presented a summary on L. citordora’s phytochemistry and its pharmacological activities. It will also discuss gaps and challenges needed to be solved. Methods: Electronic database including Web of Science, PubMed, Science Direct and Google Scholar were searched for articles published between 1973 and 2017 regarding the phytochemistry and biological activities of L. citodora. Results: Traditional uses of this plant were specially related to coagulation system, digestive system and brain. Phytochemical investigations identified flavonoids, terpenes, iridois, lignins, phenylethanoid, as the main components of the plant. Antimicrobial, neuroprotective, antinociceptive, anti hyperpropulsive, sedative, anticolitis, anxiolytic, anticonvulsant, antihyperalgesic, and anticancer properties were among the pharmacological activities of L. citriodora. The plant extract and essential oil had also demonstrated high antioxidant activity. Conclusion: Modern pharmacological studies have now validated many traditional uses of L. citrodora. The data reviewed here revealed that this plant is a potential source for the treatment of a wide range of diseases specially inflammatory diseases and neurological dysfunctions. Future human studies are needed for further confirmation of the therapeutic activities of L. citriodora.

  11. Phytochemistry, pharmacology, and clinical trials of Morus alba.

    Science.gov (United States)

    Chan, Eric Wei-Chiang; Lye, Phui-Yan; Wong, Siu-Kuin

    2016-01-01

    The present review is aimed at providing a comprehensive summary on the botany, utility, phytochemistry, pharmacology, and clinical trials of Morus alba (mulberry or sang shu). The mulberry foliage has remained the primary food for silkworms for centuries. Its leaves have also been used as animal feed for livestock and its fruits have been made into a variety of food products. With flavonoids as major constituents, mulberry leaves possess various biological activities, including antioxidant, antimicrobial, skin-whitening, cytotoxic, anti-diabetic, glucosidase inhibition, anti-hyperlipidemic, anti-atherosclerotic, anti-obesity, cardioprotective, and cognitive enhancement activities. Rich in anthocyanins and alkaloids, mulberry fruits have pharmacological properties, such as antioxidant, anti-diabetic, anti-atherosclerotic, anti-obesity, and hepatoprotective activities. The root bark of mulberry, containing flavonoids, alkaloids and stilbenoids, has antimicrobial, skin-whitening, cytotoxic, anti-inflammatory, and anti-hyperlipidemic properties. Other pharmacological properties of M. alba include anti-platelet, anxiolytic, anti-asthmatic, anthelmintic, antidepressant, cardioprotective, and immunomodulatory activities. Clinical trials on the efficiency of M. alba extracts in reducing blood glucose and cholesterol levels and enhancing cognitive ability have been conducted. The phytochemistry and pharmacology of the different parts of the mulberry tree confer its traditional and current uses as fodder, food, cosmetics, and medicine. Overall, M. alba is a multi-functional plant with promising medicinal properties. Copyright © 2016 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.

  12. Trigeminal trophic syndrome

    Directory of Open Access Journals (Sweden)

    Parimalam Kumar

    2014-01-01

    Full Text Available Trigeminal trophic syndrome (TTS is a rare cause of facial ulceration, consequent to damage to the trigeminal nerve or its central sensory connections. We reporta case of TTS in a 48-year-old woman with Bell′s palsy following herpes zoster infection. The patient was treated and counseled. There hasnot been any recurrence for 1 year and the patient is being followed-up. The diagnosis of TTS should be suspected when there is unilateral facial ulceration, especially involving the ala nasi associated with sensory impairment.

  13. Trophic flexibility and the persistence of understory birds in intensively logged rainforest.

    Science.gov (United States)

    Edwards, David P; Woodcock, Paul; Newton, Rob J; Edwards, Felicity A; Andrews, David J R; Docherty, Teegan D S; Mitchell, Simon L; Ota, Takahiro; Benedick, Suzan; Bottrell, Simon H; Hamer, Keith C

    2013-10-01

    Effects of logging on species composition in tropical rainforests are well known but may fail to reveal key changes in species interactions. We used nitrogen stable-isotope analysis of 73 species of understory birds to quantify trophic responses to repeated intensive logging of rainforest in northern Borneo and to test 4 hypotheses: logging has significant effects on trophic positions and trophic-niche widths of species, and the persistence of species in degraded forest is related to their trophic positions and trophic-niche widths in primary forest. Species fed from higher up the food chain and had narrower trophic-niche widths in degraded forest. Species with narrow trophic-niche widths in primary forest were less likely to persist after logging, a result that indicates a higher vulnerability of dietary specialists to local extinction following habitat disturbance. Persistence of species in degraded forest was not related to a species' trophic position. These results indicate changes in trophic organization that were not apparent from changes in species composition and highlight the importance of focusing on trophic flexibility over the prevailing emphasis on membership of static feeding guilds. Our results thus support the notion that alterations to trophic organization and interactions within tropical forests may be a pervasive and functionally important hidden effect of forest degradation. © 2013 Society for Conservation Biology.

  14. Assessing mesozooplankton trophic levels in the Baltic Sea and North Sea: A stable isotope study

    OpenAIRE

    Agurto, Cristian

    2007-01-01

    For decades, ecologists have studied trophic interaction in aquatic systems, and described the food web structure of dominant ecological groups based on gut content analyses. The conception of these interactions may, however, be biased by the lack of couplings to the microbial food web and direct errors in diet analyses (e.g. differences in digestion rate between food types). In this thesis, I examined the planktonic food web by analyzing the trophic structure (i.e. trophic levels) with an al...

  15. Portulaca oleracea L.: a review of phytochemistry and pharmacological effects.

    Science.gov (United States)

    Zhou, Yan-Xi; Xin, Hai-Liang; Rahman, Khalid; Wang, Su-Juan; Peng, Cheng; Zhang, Hong

    2015-01-01

    Portulaca oleracea L., belonging to the Portulacaceae family, is commonly known as purslane in English and Ma-Chi-Xian in Chinese. It is a warm-climate, herbaceous succulent annual plant with a cosmopolitan distribution. It is eaten extensively as a potherb and added in soups and salads around the Mediterranean and tropical Asian countries and has been used as a folk medicine in many countries. Diverse compounds have been isolated from Portulaca oleracea, such as flavonoids, alkaloids, polysaccharides, fatty acids, terpenoids, sterols, proteins vitamins and minerals. Portulaca oleracea possesses a wide spectrum of pharmacological properties such as neuroprotective, antimicrobial, antidiabetic, antioxidant, anti-inflammatory, antiulcerogenic, and anticancer activities. However, few molecular mechanisms of action are known. This review provides a summary of phytochemistry and pharmacological effects of this plant.

  16. Trophic strategies of unicellular plankton

    DEFF Research Database (Denmark)

    Chakraborty, Subhendu; Nielsen, Lasse Tor; Andersen, Ken Haste

    2017-01-01

    . To this end, we develop and calibrate a trait-based model for unicellular planktonic organisms characterized by four traits: cell size and investments in phototrophy, nutrient uptake, and phagotrophy. We use the model to predict how optimal trophic strategies depend on cell size under various environmental...... unicellulars are colimited by organic carbon and nutrients, and only large photoautotrophs and smaller mixotrophs are nutrient limited; (2) trophic strategy is bottom-up selected by the environment, while optimal size is top-down selected by predation. The focus on cell size and trophic strategies facilitates......Unicellular plankton employ trophic strategies ranging from pure photoautotrophs over mixotrophy to obligate heterotrophs (phagotrophs), with cell sizes from 10-8 to 1 μg C. A full understanding of how trophic strategy and cell size depend on resource environment and predation is lacking...

  17. The genus Psiadia: Review of traditional uses, phytochemistry and pharmacology.

    Science.gov (United States)

    Mahadeo, Keshika; Grondin, Isabelle; Kodja, Hippolyte; Soulange Govinden, Joyce; Jhaumeer Laulloo, Sabina; Frederich, Michel; Gauvin-Bialecki, Anne

    2018-01-10

    The genus Psiadia Jacq. ex. Willd. belongs to the Asteraceae family and includes more than 60 species. This genus grows in tropical and subtropical regions, being especially well represented in Madagascar and the Mascarene Islands (La Réunion, Mauritius and Rodrigues). Several Psiadia species have been used traditionally for their medicinal properties in Africa and the Mascarene Islands. Based on traditional knowledge, various phytochemical and pharmacological studies have been conducted. However there are no recent papers that provide an overview of the medicinal potential of Psiadia species. Therefore, the aim of this review is to provide a comprehensive summary of the botany, phytochemistry and pharmacology of Psiadia and to highlight the gaps in our knowledge for future research opportunities. The available information on traditional uses, phytochemistry and biological activities of the genus Psiadia was collected from scientific databases through a search using the keyword 'Psiadia' in 'Google Scholar', 'Pubmed', 'Sciencedirect', 'SpringerLink', 'Web of Science', 'Wiley' and 'Scifinder'. Additionally, published books and unpublished Ph.D. and MSc. dissertations were consulted for botanical information and chemical composition. Historically, species of the genus Psiadia have been used to treat a wide range of ailments including abdominal pains, colds, fevers, bronchitis, asthma, rheumatoid arthritis, skin infections and liver disorders among others. Phytochemical works led to the isolation of flavonoids, phenylpropanoids, coumarins and terpenoids. Furthermore, phytochemical compositions of the essential oils of some species have been evaluated. Crude extracts, essential oils and isolated molecules showed in vitro pharmacological activities, such as antimicrobial, anti-viral, anti-inflammatory, antiplasmodial and antileishmanial activities. Crude extracts of Psiadia dentata and Psiadia arguta have specifically been found to be potentially useful for inhibition

  18. Trophic redundancy reduces vulnerability to extinction cascades.

    Science.gov (United States)

    Sanders, Dirk; Thébault, Elisa; Kehoe, Rachel; Frank van Veen, F J

    2018-03-06

    Current species extinction rates are at unprecedentedly high levels. While human activities can be the direct cause of some extinctions, it is becoming increasingly clear that species extinctions themselves can be the cause of further extinctions, since species affect each other through the network of ecological interactions among them. There is concern that the simplification of ecosystems, due to the loss of species and ecological interactions, increases their vulnerability to such secondary extinctions. It is predicted that more complex food webs will be less vulnerable to secondary extinctions due to greater trophic redundancy that can buffer against the effects of species loss. Here, we demonstrate in a field experiment with replicated plant-insect communities, that the probability of secondary extinctions is indeed smaller in food webs that include trophic redundancy. Harvesting one species of parasitoid wasp led to secondary extinctions of other, indirectly linked, species at the same trophic level. This effect was markedly stronger in simple communities than for the same species within a more complex food web. We show that this is due to functional redundancy in the more complex food webs and confirm this mechanism with a food web simulation model by highlighting the importance of the presence and strength of trophic links providing redundancy to those links that were lost. Our results demonstrate that biodiversity loss, leading to a reduction in redundant interactions, can increase the vulnerability of ecosystems to secondary extinctions, which, when they occur, can then lead to further simplification and run-away extinction cascades. Copyright © 2018 the Author(s). Published by PNAS.

  19. Tri-trophic interactions between Bt cotton, the herbivore Aphis gossypii Glover (Homoptera: Aphididae), and the predator Chrysopa pallens (Rambur) (Neuroptera: Chrysopidae).

    Science.gov (United States)

    Guo, Jian-Ying; Wan, Fang-Hao; Dong, Liang; Lövei, Gábor L; Han, Zhao-Jun

    2008-02-01

    Tri-trophic impacts of transgenic Bacillus thuringiensis (Bt) cotton GK12 and NuCOTN 99B were studied using a predator, the great lacewing Chrysopa pallens (Rambur), and its prey, the cotton aphid Aphis gossypii Glover, in laboratory feeding experiments. The parental nontransgenic cotton cultivar of GK12 was used as control. The predator was fed with uniform (aphids from a single cultivar) or mixed prey (aphids from the three cotton cultivars provided on alternate days). Mortality and development of the immature stages, pupal body mass, adult sex ratio, fecundity, and egg viability of C. pallens were measured. When fed GK12-originated aphid prey, pupal body mass of C. pallens was significantly higher than that of the control, more females emerged, and these females laid significantly more eggs. Other parameters were not impacted. Females emerging from larvae maintained on NuCOTN 99B-originated prey laid fewer eggs than those maintained on GK12. Other measurements did not differ significantly between the two Bt cotton cultivars. Compared with the control, mixed feeding significantly prolonged pupal development time and increased pupal body mass and percentage of females but did not affect other parameters. These results indicate that C. pallens is sensitive to aphid prey from different cotton cultivars. Transgenic Bt cotton GK12-originated aphid prey has no adverse impact on survival, development, and fecundity of C. pallens. Between the two Bt cotton cultivars, NuCOTN 99B-originated aphid prey provided to C. pallens in the larval stage may lower female fecundity. Mixed feeding of C. pallens with the two Bt cotton-originated prey and non-Bt prey may have some adverse impacts on pupal development.

  20. Tithonia diversifolia (Hemsl.) A. Gray as a medicinal plant: A comprehensive review of its ethnopharmacology, phytochemistry, pharmacotoxicology and clinical relevance.

    Science.gov (United States)

    Mabou Tagne, Alex; Marino, Franca; Cosentino, Marco

    2018-06-28

    Tithonia diversifolia (TD) is widely valued in several cultures for its medicinal properties. A comprehensive review of the current understanding of this plant species is required due to emerging concerns over its efficacy, toxicity and allergenic potential. We critically summarized the current evidence on the botany, traditional use, phytochemistry, pharmacology and safety of TD, with the view to provide perspectives for developing more attractive pharmaceuticals of plant origin, but also to lay a new foundation for further investigations on this plant. A preliminary consultation of search engines such as Web of Science, PubMed, ScienceDirect and other published/unpublished resources provided an overview of extant literature on TD. Then, we meticulously screened all titles, abstracts and full-texts to establish consistency in the application of inclusion criteria. Studies were considered for inclusion if they dealt with taxonomy, global distribution, local and traditional knowledge, phytochemistry, toxicity and biological effects. 1856 articles were retrieved among which 168 were revised and included. Several studies conducted on cell lines and animals provided supporting evidence for some ethnomedicinal claims of extracts from TD. Short-term use of Tithonia extracts were effective and well-tolerated in animals when taken at lower doses. Both the toxic and therapeutic effects were attributed to bioactive principles naturally occurring in this species including sesquiterpene lactones, chlorogenic acid and flavonoids. T. diversifolia is a valuable source of bioactive compounds with significant therapeutic implications and favourable safety index. However, more rigorously designed investigations are needed to recommend the whole plant or its active ingredients as a medication, and should focus on understanding the multi-target network pharmacology of the plant, clarifying the effective doses as well as identifying the potential interactions with prescribed drugs or

  1. Long term patterns in the late summer trophic niche of the invasive pumpkinseed sunfish Lepomis gibbosus

    Directory of Open Access Journals (Sweden)

    Gkenas C.

    2016-01-01

    Full Text Available Quantifying the trophic dynamics of invasive species in novel habitats is important for predicting the success of potential invaders and evaluating their ecological effects. The North American pumpkinseed sunfish Lepomis gibbosus is a successful invader in Europe, where it has caused negative ecological effects primarily through trophic interactions. Here, we quantified variations in the late summer trophic niche of pumpkinseed during establishment and integration in the mainstem of the Guadiana river, using stomach content analyses over a period of 40 years. Pumpkinseed showed a shift from trophic specialization during establishment to trophic generalism during integration. These results were concomitant with an increase in diet breadth that was accompanied by higher individual diet specialization particularly in large individuals. Irrespective of their drivers, these changes in trophic niche suggest that the potential ecological effects of pumpkinseed on recipient ecosystems can vary temporally along the invasion process.

  2. Moringa Genus: A Review of Phytochemistry and Pharmacology

    Science.gov (United States)

    Abd Rani, Nur Zahirah; Husain, Khairana; Kumolosasi, Endang

    2018-01-01

    Moringa is a genus of medicinal plants that has been used traditionally to cure wounds and various diseases such as colds and diabetes. In addition, the genus is also consumed as a source of nutrients and widely used for purifying water. The genus consists of 13 species that have been widely cultivated throughout Asia and Africa for their multiple uses. The purpose of this review is to provide updated and categorized information on the traditional uses, phytochemistry, biological activities, and toxicological research of Moringa species in order to explore their therapeutic potential and evaluate future research opportunities. The literature reviewed for this paper was obtained from PubMed, ScienceDirect, and Google Scholar journal papers published from 1983 to March 2017. Moringa species are well-known for their antioxidant, anti-inflammatory, anticancer, and antihyperglycemic activities. Most of their biological activity is caused by their high content of flavonoids, glucosides, and glucosinolates. By documenting the traditional uses and biological activities of Moringa species, we hope to support new research on these plants, especially on those species whose biological properties have not been studied to date. PMID:29503616

  3. The Genus Spilanthes Ethnopharmacology, Phytochemistry, and Pharmacological Properties: A Review

    Science.gov (United States)

    Paulraj, Jayaraj; Govindarajan, Raghavan; Palpu, Pushpangadan

    2013-01-01

    Spilanthes spp. are popular, over-the-counter remedies; they are sold over the internet under various names and are widely used in traditional medicine in various cultures. This review will summarize the important reports on the ethnopharmacology, botany, phytochemistry, and pharmacological properties as described in the literature from recent years (1920 to 2013). Spilanthes spp. are used for more than 60 types of disorders. They are reported to contain a number of biologically active phytochemicals, although a large number of ethnopharmacological uses have been documented; only a few of these species have been investigated for their chemical and biological activities. The studies are carried out mainly on Spilanthes extracts and a few metabolites substantiate the uses of these plants in traditional medicine. Well-conducted pharmacological studies are still needed for several traditional indications, and the mechanisms of action by which the plant extracts and the active compounds exert their pharmacological effects remain to be studied. They are predominantly used as extracts in personal care products, traditional medicines, and the pharmaceutical and culinary areas. Suggestions are made regarding some of the possible mechanisms of action as to how the known compounds may exert their biological activity. PMID:24454346

  4. Parsley: a review of ethnopharmacology, phytochemistry and biological activities.

    Science.gov (United States)

    Farzaei, Mohammad Hosein; Abbasabadi, Zahra; Ardekani, Mohammad Reza Shams; Rahimi, Roja; Farzaei, Fatemeh

    2013-12-01

    To summarize comprehensive information concerning ethnomedicinal uses, phytochemistry, and pharmacological activities of parsley. Databases including PubMed, Scopus, Google Scholar, and Web of Science were searched for studies focusing on the ethnomedicinal use, phytochemical compounds and biological and pharmacological activities of parsley. Data were collected from 1966 to 2013. The search terms were: "Parsley" or "Petroselinum crispum" or "Petroselinum hortence". Parsley has been used as carminative, gastro tonic, diuretic, antiseptic of urinary tract, anti-urolithiasis, anti-dote and anti-inflammatory and for the treatment of amenorrhea, dysmenorrhea, gastrointestinal disorder, hypertension, cardiac disease, urinary disease, otitis, sniffle, diabetes and also various dermal disease in traditional and folklore medicines. Phenolic compounds and flavonoids particularly apigenin, apiin and 6"-Acetylapiin; essential oil mainly myristicin and apiol; and also coumarins are the active compounds identified in Petroselinum crispum. Wide range of pharmacological activity including antioxidant, hepatoprotective, brain protective, anti-diabetic, analgesic, spasmolytic, immunosuppressant, anti-platelet, gastroprotective, cytoprotective, laxative, estrogenic, diuretic, hypotensive, antibacterial and antifungal activities have been exhibited for this plant in modern medicine. It is expectant that this study resulted in improvement the tendencies toward Petroselinum crispum as a useful and important medicinal plant with wide range of proven medicinal activity.

  5. Traditional Uses, Phytochemistry, and Pharmacology of Olea europaea (Olive

    Directory of Open Access Journals (Sweden)

    Muhammad Ali Hashmi

    2015-01-01

    Full Text Available Aim of the Review. To grasp the fragmented information available on the botany, traditional uses, phytochemistry, pharmacology, and toxicology of Olea europaea to explore its therapeutic potential and future research opportunities. Material and Methods. All the available information on O. europaea was collected via electronic search (using Pubmed, Scirus, Google Scholar, and Web of Science and a library search. Results. Ethnomedical uses of O. europaea are recorded throughout the world where it has been used to treat various ailments. Phytochemical research had led to the isolation of flavonoids, secoiridoids, iridoids, flavanones, biophenols, triterpenes, benzoic acid derivatives, isochromans, and other classes of secondary metabolites from O. europaea. The plant materials and isolated components have shown a wide spectrum of in vitro and in vivo pharmacological activities like antidiabetic, anticonvulsant, antioxidant, anti-inflammatory, immunomodulatory, analgesic, antimicrobial, antiviral, antihypertensive, anticancer, antihyperglycemic, antinociceptive, gastroprotective, and wound healing activities. Conclusions. O. europaea emerged as a good source of traditional medicine for the treatment of various ailments. The outcomes of phytochemical and pharmacological studies reported in this review will further expand its existing therapeutic potential and provide a convincing support to its future clinical use in modern medicine.

  6. Traditional Uses, Phytochemistry, and Pharmacology of Olea europaea (Olive)

    Science.gov (United States)

    Hashmi, Muhammad Ali; Khan, Afsar; Hanif, Muhammad; Farooq, Umar; Perveen, Shagufta

    2015-01-01

    Aim of the Review. To grasp the fragmented information available on the botany, traditional uses, phytochemistry, pharmacology, and toxicology of Olea europaea to explore its therapeutic potential and future research opportunities. Material and Methods. All the available information on O. europaea was collected via electronic search (using Pubmed, Scirus, Google Scholar, and Web of Science) and a library search. Results. Ethnomedical uses of O. europaea are recorded throughout the world where it has been used to treat various ailments. Phytochemical research had led to the isolation of flavonoids, secoiridoids, iridoids, flavanones, biophenols, triterpenes, benzoic acid derivatives, isochromans, and other classes of secondary metabolites from O. europaea. The plant materials and isolated components have shown a wide spectrum of in vitro and in vivo pharmacological activities like antidiabetic, anticonvulsant, antioxidant, anti-inflammatory, immunomodulatory, analgesic, antimicrobial, antiviral, antihypertensive, anticancer, antihyperglycemic, antinociceptive, gastroprotective, and wound healing activities. Conclusions. O. europaea emerged as a good source of traditional medicine for the treatment of various ailments. The outcomes of phytochemical and pharmacological studies reported in this review will further expand its existing therapeutic potential and provide a convincing support to its future clinical use in modern medicine. PMID:25802541

  7. A review on ethnobotany, pharmacology and phytochemistry of Tabernaemontana corymbosa.

    Science.gov (United States)

    Abubakar, Ibrahim Babangida; Loh, Hwei-San

    2016-04-01

    Tabernaemontana is a genus from the plant family, Apocynaceae with vast medicinal application and widespread distribution in the tropics and subtropics of Africa, Americas and Asia. The objective of this study is to critically evaluate the ethnobotany, medicinal uses, pharmacology and phytochemistry of the species, Tabernaemontana corymbosa (Roxb. ex Wall.) and provide information on the potential future application of alkaloids isolated from different parts of the plant. T. corymbosa (Roxb. ex Wall.) parts are used as poultice, boiled juice, decoctions and infusions for treatment against ulceration, fracture, post-natal recovery, syphilis, fever, tumours and orchitis in Malaysia, China, Thailand and Bangladesh. Studies recorded alkaloids as the predominant phytochemicals in addition to phenols, saponins and sterols with vast bioactivities such as antimicrobial, analgesic, anthelmintic, vasorelaxation, antiviral and cytotoxicity. An evaluation of scientific data and traditional medicine revealed the medicinal uses of different parts of T. corymbosa (Roxb. ex Wall.) across Asia. Future studies exploring the structure-bioactivity relationship of alkaloids such as jerantinine and vincamajicine among others could potentially improve the future application towards reversing anticancer drug resistance. © 2016 Royal Pharmaceutical Society, Journal of Pharmacy and Pharmacology.

  8. A review on traditional uses, phytochemistry, pharmacology, pharmacokinetics and toxicology of the genus Peganum.

    Science.gov (United States)

    Li, Shuping; Cheng, Xuemei; Wang, Changhong

    2017-05-05

    The plants of the genus Peganum have a long history as a Chinese traditional medicine for the treatment of cough, hypertension, diabetes, asthma, jaundice, colic, lumbago, and many other human ailments. Additionally, the plants can be used as an amulet against evil-eye, dye and so on, which have become increasingly popular in Asia, Iran, Northwest India, and North Africa. The present paper reviewed the ethnopharmacology, phytochemistry, analytical methods, biological activities, metabolism, pharmacokinetics, toxicology, and drug interaction of the genus Peganum in order to assess the ethnopharmacological use and to explore therapeutic potentials and future opportunities for research. Information on studies of the genus Peganum was gathered via the Internet (using Google Scholar, Baidu Scholar, Elsevier, ACS, Pudmed, Web of Science, CNKI and EMBASE) and libraries. Additionally, information was also obtained from some local books, PhD and MS's dissertations. The genus Peganum has played an important role in traditional Chinese medicine. The main bioactive metabolites of the genus include alkaloids, flavonoids, volatile oils, etc. Scientific studies on extracts and formulations revealed a wide range of pharmacological activities, such as cholinesterase and monoamine oxidase inhibitory activities, antitumor, anti-hypertension, anticoagulant, antidiabetic, antimicrobial, insecticidal, antiparasidal, anti-leishmaniasis, antioxidant, and anti-inflammatory. Based on this review, there is some evidence for extracts' pharmacological effects on Alzheimer's and Parkinson's diseases, cancer, diabetes, hypertension. Some indications from ethnomedicine have been confirmed by pharmacological effects, such as the cholinesterase, monoamine oxidase and DNA topoisomerase inhibitory activities, hypoglycemic and vasodilation effects of this genus. The available literature showed that most of the activities of the genus Peganum can be attributed to the active alkaloids. Data regarding

  9. Rheum australe D. Don: A review of its botany, ethnobotany, phytochemistry and pharmacology

    Czech Academy of Sciences Publication Activity Database

    Rokaya, Maan Bahadur; Münzbergová, Zuzana; Tumsina, B.; Bhattarai, K. R.

    2012-01-01

    Roč. 141, č. 3 (2012), s. 761-774 ISSN 0378-8741 R&D Projects: GA ČR GA526/09/0549 Institutional support: RVO:67985939 Keywords : Rheum australe * traditional uses * phytochemistry Subject RIV: EF - Botanics Impact factor: 2.755, year: 2012

  10. Phytochemistry and pharmacology of the genus Drypetes: A review.

    Science.gov (United States)

    Wansi, Jean Duplex; Wandji, Jean; Sewald, Norbert; Nahar, Lutfun; Martin, Claire; Sarker, Satyajit Dey

    2016-08-22

    Traditional medicinal use of species of the genus Drypetes is widespread in the tropical regions. The aim of this review is to systematically appraise the literature available to date on phytochemistry, ethnopharmacology, toxicology and bioactivity (in vitro and in vivo) of crude extracts and purified compounds. Plants of the genus Drypetes (Putranjivaceae) are used in the Subsaharan African and Asian traditional medicines to treat a multitude of disorders, like dysentery, gonorrhoea, malaria, rheumatism, sinusitis, tumours, as well as for the treatment of wounds, headache, urethral problems, fever in young children, typhoid and several other ailments. Some Drypetes species are used to protect food against pests, as an aphrodisiac, a stimulant/depressant, a rodenticide and a fish poison, against insect bites, to induce conception and for general healing. This review deals with updated information on the ethnobotany, phytochemistry, and biological activities of ethnomedicinally important Drypetes species, in order to provide an input for the future research opportunities. An extensive review of the literature available in various recognized databases e.g., Google Scholar, PubMed, Science Direct, SciFinder, Web of Science, www.theplantlist.org and www.gbif.org, as well as the Herbier National du Cameroun (Yaoundé) and Botanic Gardens of Limbe databases on the uses and bioactivity of various species of the Drypetes was undertaken. The literature provided information on ethnopharmacological uses of the Subsaharan African and Asian species of the genus Drypetes, e.g., Drypetes aubrévillii, D. capillipes, D. chevalieri, D. gerrardii, D. gossweileri, D. ivorensis, D. klainei, D. natalensis, D. pellegrini (all endemic to Africa) and D. roxburghii (Asian species), for the treatment of multiple disorders. From a total of 19 species, more than 140 compounds including diterpenes, sesquiterpenes, triterpenes (friedelane, oleanane, lupane and hopane-type), flavonoids, lignans

  11. Ethnomedicinal uses, phytochemistry and pharmacological properties of the genus Boerhavia.

    Science.gov (United States)

    Patil, Kapil S; Bhalsing, Sanjivani R

    2016-04-22

    The genus Boerhavia is widely distributed in tropical, subtropical and temperate regions of the world including Mexico, America, Africa, Asia, Indian Ocean Islands, Pacific Islands and Australia. The genus Boerhavia is extensively used by local peoples and medicinal practitioners for treatments of hepatitis, urinary disorders, gastro intestinal diseases, inflammations, skin problems, infectious diseases and asthma. Present review focused on traditional uses, phytochemistry, pharmacology and toxicology of Boerhavia genus to support potential scope for advance ethnopharmacological study. Information on the Boerhavia species was collected from classical books on medicinal plants, pharmacopoeias and scientific databases like PubMed, Scopus, GoogleScholar, Web of Science and others. Also scientific literatures based on ethnomedicinal surveys, Ph.D. and M.Sc. dissertations, published papers from Elsevier, Taylor and Francis, Springer, ACS as well as Wiley publishers and reports by government bodies and documentations were assessed. A total of 180 compounds from Boerhavia genus were isolated of which B. diffusa alone shared around 131 compounds and for most of which it is currently an exclusive source. In the genus, phenolic glycosides and flavonoids contribute approximately 97 compounds. These includes eupalitin, rotenoids like boeravinones, coccineons, alkaloid i.e. betanin and punarnavine etc., showing vital pharmaceutical activities such as anticancer, anti-inflammatory, antioxidant and immunomodulatory. Boerhavia is an important genus with wide range of medicinal uses. However, most of the available scientific literatures have lacked relevant doses, duration and positive controls for examining bioefficacy of extracts and its active compounds. In some studies, taxonomic errors were encountered. Moreover, there is need for accurate methods in testing the safety and ethnomedicinal validity of Boerhavia species. Copyright © 2016. Published by Elsevier Ireland Ltd.

  12. Alkaloids from piper: a review of its phytochemistry and pharmacology.

    Science.gov (United States)

    Gutierrez, Rosa Martha Perez; Gonzalez, Adriana Maria Neira; Hoyo-Vadillo, Carlos

    2013-02-01

    Piper has been used for long timelike condiment and food, but also in traditional medicine around of the world. This work resumes the available and up to date work done on members of the Piperaceae family and their uses for therapeutic purposes. Information on Piper genus was gathered via internet using scientific databases such as Scirus, Google Scholar, CAB-abstracts, MedlinePlus, Pubmed, SciFinder, Scopus and Web of Science. The largeleafed perennial plant Piper is used for its spicy aromatic scent and flavor. It has an important presence in the cuisine of different cultures. Another quality of these plants is their known medicinal properties. It has been used as emollient, antirheumatic, diuretic, stimulant, abortifacient, anti-inflammatory, antibacterial, antifungal and antidermatophytic. A survey of the literature shows that the genus Piper is mainly known for its alkaloids with cytotoxic, chemopreventive, antimetastatic and antitumor properties in several types of cancer. Studies of its alkaloids highlight the existence of various potential leads to develop new anti-cancer agents. Modern pharmacology studies have demonstrated that its crude extracts and active compounds possess wide pharmacological activities, especially asantioxidant, anti-depressive, hepatoprotective, antimicrobial, anti-obesity, neuropharmacological, to treat cognitive disorders, anti-hyperlipidemic, anti-feedant, cardioactive, immuno-enhancing, and anti-inflamatory. All this evidence supporting its traditional uses. This review summarizes the up-to-date and comprehensive information concerning the botany, traditional use, phytochemistry and pharmacology of Piper together with its toxicology, and discusses the possible trend and scope for further research on Piper in the future.

  13. Ethnobotany, phytochemistry and pharmacology of Stephania rotunda Lour.

    Science.gov (United States)

    Desgrouas, Camille; Taudon, Nicolas; Bun, Sok-Siya; Baghdikian, Beatrice; Bory, Sothavireak; Parzy, Daniel; Ollivier, Evelyne

    2014-07-03

    Stephania rotunda Lour. (Menispermaceae) is an important traditional medicinal plant that is grown in Southeast Asia. The stems, leaves, and tubers have been used in the Cambodian, Lao, Indian and Vietnamese folk medicine systems for years to treat a wide range of ailments, including asthma, headache, fever, and diarrhoea. To provide an up-to-date, comprehensive overview and analysis of the ethnobotany, phytochemistry, and pharmacology of Stephania rotunda for its potential benefits in human health, as well as to assess the scientific evidence of traditional use and provide a basis for future research directions. Peer-reviewed articles on Stephania rotunda were acquired via an electronic search of the major scientific databases (Pubmed, Google Scholar, and ScienceDirect). Data were collected from scientific journals, theses, and books. The traditional uses of Stephania rotunda were recorded in countries throughout Southeast Asia (Cambodia, Vietnam, Laos, and India). Different parts of Stephania rotunda were used in traditional medicine to treat about twenty health disorders. Phytochemical analyses identified forty alkaloids. The roots primarily contain l-tetrahydropalmatine (l-THP), whereas the tubers contain cepharanthine and xylopinine. Furthermore, the chemical composition differs from one region to another and according to the harvest period. The alkaloids exhibited approximately ten different pharmacological activities. The main pharmacological activities of Stephania rotunda alkaloids are antiplasmodial, anticancer, and immunomodulatory effects. Sinomenine, cepharanthine, and l-stepholidine are the most promising components and have been tested in humans. The pharmacokinetic parameters have been studied for seven compounds, including the three most promising compounds. The toxicity has been evaluated for liriodenine, roemerine, cycleanine, l-tetrahydropalmatine, and oxostephanine. Stephania rotunda is traditionally used for the treatment of a wide range of

  14. Influence of climate change and trophic coupling across four trophic levels in the Celtic Sea.

    Directory of Open Access Journals (Sweden)

    Valentina Lauria

    Full Text Available Climate change has had profound effects upon marine ecosystems, impacting across all trophic levels from plankton to apex predators. Determining the impacts of climate change on marine ecosystems requires understanding the direct effects on all trophic levels as well as indirect effects mediated by trophic coupling. The aim of this study was to investigate the effects of climate change on the pelagic food web in the Celtic Sea, a productive shelf region in the Northeast Atlantic. Using long-term data, we examined possible direct and indirect 'bottom-up' climate effects across four trophic levels: phytoplankton, zooplankton, mid-trophic level fish and seabirds. During the period 1986-2007, although there was no temporal trend in the North Atlantic Oscillation index (NAO, the decadal mean Sea Surface Temperature (SST in the Celtic Sea increased by 0.66 ± 0.02 °C. Despite this, there was only a weak signal of climate change in the Celtic Sea food web. Changes in plankton community structure were found, however this was not related to SST or NAO. A negative relationship occurred between herring abundance (0- and 1-group and spring SST (0-group: p = 0.02, slope = -0.305 ± 0.125; 1-group: p = 0.04, slope = -0.410 ± 0.193. Seabird demographics showed complex species-specific responses. There was evidence of direct effects of spring NAO (on black-legged kittiwake population growth rate: p = 0.03, slope = 0.0314 ± 0.014 as well as indirect bottom-up effects of lagged spring SST (on razorbill breeding success: p = 0.01, slope = -0.144 ± 0.05. Negative relationships between breeding success and population growth rate of razorbills and common guillemots may be explained by interactions between mid-trophic level fish. Our findings show that the impacts of climate change on the Celtic Sea ecosystem is not as marked as in nearby regions (e.g. the North Sea, emphasizing the need for more research at regional scales.

  15. Influence of Climate Change and Trophic Coupling across Four Trophic Levels in the Celtic Sea

    Science.gov (United States)

    Lauria, Valentina; Attrill, Martin J.; Pinnegar, John K.; Brown, Andrew; Edwards, Martin; Votier, Stephen C.

    2012-01-01

    Climate change has had profound effects upon marine ecosystems, impacting across all trophic levels from plankton to apex predators. Determining the impacts of climate change on marine ecosystems requires understanding the direct effects on all trophic levels as well as indirect effects mediated by trophic coupling. The aim of this study was to investigate the effects of climate change on the pelagic food web in the Celtic Sea, a productive shelf region in the Northeast Atlantic. Using long-term data, we examined possible direct and indirect ‘bottom-up’ climate effects across four trophic levels: phytoplankton, zooplankton, mid-trophic level fish and seabirds. During the period 1986–2007, although there was no temporal trend in the North Atlantic Oscillation index (NAO), the decadal mean Sea Surface Temperature (SST) in the Celtic Sea increased by 0.66±0.02°C. Despite this, there was only a weak signal of climate change in the Celtic Sea food web. Changes in plankton community structure were found, however this was not related to SST or NAO. A negative relationship occurred between herring abundance (0- and 1-group) and spring SST (0-group: p = 0.02, slope = −0.305±0.125; 1-group: p = 0.04, slope = −0.410±0.193). Seabird demographics showed complex species–specific responses. There was evidence of direct effects of spring NAO (on black-legged kittiwake population growth rate: p = 0.03, slope = 0.0314±0.014) as well as indirect bottom-up effects of lagged spring SST (on razorbill breeding success: p = 0.01, slope = −0.144±0.05). Negative relationships between breeding success and population growth rate of razorbills and common guillemots may be explained by interactions between mid-trophic level fish. Our findings show that the impacts of climate change on the Celtic Sea ecosystem is not as marked as in nearby regions (e.g. the North Sea), emphasizing the need for more research at regional scales. PMID:23091621

  16. Phenological sensitivity to climate across taxa and trophic levels

    DEFF Research Database (Denmark)

    Thackeray, Stephen J.; Henrys, Peter; Hemming, Deborah

    2016-01-01

    Differences in phenological responses to climate change among species can desynchronise ecological interactions and thereby threaten ecosystem function. To assess these threats, we must quantify the relative impact of climate change on species at different trophic levels. Here, we apply a Climate...

  17. Medicinal uses, phytochemistry and pharmacology of the genus Uncaria.

    Science.gov (United States)

    Zhang, Qian; Zhao, Jiao Jiao; Xu, Jian; Feng, Feng; Qu, Wei

    2015-09-15

    The genus Uncaria belongs to the family Rubiaceae, which mainly distributed in tropical regions, such as Southeast Asia, Africa and Southeast America. Their leaves and hooks have long been thought to have healing powers and are already being tested as a treatment for asthma, cancer, cirrhosis, diabetes, hypertension, stroke and rheumatism. The present review aims to provide systematically reorganized information on the ethnopharmacology, phytochemistry and pharmacology of the genus Uncaria to support for further therapeutic potential of this genus. To better understanding this genus, information on the stereo-chemistry and structure-activity relationships in indole alkaloids is also represented. The literature study of this review is based on various databases search (SCIFinder, Science Direct, CNKI, Wiley online library, Spring Link, Web of Science, PubMed, Wanfang Data, Medalink, Google scholar, ACS, Tropicos, Council of Heads of Australasian Herbaria, The New York Botanical Garden, African Plants Database at Genera Botanical Garden, The Plant List and SEINet) and library search for Biological Abstract and some local books on ethnopharmacology. 19 species of the genus Uncaria are found to be important folk medicines in China, Malaysia, Phillippines, Africa and Southeast America, etc, and have been served for the treatment of asthma, rheumatism, hyperpyrexia, hypertension and headaches, etc. More than 200 compounds have been isolated from Uncaria, including indole alkaloids, triterpenes, flavonoids, phenols, phenylpropanoids, etc. As characteristic constituents, indole alkaloids have been considered as main efficacy component for hypertension, epilepsy, depressant, Parkinson's disease and Alzheimer's disease. In addition, pharmacokinetic and metabolism investigation reveal that the indole alkaloids are likely to be absorbed, metabolized and excreted at early time points. Moreover, the specific inhibition of CYP isozymes can regulate their hydroxylation metabolites

  18. Traditional uses, phytochemistry, pharmacology and toxicology of Codonopsis: A review.

    Science.gov (United States)

    Gao, Shi-Man; Liu, Jiu-Shi; Wang, Min; Cao, Ting-Ting; Qi, Yao-Dong; Zhang, Ben-Gang; Sun, Xiao-Bo; Liu, Hai-Tao; Xiao, Pei-Gen

    2018-06-12

    Species of the genus Codonopsis are perennial herbs mainly distributed throughout East, Southeast and Central Asia. As recorded, they have been used as traditional Chinese medicines since the Qing Dynasty, where they were claimed for strengthening the spleen and tonifying the lung, as well as nourishing blood and engendering liquid. Some species are also used as food materials in southern China and Southeast Asia, such as tea, wine, soup, plaster, and porridge. The review aims to assess the ethnopharmacological uses, explicit the material basis and pharmacological action, promote the safety of medical use, and suggest the future research potentials of Codonopsis. Information on the studies of Codonopsis was collected from scientific journals, books, and reports via library and electronic data search (PubMed, Elsevier, Scopus, Google Scholar, Springer, Science Direct, Wiley, Researchgate, ACS, EMBASE, Web of Science and CNKI). Meanwhile, it was also obtained from published works of material medica, folk records, ethnopharmacological literatures, Ph.D. and Masters Dissertation. Plant taxonomy was confirmed to the database "The Plant List" (www.theplantlist.org). Codonopsis has been used for medicinal purposes all around the world. Some species are also used as food materials in southern China and Southeast Asia. The chemical constituents of Codonopsis mainly are polyacetylenes, polyenes, flavonoids, lignans, alkaloids, coumarins, terpenoids, steroids, organic acids, saccharides, and so on. Extract of Codonopsis exhibit extensive pharmacological activities, including immune function regulation, hematopoiesis improvement, cardiovascular protection, neuroprotection, gastrointestinal function regulation, endocrine function regulation, cytotoxic and antibacterial effects, anti-aging and anti-oxidation, etc. Almost no obvious toxicity or side effect are observed and recorded for Codonopsis. The traditional uses, phytochemistry, pharmacology and toxicology of Codonopsis are

  19. Ethnobotany, phytochemistry, and pharmacology of the genus Litsea: An update.

    Science.gov (United States)

    Wang, Yun-Song; Wen, Zheng-Qi; Li, Bi-Tao; Zhang, Hong-Bin; Yang, Jing-Hua

    2016-04-02

    The genus Litsea is one of the most diverse genera of evergreen trees or shrubs belong to Lauraceae, and comprises roughly 400 species of tree that are distributed abundantly throughout tropical and subtropical Asia, North and South America. Litsea species have been used globally in traditional medicine for the treatment of various diseases including influenza, stomach aches, diarrhea, diabetes, vomiting, bone pain, inflammation, illness related to the central nervous system and other ailments. The purpose of this review is to provide updated, comprehensive and categorized information on the ethnobotany, phytochemistry and pharmacological research of Litsea species in order to explore their therapeutic potential and evaluate future research opportunities. All the available information on Litsea species was actualised by systematically searching the scientific literatures including Chinese, Korean, Japanese, Indian, and South American herbal classics, library catalogs and scientific databases (PubMed, SciFinder, Web of Science, Google Scholar, VIP and Wanfang). The Plant List, International Plant Name index and Scientific Database of China Plant Species were used to validate scientific names. 407 secondary metabolites have been reported from Litsea species. Litsea Species are sources of secondary metabolites with interesting chemical structures (alkaloids, lactones, sesquiterpenes, flavonoids, lignans, and essential oils) and significant bioactivities. Crude extracts, fractions and phytochemical constituents isolated from Litsea show a wide spectrum of in vitro and in vivo pharmacological activities including anticancer, anti-inflammatory, antimicrobial, antioxidant, antidiabetic, anti-HIV, insecticidal, etc. From data collected in this review, the genus Litsea comprises a wide range of therapeutically promising and valuable plants, and has attracted much attention owing to its multiple functions. Many traditional uses of Litsea species have now been validated by

  20. Food Web and Trophic Interaction and Development

    Czech Academy of Sciences Publication Activity Database

    Hrbáček, Jaroslav

    2010-01-01

    Roč. 3, - (2010), s. 45-70. ISBN 978-90-481-9264-9. ISSN 1875-1261 Institutional research plan: CEZ:AV0Z60170517 Keywords : biological indication * energy transfer * chlorophyll concentration * top-down effect * zooplankton size Subject RIV: DA - Hydrology ; Limnology

  1. The genus Machaerium (Fabaceae): taxonomy, phytochemistry, traditional uses and biological activities.

    Science.gov (United States)

    Amen, Yhiya M; Marzouk, Amani M; Zaghloul, Mona G; Afifi, Mohamed S

    2015-01-01

    Machaerium, in the family Fabaceae, predominantly is a genus of a Neotropical distribution of trees, shrubs, and lianas occurring from southern Mexico to Brazil and northern Argentina and as far as South America. Several Machaerium species are widely used in traditional medicine and are considered to have multiple medicinal properties. This review aims to provide up-to-date and comprehensive information on the taxonomy, phytochemistry, traditional uses and biological activities of plants in the genus Machaerium.

  2. Phytochemistry of the fossilized-cuticle frond Macroneuropteris macrophylla (Pennsylvanian seed fern, Canada)

    Energy Technology Data Exchange (ETDEWEB)

    Zodrow, Erwin L. [Palaeobotanical Laboratory, Cape Breton University, Sydney, Nova Scotia, B1P 6L2 (Canada); D' Angelo, Jose A. [IANIGLA, CCT-CONICET-Mendoza, Avda. Ruiz Leal s/n Parque Gral. San Martin (5500) Mendoza (Argentina); Mastalerz, Maria [Indiana Geological Survey, Indiana University, Bloomington, IN, 47405-2208 (United States); Cleal, Christopher J. [Department of Biodiversity and Systematic Biology, National Museum of Wales, Cathays Park, Cardiff, CF10 3NP (United Kingdom); Keefe, Dale [Molecular Spectroscopy Research Laboratory, Department of Chemistry, Cape Breton University, Sydney, Nova Scotia (Canada)

    2010-11-01

    In Canada's Sydney Coalfield, specimens of the extinct Carboniferous seed fern Macroneuropteris macrophylla (Brongniart) invariably show preservation stages intermediate between compression and fossilized-cuticle, even concerning a single pinnule. In this interdisciplinary approach, we study a ca. 300 to 350 mm long fossilized-cuticle-preserved frond section of M. macrophylla (Brongniart) that represents about one third of the length of a frond that was originally 1 m long. Size and preservation allow us to study the phytochemistry of the cuticle biomacropolymers over the length of the frond to assess what impact, if any, results would have on Carboniferous palaeophytochemotaxonomy. For comparison, the phytochemistry of compressions with their extracted cuticles from the same species and the same sample locality is also investigated. We use solid- and liquid-state, semi-quantitative Fourier transform infrared spectroscopy (FTIR) for the chemical characterization of the frond. Based on our results, we infer an essentially uniform phytochemistry over the fossilized-cuticle frond, suggesting that only a single pinnule needs to be analyzed to get an overall phytochemical picture of the frond, which has been our long-time working hypothesis. We distinguish between phytochemistry and cutinization. The latter is much less pronounced above than below the frond dichotomy, and we suggest a palaeoecological cause, rather than differing pathways of organic matter transformation. Moreover, cuticles below and above the frond dichotomy have essentially the same epidermal pattern, but those from below have features that may have been an adaptation to prevent stomatal flooding during the tropical, rainy season. This study suggests that chemically the fossilized-cuticle is more similar to the compression than to the cuticle obtained from that compression of the same species which invites reevaluation of the classical compression concept. (author)

  3. Phytochemistry of the fossilized-cuticle frond Macroneuropteris macrophylla (Pennsylvanian seed fern, Canada)

    Science.gov (United States)

    Zodrow, E.L.; D'Angelo, J. A.; Mastalerz, Maria; Cleal, C.J.; Keefe, D.

    2010-01-01

    In Canada's Sydney Coalfield, specimens of the extinct Carboniferous seed fern Macroneuropteris macrophylla (Brongniart) invariably show preservation stages intermediate between compression and fossilized-cuticle, even concerning a single pinnule. In this interdisciplinary approach, we study a ca. 300 to 350 mm long fossilized-cuticle-preserved frond section of M. macrophylla (Brongniart) that represents about one third of the length of a frond that was originally 1 m long. Size and preservation allow us to study the phytochemistry of the cuticle biomacropolymers over the length of the frond to assess what impact, if any, results would have on Carboniferous palaeophytochemotaxonomy. For comparison, the phytochemistry of compressions with their extracted cuticles from the same species and the same sample locality is also investigated. We use solid- and liquid-state, semi-quantitative Fourier transform infrared spectroscopy (FTIR) for the chemical characterization of the frond.Based on our results, we infer an essentially uniform phytochemistry over the fossilized-cuticle frond, suggesting that only a single pinnule needs to be analyzed to get an overall phytochemical picture of the frond, which has been our long-time working hypothesis. We distinguish between phytochemistry and cutinization. The latter is much less pronounced above than below the frond dichotomy, and we suggest a palaeoecological cause, rather than differing pathways of organic matter transformation. Moreover, cuticles below and above the frond dichotomy have essentially the same epidermal pattern, but those from below have features that may have been an adaptation to prevent stomatal flooding during the tropical, rainy season.This study suggests that chemically the fossilized-cuticle is more similar to the compression than to the cuticle obtained from that compression of the same species which invites reevaluation of the classical compression concept. ?? 2010 Elsevier B.V.

  4. Mesoscale eddies are oases for higher trophic marine life

    KAUST Repository

    Godø , Olav R.; Samuelsen, Annette; Macaulay, Gavin J.; Patel, Ruben; Hjø llo, Solfrid Sæ tre; Horne, John; Kaartvedt, Stein; Johannessen, Johnny A.

    2012-01-01

    Mesoscale eddies stimulate biological production in the ocean, but knowledge of energy transfers to higher trophic levels within eddies remains fragmented and not quantified. Increasing the knowledge base is constrained by the inability of traditional sampling methods to adequately sample biological processes at the spatio-temporal scales at which they occur. By combining satellite and acoustic observations over spatial scales of 10 s of km horizontally and 100 s of m vertically, supported by hydrographical and biological sampling we show that anticyclonic eddies shape distribution and density of marine life from the surface to bathyal depths. Fish feed along density structures of eddies, demonstrating that eddies catalyze energy transfer across trophic levels. Eddies create attractive pelagic habitats, analogous to oases in the desert, for higher trophic level aquatic organisms through enhanced 3-D motion that accumulates and redistributes biomass, contributing to overall bioproduction in the ocean. Integrating multidisciplinary observation methodologies promoted a new understanding of biophysical interaction in mesoscale eddies. Our findings emphasize the impact of eddies on the patchiness of biomass in the sea and demonstrate that they provide rich feeding habitat for higher trophic marine life. 2012 God et al.

  5. Mesoscale eddies are oases for higher trophic marine life.

    Directory of Open Access Journals (Sweden)

    Olav R Godø

    Full Text Available Mesoscale eddies stimulate biological production in the ocean, but knowledge of energy transfers to higher trophic levels within eddies remains fragmented and not quantified. Increasing the knowledge base is constrained by the inability of traditional sampling methods to adequately sample biological processes at the spatio-temporal scales at which they occur. By combining satellite and acoustic observations over spatial scales of 10 s of km horizontally and 100 s of m vertically, supported by hydrographical and biological sampling we show that anticyclonic eddies shape distribution and density of marine life from the surface to bathyal depths. Fish feed along density structures of eddies, demonstrating that eddies catalyze energy transfer across trophic levels. Eddies create attractive pelagic habitats, analogous to oases in the desert, for higher trophic level aquatic organisms through enhanced 3-D motion that accumulates and redistributes biomass, contributing to overall bioproduction in the ocean. Integrating multidisciplinary observation methodologies promoted a new understanding of biophysical interaction in mesoscale eddies. Our findings emphasize the impact of eddies on the patchiness of biomass in the sea and demonstrate that they provide rich feeding habitat for higher trophic marine life.

  6. Mesoscale eddies are oases for higher trophic marine life

    KAUST Repository

    Godø, Olav R.

    2012-01-17

    Mesoscale eddies stimulate biological production in the ocean, but knowledge of energy transfers to higher trophic levels within eddies remains fragmented and not quantified. Increasing the knowledge base is constrained by the inability of traditional sampling methods to adequately sample biological processes at the spatio-temporal scales at which they occur. By combining satellite and acoustic observations over spatial scales of 10 s of km horizontally and 100 s of m vertically, supported by hydrographical and biological sampling we show that anticyclonic eddies shape distribution and density of marine life from the surface to bathyal depths. Fish feed along density structures of eddies, demonstrating that eddies catalyze energy transfer across trophic levels. Eddies create attractive pelagic habitats, analogous to oases in the desert, for higher trophic level aquatic organisms through enhanced 3-D motion that accumulates and redistributes biomass, contributing to overall bioproduction in the ocean. Integrating multidisciplinary observation methodologies promoted a new understanding of biophysical interaction in mesoscale eddies. Our findings emphasize the impact of eddies on the patchiness of biomass in the sea and demonstrate that they provide rich feeding habitat for higher trophic marine life. 2012 God et al.

  7. Vitamin D and muscle trophicity.

    Science.gov (United States)

    Domingues-Faria, Carla; Boirie, Yves; Walrand, Stéphane

    2017-05-01

    We review recent findings on the involvement of vitamin D in skeletal muscle trophicity. Vitamin D deficiencies are associated with reduced muscle mass and strength, and its supplementation seems effective to improve these parameters in vitamin D-deficient study participants. Latest investigations have also evidenced that vitamin D is essential in muscle development and repair. In particular, it modulates skeletal muscle cell proliferation and differentiation. However, discrepancies still exist about an enhancement or a decrease of muscle proliferation and differentiation by the vitamin D. Recently, it has been demonstrated that vitamin D influences skeletal muscle cell metabolism as it seems to regulate protein synthesis and mitochondrial function. Finally, apart from its genomic and nongenomic effects, recent investigations have demonstrated a genetic contribution of vitamin D to muscle functioning. Recent studies support the importance of vitamin D in muscle health, and the impact of its deficiency in regard to muscle mass and function. These 'trophic' properties are of particular importance for some specific populations such as elderly persons and athletes, and in situations of loss of muscle mass or function, particularly in the context of chronic diseases.

  8. Trophic shifts of a generalist consumer in response to resource pulses.

    Directory of Open Access Journals (Sweden)

    Pei-Jen L Shaner

    2011-03-01

    Full Text Available Trophic shifts of generalist consumers can have broad food-web and biodiversity consequences through altered trophic flows and vertical diversity. Previous studies have used trophic shifts as indicators of food-web responses to perturbations, such as species invasion, and spatial or temporal subsidies. Resource pulses, as a form of temporal subsidies, have been found to be quite common among various ecosystems, affecting organisms at multiple trophic levels. Although diet switching of generalist consumers in response to resource pulses is well documented, few studies have examined if the switch involves trophic shifts, and if so, the directions and magnitudes of the shifts. In this study, we used stable carbon and nitrogen isotopes with a Bayesian multi-source mixing model to estimate proportional contributions of three trophic groups (i.e. producer, consumer, and fungus-detritivore to the diets of the White-footed mouse (Peromyscus leucopus receiving an artificial seed pulse or a naturally-occurring cicadas pulse. Our results demonstrated that resource pulses can drive trophic shifts in the mice. Specifically, the producer contribution to the mouse diets was increased by 32% with the seed pulse at both sites examined. The consumer contribution to the mouse diets was also increased by 29% with the cicadas pulse in one of the two grids examined. However, the pattern was reversed in the second grid, with a 13% decrease in the consumer contribution with the cicadas pulse. These findings suggest that generalist consumers may play different functional roles in food webs under perturbations of resource pulses. This study provides one of the few highly quantitative descriptions on dietary and trophic shifts of a key consumer in forest food webs, which may help future studies to form specific predictions on changes in trophic interactions following resource pulses.

  9. Global change in the trophic functioning of marine food webs

    DEFF Research Database (Denmark)

    Maureaud, Aurore; Gascuel, Didier; Colléter, Mathieu

    2017-01-01

    and life history traits of marine species, we tested the hypothesis that anthropogenic ecological impacts may have led to changes in the global parameters defining the transfers of biomass within the food web. First, we developed two indicators to assess such changes: the Time Cumulated Indicator (TCI......The development of fisheries in the oceans, and other human drivers such as climate warming, have led to changes in species abundance, assemblages, trophic interactions, and ultimately in the functioning of marine food webs. Here, using a trophodynamic approach and global databases of catches......) measuring the residence time of biomass within the food web, and the Efficiency Cumulated Indicator (ECI) quantifying the fraction of secondary production reaching the top of the trophic chain. Then, we assessed, at the large marine ecosystem scale, the worldwide change of these two indicators over the 1950...

  10. Echinoderms display morphological and behavioural phenotypic plasticity in response to their trophic environment.

    Directory of Open Access Journals (Sweden)

    Adam D Hughes

    Full Text Available The trophic interactions of sea urchins are known to be the agents of phase shifts in benthic marine habitats such as tropical and temperate reefs. In temperate reefs, the grazing activity of sea urchins has been responsible for the destruction of kelp forests and the formation of 'urchin barrens', a rocky habitat dominated by crustose algae and encrusting invertebrates. Once formed, these urchin barrens can persist for decades. Trophic plasticity in the sea urchin may contribute to the stability and resilience of this alternate stable state by increasing diet breadth in sea urchins. This plasticity promotes ecological connectivity and weakens species interactions and so increases ecosystem stability. We test the hypothesis that sea urchins exhibit trophic plasticity using an approach that controls for other typically confounding environmental and genetic factors. To do this, we exposed a genetically homogenous population of sea urchins to two very different trophic environments over a period of two years. The sea urchins exhibited a wide degree of phenotypic trophic plasticity when exposed to contrasting trophic environments. The two populations developed differences in their gross morphology and the test microstructure. In addition, when challenged with unfamiliar prey, the response of each group was different. We show that sea urchins exhibit significant morphological and behavioural phenotypic plasticity independent of their environment or their nutritional status.

  11. Spider foraging strategy affects trophic cascades under natural and drought conditions.

    Science.gov (United States)

    Liu, Shengjie; Chen, Jin; Gan, Wenjin; Schaefer, Douglas; Gan, Jianmin; Yang, Xiaodong

    2015-07-23

    Spiders can cause trophic cascades affecting litter decomposition rates. However, it remains unclear how spiders with different foraging strategies influence faunal communities, or present cascading effects on decomposition. Furthermore, increased dry periods predicted in future climates will likely have important consequences for trophic interactions in detritus-based food webs. We investigated independent and interactive effects of spider predation and drought on litter decomposition in a tropical forest floor. We manipulated densities of dominant spiders with actively hunting or sit-and-wait foraging strategies in microcosms which mimicked the tropical-forest floor. We found a positive trophic cascade on litter decomposition was triggered by actively hunting spiders under ambient rainfall, but sit-and-wait spiders did not cause this. The drought treatment reversed the effect of actively hunting spiders on litter decomposition. Under drought conditions, we observed negative trophic cascade effects on litter decomposition in all three spider treatments. Thus, reduced rainfall can alter predator-induced indirect effects on lower trophic levels and ecosystem processes, and is an example of how such changes may alter trophic cascades in detritus-based webs of tropical forests.

  12. A review of traditional pharmacological uses, phytochemistry, and pharmacological activities of Tribulus terrestris.

    Science.gov (United States)

    Zhu, Wenyi; Du, Yijie; Meng, Hong; Dong, Yinmao; Li, Li

    2017-07-11

    Tribulus terrestris L. (TT) is an annual plant of the family Zygophyllaceae that has been used for generations to energize, vitalize, and improve sexual function and physical performance in men. The fruits and roots of TT have been used as a folk medicine for thousands of years in China, India, Sudan, and Pakistan. Numerous bioactive phytochemicals, such as saponins and flavonoids, have been isolated and identified from TT that are responsible alone or in combination for various pharmacological activities. This review provides a comprehensive overview of the traditional applications, phytochemistry, pharmacology and overuse of TT and provides evidence for better medicinal usage of TT.

  13. Effects of genotype, elevated CO2 and elevated O3 on aspen phytochemistry and aspen leaf beetle Chrysomela crotchi performance

    Science.gov (United States)

    Leanne M. Vigue; Richard L. Lindroth

    2010-01-01

    Trembling aspen Populus tremuloides Michaux is an important forest species in the Great Lakes region and displays tremendous genetic variation in foliar chemistry. Elevated carbon dioxide (CO2) and ozone (O3) may also influence phytochemistry and thereby alter the performance of insect herbivores such as...

  14. Interannual variability in lower trophic levels on the Alaskan Shelf

    Science.gov (United States)

    Batten, Sonia D.; Raitsos, Dionysios E.; Danielson, Seth; Hopcroft, Russell; Coyle, Kenneth; McQuatters-Gollop, Abigail

    2018-01-01

    This study describes results from the first 16 years of the Continuous Plankton Recorder (CPR) program that has sampled the lower trophic levels (restricted to larger, hard-shelled phytoplankton and robust zooplankton taxa) on the Alaskan shelf. Sampling took place along transects from the open ocean across the shelf (to the entrance to Prince William Sound from 2000 to 2003 and into Cook Inlet from 2004 to 2015) to provide plankton abundance data, spring through autumn of each year. We document interannual variability in concentration and composition of the plankton community of the region over this time period. At least in part and through correlative relationships, this can be attributed to changes in the physical environment, particularly direct and indirect effects of temperature. For example; spring mixed layer depth is shown to influence the timing of the spring diatom peak and warmer years are biased towards smaller copepod species. A significant positive relationship between temperature, diatom abundance and zooplankton biomass existed from 2000 to 2013 but was not present in the warm years of 2014 and 2015. These results suggest that anomalous warming events, such as the "heat wave" of 2014-2015, could fundamentally influence typical lower trophic level patterns, possibly altering trophic interactions.

  15. The implementation of case study with module-assisted to improve students' understanding on phytochemistry course

    Science.gov (United States)

    Julianto, Tatang Shabur; Fitriastuti, Dhina; Diniaty, Artina; Fauzi'ah, Lina; Arlianty, Widinda Normalia; Febriana, Beta Wulan; Muhaimin

    2017-12-01

    Phytochemistry is one of the course in Chemistry Department's curriculum which discusses about biosynthetic path of secondary metabolite compound in a plant, classification of secondary metabolite compound, isolation technique, and identification analysis. This course is expected to be able to bridge the generations of a nation that has expertise in managing the natural resources of Indonesian plants. In this research, it was evaluated the implementation of case study learning method towards students' understanding on phytochemistry course. The learning processes were conducted in 2 cycles i.e. before and after midterm. The first seven themes of materials before midterm were learned with case study method and the next seven themes of materials were studied with the same method with the module-assisted. The results showed that there was enhancement of students' understanding in class D that were obtained from comparison of midterm and final test. Contrarily, the students of class C have no significant enhancement. In addition, it was predicted that understanding enhancement was strongly influenced by the life skills and the motivation of students especially the academic skills aspect.

  16. Diospyros lycioides Desf.: Review of its botany, medicinal uses, pharmacological activities and phytochemistry

    Directory of Open Access Journals (Sweden)

    Alfred Maroyi

    2018-01-01

    Full Text Available Diospyros lycioides Desf. (D. lycioides is traditionally used as herbal medicine against various human and animal ailments in tropical Africa. The present paper reviewed information on botany, medicinal uses, phytochemistry and pharmacological activities of D. lycioides. This review was compiled using scientific literature from electronic search engine such as PubMed, Scopus, ScienceDirect, Springerlink, BioMed Central, Scielo, Medline and Science domain. Additional literatures were obtained from book chapters, books, dissertations, websites and other scientific publications. D. lycioides is used as traditional medicine in 50% of the countries where the species is native in tropical Africa. This study recorded 22 medicinal uses of D. lycioides which included abdominal pains, infertility in women, sexually transmitted infections, and used as chewing sticks (or mouthwash, toothbrushes and ethnoveterinary medicine. D. lycioides extracts demonstrated anti-adhesive, anti-inflammatory, antimetastatic, antioxidant, antifungal, antiproliferative, mutagenicity and antibacterial activities. Future research should focus on the pharmacological properties, phytochemistry, clinical trials and pharmacokinetics of D. lycioides which will enhance the therapeutic potential of the species.

  17. Platycladus orientalis leaves: a systemic review on botany, phytochemistry and pharmacology.

    Science.gov (United States)

    Shan, Ming-Qiu; Shang, Jing; Ding, An-Wei

    2014-01-01

    Platycladus orientalis leaves (Cebaiye) have been used for thousands of years as traditional Chinese medicine (TCM). According to the theory of TCM, they are categorized as a blood-cooling and hematostatic herb. In clinical practice, they were usually prescribed with heat-clearing herbs to reinforce the efficacy of hemostasis. The review provides the up-to-date information from 1980 to present that is available on the botany, processing research, phytochemistry, pharmacology and toxicology of the leaves. The information is collected from scientific journals, books, theses and reports via library and electronic search (Google Scholar, Pubmed and CNKI). Through literature reports, we can find that the leaves show a wide spectrum of pharmacological activities, such as anti-inflammatory, antioxidant, antimicrobial, disinsection, anticancer, diuretic, hair growth-promoting, neuroprotective and antifibrotic activities. Diterpene and flavonoids would be active constituents in P. orientalis leaves. Many studies have provided evidence for various traditional uses. However, there is a great need for additional studies to elucidate the mechanism of blood-cooling and hematostatic activity of the leaves. Therefore, the present review on the botany, traditional uses, phytochemistry and toxicity has provided preliminary information for further studies of this herb.

  18. Warburgia: a comprehensive review of the botany, traditional uses and phytochemistry.

    Science.gov (United States)

    Leonard, Carmen M; Viljoen, Alvaro M

    2015-05-13

    The genus Warburgia (Canellaceae) is represented by several medicinal trees found exclusively on the African continent. Traditionally, extracts and products produced from Warburgia species are regarded as important natural African antibiotics and have been used extensively as part of traditional healing practices for the treatment of fungal, bacterial and protozoal infections in both humans and animals. We here aim to collate and review the fragmented information on the ethnobotany, phytochemistry and biological activities of ethnomedicinally important Warburgia species and present recommendations for future research. Peer-reviewed articles using "Warburgia" as search term ("all fields") were retrieved from Scopus, ScienceDirect, SciFinder and Google Scholar with no specific time frame set for the search. In addition, various books were consulted that contained botanical and ethnopharmacological information. The ethnopharmacology, phytochemistry and biological activity of Warburgia are reviewed. Most of the biological activities are attributed to the drimane sesquiterpenoids, including polygodial, warburganal, muzigadial, mukaadial and ugandensial, flavonoids and miscellaneous compounds present in the various species. In addition to anti-infective properties, Warburgia extracts are also used to treat a wide range of ailments, including stomach aches, fever and headaches, which may also be a manifestation of infections. The need to record anecdotal evidence is emphasised and conservation efforts are highlighted to contribute to the protection and preservation of one of Africa's most coveted botanical resources. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  19. Trophic ulcers in the carpal tunnel syndrome

    Directory of Open Access Journals (Sweden)

    Abelardo Q.-C. Araújo

    1993-09-01

    Full Text Available A patient with carpal tunnel syndrome (CTS and trophic ulcers is described. Despite the healing of the ulcers after surgery for CTS, the severe sensory deficit and the electrophysiological tests have not shown any significant improvement. We think these findings argue against the hypothesis of the sensory deficit being responsible for the trophic ulcers. We favor a major role for the sympathetic disturbances as the main cause for those lesions.

  20. Persistence of trophic hotspots and relation to human impacts within an upwelling marine ecosystem.

    Science.gov (United States)

    Santora, Jarrod A; Sydeman, William J; Schroeder, Isaac D; Field, John C; Miller, Rebecca R; Wells, Brian K

    2017-03-01

    Human impacts (e.g., fishing, pollution, and shipping) on pelagic ecosystems are increasing, causing concerns about stresses on marine food webs. Maintaining predator-prey relationships through protection of pelagic hotspots is crucial for conservation and management of living marine resources. Biotic components of pelagic, plankton-based, ecosystems exhibit high variability in abundance in time and space (i.e., extreme patchiness), requiring investigation of persistence of abundance across trophic levels to resolve trophic hotspots. Using a 26-yr record of indicators for primary production, secondary (zooplankton and larval fish), and tertiary (seabirds) consumers, we show distributions of trophic hotspots in the southern California Current Ecosystem result from interactions between a strong upwelling center and a productive retention zone with enhanced nutrients, which concentrate prey and predators across multiple trophic levels. Trophic hotspots also overlap with human impacts, including fisheries extraction of coastal pelagic and groundfish species, as well as intense commercial shipping traffic. Spatial overlap of trophic hotspots with fisheries and shipping increases vulnerability of the ecosystem to localized depletion of forage fish, ship strikes on marine mammals, and pollution. This study represents a critical step toward resolving pelagic areas of high conservation interest for planktonic ecosystems and may serve as a model for other ocean regions where ecosystem-based management and marine spatial planning of pelagic ecosystems is warranted. © 2016 by the Ecological Society of America.

  1. Biomass changes and trophic amplification of plankton in a warmer ocean

    KAUST Repository

    Chust, Guillem

    2014-05-07

    Ocean warming can modify the ecophysiology and distribution of marine organisms, and relationships between species, with nonlinear interactions between ecosystem components potentially resulting in trophic amplification. Trophic amplification (or attenuation) describe the propagation of a hydroclimatic signal up the food web, causing magnification (or depression) of biomass values along one or more trophic pathways. We have employed 3-D coupled physical-biogeochemical models to explore ecosystem responses to climate change with a focus on trophic amplification. The response of phytoplankton and zooplankton to global climate-change projections, carried out with the IPSL Earth System Model by the end of the century, is analysed at global and regional basis, including European seas (NE Atlantic, Barents Sea, Baltic Sea, Black Sea, Bay of Biscay, Adriatic Sea, Aegean Sea) and the Eastern Boundary Upwelling System (Benguela). Results indicate that globally and in Atlantic Margin and North Sea, increased ocean stratification causes primary production and zooplankton biomass to decrease in response to a warming climate, whilst in the Barents, Baltic and Black Seas, primary production and zooplankton biomass increase. Projected warming characterized by an increase in sea surface temperature of 2.29 ± 0.05 °C leads to a reduction in zooplankton and phytoplankton biomasses of 11% and 6%, respectively. This suggests negative amplification of climate driven modifications of trophic level biomass through bottom-up control, leading to a reduced capacity of oceans to regulate climate through the biological carbon pump. Simulations suggest negative amplification is the dominant response across 47% of the ocean surface and prevails in the tropical oceans; whilst positive trophic amplification prevails in the Arctic and Antarctic oceans. Trophic attenuation is projected in temperate seas. Uncertainties in ocean plankton projections, associated to the use of single global and

  2. Biomass changes and trophic amplification of plankton in a warmer ocean

    KAUST Repository

    Chust, Guillem; Allen, Julian Icarus; Bopp, Laurent; Schrum, Corinna; Holt, Jason T.; Tsiaras, Kostas P.; Zavatarelli, Marco; Chifflet, Marina; Cannaby, Heather; Dadou, Isabelle C.; Daewel, Ute; Wakelin, Sarah L.; Machú , Eric; Pushpadas, Dhanya; Butenschö n, Momme; Artioli, Yuri; Petihakis, George; Smith, Chris J M; Garç on, Vé ronique C.; Goubanova, Katerina; Le Vu, Briac; Fach, Bettina A.; Salihoglu, Baris; Clementi, Emanuela; Irigoien, Xabier

    2014-01-01

    Ocean warming can modify the ecophysiology and distribution of marine organisms, and relationships between species, with nonlinear interactions between ecosystem components potentially resulting in trophic amplification. Trophic amplification (or attenuation) describe the propagation of a hydroclimatic signal up the food web, causing magnification (or depression) of biomass values along one or more trophic pathways. We have employed 3-D coupled physical-biogeochemical models to explore ecosystem responses to climate change with a focus on trophic amplification. The response of phytoplankton and zooplankton to global climate-change projections, carried out with the IPSL Earth System Model by the end of the century, is analysed at global and regional basis, including European seas (NE Atlantic, Barents Sea, Baltic Sea, Black Sea, Bay of Biscay, Adriatic Sea, Aegean Sea) and the Eastern Boundary Upwelling System (Benguela). Results indicate that globally and in Atlantic Margin and North Sea, increased ocean stratification causes primary production and zooplankton biomass to decrease in response to a warming climate, whilst in the Barents, Baltic and Black Seas, primary production and zooplankton biomass increase. Projected warming characterized by an increase in sea surface temperature of 2.29 ± 0.05 °C leads to a reduction in zooplankton and phytoplankton biomasses of 11% and 6%, respectively. This suggests negative amplification of climate driven modifications of trophic level biomass through bottom-up control, leading to a reduced capacity of oceans to regulate climate through the biological carbon pump. Simulations suggest negative amplification is the dominant response across 47% of the ocean surface and prevails in the tropical oceans; whilst positive trophic amplification prevails in the Arctic and Antarctic oceans. Trophic attenuation is projected in temperate seas. Uncertainties in ocean plankton projections, associated to the use of single global and

  3. Biomass changes and trophic amplification of plankton in a warmer ocean.

    Science.gov (United States)

    Chust, Guillem; Allen, J Icarus; Bopp, Laurent; Schrum, Corinna; Holt, Jason; Tsiaras, Kostas; Zavatarelli, Marco; Chifflet, Marina; Cannaby, Heather; Dadou, Isabelle; Daewel, Ute; Wakelin, Sarah L; Machu, Eric; Pushpadas, Dhanya; Butenschon, Momme; Artioli, Yuri; Petihakis, George; Smith, Chris; Garçon, Veronique; Goubanova, Katerina; Le Vu, Briac; Fach, Bettina A; Salihoglu, Baris; Clementi, Emanuela; Irigoien, Xabier

    2014-07-01

    Ocean warming can modify the ecophysiology and distribution of marine organisms, and relationships between species, with nonlinear interactions between ecosystem components potentially resulting in trophic amplification. Trophic amplification (or attenuation) describe the propagation of a hydroclimatic signal up the food web, causing magnification (or depression) of biomass values along one or more trophic pathways. We have employed 3-D coupled physical-biogeochemical models to explore ecosystem responses to climate change with a focus on trophic amplification. The response of phytoplankton and zooplankton to global climate-change projections, carried out with the IPSL Earth System Model by the end of the century, is analysed at global and regional basis, including European seas (NE Atlantic, Barents Sea, Baltic Sea, Black Sea, Bay of Biscay, Adriatic Sea, Aegean Sea) and the Eastern Boundary Upwelling System (Benguela). Results indicate that globally and in Atlantic Margin and North Sea, increased ocean stratification causes primary production and zooplankton biomass to decrease in response to a warming climate, whilst in the Barents, Baltic and Black Seas, primary production and zooplankton biomass increase. Projected warming characterized by an increase in sea surface temperature of 2.29 ± 0.05 °C leads to a reduction in zooplankton and phytoplankton biomasses of 11% and 6%, respectively. This suggests negative amplification of climate driven modifications of trophic level biomass through bottom-up control, leading to a reduced capacity of oceans to regulate climate through the biological carbon pump. Simulations suggest negative amplification is the dominant response across 47% of the ocean surface and prevails in the tropical oceans; whilst positive trophic amplification prevails in the Arctic and Antarctic oceans. Trophic attenuation is projected in temperate seas. Uncertainties in ocean plankton projections, associated to the use of single global and

  4. Fatty acid trophic markers and trophic links among seston, crustacean zooplankton and the siphonophore Nanomia cara in Georges Basin and Oceanographer Canyon (NW Atlantic

    Directory of Open Access Journals (Sweden)

    Sergio Rossi

    2008-06-01

    Full Text Available Fatty acid concentrations expressed as percentages of total fatty acid pools in seston, stage V copepodites of Calanus finmarchicus, adults of the euphausiid Meganyctiphanes norvegica, and the physonect siphonophore Nanomia cara were used to elucidate trophic links in Georges Basin and Oceanographer Canyon in September 2003. Seston at both locations was refractory and comprised mainly of saturated fatty acids. Phytoplankton did not contribute significantly to the fatty acid composition of seston or higher trophic levels. Only four fatty acids, i.e. 14:0, 16:0, 16:1 (n–7 and 18:1 (n–7, were transferred from seston to C. finmarchicus or M. norvegica, which suggested weak trophic interactions. Fatty acids transferred from the two species of crustaceans to N. cara included the same four fatty acids, along with three polyunsaturated fatty acids found in relatively high concentrations in both crustaceans, i.e. 20:3 (n–6, 20:5 (n–3 and 22:6 (n–3. In addition, 18:1 (n–9, which occurred in relatively high concentrations only in M. norvegica, and 18:0 and 18:2 (n–6, which were found in low concentrations in both crustaceans, also appeared to be transferred to N. cara. Overall, fatty acid trophic markers proved useful for identifying trophic links to N. cara.

  5. Traditional uses, phytochemistry and biological activities of Cotula ...

    African Journals Online (AJOL)

    compound were elucidated by HPLC-ESI-MS. (Figure 3). .... constituents: these interactions may produce synergistic ... Total available carbohydrates and total protein contents of the ... Pourmohammad A. Application of molecular markers in medicinal plant ... Atef C, Chefrour A. Seasonal biometric and dynamic monitoring of ...

  6. Ecosystem regime shifts disrupt trophic structure.

    Science.gov (United States)

    Hempson, Tessa N; Graham, Nicholas A J; MacNeil, M Aaron; Hoey, Andrew S; Wilson, Shaun K

    2018-01-01

    Regime shifts between alternative stable ecosystem states are becoming commonplace due to the combined effects of local stressors and global climate change. Alternative states are characterized as substantially different in form and function from pre-disturbance states, disrupting the delivery of ecosystem services and functions. On coral reefs, regime shifts are typically characterized by a change in the benthic composition from coral to macroalgal dominance. Such fundamental shifts in the benthos are anticipated to impact associated fish communities that are reliant on the reef for food and shelter, yet there is limited understanding of how regime shifts propagate through the fish community over time, relative to initial or recovery conditions. This study addresses this knowledge gap using long-term data of coral reef regime shifts and recovery on Seychelles reefs following the 1998 mass bleaching event. It shows how trophic structure of the reef fish community becomes increasingly dissimilar between alternative reef ecosystem states (regime-shifted vs. recovering) with time since disturbance. Regime-shifted reefs developed a concave trophic structure, with increased biomass in base trophic levels as herbivorous species benefitted from increased algal resources. Mid trophic level species, including specialists such as corallivores, declined with loss of coral habitat, while biomass was retained in upper trophic levels by large-bodied, generalist invertivores. Recovering reefs also experienced an initial decline in mid trophic level biomass, but moved toward a bottom-heavy pyramid shape, with a wide range of feeding groups (e.g., planktivores, corallivores, omnivores) represented at mid trophic levels. Given the importance of coral reef fishes in maintaining the ecological function of coral reef ecosystems and their associated fisheries, understanding the effects of regime shifts on these communities is essential to inform decisions that enhance ecological

  7. Jurema-Preta (Mimosa tenuiflora [Willd.] Poir.: a review of its traditional use, phytochemistry and pharmacology

    Directory of Open Access Journals (Sweden)

    Rafael Sampaio Octaviano de Souza

    2008-10-01

    Full Text Available Numerous plant species are used throughout the world to achieve the modified states of conscientiousness. Some of them have been used for the therapeutic purposes, such as Mimosa tenuiflora (Willd Poir. (family Mimosaceae known as "jurema-preta", an hallucinogenic plant traditionally used for curing and divination by the Indians of northeastern Brazil. In this review, several aspects of the use, phytochemistry, and pharmacology of this plant are considered.Numerosas espécies de plantas são usadas para alterar estados de consciência. Algumas são utilizadas para fins terapêuticos, como Mimosa tenuiflora (Willd Poir. (Mimosaceae conhecida como "jurema-preta", uma planta alucinógena, tradicionalmente utilizada pelos índios no nordeste do Brasil. Nesta revisão, são considerados diversos aspectos do uso, fitoquímica e farmacologia desta planta.

  8. Review of the botanical characteristics, phytochemistry, and pharmacology of Astragalus membranaceus (Huangqi).

    Science.gov (United States)

    Fu, Juan; Wang, Zenghui; Huang, Linfang; Zheng, Sihao; Wang, Dongmei; Chen, Shilin; Zhang, Haitao; Yang, Shihai

    2014-09-01

    Astragalus membranaceus is one of the most widely used traditional Chinese herbal medicines. It is used as immune stimulant, tonic, antioxidant, hepatoprotectant, diuretic, antidiabetic, anticancer, and expectorant. The current paper reviews the botanical characteristics, phytochemistry, and pharmacology of Astragali Radix. Information on Astragali Radix was gathered via the Internet (using Google Scholar, Baidu Scholar, Elsevier, ACS, Medline Plus, CNKI, and Web of Science) as well as from libraries and local books. More than 100 compounds, including flavonoids, saponins, polysaccharides, and amino acids, have so far been identified, and the various biological activities of the compounds have been reported. As an important traditional Chinese medicine, further studies on Astragali Radix can lead to the development of new drugs and therapies for various diseases. The improvement of its utilization should be studied further. Copyright © 2014 John Wiley & Sons, Ltd.

  9. A Review on the Phytochemistry, Pharmacology, Pharmacokinetics and Toxicology of Geniposide, a Natural Product

    Directory of Open Access Journals (Sweden)

    Mingqiu Shan

    2017-10-01

    Full Text Available Iridoid glycosides are natural products occurring widely in many herbal plants. Geniposide (C17H24O10 is a well-known one, present in nearly 40 species belonging to various families, especially the Rubiaceae. Along with this herbal component, dozens of its natural derivatives have also been isolated and characterized by researchers. Furthermore, a large body of pharmacological evidence has proved the various biological activities of geniposide, such as anti-inflammatory, anti-oxidative, anti-diabetic, neuroprotective, hepatoprotective, cholagogic effects and so on. However, there have been some research articles on its toxicity in recent years. Therefore, this review paper aims to provide the researchers with a comprehensive profile of geniposide on its phytochemistry, pharmacology, pharmacokinetics and toxicology in order to highlight some present issues and future perspectives as well as to help us develop and utilize this iridoid glycoside more efficiently and safely.

  10. Radix Bupleuri: A Review of Traditional Uses, Botany, Phytochemistry, Pharmacology, and Toxicology.

    Science.gov (United States)

    Yang, Fude; Dong, Xiaoxv; Yin, Xingbin; Wang, Wenping; You, Longtai; Ni, Jian

    2017-01-01

    Radix Bupleuri (Chaihu) has been used as a traditional medicine for more than 2000 years in China, Japan, Korea, and other Asian countries. Phytochemical studies demonstrated that this plant contains essential oils, triterpenoid saponins, polyacetylenes, flavonoids, lignans, fatty acids, and sterols. Crude extracts and pure compounds isolated from Radix Bupleuri exhibited various biological activities, such as anti-inflammatory, anticancer, antipyretic, antimicrobial, antiviral, hepatoprotective, neuroprotective, and immunomodulatory effects. However, Radix Bupleuri could also lead to hepatotoxicity, particularly in high doses and with long-term use. Pharmacokinetic studies have demonstrated that the major bioactive compounds (saikosaponins a, b 2 , c, and d) were absorbed rapidly in rats after oral administration of the extract of Radix Bupleuri . This review aims to comprehensively summarize the traditional uses, botany, phytochemistry, pharmacology, toxicology, and pharmacokinetics of Radix Bupleuri reported to date with an emphasis on its biological properties and mechanisms of action.

  11. A review of traditional uses, phytochemistry and pharmacology of Portulaca oleracea L.

    Science.gov (United States)

    Iranshahy, Milad; Javadi, Behjat; Iranshahi, Mehrdad; Jahanbakhsh, Seyedeh Pardis; Mahyari, Saman; Hassani, Faezeh Vahdati; Karimi, Gholamreza

    2017-06-09

    Portulaca oleracea L. is a widespread medicinal plant that is used not only as an edible plant, but also as a traditional medicine for alleviating a wide spectrum of diseases. It is a well-known plant in the European Traditional Medicine. PA is mentioned by Dioscorides (40-90 CE), with the name of "andrachne". In this study, we provide detailed information on botany, traditional uses, phytochemistry, pharmacological uses, pharmacokinetics and safety of P. oleracea. An extensive search on electronic databases including PubMed, Web of Science, Google Scholar, ScienceDirect, Scopus, conference papers, local herbal encyclopedias, articles, books (in English, French, Arabic, Persian, etc.) and also a number of unpublished handwritten manuscripts was done to find articles have been published between 1956 and 2015 on pharmacology and phytochemistry of P. oleracea. P. oleracea has been addressed in De Materia Medica as an astringent, and a remedy for headaches, inflammation of the eyes and other organs, burning of the stomach, erysipela, disorders of the bladder, numbness of the teeth, excessive sexual desire, burning fevers, worms, dysentery, hemorrhoids, eruptions of blood, and bites. Phytochemical investigations revealed that this plant a wide range of secondary metabolites including alkaloids, terpenoids, flavonoids and organic acids. The most important pharmacological activities are renoprotective activities and effects on metabolism. P. oleracea could successfully decrease blood glucose and lipid profile of patients with metabolic syndrome. The safety of P. oleracea has been reported in many clinical trials. Modern pharmacological studies have now proven many traditional uses of P. oleracea, including anti-hyperglycemic and anti-hyperlipidemic, renoprotective and hepatoprotective effects. In addition, in many clinical trials P. oleracea showed no adverse effects and constipation was reported as the most frequent adverse effect. Copyright © 2017 Elsevier Ireland Ltd

  12. Rheum australe D. Don: a review of its botany, ethnobotany, phytochemistry and pharmacology.

    Science.gov (United States)

    Rokaya, Maan Bahadur; Münzbergová, Zuzana; Timsina, Binu; Bhattarai, Krishna Ram

    2012-06-14

    Rheum australe D. Don (Polygonaceae) has been commonly used in traditional medicine for a wide range of ailments related to the circulatory, digestive, endocrine, respiratory and skeletal systems as well as to infectious diseases. To provide the up-to-date information that is available on the botany, traditional uses, phytochemistry, pharmacology and toxicology of Rheum australe. Additionally, to highlight the possible uses of this species to treat different diseases and to provide a basis for future research. The present review covers the literature available from 1980 to 2011. The information was collected from scientific journals, books, theses and reports via a library and electronic search (Google Scholar, Web of Science and ScienceDirect). Ethnomedical uses of Rheum australe have been recorded from China, India, Nepal and Pakistan for 57 different types of ailments. The phytochemical studies have shown the presence of many secondary metabolites belonging to anthraquinones, stilbenes, anthrones, oxantrone ethers and esters, chromones, flavonoids, carbohydrate, lignans, phenols and sterols. Crude extracts and isolated compounds from Rheum australe show a wide spectrum of pharmacological activities, such as antidiabetic, anti-inflammatory, antifungal, antimicrobial, antioxidant, anticancer, hepatoprotective and immune-enhancing activities, as well as a usefulness for improving renal function. Rheum australe has been widely used source of medicine for years without any adverse effects. Many studies have provided evidence for various traditional uses. However, there is a need for additional studies of the isolated compounds to validate the traditional uses in human models. The present review on the botany, traditional uses, phytochemistry and toxicity has provided preliminary information for further studies and commercial exploitations of the plant. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  13. Changes in the trophic structure of the northern Benguela before ...

    African Journals Online (AJOL)

    The dominant small pelagic fish, characteristic of upwelling systems, were replaced ... as did the weighted trophic level of the community (excluding plankton), after the ... may have altered the trophic control mechanism operating in the system, ...

  14. Missing lynx and trophic cascades in food webs: A reply to Ripple et al.

    Science.gov (United States)

    John R. Squires; Nicholas J. DeCesare; Mark Hebblewhite; Joel Berger

    2012-01-01

    Ripple et al. (2011) proposed a hypothesis that the recovery of gray wolves (Canis lupus) may positively affect the viability of threatened Canada lynx (Lynx canadensis) populations in the contiguous United States through indirect species interactions. Ripple et al. (2011) proposed 2 key trophic linkages connecting wolf restoration with lynx recovery. First, recovering...

  15. Trophic level stability-inducing effects of predaceous early juvenile fish in an estuarine mesocosm study.

    Directory of Open Access Journals (Sweden)

    Ryan J Wasserman

    Full Text Available Classically, estuarine planktonic research has focussed largely on the physico-chemical drivers of community assemblages leaving a paucity of information on important biological interactions.Within the context of trophic cascades, various treatments using in situ mesocosms were established in a closed estuary to highlight the importance of predation in stabilizing estuarine plankton abundances. Through either the removal (filtration or addition of certain planktonic groups, five different trophic systems were established. These treatments contained varied numbers of trophic levels and thus different "predators" at the top of the food chain. The abundances of zooplankton (copepod and polychaete, ciliate, micro-flagellate, nano-flagellate and bacteria were investigated in each treatment, over time. The reference treatment containing apex zooplanktivores (early juvenile mullet and plankton at natural densities mimicked a natural, stable state of an estuary. Proportional variability (PV and coefficient of variation (CV of temporal abundances were calculated for each taxon and showed that apex predators in this experimental ecosystem, when compared to the other systems, induced stability. The presence of these predators therefore had consequences for multiple trophic levels, consistent with trophic cascade theory.PV and CV proved useful indices for comparing stability. Apex predators exerted a stabilizing pressure through feeding on copepods and polychaetes which cascaded through the ciliates, micro-flagellates, nano-flagellates and bacteria. When compared with treatments without apex predators, the role of predation in structuring planktonic communities in closed estuaries was highlighted.

  16. First direct evidence of a vertebrate three-level trophic chain in the fossil record.

    Science.gov (United States)

    Kriwet, Jürgen; Witzmann, Florian; Klug, Stefanie; Heidtke, Ulrich H J

    2008-01-22

    We describe the first known occurrence of a Permian shark specimen preserving two temnospondyl amphibians in its digestive tract as well as the remains of an acanthodian fish, which was ingested by one of the temnospondyls. This exceptional find provides for the first time direct evidence of a vertebrate three-level food chain in the fossil record with the simultaneous preservation of three trophic levels. Our analysis shows that small-sized Lower Permian xenacanthid sharks of the genus Triodus preyed on larval piscivorous amphibians. The recorded trophic interaction can be explained by the adaptation of certain xenacanthids to fully freshwater environments and the fact that in these same environments, large temnospondyls occupied the niche of modern crocodiles. This unique faunal association has not been documented after the Permian and Triassic. Therefore, this Palaeozoic three-level food chain provides strong and independent support for changes in aquatic trophic chain structures through time.

  17. The exploration of trophic structure modeling using mass balance Ecopath model of Tangerang coastal waters

    Science.gov (United States)

    Dewi, N. N.; Kamal, M.; Wardiatno, Y.; Rozi

    2018-04-01

    Ecopath model approach was used to describe trophic interaction, energy flows and ecosystem condition of Tangerang coastal waters. This model consists of 42 ecological groups, of which 41 are living groups and one is a detritus group. Trophic levels of these groups vary between 1.0 (for primary producers and detritus) to 4.03 (for tetraodontidae). Groups with trophic levels 2≤TLfish, while detritus has a positive impact on the majority of demersal fish. Leiognathidae havea negative impact on phytoplankton, zooplankton and several other groups. System omnivory index for this ecosystem is 0.151. System primary production/respiration (P/R) ratio of Tangerang coastal waters is 1.505. This coastal ecosystem is an immatureecosystem because it hasdegraded. Pedigree index for this model is 0.57. This model describes ecosystem condition affected by overfishing and antropogenic activities. Therefore, through Ecopath model we provide some suggestions about the ecosystem-based fisheries management.

  18. Modeling lake trophic state: a random forest approach

    Science.gov (United States)

    Productivity of lentic ecosystems has been well studied and it is widely accepted that as nutrient inputs increase, productivity increases and lakes transition from low trophic state (e.g. oligotrophic) to higher trophic states (e.g. eutrophic). These broad trophic state classi...

  19. Modelling emergent trophic strategies in plankton

    DEFF Research Database (Denmark)

    Andersen, Ken Haste; Aksnes, Dag L.; Berge, Terje

    2015-01-01

    Plankton are typically divided into phytoplankton and zooplankton in marine ecosystem models. Yet, most protists in the photic zone engage in some degree of phagotrophy, and it has been suggested that trophic strategy is really a continuum between pure phototrophs (phytoplankton) and pure...

  20. Trophically available metal - A variable feast

    International Nuclear Information System (INIS)

    Rainbow, Philip S.; Luoma, Samuel N.; Wang Wenxiong

    2011-01-01

    Assimilation of trace metals by predators from prey is affected by the physicochemical form of the accumulated metal in the prey, leading to the concept of a Trophically Available Metal (TAM) component in the food item definable in terms of particular subcellular fractions of accumulated metal. As originally defined TAM consists of soluble metal forms and metal associated with cell organelles, the combination of separated fractions which best explained particular results involving a decapod crustacean predator feeding on bivalve mollusc tissues. Unfortunately TAM as originally defined has subsequently frequently been used in the literature as an absolute description of that component of accumulated metal that is trophically available in all prey to all consumers. It is now clear that what is trophically available varies between food items, consumers and metals. TAM as originally defined should be seen as a useful starting hypothesis, not as a statement of fact. - Trophically Available Metal (TAM), the component of accumulated metal in food that is taken up by a feeding animal, varies with food type and consumer.

  1. Trophically available metal - A variable feast

    Energy Technology Data Exchange (ETDEWEB)

    Rainbow, Philip S., E-mail: p.rainbow@nhm.ac.uk [Department of Zoology, Natural History Museum, Cromwell Rd, London SW7 5BD (United Kingdom); Luoma, Samuel N. [Department of Zoology, Natural History Museum, Cromwell Rd, London SW7 5BD (United Kingdom); John Muir Institute of the Environment, University of California, Davis, CA 95616 (United States); Wang Wenxiong [College of Marine and Environmental Sciences, State Key Laboratory for Marine Environmental Sciences, Xiamen University, Fujian (China)

    2011-10-15

    Assimilation of trace metals by predators from prey is affected by the physicochemical form of the accumulated metal in the prey, leading to the concept of a Trophically Available Metal (TAM) component in the food item definable in terms of particular subcellular fractions of accumulated metal. As originally defined TAM consists of soluble metal forms and metal associated with cell organelles, the combination of separated fractions which best explained particular results involving a decapod crustacean predator feeding on bivalve mollusc tissues. Unfortunately TAM as originally defined has subsequently frequently been used in the literature as an absolute description of that component of accumulated metal that is trophically available in all prey to all consumers. It is now clear that what is trophically available varies between food items, consumers and metals. TAM as originally defined should be seen as a useful starting hypothesis, not as a statement of fact. - Trophically Available Metal (TAM), the component of accumulated metal in food that is taken up by a feeding animal, varies with food type and consumer.

  2. Species richness and trophic diversity increase decomposition in a co-evolved food web.

    Directory of Open Access Journals (Sweden)

    Benjamin Baiser

    Full Text Available Ecological communities show great variation in species richness, composition and food web structure across similar and diverse ecosystems. Knowledge of how this biodiversity relates to ecosystem functioning is important for understanding the maintenance of diversity and the potential effects of species losses and gains on ecosystems. While research often focuses on how variation in species richness influences ecosystem processes, assessing species richness in a food web context can provide further insight into the relationship between diversity and ecosystem functioning and elucidate potential mechanisms underpinning this relationship. Here, we assessed how species richness and trophic diversity affect decomposition rates in a complete aquatic food web: the five trophic level web that occurs within water-filled leaves of the northern pitcher plant, Sarracenia purpurea. We identified a trophic cascade in which top-predators--larvae of the pitcher-plant mosquito--indirectly increased bacterial decomposition by preying on bactivorous protozoa. Our data also revealed a facultative relationship in which larvae of the pitcher-plant midge increased bacterial decomposition by shredding detritus. These important interactions occur only in food webs with high trophic diversity, which in turn only occur in food webs with high species richness. We show that species richness and trophic diversity underlie strong linkages between food web structure and dynamics that influence ecosystem functioning. The importance of trophic diversity and species interactions in determining how biodiversity relates to ecosystem functioning suggests that simply focusing on species richness does not give a complete picture as to how ecosystems may change with the loss or gain of species.

  3. Trophic diversity of Poznań Lakeland lakes

    Directory of Open Access Journals (Sweden)

    Dzieszko Piotr

    2015-06-01

    Full Text Available The main goal of the presented work is to determine the current trophic state of 31 lakes located in Poznań Lakeland. These lakes are included in the lake monitoring programme executed by the Voivodship Environmental Protection Inspectorate in Poznań. The place in the trophic classification for investigated lakes was determined as well as the relationships between their trophic state indices. The trophic state of investigated lakes in the research area is poor. More than a half of the investigated lakes are eutrophic. Depending on the factor that is taken into account the trophic state of investigated lakes differs radically.

  4. Table scraps: inter-trophic food provisioning by pumas.

    Science.gov (United States)

    Elbroch, L Mark; Wittmer, Heiko U

    2012-10-23

    Large carnivores perform keystone ecological functions through direct predation, or indirectly, through food subsidies to scavengers or trophic cascades driven by their influence on the distributions of their prey. Pumas (Puma concolor) are an elusive, cryptic species difficult to study and little is known about their inter-trophic-level interactions in natural communities. Using new GPS technology, we discovered that pumas in Patagonia provided 232 ± 31 kg of edible meat/month/100 km(2) to near-threatened Andean condors (Vultur gryphus) and other members of a diverse scavenger community. This is up to 3.1 times the contributions by wolves (Canis lupus) to communities in Yellowstone National Park, USA, and highlights the keystone role large, solitary felids play in natural systems. These findings are more pertinent than ever, for managers increasingly advocate controlling pumas and other large felids to bolster prey populations and mitigate concerns over human and livestock safety, without a full understanding of the potential ecological consequences of their actions.

  5. Global change in the trophic functioning of marine food webs.

    Directory of Open Access Journals (Sweden)

    Aurore Maureaud

    Full Text Available The development of fisheries in the oceans, and other human drivers such as climate warming, have led to changes in species abundance, assemblages, trophic interactions, and ultimately in the functioning of marine food webs. Here, using a trophodynamic approach and global databases of catches and life history traits of marine species, we tested the hypothesis that anthropogenic ecological impacts may have led to changes in the global parameters defining the transfers of biomass within the food web. First, we developed two indicators to assess such changes: the Time Cumulated Indicator (TCI measuring the residence time of biomass within the food web, and the Efficiency Cumulated Indicator (ECI quantifying the fraction of secondary production reaching the top of the trophic chain. Then, we assessed, at the large marine ecosystem scale, the worldwide change of these two indicators over the 1950-2010 time-periods. Global trends were identified and cluster analyses were used to characterize the variability of trends between ecosystems. Results showed that the most common pattern over the study period is a global decrease in TCI, while the ECI indicator tends to increase. Thus, changes in species assemblages would induce faster and apparently more efficient biomass transfers in marine food webs. Results also suggested that the main driver of change over that period had been the large increase in fishing pressure. The largest changes occurred in ecosystems where 'fishing down the marine food web' are most intensive.

  6. Invisible trophic links? Quantifying the importance of non-standard food sources for key intertidal avian predators in the Eastern Atlantic

    NARCIS (Netherlands)

    Lourenço, P.M.; Catry, T.; Lopes, R.J.; Piersma, T.; Granadeiro, J.P.

    2017-01-01

    Coastal wetlands are heterogeneous systems with multiple inputs and complex interactionswithin local food webs. Interpreting such complexity is limited by incomplete knowledgeof trophic interactions among organisms. Although widely recognized as secondary consumersand predators of intertidal

  7. Saussurea involucrata: A review of the botany, phytochemistry and ethnopharmacology of a rare traditional herbal medicine.

    Science.gov (United States)

    Chik, Wai-I; Zhu, Lin; Fan, Lan-Lan; Yi, Tao; Zhu, Guo-Yuan; Gou, Xiao-Jun; Tang, Yi-Na; Xu, Jun; Yeung, Wing-Ping; Zhao, Zhong-Zhen; Yu, Zhi-Ling; Chen, Hu-Biao

    2015-08-22

    Saussurea involucrata Matsum. & Koidz. is an endangered species of the Asteraceae family, growing in the high mountains of central Asia. It has been, and is, widely used in traditional Uyghur, Mongolian and Kazakhstan medicine as well as in Traditional Chinese Medicine as Tianshan Snow Lotus (Chinese: ). In traditional medical theory, S. involucrata can promote blood circulation, thereby alleviating all symptoms associated with poor circulation. It also reputedly eliminates cold and dampness from the body, diminishes inflammation, invigorates, and strengthens Yin and Yang. It has long been used to treat rheumatoid arthritis, cough with cold, stomach ache, dysmenorrhea, and altitude sickness in Uyghur and Chinese medicine. To comprehensively summarize the miscellaneous research that has been done regarding the botany, ethnopharmacology, phytochemistry, biological activity, and toxicology of S. involucrata. An extensive review of the literature was carried out. Apart from different electronic databases including SciFinder, Chinese National Knowledge Infrastructure (CNKI), ScienceDirect that were sourced for information, abstracts, full-text articles and books written in English and Chinese, including those traditional records tracing back to the Qing Dynasty. Pharmacopoeia of China and other local herbal records in Uighur, Mongolian and Kazakhstan ethnomedicines were investigated and compared for pertinent information. The phytochemistry of S. involucrata has been comprehensively investigated. More than 70 compounds have been isolated and identified; they include phenylpropanoids, flavonoids, coumarins, lignans, sesquiterpenes, steroids, ceramides, polysaccharides. Scientific studies on the biological activity of S. involucrata are equally numerous. The herb has been shown to have anti-neoplastic, anti-inflammatory, analgesic, anti-oxidative, anti-fatigue, anti-aging, anti-hypoxic, neuroprotective and immunomodulating effects. Many have shown correlations to the

  8. Ethnobotany, phytochemistry and neuropharmacological effects of Petiveria alliacea L. (Phytolaccaceae): A review.

    Science.gov (United States)

    Luz, Diandra Araújo; Pinheiro, Alana Miranda; Silva, Mallone Lopes; Monteiro, Marta Chagas; Prediger, Rui Daniel; Ferraz Maia, Cristiane Socorro; Fontes-Júnior, Enéas Andrade

    2016-06-05

    Petiveria alliacea L. commonly grows in the tropical regions of the Americas such as the Amazon forest, Central America, Caribbean islands and Mexico, as well as specific regions of Africa. Popularly known by several different names including 'mucuracaá', 'guiné' and 'pipi', P. alliacea has been used in traditional medicine for the treatment of various central nervous system (CNS) disorders, such as anxiety, pain, memory deficits and seizures, as well as for its anaesthetic and sedative properties. Furthermore, the use of this species for religious ceremonies has been reported since the era of slavery in the Americas. Therefore, the present review aims to provide a critical and comprehensive overview of the ethnobotany, phytochemistry and pharmacological properties of P. alliacea, focusing on CNS pharmacological effects, in order to identify scientific lacunae and to open new perspectives for future research. A literature search was performed on P. alliacea using ethnobotanical textbooks, published articles in peer-reviewed journals, unpublished materials, government survey reports and scientific databases such as PubMed, Scopus, Web of Science, Science Direct and Google Scholar. The Plant List, International Plant Name Index and Kew Botanical Garden Plant name databases were used to validate the scientific names. Crude extracts, fractions and phytochemical constituents isolated from various parts of P. alliacea show a wide spectrum of neuropharmacological activities including anxiolytic, antidepressant, antinociceptive and anti-seizure, and as cognitive enhancers. Phytochemistry studies of P. alliacea indicate that this plant contains a diversity of biologically active compounds, with qualitative and quantitative variations of the major compounds depending on the region of collection and the harvest season, such as essential oil (Petiverina), saponinic glycosides, isoarborinol-triterpene, isoarborinol-acetate, isoarborinol-cinnamate, steroids, alkaloids

  9. Ethnobotany, phytochemistry, toxicology and pharmacological properties of Terminalia sericea Burch. ex DC. (Combretaceae) - A review.

    Science.gov (United States)

    Mongalo, N I; McGaw, L J; Segapelo, T V; Finnie, J F; Van Staden, J

    2016-12-24

    The use of medicinal plants in the treatment of infections is ancient. A wide variety of ethnotherapeutic properties and pharmacological actions has been attributed to Terminalia sericea. Studies by various groups of investigators reveal that it is a multipurpose medicinal plant used mostly in the treatment of diarrhoea, sexually transmitted infections, skin rashes, tuberculosis and other infections. The current paper is aimed at providing an overview of the ethnomedicinal uses, toxicology, pharmacology and the phytochemistry of Terminalia sericea. Information was retrieved using various search engines, including Pubmed, Science Direct, Google Scholar, Scielo, SciFinder and Scopus. The key words used included Terminalia sericea, secondary metabolites, phytochemistry, biological activity, pharmacology, ethnobotanical survey, medicinal uses, safety, toxicology and other related words. Terminalia sericea is an important medicinal plant which possesses anti-HIV, anti-fungal, anti-bacterial, anticancer, lipolytic, wound healing, antiparasitic, anti-inflammatory and anti-oxidant activity, as the most valuable biological activities, thus lending pharmacological support to the plant's folkloric uses in indigenous medicine. Toxicologically, the extracts and isolated compounds from the plant species may have mild toxic effects. Phytochemically, the plant species possesses valuable compounds including triterpenes, alkaloids and flavonoids which may well contribute to its biological activity. Terminalia sericea contains secondary metabolites which are valuable in the treatment of a variety of human infections, including community acquired infections which may be prevalent in developing countries. The degree of toxicity reported in various extracts warrants further exploration of the cytotoxicity of the plant species, both against normal human cell lines and in vivo. Moreover, the acetylcholinesterase inhibitory and anti-inflammatory effects also need to be further

  10. Botany, ethnomedicines, phytochemistry and pharmacology of Himalayan paeony (Paeonia emodi Royle.).

    Science.gov (United States)

    Ahmad, Mushtaq; Malik, Khafsa; Tariq, Akash; Zhang, Guolin; Yaseen, Ghulam; Rashid, Neelam; Sultana, Shazia; Zafar, Muhammad; Ullah, Kifayat; Khan, Muhammad Pukhtoon Zada

    2018-06-28

    Himalayan paeony (Paeonia emodi Royle.) is an important species used to treat various diseases. This study aimed to compile the detailed traditional medicinal uses, phytochemistry, pharmacology and toxicological investigations on P. emodi. This study also highlights taxonomic validity, quality of experimental designs and shortcomings in previously reported information on Himalayan paeony. The data was extracted from unpublished theses (Pakistan, China, India and Nepal), and different published research articles confined to pharmacology, phytochemistry and antimicrobial activities using different databases through specific keywords. The relevant information regarding medicinal uses, taxonomic/common names, part used, collection and identification source, authentication, voucher specimen number, plant extracts and their characterization, isolation and identification of phytochemicals, methods of study in silico, in vivo or in vitro, model organism used, dose and duration, minimal active concentration, zone of inhibition (antimicrobial study), bioactive compound(s), mechanism of action on single or multiple targets, and toxicological information. P. emodi is reported for diverse medicinal uses with pharmacological properties like antioxidant, nephroprotective, lipoxygenase inhibitory, cognition and oxidative stress release, cytotoxic, anti-inflammatory, antiepileptic, anticonvulsant, haemaglutination, alpha-chymotrypsin inhibitory, hepatoprotective, hepatic chromes and pharmacokinetics of carbamazepine expression, β-glucuronidase inhibitory, spasmolytic and spasmogenic, and airway relaxant. Data confined to its taxonomic validity, shows 10% studies with correct taxonomic name while 90% studies with incorrect taxonomic, pharmacopeial and common names. The literature reviewed, shows lack of collection source (11 reports), without proper source of identification (15 reports), 33 studies without voucher specimen number, 26 reports lack information on authentic herbarium

  11. Trophic dynamics of a simple model ecosystem.

    Science.gov (United States)

    Bell, Graham; Fortier-Dubois, Étienne

    2017-09-13

    We have constructed a model of community dynamics that is simple enough to enumerate all possible food webs, yet complex enough to represent a wide range of ecological processes. We use the transition matrix to predict the outcome of succession and then investigate how the transition probabilities are governed by resource supply and immigration. Low-input regimes lead to simple communities whereas trophically complex communities develop when there is an adequate supply of both resources and immigrants. Our interpretation of trophic dynamics in complex communities hinges on a new principle of mutual replenishment, defined as the reciprocal alternation of state in a pair of communities linked by the invasion and extinction of a shared species. Such neutral couples are the outcome of succession under local dispersal and imply that food webs will often be made up of suites of trophically equivalent species. When immigrants arrive from an external pool of fixed composition a similar principle predicts a dynamic core of webs constituting a neutral interchange network, although communities may express an extensive range of other webs whose membership is only in part predictable. The food web is not in general predictable from whole-community properties such as productivity or stability, although it may profoundly influence these properties. © 2017 The Author(s).

  12. Trophic position of soil nematodes in boreal forests as indicated by stable isotope analysis

    Science.gov (United States)

    Kudrin, Alexey; Tsurikov, Sergey

    2016-04-01

    Despite the well-developed trophic classification of soil nematodes, their position in soil food webs is still little understood. Observed deviations from the typical feeding strategy indicate that a simplified trophic classification probably does not fully reflect actual trophic interactions. Furthermore, the extent and functional significance of nematodes as prey for other soil animals remains unknown. Stable isotope analysis (SIA) is powerful tool for investigating the structure of soil food webs, but its application to the study of soil nematodes has been limited to only a few studies. We used stable isotope analysis to gain a better understanding of trophic links of several groups of soil nematodes in two boreal forests on albeluvisol. We investigated four taxonomic groups of nematodes: Mononchida, Dorylaimida, Plectidae and Tylenchidae (mostly from the genus Filenchus), that according to the conventional trophic classification represent predators, omnivores, bacterivores and root-fungal feeders, respectively. To assess the trophic position of nematodes, we used a comparison against a set of reference species including herbivorous, saprophagous and predatory macro-invertebrates, oribatid and mesostigmatid mites, and collembolans. Our results suggest that trophic position of the investigated groups of soil nematodes generally corresponds to the conventional classification. All nematodes were enriched in 13C relative to Picea abies roots and litter, and mycorrhizal fungal mycelium. Root-fungal feeders Tylenchidae had δ15N values similar to those of earthworms, enchytraeids and Entomobrya collembolans, but slightly lower δ13C values. Bacterivorous Plectidae were either equal or enriched in 15N compared with saprophagous macroinvertebrates and most mesofauna species. Omnivorous Dorylaimida and predatory Mononchida were further enriched in 15N and their isotopic signature was similar to that of predatory arthropods. These data confirm a clear separation of

  13. Origins, Phytochemistry, Pharmacology, Analytical Methods and Safety of Cortex Moutan (Paeonia suffruticosa Andrew: A Systematic Review

    Directory of Open Access Journals (Sweden)

    Zhiqiang Wang

    2017-06-01

    Full Text Available Cortex Moutan (CM, a well-known traditional Chinese medicine, is commonly used for treating various diseases in China and other eastern Asian countries. Recorded in Pharmacopeias of several countries, CM is now drawing increasing attention and under extensive studies in various fields. Phytochemical studies indicate that CM contains many valuable secondary metabolites, such as monoterpene glycosides and phenols. Ample evidence from pharmacological researches suggest that CM has a wide spectrum of activities, such as anti-inflammatory, anti-oxidant, anti-tumor, anti-diabetic, cardiovascular protective, neuroprotective, hepatoprotective effects. Moreover, various analytical methods were established for the quality evaluation and safety control of CM. This review synopsizes updated information concerning the origins, phytochemistry, pharmacology, analytical method and safety of CM, aiming to provide favorable references for modern CM research and application. In conclusion, continuing pharmacological investigations concerning CM should be conducted to unravel its pharmacological mechanisms. Further researches are necessary to obtain comprehensive and applicable analytical approach for quality evaluation and establish harmonized criteria of CM.

  14. Phytochemistry of the carnivorous sundew genus Drosera (Droseraceae) - future perspectives and ethnopharmacological relevance.

    Science.gov (United States)

    Egan, Paul A; van der Kooy, Frank

    2013-10-01

    Species of the carnivorous genus Drosera L. have long been a source of valuable natural products. The various phytochemicals characteristic of these species, particularly 1,4-naphthoquinones and flavonoids, have contributed to the diverse utilization of sundews in traditional medicine systems worldwide. A growing number of studies have sought to investigate the comparative phytochemistry of Drosera species for improved sources of pharmaceutically important compounds. The outcomes of these studies are here collated, with emergent trends discussed in detail. Important factors which affect production of secondary metabolites in plants are critically examined, such as environmental influences and in vitro culture, and recommendations subsequently presented based on this. Explicitly, the current review aims to i) present an updated, comprehensive listing of the phytochemical constituents of the genus (including quantitative data where available), ii) summarize important factors which may influence the production of phytopharmaceuticals in plants, and iii) recommend guidelines for future research based on the above, including improved standardization and quality control. We have also included a section discussing future perspectives of research on Drosera spp. based on three different research lines i) the potential to produce much needed lead compounds for treatment of tuberculosis, ii) the potential role of anthocyanins in nitrogen transport, and iii) research into 'Natural Deep Eutectic' solvents produced by Drosera spp. in the droplets or 'dew' employed to capture insect prey. Copyright © 2013 Verlag Helvetica Chimica Acta AG, Zürich.

  15. Pharmacognosy, Phytochemistry and Pharmacological Properties of Achillea millefolium L.: A Review.

    Science.gov (United States)

    Ali, Sofi Imtiyaz; Gopalakrishnan, B; Venkatesalu, V

    2017-08-01

    Achillea millefoilum L. (Yarrow) is an important species of Asteraceae family with common utilization in traditional medicine of several cultures from Europe to Asia for the treatment of spasmodic gastrointestinal disorders, hepatobiliary, gynecological disorders, against inflammation and for wound healing. An extensive review of literature was made on A. millefoilum L. using ethno botanical text books, published articles in peer-reviewed journals, unpublished materials and scientific databases. The Plant List, International Plant Name Index and Kew Botanical Garden databases were used to authenticate the scientific names. Monoterpenes are the most representative metabolites constituting 90% of the essential oils in relation to the sesquiterpenes, and a wide range of chemical compounds have also been reported. Different pharmacological experiments in many in-vitro and in-vivo models have proved the potential of A. millefoilum with antiinflammatory, antiulcer, anticancer activities etc. lending support to the rationale behind numerous of its traditional uses. Due to the noteworthy pharmacological activities, A. millefoilum will be a better option for new drug discovery. The present review will comprehensively summarize the pharmacognosy, phytochemistry and ethnopharmacology of A. millefoilum reported to date, with emphasis on more in vitro, clinical and pathological studies needed to investigate the unexploited potential of this plant. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  16. Foeniculum vulgare Mill: A Review of Its Botany, Phytochemistry, Pharmacology, Contemporary Application, and Toxicology

    Directory of Open Access Journals (Sweden)

    Shamkant B. Badgujar

    2014-01-01

    Full Text Available Foeniculum vulgare Mill commonly called fennel has been used in traditional medicine for a wide range of ailments related to digestive, endocrine, reproductive, and respiratory systems. Additionally, it is also used as a galactagogue agent for lactating mothers. The review aims to gather the fragmented information available in the literature regarding morphology, ethnomedicinal applications, phytochemistry, pharmacology, and toxicology of Foeniculum vulgare. It also compiles available scientific evidence for the ethnobotanical claims and to identify gaps required to be filled by future research. Findings based on their traditional uses and scientific evaluation indicates that Foeniculum vulgare remains to be the most widely used herbal plant. It has been used for more than forty types of disorders. Phytochemical studies have shown the presence of numerous valuable compounds, such as volatile compounds, flavonoids, phenolic compounds, fatty acids, and amino acids. Compiled data indicate their efficacy in several in vitro and in vivo pharmacological properties such as antimicrobial, antiviral, anti-inflammatory, antimutagenic, antinociceptive, antipyretic, antispasmodic, antithrombotic, apoptotic, cardiovascular, chemomodulatory, antitumor, hepatoprotective, hypoglycemic, hypolipidemic, and memory enhancing property. Foeniculum vulgare has emerged as a good source of traditional medicine and it provides a noteworthy basis in pharmaceutical biology for the development/formulation of new drugs and future clinical uses.

  17. Alepidea amatymbica Eckl. & Zeyh.: A Review of Its Traditional Uses, Phytochemistry, Pharmacology, and Toxicology

    Directory of Open Access Journals (Sweden)

    O. A. Wintola

    2014-01-01

    Full Text Available Alepidea amatymbica is an important medicinal plant in Southern Africa with a long history of traditional use for the management of conditions like colds, coughs, sore throat, influenza, asthma, and abdominal cramps. Despite the much acclaimed traditional uses of the plant, there is a dearth of scientific information on the review of this plant. Hence, this review is aimed at providing information on the botany, phytochemistry, pharmacology, and toxicology of A. amatymbica. This review uses all the synonyms of the plant obtained from the plant list. Google scholar, Science Direct, PubMed, and Scopus were made use of in addition to the University of Fort Hare’s online databases. All the phytochemical studies on Alepidea amatymbica obtained from the literature reported the presence of kaurene-type diterpenoids and their derivatives. Pharmacological areas identified on A. amatymbica fresh and dried extract include antibacterial, antifungal, sedative, astringent, antimalarial, anti-inflammatory, antihelminthes, antihypertensive, anti-HIV, and diuretic activities. Literature search on A. amatymbica revealed the use of cell line, brine shrimps, and rats for the determination of the toxicity in the plant. Clinical trials and product development to fully exploit the medicinal value are also required to validate its folklore use in traditional medicine.

  18. Phytochemistry and gastrointestinal benefits of the medicinal spice, Capsicum annuum L. (Chilli): a review.

    Science.gov (United States)

    Maji, Amal K; Banerji, Pratim

    2016-06-01

    Dietary spices and their active constituents provide various beneficial effects on the gastrointestinal system by variety of mechanisms such as influence of gastric emptying, stimulation of gastrointestinal defense and absorption, stimulation of salivary, intestinal, hepatic, and pancreatic secretions. Capsicum annuum (Solanaceae), commonly known as chilli, is a medicinal spice used in various Indian traditional systems of medicine and it has been acknowledged to treat various health ailments. Therapeutic potential of chilli and capsaicin were well documented; however, they act as double-edged sword in many physiological circumstances. In traditional medicine chilli has been used against various gastrointestinal complains such as dyspepsia, loss of appetite, gastroesophageal reflux disease, gastric ulcer, and so on. In chilli, more than 200 constituents have been identified and some of its active constituents play numerous beneficial roles in various gastrointestinal disorders such as stimulation of digestion and gastromucosal defense, reduction of gastroesophageal reflux disease (GERD) symptoms, inhibition of gastrointestinal pathogens, ulceration and cancers, regulation of gastrointestinal secretions and absorptions. However, further studies are warranted to determine the dose ceiling limit of chilli and its active constituents for their utilization as gastroprotective agents. This review summarizes the phytochemistry and various gastrointestinal benefits of chilli and its various active constituents.

  19. Traditional Uses, Phytochemistry, and Bioactivities of Cananga odorata (Ylang-Ylang)

    Science.gov (United States)

    Tan, Loh Teng Hern; Lee, Learn Han; Yin, Wai Fong; Chan, Chim Kei; Chan, Kok Gan

    2015-01-01

    Ylang-ylang (Cananga odorata Hook. F. & Thomson) is one of the plants that are exploited at a large scale for its essential oil which is an important raw material for the fragrance industry. The essential oils extracted via steam distillation from the plant have been used mainly in cosmetic industry but also in food industry. Traditionally, C. odorata is used to treat malaria, stomach ailments, asthma, gout, and rheumatism. The essential oils or ylang-ylang oil is used in aromatherapy and is believed to be effective in treating depression, high blood pressure, and anxiety. Many phytochemical studies have identified the constituents present in the essential oils of C. odorata. A wide range of chemical compounds including monoterpene, sesquiterpenes, and phenylpropanoids have been isolated from this plant. Recent studies have shown a wide variety of bioactivities exhibited by the essential oils and the extracts of C. odorata including antimicrobial, antibiofilm, anti-inflammatory, antivector, insect-repellent, antidiabetic, antifertility and antimelanogenesis activities. Thus, the present review summarizes the information concerning the traditional uses, phytochemistry, and biological activities of C. odorata. This review is aimed at demonstrating that C. odorata not only is an important raw material for perfume industry but also considered as a prospective useful plant to agriculture and medicine. PMID:26294929

  20. Clinacanthus nutans: A review of the medicinal uses, pharmacology and phytochemistry.

    Science.gov (United States)

    Alam, Ariful; Ferdosh, Sahena; Ghafoor, Kashif; Hakim, Abdul; Juraimi, Abdul Shukor; Khatib, Alfi; Sarker, Zaidul I

    2016-04-01

    Clinacanthus nutans Lindau is known as snake grass belonging to the Acanthaceae family. This plant has diverse and potential medicinal uses in traditional herbal medicine for treating skin rashes, insects and snake bites, lesions caused by herpes simplex virus, diabetes, and gout in Malaysia, Indonesia, Thailand and China. Phytochemical investigations documented the varied contents of bioactive compounds from this plant namely flavonoids, glycosides, glycoglycerolipids, cerebrosides and monoacylmonogalatosylglycerol. The pharmacological experiment proved that various types of extracts and pure compounds from this species exhibited a broad range of biological properties such as anti-inflammatory, antiviral, antioxidant, and anti-diabetic activities. The findings of toxicity study showed that extracts from this plant did not show any toxicity thus it can be used as strong therapeutic agents for specific diseased conditions. However, further experiments on chemical components and their mode of action showing biological activities are required to elucidate the complete phytochemical profile and assess to confirm their suitability for future drugs. This review summarizes the medicinal uses, phytochemistry and pharmacology of this plant in order to explore its therapeutic potential and gaps necessitating for prospected research work. Copyright © 2016 Hainan Medical College. Production and hosting by Elsevier B.V. All rights reserved.

  1. A review on the ethnomedicinal uses, phytochemistry and pharmacology of Alpinia officinarum Hance.

    Science.gov (United States)

    Abubakar, Ibrahim Babangida; Malami, Ibrahim; Yahaya, Yakubu; Sule, Sahabi Manga

    2018-05-25

    Alpinia officinarum Hance is a perennial plant that has been traditionally used for many decades to treat several ailments including inflammation, pain, stomach-ache, cold, amongst others. Pharmacological studies over the years have demonstrated remarkable bioactivities that could be further explored for development of new therapeutic agents against various ailments. The paper critically reviewed the ethno-medicinal uses, pharmacology, and phytochemistry of A. officinarum. Keywords including A. officinarum and its synonyms were searched using electronic databases including ISI web of knowledge, Science direct, Scopus, PubMed, Google scholar and relevant database for Masters and Doctoral theses. A. officinarum is prepared in Asia, Turkey, Morocco and Iran as a decoction, infusion or juice as a single preparation or in combination with other herbs, food or drinks for the treatment of general health problems including cold, inflammation, digestive disorders, etc. Pharmacological studies revealed the potent in vitro and in vivo bioactivities of various parts of A. officinarum that include anti-inflammatory, cytotoxicity, homeostasis, lipid regulation, antioxidant, antiviral, antimicrobial, antiosteoporosis, etc. Over 90 phytochemical constituents have been identified and isolated from A. officinarum comprising vastly of phenolic compounds especially diarylheptanoids isolated from the rhizome and considered the most active bioactive components. In vitro and in vivo studies have confirmed the potency of A. officinarum. However, further studies are required to establish the mechanisms mediating its bioactivities in relation to the medicinal uses as well as investigating any potential toxicity for future clinical studies. Copyright © 2018 Elsevier B.V. All rights reserved.

  2. IMPPAT: A curated database of Indian Medicinal Plants, Phytochemistry And Therapeutics.

    Science.gov (United States)

    Mohanraj, Karthikeyan; Karthikeyan, Bagavathy Shanmugam; Vivek-Ananth, R P; Chand, R P Bharath; Aparna, S R; Mangalapandi, Pattulingam; Samal, Areejit

    2018-03-12

    Phytochemicals of medicinal plants encompass a diverse chemical space for drug discovery. India is rich with a flora of indigenous medicinal plants that have been used for centuries in traditional Indian medicine to treat human maladies. A comprehensive online database on the phytochemistry of Indian medicinal plants will enable computational approaches towards natural product based drug discovery. In this direction, we present, IMPPAT, a manually curated database of 1742 Indian Medicinal Plants, 9596 Phytochemicals, And 1124 Therapeutic uses spanning 27074 plant-phytochemical associations and 11514 plant-therapeutic associations. Notably, the curation effort led to a non-redundant in silico library of 9596 phytochemicals with standard chemical identifiers and structure information. Using cheminformatic approaches, we have computed the physicochemical, ADMET (absorption, distribution, metabolism, excretion, toxicity) and drug-likeliness properties of the IMPPAT phytochemicals. We show that the stereochemical complexity and shape complexity of IMPPAT phytochemicals differ from libraries of commercial compounds or diversity-oriented synthesis compounds while being similar to other libraries of natural products. Within IMPPAT, we have filtered a subset of 960 potential druggable phytochemicals, of which majority have no significant similarity to existing FDA approved drugs, and thus, rendering them as good candidates for prospective drugs. IMPPAT database is openly accessible at: https://cb.imsc.res.in/imppat .

  3. Traditional Uses, Phytochemistry, and Bioactivities of Cananga odorata (Ylang-Ylang

    Directory of Open Access Journals (Sweden)

    Loh Teng Hern Tan

    2015-01-01

    Full Text Available Ylang-ylang (Cananga odorata Hook. F. & Thomson is one of the plants that are exploited at a large scale for its essential oil which is an important raw material for the fragrance industry. The essential oils extracted via steam distillation from the plant have been used mainly in cosmetic industry but also in food industry. Traditionally, C. odorata is used to treat malaria, stomach ailments, asthma, gout, and rheumatism. The essential oils or ylang-ylang oil is used in aromatherapy and is believed to be effective in treating depression, high blood pressure, and anxiety. Many phytochemical studies have identified the constituents present in the essential oils of C. odorata. A wide range of chemical compounds including monoterpene, sesquiterpenes, and phenylpropanoids have been isolated from this plant. Recent studies have shown a wide variety of bioactivities exhibited by the essential oils and the extracts of C. odorata including antimicrobial, antibiofilm, anti-inflammatory, antivector, insect-repellent, antidiabetic, antifertility and antimelanogenesis activities. Thus, the present review summarizes the information concerning the traditional uses, phytochemistry, and biological activities of C. odorata. This review is aimed at demonstrating that C. odorata not only is an important raw material for perfume industry but also considered as a prospective useful plant to agriculture and medicine.

  4. Traditional uses, phytochemistry and pharmacology of the medicinal species of the genus Cordia (Boraginaceae).

    Science.gov (United States)

    Oza, Manisha J; Kulkarni, Yogesh A

    2017-07-01

    Cordia (family Boraginaceae) is a genus of deciduous flowering trees or shrubs comprising more than 300 species distributed widely in the tropical regions. The aim of this review was to provide exhaustive scientific information on traditional uses, phytochemistry and pharmacological activities of the 36 important species with medicinal value from the genus Cordia, to divulge prospects for further research on its therapeutic potential. Leaves, fruit, bark and seed of a majority of the species were found to possess abundant ethnomedicinal value, but leaves were found to be used most frequently to treat many ailments such as respiratory disorders, stomach pain, wound, inflammation, myalgia, cough, dysentery and diarrhoea. The phytochemical investigation of 36 species resulted in isolation of 293 chemical constituents from various chemical classes. The crude extracts, fractions, essential oils and pure compounds isolated from various Cordia species were reported to have a varied range of pharmacological activities. Many of the traditional uses of the genus Cordia were supported by the results obtained from pharmacological studies performed using various extracts or pure compounds. More attention should be given to the biological evaluation using pure phytochemicals and to identify the mechanism of actions and exploring this genus for new drug discovery. © 2017 Royal Pharmaceutical Society.

  5. A Review of the Botany, Phytochemistry, Pharmacology and Toxicology of Rubiae Radix et Rhizoma

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    Mingqiu Shan

    2016-12-01

    Full Text Available Rubia cordifolia Linn (Rubiaceae is a climbing perennial herbal plant, which is widely distributed in China and India. Its root and rhizome, Rubiae Radix et Rhizoma (called Qiancao in China and Indian madder in India, is a well known phytomedicine used for hematemesis, epistaxis, flooding, spotting, traumatic bleeding, amenorrhea caused by obstruction, joint impediment pain, swelling and pain caused by injuries from falls. In addition, it is a kind of pigment utilized as a food additive and a dye for wool or fiber. This review mainly concentrates on studies of the botany, phytochemistry, pharmacology and toxicology of this Traditional Chinese Medicine. The phytochemical evidences indicated that over a hundred chemical components have been found and isolated from the medicine, such as anthraquinones, naphthoquinones, triterpenoids, cyclic hexapeptides and others. These components are considered responsible for the various bioactivities of the herbal drug, including anti-oxidation, anti-inflammation, immunomodulation, antitumor, effects on coagulation-fibrinolysis system, neuroprotection and other effects. Additionally, based on these existing results, we also propose some interesting future research directions. Consequently, this review should help us to more comprehensively understand and to more fully utilize the herbal medicine Rubiae Radix et Rhizoma.

  6. Medicinal Uses, Phytochemistry, and Pharmacology of Origanum onites (L.): A Review.

    Science.gov (United States)

    Tepe, Bektas; Cakir, Ahmet; Sihoglu Tepe, Arzuhan

    2016-05-01

    Origanum onites L., known as Turkish oregano, has great traditional, medicinal, preservative, and commercial importance. It is used for the treatment of several kinds of ailments, such as gastrointestinal disorders, diabetes, high cholesterol, leukemia, bronchitis, etc. In this review, traditional use, phytochemistry, and pharmacology of O. onites reported between 1988 and 2014 were discussed. This review was prepared based on literature survey on scientific journals and books from libraries and electronic sources, such as Web of Science, PubMed, Scopus, Google Scholar, etc. All databases were searched up to June 2014. Several different classes of terpenoids, triterpene acids, phenolic acids, hydroquinones, flavonoids, hydrocarbons, sterols, pigments, fatty acids, tocopherols, and inorganic compounds were detected mainly in the aerial parts of this plant. Pharmacological studies revealed that extracts obtained from several solvents and individual compounds exhibited antimicrobial, antiviral, antioxidant, insecticidal, anticancer, hepatoprotective, genotoxic, antidiabetic, cholinesterase inhibitory, anti-inflammatory, analgesic activities, etc. O. onites, in general, exhibited remarkable activity potential in almost all test systems. The results of toxicity studies indicated that O. onites did not show any significant toxicity and mutagenicity on Drosophila and Salmonella. Toxicity of the extracts/essential oils and also individual compounds should be evaluated on mammalian cells to ensure their safety. The bioactivity of individual compounds aside from terpenoids should also be assessed in detail. Additionally, mode of action for the bioactive compounds should be evaluated to understand the complex pharmacological effects of these phytochemicals. © 2016 Verlag Helvetica Chimica Acta AG, Zürich.

  7. A review on ethnobotany, phytochemistry and pharmacology of plant genus Caralluma R. Br.

    Science.gov (United States)

    Adnan, Muhammad; Jan, Saleem; Mussarat, Sakina; Tariq, Akash; Begum, Shaheen; Afroz, Anila; Shinwari, Zabta Khan

    2014-10-01

    Caralluma is a xerophytic genus used as traditional medicine for the treatment of diabetes, inflammation, leprosy, obesity and rheumatism. Objectives of this review are to establish a relationship between traditional uses and scientific studies by critically evaluating the available fragmented literature on ethnobotany, pharmacology, phytochemistry and toxicology of genus Caralluma. Ethnomedical uses of Caralluma have been recorded from various countries such as China, India, Iran and Pakistan for six major classes of diseases including diabetes and gastrointestinal disorders. This review indicated the efficacy of genus Caralluma in several in vitro and in vivo pharmacological properties such as antimicrobial, antioxidant and anticancer activity. These bioactivity might be due to the presence of certain classes of compounds in genus Caralluma including pregnane glycosides, flavonoid glycosides and flavones. Traditional uses and scientific evaluation of Caralluma indicates that it is one of the most widely used genus in some parts of the world. Further studies on the structural activity relationship of some of the isolated compound may improve their biological potency as well as scientific exploitation of traditional uses of the genus. © 2014 Royal Pharmaceutical Society.

  8. Syzygium Cordatum Hochst. ex Krauss: An Overview of Its Ethnobotany, Phytochemistry and Pharmacological Properties

    Directory of Open Access Journals (Sweden)

    Alfred Maroyi

    2018-05-01

    Full Text Available Syzygium cordatum is a valuable medicinal plant in the materia medica of east and southern Africa. The aim of this study was to review the botany, medicinal uses, phytochemistry and ethnopharmacological properties of S. cordatum. Relevant literature search was carried out using internet sources such as ACS, Web of Science, Wiley, SpringerLink, Scopus, Mendeley, Google Scholar, Pubmed, SciFinder, BioMed Central, Science Direct and Elsevier. Other literature sources were conference papers, book chapters, books, theses and websites. The leaves, roots, bark and fruits of S. cordatum are used as ethnomedicines against 24 human diseases such as gastro-intestinal disorders, burns, sores, wounds, colds, cough, respiratory complaints, sexually transmitted infections (STIs, tuberculosis, fever and malaria. Several phytochemical compounds including alkaloids, anthocyanidin, essential oils, flavonoids, leucoanthocyanidin, phenols, phytosterols, saponins, simple sugars, terpenoids and triterpenoid have been identified from S. cordatum. Pharmacological evaluations revealed that S. cordatum is characterized by several biological activities including antibacterial, antifungal, antidiarrheal, anti-sexually transmitted infections, antidiabetic, anticholinesterase, anti-inflammatory, antileishmanial, antioxidant, antiplasmodial and anti-proteus. These pharmacological findings lend credence to the traditional ethnomedicinal uses and ethnopharmacological importance of S. cordatum. Future research on the species should identify the biological compounds, their mode of action and physiological pathways and clinical relevance.

  9. A Review of the Botany, Phytochemistry, Pharmacology and Toxicology of Rubiae Radix et Rhizoma.

    Science.gov (United States)

    Shan, Mingqiu; Yu, Sheng; Yan, Hui; Chen, Peidong; Zhang, Li; Ding, Anwei

    2016-12-20

    Rubia cordifolia Linn (Rubiaceae) is a climbing perennial herbal plant, which is widely distributed in China and India. Its root and rhizome, Rubiae Radix et Rhizoma (called Qiancao in China and Indian madder in India), is a well known phytomedicine used for hematemesis, epistaxis, flooding, spotting, traumatic bleeding, amenorrhea caused by obstruction, joint impediment pain, swelling and pain caused by injuries from falls. In addition, it is a kind of pigment utilized as a food additive and a dye for wool or fiber. This review mainly concentrates on studies of the botany, phytochemistry, pharmacology and toxicology of this Traditional Chinese Medicine. The phytochemical evidences indicated that over a hundred chemical components have been found and isolated from the medicine, such as anthraquinones, naphthoquinones, triterpenoids, cyclic hexapeptides and others. These components are considered responsible for the various bioactivities of the herbal drug, including anti-oxidation, anti-inflammation, immunomodulation, antitumor, effects on coagulation-fibrinolysis system, neuroprotection and other effects. Additionally, based on these existing results, we also propose some interesting future research directions. Consequently, this review should help us to more comprehensively understand and to more fully utilize the herbal medicine Rubiae Radix et Rhizoma.

  10. Botany, Phytochemistry, Pharmacology and Toxicity of Strychnos nux-vomica L.: A Review.

    Science.gov (United States)

    Guo, Rixin; Wang, Ting; Zhou, Guohong; Xu, Mengying; Yu, Xiankuo; Zhang, Xiao; Sui, Feng; Li, Chun; Tang, Liying; Wang, Zhuju

    2018-01-01

    Strychnos nux-vomica L. belongs to the genus Strychnos of the family Loganiaceae and grows in Sri Lanka, India and Australia. The traditional medicinal component is its seed, called Nux vomica. This study provides a relevant and comprehensive review of S. nux-vomica L., including its botany, ethnopharmacology, phytochemistry, pharmacology and toxicology, thus providing a foundation for future studies. Up to the present day, over 84 compounds, including alkaloids, iridoid glycosides, flavonoid glycosides, triterpenoids, steroids and organic acids, among others, have been isolated and identified from S. nux-vomica. These compounds possess an array of biological activities, including effects on the nervous system, analgesic and anti-inflammatory actions, antitumor effects, inhibition of the growth of pathogenic microorganisms and regulation of immune function. Furthermore, toxicity and detoxification methods are preliminarily discussed toward the end of this review. In further research on S. nux-vomica, bioactivity-guided isolation strategies should be emphasized. Its antitumor effects should be investigated further and in vivo animal experiments should be performed alongside in vitro testing. The pharmacological activity and toxicology of strychnine [Formula: see text]-oxide and brucine [Formula: see text]-oxide should be studied to explore the detoxification mechanism associated with processing more deeply.

  11. Euclea undulata Thunb.: Review of its botany, ethnomedicinal uses, phytochemistry and biological activities.

    Science.gov (United States)

    Maroyi, Alfred

    2017-11-01

    Euclea undulata (E. undulata) is traditionally used for the treatment of body pains, chest complaints, cough, diabetes, diarrhoea, headaches, heart diseases and toothaches in southern Africa. This study was aimed at reviewing the botany, ethnopharmacology and biological activities of E. undulata in southern Africa. Results presented in this study are based on review of literature using search engines such as Science Direct, Springerlink, Scopus, PubMed, Web of Science, BioMed Central and Google Scholar. Herbal medicine is prepared from the decoctions of the roots, bark and leaves, and extracts of these plant parts have demonstrated anticholinesterase, anti-inflammatory, antimicrobial, antimycobacterial, antiplasmodial, antioxidant and hypoglycaemic activities. Multiple classes of phytochemical compounds such alkaloids, diterpenes, fatty acids, flavonoids, glycosides, naphthoquinones, phenolics, phytosterols, reducing sugars, saponins and tannins have been isolated from the species. E. undulata has a lot of potential as herbal medicine in tropical Africa, and advanced research is required aimed at correlating its medicinal uses with the phytochemistry and pharmacological properties. Copyright © 2017 Hainan Medical University. Production and hosting by Elsevier B.V. All rights reserved.

  12. Euphorbia neriifolia L.: Review on botany, ethnomedicinal uses, phytochemistry and biological activities.

    Science.gov (United States)

    Mali, Prashant Y; Panchal, Shital S

    2017-05-01

    The present review is intended to provide information on botany, ethnomedicinal uses, phytochemistry and biological activities of various parts of Euphorbia neriifolia (E. neriifolia). E. neriifolia has several ethnomedicinal uses. The latex of E. neriifolia is used as laxative, purgative, rubefacient, carminative and expectorant as well as in treatment of whooping cough, gonorrhoea, leprosy, asthma, dyspepsia, jaundice, enlargement of the spleen, tumours, stone in the bladder, abdominal troubles and leucoderma. Leaves are brittle, heating, carminative, and good for improving the appetite and treatment of tumours, pains, inflammations, abdominal swellings and bronchial infections. Roots are used as symptomatic treatment of snake bite, scorpion sting and antispasmodic. Various plant parts or whole E. neriifolia extract and its isolates have been reported scientifically using various in-vivo and in-vitro experimental methods for anaesthetic, analgesic, anti-anxiety, anti-convulsant, anti-psychotic, anti-arthritis, anti-carcinogenic, antidiabetic, anti-diarrhoeal, anti-inflammatory, anti-thrombotic, antimicrobial, antioxidant, antiulcer, cytotoxic, death-receptor expression enhancing, dermal irritation, diuretic, haemolytic, immunomodulatory, radioprotective, scorpion venom and wound healing properties. It is reported to have chemical constituents like, neriifolin-S, neriifolin, neriifoliene, euphol, neriifolione, cycloartenol, nerifoliol, lectin, euphonerins A-G, 3-O-acetyl-8-O-tigloylingol, taraxerol, antiquorin, etc. Identified chemical constituents are still required to be explored for their advanced isolation techniques and biological activities. Copyright © 2017 Hainan Medical University. Production and hosting by Elsevier B.V. All rights reserved.

  13. Trait- and size-based descriptions of trophic links in freshwater food webs: current status and perspectives

    Directory of Open Access Journals (Sweden)

    David S. Boukal

    2014-04-01

    Full Text Available Biotic interactions in aquatic communities are dominated by predation, and the distribution of trophic link strengths in aquatic food webs crucially impacts their dynamics and stability. Although individual body size explains a large proportion of variation in trophic link strengths in aquatic habitats, current predominately body size-based views can gain additional realism by incorporating further traits. Functional traits that potentially affect the strength of trophic links can be classified into three groups: i body size, ii traits that identify the spatiotemporal overlap between the predators and their prey, and iii predator foraging and prey vulnerability traits, which are readily available for many taxa. Relationship between these trait groups and trophic link strength may be further modified by population densities, habitat complexity, temperature and other abiotic factors. I propose here that this broader multi-trait framework can utilize concepts, ideas and existing data from research on metabolic ecology, ecomorphology, animal personalities and role of habitats in community structuring. The framework can be used to investigate non-additive effects of traits on trophic interactions, shed more light on the structuring of local food webs and evaluate the merits of taxonomic and functional group approaches in the description of predator-prey interactions. Development of trait- and size-based descriptions of food webs could be particularly fruitful in limnology given the relative paucity of well resolved datasets in standing waters. 

  14. Traditional uses, botany, phytochemistry, pharmacology and toxicology of Panax notoginseng (Burk.) F.H. Chen: A review.

    Science.gov (United States)

    Wang, Ting; Guo, Rixin; Zhou, Guohong; Zhou, Xidan; Kou, Zhenzhen; Sui, Feng; Li, Chun; Tang, Liying; Wang, Zhuju

    2016-07-21

    Panax notoginseng (Burk.) F.H. Chen is a widely used traditional Chinese medicine known as Sanqi or Tianqi in China. This plant, which is distributed primarily in the southwest of China, has wide-ranging pharmacological effects and can be used to treat cardiovascular diseases, pain, inflammation and trauma as well as internal and external bleeding due to injury. This paper provides up-to-date information on investigations of this plant, including its botany, ethnopharmacology, phytochemistry, pharmacology and toxicology. The possible uses and perspectives for future investigation of this plant are also discussed. The relevant information on Panax notoginseng (Burk.) F.H. Chen was collected from numerous resources, including classic books about Chinese herbal medicine, and scientific databases, including Pubmed, SciFinder, ACS, Ebsco, Elsevier, Taylor, Wiley and CNKI. More than 200 chemical compounds have been isolated from Panax notoginseng (Burk.) F.H. Chen, including saponins, flavonoids and cyclopeptides. The plant has pharmacological effects on the cardiovascular system, immune system as well as anti-inflammatory, anti-atherosclerotic, haemostatic and anti-tumour activities, etc. Panax notoginseng is a valuable traditional Chinese medical herb with multiple pharmacological effects. This review summarizes the botany, ethnopharmacology, phytochemistry, pharmacology and toxicology of P. notoginseng, and presents the constituents and their corresponding chemical structures found in P. notoginseng comprehensively for the first time. Future research into its phytochemistry of bio-active components should be performed by using bioactivity-guided isolation strategies. Further work on elucidation of the structure-function relationship among saponins, understanding of multi-target network pharmacology of P. notoginseng, as well as developing its new clinical usage and comprehensive utilize will enhance the therapeutic potentials of P. notoginseng. Copyright © 2016

  15. Damped trophic cascades driven by fishing in model marine ecosystems

    DEFF Research Database (Denmark)

    Andersen, Ken Haste; Pedersen, Martin

    2010-01-01

    The largest perturbation on upper trophic levels of many marine ecosystems stems from fishing. The reaction of the ecosystem goes beyond the trophic levels directly targeted by the fishery. This reaction has been described either as a change in slope of the overall size spectrum or as a trophic...... cascade triggered by the removal of top predators. Here we use a novel size- and trait-based model to explore how marine ecosystems might react to perturbations from different types of fishing pressure. The model explicitly resolves the whole life history of fish, from larvae to adults. The results show...... that fishing does not change the overall slope of the size spectrum, but depletes the largest individuals and induces trophic cascades. A trophic cascade can propagate both up and down in trophic levels driven by a combination of changes in predation mortality and food limitation. The cascade is damped...

  16. Invasive ants compete with and modify the trophic ecology of hermit crabs on tropical islands.

    Science.gov (United States)

    McNatty, Alice; Abbott, Kirsti L; Lester, Philip J

    2009-05-01

    Invasive species can dramatically alter trophic interactions. Predation is the predominant trophic interaction generally considered to be responsible for ecological change after invasion. In contrast, how frequently competition from invasive species contributes to the decline of native species remains controversial. Here, we demonstrate how the trophic ecology of the remote atoll nation of Tokelau is changing due to competition between invasive ants (Anoplolepis gracilipes) and native terrestrial hermit crabs (Coenobita spp.) for carrion. A significant negative correlation was observed between A. gracilipes and hermit crab abundance. On islands with A. gracilipes, crabs were generally restricted to the periphery of invaded islands. Very few hermit crabs were found in central areas of these islands where A. gracilipes abundances were highest. Ant exclusion experiments demonstrated that changes in the abundance and distribution of hermit crabs on Tokelau are a result of competition. The ants did not kill the hermit crabs. Rather, when highly abundant, A. gracilipes attacked crabs by spraying acid and drove crabs away from carrion resources. Analysis of naturally occurring N and C isotopes suggests that the ants are effectively lowering the trophic level of crabs. According to delta(15) N values, hermit crabs have a relatively high trophic level on islands where A. gracilipes have not invaded. In contrast, where these ants have invaded we observed a significant decrease in delta(15) N for all crab species. This result concurs with our experiment in suggesting long-term exclusion from carrion resources, driving co-occurring crabs towards a more herbivorous diet. Changes in hermit crab abundance or distribution may have major ramifications for the stability of plant communities. Because A. gracilipes have invaded many tropical islands where the predominant scavengers are hermit crabs, we consider that their competitive effects are likely to be more prominent in

  17. Responses of trophic structure and zooplankton community to salinity and temperature in Tibetan lakes: Implication for the effect of climate warming.

    Science.gov (United States)

    Lin, Qiuqi; Xu, Lei; Hou, Juzhi; Liu, Zhengwen; Jeppesen, Erik; Han, Bo-Ping

    2017-11-01

    Warming has pronounced effects on lake ecosystems, either directly by increased temperatures or indirectly by a change in salinity. We investigated the current status of zooplankton communities and trophic structure in 45 Tibetan lakes along a 2300 m altitude and a 76 g/l salinity gradient. Freshwater to hyposaline lakes mainly had three trophic levels: phytoplankton, small zooplankton and fish/Gammarus, while mesosaline to hypersaline lakes only had two: phytoplankton and large zooplankton. Zooplankton species richness declined significantly with salinity, but did not relate with temperature. Furthermore, the decline in species richness with salinity in lakes with two trophic levels was much less abrupt than in lakes with three trophic levels. The structural variation of the zooplankton community depended on the length of the food chain, and was significantly explained by salinity as the critical environmental variable. The zooplankton community shifted from dominance of copepods and small cladoceran species in the lakes with low salinity and three trophic levels to large saline filter-feeding phyllopod species in those lakes with high salinity and two trophic levels. The zooplankton to phytoplankton biomass ratio was positively related with temperature in two-trophic-level systems and vice versa in three-trophic-level systems. As the Tibetan Plateau is warming about three times faster than the global average, our results imply that warming could have a considerable impact on the structure and function of Tibetan lake ecosystems, either via indirect effects of salinization/desalinization on species richness, composition and trophic structure or through direct effects of water temperature on trophic interactions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. POTENTIAL FOR DEVELOPMENT OF INTEGRATED MULTI-TROPHIC AQUACULTURE (IMTA IN THE ADRIATIC SEA

    Directory of Open Access Journals (Sweden)

    Danijel Kanski

    2012-12-01

    Full Text Available Over recent years, scientific interest for investigating ecological, economical and social effects of Integrated Multi-trophic Aquaculture (IMTA has increased worldwide. Its development in the Mediterranean, including the Adriatic Sea, is still in the early stages. The main obstacle preventing IMTA to be commercially adopted is the lack of scientific information on choosing compatible species, knowing the carrying capacity of a production area and interactions between species feeding at different trophic levels, as well as its socio–economic impacts. Current experience in the area is based on smaller experimental studies of local importance but they generally give a good insight into potential of IMTA and its interactions with the environment. The aim of this paper was to overview current literature and experiences worldwide and to review the potential for adopting IMTA principles in the Adriatic Sea.

  19. Uncovering trophic positions and food resources of soil animals using bulk natural stable isotope composition.

    Science.gov (United States)

    Potapov, Anton M; Tiunov, Alexei V; Scheu, Stefan

    2018-06-19

    Despite the major importance of soil biota in nutrient and energy fluxes, interactions in soil food webs are poorly understood. Here we provide an overview of recent advances in uncovering the trophic structure of soil food webs using natural variations in stable isotope ratios. We discuss approaches of application, normalization and interpretation of stable isotope ratios along with methodological pitfalls. Analysis of published data from temperate forest ecosystems is used to outline emerging concepts and perspectives in soil food web research. In contrast to aboveground and aquatic food webs, trophic fractionation at the basal level of detrital food webs is large for carbon and small for nitrogen stable isotopes. Virtually all soil animals are enriched in 13 C as compared to plant litter. This 'detrital shift' likely reflects preferential uptake of 13 C-enriched microbial biomass and underlines the importance of microorganisms, in contrast to dead plant material, as a major food resource for the soil animal community. Soil organic matter is enriched in 15 N and 13 C relative to leaf litter. Decomposers inhabiting mineral soil layers therefore might be enriched in 15 N resulting in overlap in isotope ratios between soil-dwelling detritivores and litter-dwelling predators. By contrast, 13 C content varies little between detritivores in upper litter and in mineral soil, suggesting that they rely on similar basal resources, i.e. little decomposed organic matter. Comparing vertical isotope gradients in animals and in basal resources can be a valuable tool to assess trophic interactions and dynamics of organic matter in soil. As indicated by stable isotope composition, direct feeding on living plant material as well as on mycorrhizal fungi is likely rare among soil invertebrates. Plant carbon is taken up predominantly by saprotrophic microorganisms and channelled to higher trophic levels of the soil food web. However, feeding on photoautotrophic microorganisms and non

  20. Combination treatment of elevated UVB radiation, CO2 and temperature has little effect on silver birch (Betula pendula) growth and phytochemistry.

    Science.gov (United States)

    Lavola, Anu; Nybakken, Line; Rousi, Matti; Pusenius, Jyrki; Petrelius, Mari; Kellomäki, Seppo; Julkunen-Tiitto, Riitta

    2013-12-01

    Elevations of carbon dioxide, temperature and ultraviolet-B (UBV) radiation in the growth environment may have a high impact on the accumulation of carbon in plants, and the different factors may work in opposite directions or induce additive effects. To detect the changes in the growth and phytochemistry of silver birch (Betula pendula) seedlings, six genotypes were exposed to combinations of ambient or elevated levels of CO2 , temperature and UVB radiation in top-closed chambers for 7 weeks. The genotypes were relatively similar in their responses, and no significant interactive effects of three-level climate factors on the measured parameters were observed. Elevated UVB had no effect on growth, nor did it alter plant responses to CO2 and/or temperature in combined treatments. Growth in all plant parts increased under elevated CO2 , and height and stem biomass increased under elevated temperature. Increased carbon distribution to biomass did not reduce its allocation to phytochemicals: condensed tannins, most flavonols and phenolic acids accumulated under elevated CO2 and elevated UVB, but this effect disappeared under elevated temperature. Leaf nitrogen content decreased under elevated CO2 . We conclude that, as a result of high genetic variability in phytochemicals, B. pendula seedlings have potential to adapt to the tested environmental changes. The induction in protective flavonoids under UVB radiation together with the positive impact of elevated CO2 and temperature mitigates possible UVB stress effects, and thus atmospheric CO2 concentration and temperature are the climate change factors that will dictate the establishment and success of birch at higher altitudes in the future. © 2013 Scandinavian Plant Physiology Society.

  1. Trophic level responses differ as climate warms in Ireland

    Science.gov (United States)

    Donnelly, Alison; Yu, Rong; Liu, Lingling

    2015-08-01

    Effective ecosystem functioning relies on successful species interaction. However, this delicate balance may be disrupted if species do not respond to environmental change at a similar rate. Here we examine trends in the timing of spring phenophases of groups of species occupying three trophic levels as a potential indicator of ecosystem response to climate warming in Ireland. The data sets were of varying length (1976-2009) and from varying locations: (1) timing of leaf unfolding and May Shoot of a range of broadleaf and conifer tree species, (2) first appearance dates of a range of moth species, and (3) first arrival dates of a range of spring migrant birds. All three groups revealed a statistically significant ( Pphenology that was driven by rising spring temperature ( P<0.05; 0.45 °C /decade). However, the rate of advance was greater for moths (1.8 days/year), followed by birds (0.37 days/year) and trees (0.29 days/year). In addition, the length of time between (1) moth emergence and leaf unfolding and (2) moth emergence and bird arrival decreased significantly ( P<0.05 and P<0.001, respectively), indicating a decrease in the timing between food supply and demand. These differing trophic level response rates demonstrate the potential for a mismatch in the timing of interdependent phenophases as temperatures rise. Even though these data were not specifically collected to examine climate warming impacts, we conclude that such data may be used as an early warning indicator and as a means to monitor the potential for future ecosystem disruption to occur as climate warms.

  2. Potential trophic cascades triggered by the barred owl range expansion

    Science.gov (United States)

    Holm, Samantha R.; Noon, Barry R.; Wiens, David; Ripple, William J.

    2016-01-01

    Recently, the barred owl (Strix varia) has expanded its range into the Pacific Northwest of the United States resulting in pronounced effects on the demography and behavior of the northern spotted owl (S. occidentalis caurina). The range expansion has brought together historically allopatric species, creating the potential for significant changes in the avian predator community with possible cascading effects on food-web dynamics. The adverse effects of the barred owl on the behavior and demography of the northern spotted owl are well-documented, but little is known about the immediate and long-term effects changes in the predator community may have on native species composition and ecosystem processes. Based on northern spotted owl and barred owl selection for diet and habitat resources, there is a potential for trophic cascades within the region's predator and prey communities, differing responses by their shared and unique prey species, and possible direct and indirect effects on ecosystem processes. We explored the possible ecological consequences of the barred owl range expansion to wildlife communities of the Pacific Northwest based on the theoretical underpinnings of predator–prey relationships, interspecific competition, intraguild predation, and potential cascading trophic interactions. Negative effects on fitness of northern spotted owls because of interspecific competition with barred owls are strong selection forces that may contribute to the regional extinction of the northern spotted owl. In addition, we posit that shared prey species and those uniquely consumed by barred owls, along with other competing native predators, may experience changes in behavior, abundance, and distribution as a result of increased rates of predation by rapidly expanding populations of barred owls.

  3. "Wild cannabis": A review of the traditional use and phytochemistry of Leonotis leonurus.

    Science.gov (United States)

    Nsuala, Baudry N; Enslin, Gill; Viljoen, Alvaro

    2015-11-04

    Leonotis leonurus, locally commonly known as "wilde dagga" (=wild cannabis), is traditionally used as a decoction, both topically and orally, in the treatment of a wide variety of conditions such as haemorrhoids, eczema, skin rashes, boils, itching, muscular cramps, headache, epilepsy, chest infections, constipation, spider and snake bites. The dried leaves and flowers are also smoked to relieve epilepsy. The leaves and flowers are reported to produce a mild euphoric effect when smoked and have been said to have a similar, although less potent, psychoactive effect to cannabis. To amalgamate the botanical aspects, ethnopharmacology, phytochemistry, biological activity, toxicity and commercial aspects of the scientific literature available on L. leonurus. An extensive review of the literature from 1900 to 2015 was carried out. Electronic databases including Scopus, SciFinder, Pubmed, Google Scholar and Google were used as data sources. All abstracts, full-text articles and books written in English were considered. The phytochemistry of particularly the non-volatile constituents of L. leonurus has been comprehensively investigated due to interest generated as a result of the wide variety of biological effects reported for this plant. More than 50 compounds have been isolated and characterised. L. leonurus contains mainly terpenoids, particularly labdane diterpenes, the major diterpene reported is marrubiin. Various other compounds have been reported by some authors to have been isolated from the plant, including, in the popular literature only, the mildly psychoactive alkaloid, leonurine. Leonurine has however, never been reported by any scientific analysis of the extracts of L. leonurus. Despite the publication of various papers on L. leonurus, there is still, however, the need for definitive research and clarification of other compounds, including alkaloids and essential oils from L. leonurus, as well as from other plant parts, such as the roots which are

  4. The genus Desmodium (Fabaceae)-traditional uses in Chinese medicine, phytochemistry and pharmacology.

    Science.gov (United States)

    Ma, Xueqin; Zheng, Chengjian; Hu, Changling; Rahman, Khalid; Qin, Luping

    2011-11-18

    Plants of the genus Desmodium (Fabaceae), such as Desmodium styracifolium (Osbeck) Merr. and Desmodium gyrans (L. f.) DC., have a long history of medical use in Traditional Chinese Medicine to treat various ailments including rheumatism, pyrexia, dysentery, wounds, cough, malaria, hepatitis, hemoptysis, etc. In the theory of Traditional Chinese Medicine, most species have the effect of relieving internal heat or fever, neutralizing toxins, inhibiting pain, invigorating blood circulation, suppressing cough and alleviating dyspnea. A bibliographic investigation was accomplished by analyzing secondary sources including Chinese Herbal Classics, and worldwide accepted scientific databases (Pubmed, Scopus and Web of Science, SciFinder) were scrutinized for the available information on the ethnopharmacological uses in Chinese medicine, phytochemistry, pharmacology and toxicology of Desmodium species. The genus Desmodium is a large member of the Papilionaceae (Fabaceae) family. It contains about 350 plant species used for both feeding stuffs and herbal medicines, of which only about 30 species have been phytochemically or pharmacologically investigated. Desmodium plant extracts, as well as the active principles, have been experimentally studied for their anti-inflammatory, cytotoxic, antidiabetic, antinephrolithic, antibacterial, and nootropic activities in vitro or in vivo. And so far, a total of 212 compounds have been isolated from 15 Desmodium species and characterized mainly as flavonoids and alkaloids, followed by terpenoids, steroids, phenols, phenylpropanoids, glycosides and a number of volatile oils. The remaining unrevealed species are recorded chiefly in Asia and Africa being used in empirical treatment for various diseases. Desmodium species have long been used in TCM to treat various ailments. Available scientific references revealed that the traditional medical uses of some important Desmodium species in TCM have been evaluated by modern pharmacological

  5. Phytochemistry, biological activities and potential of annatto in natural colorant production for industrial applications - A review.

    Science.gov (United States)

    Shahid-Ul-Islam; Rather, Luqman J; Mohammad, Faqeer

    2016-05-01

    Bixa orellana commonly known as annatto is one of the oldest known natural dye yielding plants native to Central and South America. Various parts of annatto have been widely used in the traditional medical system for prevention and treatment of a wide number of health disorders. The plethora of traditional uses has encouraged researchers to identify and isolate phytochemicals from all parts of this plant. Carotenoids, apocarotenoids, terpenes, terpenoids, sterols, and aliphatic compounds are main compounds found in all parts of this plant and are reported to exhibit a wide range of pharmacological activities. In recent years annatto has received tremendous scientific interest mainly due to the isolation of yellow-orange natural dye from its seeds which exhibits high biodegradability, low toxicity, and compatibility with the environment. Considerable research work has already been done and is currently underway for its applications in food, textile, leather, cosmetic, solar cells, and other industries. The present review provides up-to-date systematic and organized information on the traditional usage, phytochemistry and pharmacology of annatto. It also highlights its non-food industrial applications in order to bring more interest on this dye plant, identifies the existing gaps and provides potential for future studies. Studies reported in this review have demonstrated that annatto holds a great potential for being exploited as source of drugs and a potential natural dye. However, further efforts are required to identify extract biomolecules and their action mechanisms in exhibiting certain biological activities in order to understand the full phytochemical profile and the complex pharmacological effects of this plant.

  6. Pandanus odoratissimus (Kewda): A Review on Ethnopharmacology, Phytochemistry, and Nutritional Aspects.

    Science.gov (United States)

    Adkar, Prafulla P; Bhaskar, V H

    2014-01-01

    Pandanus odoratissimus Linn. (family: Pandanaceae) is traditionally recommended by the Indian Ayurvedic medicines for treatment of headache, rheumatism, spasm, cold/flu, epilepsy, wounds, boils, scabies, leucoderma, ulcers, colic, hepatitis, smallpox, leprosy, syphilis, and cancer and as a cardiotonic, antioxidant, dysuric, and aphrodisiac. It contains phytochemicals, namely, lignans and isoflavones, coumestrol, alkaloids, steroids, carbohydrates, phenolic compounds, glycosides, proteins, amino acids as well as vitamins and nutrients, and so forth. It is having immense importance in nutrition. A 100 g edible Pandanus pericarp is mainly comprised of water and carbohydrates (80 and 17 g, resp.) and protein (1.3 mg), fat (0.7 mg), and fiber (3.5 g). Pandanus fruits paste provides 321 kilocalories, protein (2.2 g), calcium (134 mg), phosphorus (108 mg), iron (5.7 mg), thiamin (0.04 mg), vitamin C (5 mg), and beta-carotene (19 to 19,000 μg) (a carotenoid that is a precursor to vitamin A). Pandanus fruit is an important source of vitamins C, B1, B2, B3, and so forth, usually prepared as a Pandanus floured drink. Traditional claims were scientifically evaluated by the various authors and the phytochemical profile of plant parts was well established. The methods for analytical estimations were developed. However, there is paucity of systematic compilation of scientifically important information about this plant. In the present review we have systematically reviewed and compiled information of pharmacognostic, ethnopharmacology, phytochemistry, pharmacology, nutritional aspects, and analytical methods. This review will enrich knowledge leading the way into the discovery of new therapeutic agents with improved and intriguing pharmacological properties.

  7. Phytochemistry, Brine shrimp lethality and mice acute oral toxicity studies on seed extracts of Vernonia anthelmintica.

    Science.gov (United States)

    Jamil, Subia; Khan, Rafeeq Alam; Afroz, Syeda; Ahmed, Shadab

    2016-11-01

    Despite the widespread use of Vernonia anthelmintica seeds in traditional medicine, the need to establish the safety of the Vernonia anthelmintica is required to ascertain the safe use of this herbal medicine. The aim of the present study is to establish the acute toxicity profile of different extracts of Vernonia anthelmintica. Hexane and ethanol extract of Vernonia Anthelmintica has been studied for its brine shrimp lethality potential. Water decoction (WDVA), Hexane (HEVA) and Ethanol (EEVA) extracts of Vernonia anthelmintica has also been evaluated for their in-vivo acute oral toxicity in mice by Lorke's method. Phytochemistry of all three extracts was also evaluated for the presence of their secondary metabolites. All three extracts showed the presence of flavonoids and terpenoids, while alkaloids, tannins and fixed oils were present in HEVA and EEVA. Furthermore EEVA also showed presence of carbohydrates and HEVA also showed the presence of cardiac glycosides. Ethanol and hexane extracts of Vernonia anthelmintica showed a positive cytotoxicity in brine shrimp lethality test at 24 hours with LC50 104.16 (224.0-48.05)μg/ml and 216.11μg/ml (378.2-128.7) respectively as compared to standard drug etoposide LC50 7.46μg/ml. The oral LD50 for EEVA, HEVA and WDVA in mice by Lorke's method was greater than 5000mg/kg. The result of brine shrimp lethality test clearly exhibited the presence of bioactive compounds with cytotoxic potential; however seems to be safe for oral use since LD50 was higher than 5000mg/kg and thus safety of acute dosing in vivo practices is justified.

  8. Cardiovascular aspects of geriatric medicines in traditional Persian medicine; a review of phytochemistry and pharmacology.

    Science.gov (United States)

    Zarshenas, Mohammad M; Jamshidi, Sahar; Zargaran, Arman

    2016-10-15

    Geriatrics are a group of patients over 65 years and with multiple comorbidities and different functional impairments. Apart from decline in body mass, presence of exhaustion and general fatigue, an aged person may also suffer from various disorders. Approximately, around 30% of geriatric subjects have significant cardiovascular ailments. Apart from the intensive management of cardiovascular aspects in elderly, monitoring of the complementary cardiac medicine in those people should be received more attention. There are many management lines for a cardio-geriatric condition in Traditional Persian Medicine (TPM). Accordingly, this paper aimed to deal with those medicaments as well as evidence-based clinical aspects and phytochemistry. By searching through main pharmaceutical manuscripts of Persian medicine during 10th-18th centuries (A.D.), concurrently, natural medicines for geriatrics and remedies for cardiovascular ailments were derived. On the other side, related phytochemical and pharmacological aspects of those remedies were highlighted. In all, 38 cardiovascular and 34 geriatric medicaments were found in those manuscripts. Antihyperlipidemic and cholesterol lowering activities of those medicines were the most reported activities in current medicine. However, other pharmacological reports were related to hypotensive, coagulant, cardio-protective and cardiotonic activities. In regard of the chemical composition, medicaments were mainly of polyphenols and flavonoids and also most of the employed extracts and fractions were yielded from polar or semi-polar solvents. With reference to these findings, flavonoid-rich medicaments from Persian medicine may be selected as considerable herbs for geriatrics with cardiovascular ailments. Copyright © 2016 Elsevier GmbH. All rights reserved.

  9. Averrhoa bilimbi Linn.: A review of its ethnomedicinal uses, phytochemistry, and pharmacology

    Directory of Open Access Journals (Sweden)

    Alhassan Muhammad Alhassan

    2016-01-01

    Full Text Available Averrhoa bilimbi Linn. is principally cultivated for medicinal purposes in many tropical and subtropical countries of the world. Literature survey about this plant shows that A. bilimbi is mainly used as a folk medicine in the treatment of diabetes mellitus, hypertension, and as an antimicrobial agent. The prime objective of this review is to accumulate and organize literature based on traditional claims and correlate those with current findings on the use of A. bilimbi in the management of different ailments. Through interpreting already published scientific manuscripts (1995 through 2015 retrieved from the different scientific search engines, namely Medline, PubMed, EMBASE, and Science Direct databases, published articles and reports covering traditional and scientific literature related to A. bilimbi's potential role against various ailments have been thoroughly evaluated, interpreted, and discussed. Several pharmacological studies have demonstrated the ability of this plant to act as antidiabetic, antihypertensive, thrombolytic, antimicrobial, antioxidant, hepatoprotective, and hypolipidemic agent. A. bilimbi holds great value in the complementary and alternative medicine as evidenced by the substantial amount of research on it. Therefore, we aimed to compile an up-to-date and comprehensive review of A. bilimbi that covers its traditional and folk medicine uses, phytochemistry, and pharmacology. Hence, this paper presents an up-to-date and comprehensive review of the ethnomedicinal uses, different chemical constituents, and pharmacological activities of A. bilimbi. So far, the biologically active agents have not been isolated from this plant and this can be a good scientific study for the future antidiabetic, antihypertensive, and antimicrobial implications. Hence, this review targets at emphasizing the diverse traditional claims and pharmacological activities of A. bilimbi with respect to carrying out more scientific studies to isolate

  10. Pandanus odoratissimus (Kewda: A Review on Ethnopharmacology, Phytochemistry, and Nutritional Aspects

    Directory of Open Access Journals (Sweden)

    Prafulla P. Adkar

    2014-01-01

    Full Text Available Pandanus odoratissimus Linn. (family: Pandanaceae is traditionally recommended by the Indian Ayurvedic medicines for treatment of headache, rheumatism, spasm, cold/flu, epilepsy, wounds, boils, scabies, leucoderma, ulcers, colic, hepatitis, smallpox, leprosy, syphilis, and cancer and as a cardiotonic, antioxidant, dysuric, and aphrodisiac. It contains phytochemicals, namely, lignans and isoflavones, coumestrol, alkaloids, steroids, carbohydrates, phenolic compounds, glycosides, proteins, amino acids as well as vitamins and nutrients, and so forth. It is having immense importance in nutrition. A 100 g edible Pandanus pericarp is mainly comprised of water and carbohydrates (80 and 17 g, resp. and protein (1.3 mg, fat (0.7 mg, and fiber (3.5 g. Pandanus fruits paste provides 321 kilocalories, protein (2.2 g, calcium (134 mg, phosphorus (108 mg, iron (5.7 mg, thiamin (0.04 mg, vitamin C (5 mg, and beta-carotene (19 to 19,000 μg (a carotenoid that is a precursor to vitamin A. Pandanus fruit is an important source of vitamins C, B1, B2, B3, and so forth, usually prepared as a Pandanus floured drink. Traditional claims were scientifically evaluated by the various authors and the phytochemical profile of plant parts was well established. The methods for analytical estimations were developed. However, there is paucity of systematic compilation of scientifically important information about this plant. In the present review we have systematically reviewed and compiled information of pharmacognostic, ethnopharmacology, phytochemistry, pharmacology, nutritional aspects, and analytical methods. This review will enrich knowledge leading the way into the discovery of new therapeutic agents with improved and intriguing pharmacological properties.

  11. Recent trends in phytochemistry, ethnobotany and pharmacological significance of Alchornea cordifolia (Schumach. & Thonn.) Muell. Arg.

    Science.gov (United States)

    Boniface, Pone Kamdem; Ferreira, Sabrina Baptista; Kaiser, Carlos Roland

    2016-09-15

    Alchornea cordifolia (Schumach. & Thonn.) Muell. Arg. (Euphorbiaceae) (A. cordifolia) is widely distributed throughout tropical Africa, where it is used extensively in traditional medicine. Conditions for which the plant has enjoyed wide use are: coughs, gonorrhoea, infertility, prostatitis, bacterial infections, diarrhoea, ulcers, pain, inflammation, fever and bronchial troubles. This review summarizes the achievements of the investigations in traditional uses, ethnobotany, phytochemistry, biological activities and toxicological profile of A. cordifolia; this review also describes the shortcomings of studies on this herbal drug and thus serves as the basis of further scientific research and development of this traditional herbal drug. A. cordifolia-related information was collected from various resources including published articles in peer-reviewed journals, unpublished materials, textbooks, government survey reports and scientific databases such as Scifinder®, Pubmed, Science Direct, Wiley, Springer, ACS, Scielo, Web of Science and other web search instruments (Google, Yahoo), published on the subject from 1950 to 2016. 'The Plant List' (www.theplantlist.org) and 'Kew Royal Botanic Gardens' (mpns.kew.org) were used to validate the scientific name of the plant. The literature revealed several reports on traditional uses, biological activities, chemical constituents and toxicological evaluation of A. cordifolia. The phytochemical information indicates identification of 95 compounds including fatty acids, terpenoids, flavonoids, phenolic acids, alkaloids, which exhibited various pharmacological activities such as wound healing, anti-inflammation, anticancer, antioxidant, immunomodulation, antidiarrhoeal, antimicrobial, antidepressant, hepatoprotective, antiplasmodial and anxiolytic. However, there are still significant gaps in the completeness of our understanding of A. cordifolia bioactivity, therapeutic value, and roles played by each of the numerous

  12. Tagetes lucida Cav.: Ethnobotany, phytochemistry and pharmacology of its tranquilizing properties.

    Science.gov (United States)

    Pérez-Ortega, G; González-Trujano, M E; Ángeles-López, G E; Brindis, F; Vibrans, H; Reyes-Chilpa, R

    2016-04-02

    Morelos State is one of the most important regions of Mexico where several plant species are used in traditional medicine to influence central nervous system (CNS) activity; for example Tagetes lucida Cav. To investigate the ethnobotany, phytochemistry and pharmacology of the tranquilizing properties of T. lucida aerial parts. Data on the medicinal uses of T. lucida were explored by interviewing healers and merchants of local markets in different regions of Morelos State by using a questionnaire. Anxiolytic and/or sedative-like responses of the T. lucida were investigated in experimental models in mice such as: open-field, exploration cylinder, hole-board, plus-maze, and the barbituric-induced hypnosis potentiation. The possible mechanism of action was explored in the presence of WAY100635 (0.32mg/kg, i.p.) and flumazenil (10mg/kg, i.p.) antagonists. A feasible active compound was isolated and identified by using conventional chromatography, including UHPLC and MS (DART) [M+H]+ techniques. Interviews of healers and merchants from ten local regions of Morelos State showed that they recommended T. lucida as infusion and as tincture for several culture-bound syndromes associated with the CNS. Anxiolytic and sedative-like activities of polar extracts were corroborated in the experimental models; these effects were inhibited in the presence of 5-HT1A and GABA/BDZ receptor antagonists. Dimethylfraxetin was identified as one possible active compound. The results support the anxiolytic and sedative-like properties of T. lucida in traditional medicine by involving serotonergic and GABAergic neurotransmission and coumarinic constituents. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  13. Chytrid parasitism facilitates trophic transfer between bloom-forming cyanobacteria and zooplankton (Daphnia).

    Science.gov (United States)

    Agha, Ramsy; Saebelfeld, Manja; Manthey, Christin; Rohrlack, Thomas; Wolinska, Justyna

    2016-10-13

    Parasites are rarely included in food web studies, although they can strongly alter trophic interactions. In aquatic ecosystems, poorly grazed cyanobacteria often dominate phytoplankton communities, leading to the decoupling of primary and secondary production. Here, we addressed the interface between predator-prey and host-parasite interactions by conducting a life-table experiment, in which four Daphnia galeata genotypes were maintained on quantitatively comparable diets consisting of healthy cyanobacteria or cyanobacteria infected by a fungal (chytrid) parasite. In four out of five fitness parameters, at least one Daphnia genotype performed better on parasitised cyanobacteria than in the absence of infection. Further treatments consisting of purified chytrid zoospores and heterotrophic bacteria suspensions established the causes of improved fitness. First, Daphnia feed on chytrid zoospores which trophically upgrade cyanobacterial carbon. Second, an increase in heterotrophic bacterial biomass, promoted by cyanobacterial decay, provides an additional food source for Daphnia. In addition, chytrid infection induces fragmentation of cyanobacterial filaments, which could render cyanobacteria more edible. Our results demonstrate that chytrid parasitism can sustain zooplankton under cyanobacterial bloom conditions, and exemplify the potential of parasites to alter interactions between trophic levels.

  14. Assessing Lake Trophic Status: A Proportional Odds Logistic Regression Model

    Science.gov (United States)

    Lake trophic state classifications are good predictors of ecosystem condition and are indicative of both ecosystem services (e.g., recreation and aesthetics), and disservices (e.g., harmful algal blooms). Methods for classifying trophic state are based off the foundational work o...

  15. Aspects of the trophic ecology of Liza falcipinnis (Valenciennes 1836)

    African Journals Online (AJOL)

    Aspects of the trophic ecology of Liza falcipinnis (Valenciennes) were studied in the Cross River Estuary (CRE) east of the Niger Delta (Nigeria). The trophic spectrum showed that L. falcipinnis fed on a wide variety of food resources. From the index of relative importance (IRI), L. falcipinnis fed primarily on diatoms, FPOM, ...

  16. Climate Change and Baleen Whale Trophic Cascades in Greenland

    Science.gov (United States)

    2009-09-30

    DISTRIBUTION STATEMENT A: Approved for public release; distribution is unlimited. Climate Change and Baleen Whale Trophic Cascades in Greenland...SUBTITLE Climate Change And Baleen Whale Trophic Cascades In Greenland 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S

  17. Indirect effects and traditional trophic cascades: a test involving wolves, coyotes, and pronghorn.

    Science.gov (United States)

    Berger, Kim Murray; Gese, Eric M; Berger, Joel

    2008-03-01

    The traditional trophic cascades model is based on consumer resource interactions at each link in a food chain. However, trophic-level interactions, such as mesocarnivore release resulting from intraguild predation, may also be important mediators of cascades. From September 2001 to August 2004, we used spatial and seasonal heterogeneity in wolf distribution and abundance in the southern Greater Yellowstone Ecosystem to evaluate whether mesopredator release of coyotes (Canis latrans), resulting from the extirpation of wolves (Canis lupus), accounts for high rates of coyote predation on pronghorn (Antilocapra americana) fawns observed in some areas. Results of this ecological perturbation in wolf densities, coyote densities, and pronghorn neonatal survival at wolf-free and wolf-abundant sites support the existence of a species-level trophic cascade. That wolves precipitated a trophic cascade was evidenced by fawn survival rates that were four-fold higher at sites used by wolves. A negative correlation between coyote and wolf densities supports the hypothesis that interspecific interactions between the two species facilitated the difference in fawn survival. Whereas densities of resident coyotes were similar between wolf-free and wolf-abundant sites, the abundance of transient coyotes was significantly lower in areas used by wolves. Thus, differential effects of wolves on solitary coyotes may be an important mechanism by which wolves limit coyote densities. Our results support the hypothesis that mesopredator release of coyotes contributes to high rates of coyote predation on pronghorn fawns, and demonstrate the importance of alternative food web pathways in structuring the dynamics of terrestrial systems.

  18. Unrevealing Parasitic Trophic Interactions—A Molecular Approach for Fluid-Feeding Fishes

    Directory of Open Access Journals (Sweden)

    Karine O. Bonato

    2018-03-01

    Full Text Available Fish diets have been traditionally studied through the direct visual identification of food items found in their stomachs. Stomach contents of Vandeliinae and Stegophilinae (family Trichomycteridae parasite catfishes, however, cannot be identified by usual optical methods due to their mucophagic, lepidophagic, or hematophagic diets, in such a way that the trophic interactions and the dynamics of food webs in aquatic systems involving these catfishes are mostly unknown. The knowledge about trophic interactions, including difficult relation between parasites and hosts, are crucial to understand the whole working of food webs. In this way, molecular markers can be useful to determine the truly hosts of these catfishes, proving a preference in their feeding behavior for specific organisms and not a generalist. Sequences of cytochrome oxidase subunit 1 (COI were successfully extracted and amplified from mucus or scales found in the stomach contents of two species of stegophilines, Homodiaetus anisitsi, and Pseudostegophilus maculatus, to identify the host species. The two species were found to be obligatory mucus-feeders and occasionally lepidophagic. Selection of host species is associated to host behavior, being constituted mainly by substrate-sifting benthivores. Characiformes are preferred hosts, but host choice depends on what characiform species are available in their environments, usually corresponding to the most abundant species. This is the first time that host species of parasitic fishes bearing mucophagous habits are identified, and demonstrates the effectiveness of the extraction and amplification of mitochondrial DNA from the ingested mucus in gut contents. The molecular markers effectively allowed determine parasite preferences and helps in better understanding the food web and trophic interaction on which fish species are involved. Despite, the methodology applied here can be used for an infinitive of organisms improving ecological

  19. Spatially Explicit Modeling Reveals Cephalopod Distributions Match Contrasting Trophic Pathways in the Western Mediterranean Sea.

    Directory of Open Access Journals (Sweden)

    Patricia Puerta

    Full Text Available Populations of the same species can experience different responses to the environment throughout their distributional range as a result of spatial and temporal heterogeneity in habitat conditions. This highlights the importance of understanding the processes governing species distribution at local scales. However, research on species distribution often averages environmental covariates across large geographic areas, missing variability in population-environment interactions within geographically distinct regions. We used spatially explicit models to identify interactions between species and environmental, including chlorophyll a (Chla and sea surface temperature (SST, and trophic (prey density conditions, along with processes governing the distribution of two cephalopods with contrasting life-histories (octopus and squid across the western Mediterranean Sea. This approach is relevant for cephalopods, since their population dynamics are especially sensitive to variations in habitat conditions and rarely stable in abundance and location. The regional distributions of the two cephalopod species matched two different trophic pathways present in the western Mediterranean Sea, associated with the Gulf of Lion upwelling and the Ebro river discharges respectively. The effects of the studied environmental and trophic conditions were spatially variant in both species, with usually stronger effects along their distributional boundaries. We identify areas where prey availability limited the abundance of cephalopod populations as well as contrasting effects of temperature in the warmest regions. Despite distributional patterns matching productive areas, a general negative effect of Chla on cephalopod densities suggests that competition pressure is common in the study area. Additionally, results highlight the importance of trophic interactions, beyond other common environmental factors, in shaping the distribution of cephalopod populations. Our study presents

  20. Trophic flow structure of the Danajon ecosystem (Central Philippines) and impacts of illegal and destructive fishing practices

    Science.gov (United States)

    Bacalso, Regina Therese M.; Wolff, Matthias

    2014-11-01

    A trophic model of the shallow Danajon Bank, in the Central Visayas, Philippines was developed using a mass-balance approach (Ecopath) to describe the system characteristics and fisheries interactions. The Ecopath model is composed of 37 functional groups and 17 fishing fleet types reflecting the high diversity of catches and fishing operations in the Danajon Bank. Collectively, the catch is dominated by lower trophic level fish and invertebrates as reflected in the mean trophic level of the fishery (2.95). The low biomass and high exploitation levels for many upper trophic level groups and the little evidence for strong natural physical disturbances suggest that top-down fishery is the main driver of system dynamics. The mixed trophic impacts (MTI) analysis reveals the role of the illegal and destructive fishing operations in influencing the ecosystem structure and dynamics. Furthermore, the illegal fisheries' estimated collective annual harvest is equivalent to nearly a quarter of the entire municipal fisheries catch in the area. Improved fisheries law enforcement by the local government units to curb these illegal and destructive fishing operations could substantially increase the potential gains of the legal fisheries.

  1. Trigeminal Trophic Syndrome – Case Report

    Directory of Open Access Journals (Sweden)

    Boštjan Matos

    2015-05-01

    Full Text Available 1024x768 Trigeminal trophic syndrome is a rare condition resulting from compulsive self-manipulation of the skin after a peripheral or central injury to the trigeminal system. The classic triad consists of trigeminal anesthesia, facial paresthesias, and crescentric lateral nasal alar erosion and ulceration. Although the symptoms are visibly clear, the diagnosis is not easy to establish. The appearance of the ulcers mimics many other disease entities such as neoplasm, infection, granulomatous disease, vasculitis and factitial dermatitis. Trigeminal trophic syndrome should be considered with a positive neurologic history and when laboratory and biopsy workup is inconclusive. Once diagnosis is confirmed, treatment is complicated and often multidisciplinary. We report a case of a woman who developed a strictly unilateral crescent ulcer of the ala nasi after resection of an statoacoustic neurinoma. A clinician who is faced with a patient with nasal ulceration should consider this diagnosis.     Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

  2. Trophic cascades linking wolves (Canis lupus), coyotes (Canis latrans), and small mammals

    Science.gov (United States)

    Miller, B.J.; Harlow, H.J.; Harlow, T.S.; Biggins, D.; Ripple, W.J.

    2012-01-01

    When large carnivores are extirpated from ecosystems that evolved with apex predators, these systems can change at the herbivore and plant trophic levels. Such changes across trophic levels are called cascading effects and they are very important to conservation. Studies on the effects of reintroduced wolves in Yellowstone National Park have examined the interaction pathway of wolves (Canis lupus L., 1758) to ungulates to plants. This study examines the interaction effects of wolves to coyotes to rodents (reversing mesopredator release in the absence of wolves). Coyotes (Canis latrans Say, 1823) generally avoided areas near a wolf den. However, when in the proximity of a den, they used woody habitats (pine or sage) compared with herbaceous habitats (grass or forb or sedge)- when they were away from the wolf den. Our data suggested a significant increase in rodent numbers, particularly voles (genus Microtus Schrank, 1798), during the 3-year study on plots that were within 3 km of the wolf den, but we did not detect a significant change in rodent numbers over time for more distant plots. Predation by coyotes may have depressed numbers of small mammals in areas away from the wolf den. These factors indicate a top-down effect by wolves on coyotes and subsequently on the rodents of the area. Restoration of wolves could be a powerful tool for regulating predation at lower trophic levels.

  3. Effect of grazers and viruses on bacterial community structure and production in two contrasting trophic lakes

    Directory of Open Access Journals (Sweden)

    Domaizon Isabelle

    2011-04-01

    Full Text Available Abstract Background Over the last 30 years, extensive studies have revealed the crucial roles played by microbes in aquatic ecosystems. It has been shown that bacteria, viruses and protozoan grazers are dominant in terms of abundance and biomass. The frequent interactions between these microbiological compartments are responsible for strong trophic links from dissolved organic matter to higher trophic levels, via heterotrophic bacteria, which form the basis for the important biogeochemical roles of microbial food webs in aquatic ecosystems. To gain a better understanding of the interactions between bacteria, viruses and flagellates in lacustrine ecosystems, we investigated the effect of protistan bacterivory on bacterial abundance, production and structure [determined by 16S rRNA PCR-DGGE], and viral abundance and activity of two lakes of contrasting trophic status. Four experiments were conducted in the oligotrophic Lake Annecy and the mesotrophic Lake Bourget over two seasons (early spring vs. summer using a fractionation approach. In situ dark vs. light incubations were performed to consider the effects of the different treatments in the presence and absence of phototrophic activity. Results The presence of grazers (i.e. Conclusions Our results highlight the importance of a synergistic effect, i.e. the positive influence of grazers on viral activities in sustaining (directly and indirectly bacterial production and affecting composition, in both oligotrophic and mesotrophic lakes.

  4. Fatty acid biomarkers: validation of food web and trophic markers using C-13-labelled fatty acids in juvenile sandeel ( Ammodytes tobianus )

    DEFF Research Database (Denmark)

    Dalsgaard, Anne Johanne Tang; St. John, Michael

    2004-01-01

    A key issue in marine science is parameterizing trophic interactions in marine food webs, thereby developing an understanding of the importance of top-down and bottom-up controls on populations of key trophic players. This study validates the utility of fatty acid food web and trophic markers usi......), respectively. Lack of temporal trends in nonlabelled fatty acids confirmed the conservative incorporation of labelled fatty acids by the fish.......A key issue in marine science is parameterizing trophic interactions in marine food webs, thereby developing an understanding of the importance of top-down and bottom-up controls on populations of key trophic players. This study validates the utility of fatty acid food web and trophic markers using...... C-13-labelled fatty acids to verify the conservative incorporation of fatty acid tracers by juvenile sandeel (Ammodytes tobianus) and assess their uptake, clearance, and metabolic turnover rates. Juvenile sandeel were fed for 16 days in the laboratory on a formulated diet enriched in (13)C16...

  5. Trophic cascades: the primacy of trait-mediated indirect interactions

    Czech Academy of Sciences Publication Activity Database

    Schmitz, O. J.; Křivan, Vlastimil; Ovadia, O.

    2004-01-01

    Roč. 7, - (2004), s. 153-163 ISSN 1461-023X R&D Projects: GA ČR GA201/03/0091 Institutional research plan: CEZ:AV0Z5007907 Keywords : adaptive foraging * anti-predator behaviour * cascading effects Subject RIV: EH - Ecology, Behaviour Impact factor: 3.914, year: 2004

  6. Interacting trophic forcing and the population dynamics of herring

    DEFF Research Database (Denmark)

    Lindegren, Martin; Ostman, Orjan; Gardmark, Anna

    2011-01-01

    -up nor top-down, but rather through multiple external and internal drivers. While in many studies single drivers have been identified, potential synergies of multiple factors, as well as their relative importance in regulating population dynamics of small pelagic fish, is a largely unresolved issue....... Using a statistical, age-structured modeling approach, we demonstrate the relative importance and influence of bottom-up (e.g., climate, zooplankton availability) and top-down (i.e., fishing and predation) factors on the population dynamics of Bothnian Sea herring (Clupea harengus) throughout its life...... cycle. Our results indicate significant bottom-up effects of zooplankton and interspecific competition from sprat (Sprattus sprattus), particularly on younger age classes of herring. Although top-down forcing through fishing and predation by grey seals (Halichoerus grypus) and Atlantic cod (Gadus morhua...

  7. Adaptive evolution of body size subject to indirect effect in trophic cascade system.

    Science.gov (United States)

    Wang, Xin; Fan, Meng; Hao, Lina

    2017-09-01

    Trophic cascades represent a classic example of indirect effect and are wide-spread in nature. Their ecological impact are well established, but the evolutionary consequences have received even less theoretical attention. We theoretically and numerically investigate the trait (i.e., body size of consumer) evolution in response to indirect effect in a trophic cascade system. By applying the quantitative trait evolutionary theory and the adaptive dynamic theory, we formulate and explore two different types of eco-evolutionary resource-consumer-predator trophic cascade model. First, an eco-evolutionary model incorporating the rapid evolution is formulated to investigate the effect of rapid evolution of the consumer's body size, and to explore the impact of density-mediate indirect effect on the population dynamics and trait dynamics. Next, by employing the adaptive dynamic theory, a long-term evolutionary model of consumer body size is formulated to evaluate the effect of long-term evolution on the population dynamics and the effect of trait-mediate indirect effect. Those models admit rich dynamics that has not been observed yet in empirical studies. It is found that, both in the trait-mediated and density-mediated system, the body size of consumer in predator-consumer-resource interaction (indirect effect) evolves smaller than that in consumer-resource and predator-consumer interaction (direct effect). Moreover, in the density-mediated system, we found that the evolution of consumer body size contributes to avoiding consumer extinction (i.e., evolutionary rescue). The trait-mediate and density-mediate effects may produce opposite evolutionary response. This study suggests that the trophic cascade indirect effect affects consumer evolution, highlights a more comprehensive mechanistic understanding of the intricate interplay between ecological and evolutionary force. The modeling approaches provide avenue for study on indirect effects from an evolutionary perspective

  8. Salinization triggers a trophic cascade in experimental freshwater communities with varying food-chain length.

    Science.gov (United States)

    Hintz, William D; Mattes, Brian M; Schuler, Matthew S; Jones, Devin K; Stoler, Aaron B; Lind, Lovisa; Relyea, Rick A

    2017-04-01

    The application of road deicing salts in northern regions worldwide is changing the chemical environment of freshwater ecosystems. Chloride levels in many lakes, streams, and wetlands exceed the chronic and acute thresholds established by the United States and Canada for the protection of freshwater biota. Few studies have identified the impacts of deicing salts in stream and wetland communities and none have examined impacts in lake communities. We tested how relevant concentrations of road salt (15, 100, 250, 500, and 1000 mg Cl - /L) interacted with experimental communities containing two or three trophic levels (i.e., no fish vs. predatory fish). We hypothesized that road salt and fish would have a negative synergistic effect on zooplankton, which would then induce a trophic cascade. We tested this hypothesis in outdoor mesocosms containing filamentous algae, periphyton, phytoplankton, zooplankton, several macroinvertebrate species, and fish. We found that the presence of fish and high salt had a negative synergistic effect on the zooplankton community, which in turn caused an increase in phytoplankton. Contributing to the magnitude of this trophic cascade was a direct positive effect of high salinity on phytoplankton abundance. Cascading effects were limited with respect to impacts on the benthic food web. Periphyton and snail grazers were unaffected by the salt-induced trophic cascade, but the biomass of filamentous algae decreased as a result of competition with phytoplankton for light or nutrients. We also found direct negative effects of high salinity on the biomass of filamentous algae and amphipods (Hyalella azteca) and the mortality of banded mystery snails (Viviparus georgianus) and fingernail clams (Sphaerium simile). Clam mortality was dependent on the presence of fish, suggesting a non-consumptive interactive effect with salt. Our results indicate that globally increasing concentrations of road salt can alter community structure via both direct

  9. Acute oral toxicity test and phytochemistry of some West African medicinal plants.

    Science.gov (United States)

    Awobajo, F O; Omorodion-Osagie, E; Olatunji-Bello, I I; Adegoke, O A; Adeleke, T I

    2009-01-01

    Although there is increased acceptance and utilization of medicinal plants worldwide, many are used indiscriminately without recourse to any safety test. Thus, the need for toxicity tests to determine the safe dose for oral consumption. LD50 and phytochemistry of four medicinal plants of West Africa were investigated. Thirty male and non pregnant female Swiss albino mice weighing 20grams each were used for this study. They were divided into the Control (C), Oldenlandia corymbosa L. aqueous leaf-extract treated (OCG), Parquetina nigrescens aqueous leaf extract treated (PNG), Hybanthus enneaspermus aqueous leaf extract treated (HEG), Ficus carica leaf extract treated (FCG) and Sesamum indicum aqueous seeds extract treated group (SIG). Each group except the control was further divided into four sub-groups of six mice each, and were administered orally, graded doses (SI; 1, 2, 4 and 8, PN; 2.5, 5, 10 and 20, OC; 5, 10, 20 and 40, FC; 1, 2, 4 and 8, HE; 4, 8, 16, 32) of the aqueous extract of each plant (g/kg body weight) after 12 hours fasting. The dry aqueous leaf extracts of HE, OC, PN, FC all have dark brown colour and pH ranging from 6.1 to 7.2 while the seed extract of SI has a light brown color with pH of 7.0. Flavonoids, cardiac glycosides, anthocyanosides, saponin, and reducing sugar were present in all extracts, while cyanogenic glycoside was present only in HE. LD50 determination results obtained using Thompson and Finney methods were as follows; OC; 14.14 +/- 0.27 and 10.56 +/- 0.20, PN; 12.60 +/- 0.10 and 13.10 +/- 0.10, HE; 8.14 +/- 0.30 and 8.24 +/- 0.35, FC; 3.36 +/- 0.26 and 4.00 +/- 0.04, SI; 4.00 +/- 0.10 and 3.10 +/- 0.22 respectively (LD50 values are in g/kg body weight. The results of this study have provided an oral LD50 from where a safe dose can be chosen for further research into the merits of the consumption of these medicinal plants.

  10. Angelica sinensis in China-A review of botanical profile, ethnopharmacology, phytochemistry and chemical analysis.

    Science.gov (United States)

    Wei, Wen-Long; Zeng, Rui; Gu, Cai-Mei; Qu, Yan; Huang, Lin-Fang

    2016-08-22

    Angelica sinensis (Oliv.) Diels, known as Dang Gui (in Chinese), is a traditional medicinal and edible plant that has long been used for tonifying, replenishing, and invigorating blood as well as relieving pain, lubricating the intestines, and treating female irregular menstruation and amenorrhea. A. sinensis has also been used as a health product and become increasingly popular in China, Japan, and Korea. This paper aims to provide a systemic review of traditional uses of A. sinensis and its recent advances in the fields of phytochemistry, analytical methods and toxicology. In addition, possible trends, therapeutic potentials, and perspectives for future research of this plant are also briefly discussed. An extensive review of the literature was conducted, and electronic databases including China National Knowledge Infrastructure, PubMed, Google Scholar, Science Direct, and Reaxys were used to assemble the data. Ethnopharmacological literature and digitalised sources of academic libraries were also systematically searched. In addition, information was obtained from local books and The Plant List (TPL, www.theplantlist.org). This study reviews the progress in chemical analysis of A. sinensis and its preparations. Previously and newly established methods, including spectroscopy, thin-layer chromatography (TLC), gas chromatography (GC), high-performance liquid chromatography (HPLC), ultra-performance liquid chromatography(UPLC), and nuclear magnetic resonance analysis (NMR), are summarized. Moreover, identified bioactive components such as polysaccharides, ligustilide and ferulic acid were reviewed, along with analytical methods for quantitative and qualitative determination of target analytes, and fingerprinting authentication, quality evaluation of A. sinensis, and toxicology and pharmacodynamic studies. Scientific reports on crude extracts and pure compounds and formulations revealed a wide range of pharmacological activities, including anti-inflammatory activity

  11. Phytochemistry, pharmacology and traditional uses of different Epilobium species (Onagraceae): a review.

    Science.gov (United States)

    Granica, Sebastian; Piwowarski, Jakub P; Czerwińska, Monika E; Kiss, Anna K

    2014-10-28

    The Epilobium genus (willowherb) comprises of ca. 200 species of herbaceous plants distributed around the world. Infusions prepared form willowherbs have been traditionally used externally in skin and mucosa infections and in the treatment of benign prostate hyperplasia. Nowadays extracts from different Epilobium species are widely used by patients, however the lack of clinical studies does not allow to fully establish their efficacy. The present review summarizes published data on phytochemistry, ethnopharmacological use and pharmacological studies concerning willowherb species investigated throughout past few decades. Literature survey was performed using Scopus, PubMed, Web of Science and Reaxys databases looking for papers and patents focused on chemical composition and bioactivity of Epilobium species. Systematic research in ethnopharmacological literature in digitalized sources of academic libraries was also carried out. The chemical composition of different Epilobium species and their bioactivities are described. The detailed information on constituents isolated and detected by chromatographic methods is given. The studies show that polyphenols are main compounds occurring in Epilobium herb among which flavonoids, phenolic acids and tannins (oenothein B and oenothein A) are dominating constituents. The extracts and some isolated compounds from Epilobium sp. were shown to possess antimicrobial, anti-proliferative, anti-inflammatory, analgesic and antioxidative activities. Because many studies suggest that oenothein B as dominating constituent may be responsible for Epilobium sp. pharmacological effects, its documented bioactivities were also described. The pharmacological studies performed on Epilobium justify the traditional use of this species in external and in gastrointestinal inflammations. As far as the treatment of benign prostate hyperplasia (BPH) is considered, in the literature, there are some reports indicating that Epilobium extracts have a

  12. Citri Reticulatae Pericarpium (Chenpi): Botany, ethnopharmacology, phytochemistry, and pharmacology of a frequently used traditional Chinese medicine.

    Science.gov (United States)

    Yu, Xin; Sun, Shuang; Guo, Yuyan; Liu, Yan; Yang, Dayu; Li, Guoyu; Lü, Shaowa

    2018-06-28

    Citri Reticulatae Pericarpium (Rutaceae, CRP), commonly called as Chenpi () in Chinese, is most frequently used as a qi-regulating drug in thousands of Chinese medicine prescriptions. CRP is found mainly in major citrus-producing areas such as the Guangdong, Guangxi, Sichuan, Fujian, and Zhejiang Provinces of China. Since thousands of years in China, CRP has been used widely in clinical practice to treat nausea, vomiting, indigestion, anepithymia, diarrhea, cough, expectoration, and so on. Currently, CRP is listed in the Pharmacopoeia of the People's Republic of China. The present paper reviews the botany, ethnopharmacology, phytochemistry, pharmacology, quality control, and toxicology of CRP. Information on CRP was gathered from various sources including the books on traditional Chinese herbal medicine; scientific databases including Elsevier, PubMed, and ScienceDirect; Baidu Scholar; CNKI; and others and from different professional websites. Approximately 140 chemical compounds have been isolated and identified from CRP. Among them, volatile oils and flavonoids are generally considered as the main bioactive and characteristic ingredients. CRP possesses wide pharmacological effects such as having a beneficial effect on the cardiovascular, digestive, and respiratory systems, antitumor, antioxidant, and anti-inflammatory properties; and a protective effect on the liver and nerve. Moreover, hesperidin is chosen as an indicator in the quantitative determination of CRP, and the quantity of aflatoxin in CRP must not exceed the standard limit mentioned in the pharmacopoeia. In brief, CRP has a warming nature, and hence, it can be used in harmony with a lot of medicines. CRP not only exhibits its effects individually but also aids other medicines exhibit a better effect. CRP can be consumed with tea, food, alcohol, and medicine. Irrespective of the form it is being consumed, CRP not only shows a synergistic effect but also has strengths on its own. Modern pharmacological

  13. A review of the medicinal uses, phytochemistry and pharmacology of the genus Sapium.

    Science.gov (United States)

    Al Muqarrabun, L M R; Ahmat, N; Aris, S Ruzaina S

    2014-08-08

    Several species from the genus Sapium possess a broad range of medicinal properties and they have been used as traditional medicines by indigenous groups in several regions such as Malaysia, Africa, Southern China and Bolivia. Most of the species reported to possess therapeutic effects which are used for the treatment of skin-related diseases such as eczema and dermatitis, but they may also be used for overstrain, lumbago, constipation and hernia. Species of this genus are also used to treat wounds and snake bites. In addition, the saps/latex of Sapium glandulosum, Sapium indicum and Sapium sebiferum have/has toxic effects and are used as bird and fish poisons. This review discusses the current knowledge of the medicinal uses, phytochemistry, biological activities and toxicities of species from the genus Sapium to reveal their therapeutic potentials and gaps offering opportunities for future research. This review is based on a literature study of scientific journals and books from libraries and electronic sources, such as ScienceDirect, PubMed and ACS. As many as 65 compounds are included in this review. They belong to different classes of compounds including flavonoids, terpenoids and several other types of compounds, such as alkaloids, phenolic acids and amides. The pharmacological studies revealed that various types of preparations, extracts and single compounds of species from this genus exhibited a broad spectrum of biological activities including antioxidant, antimicrobial, anti-inflammatory and cytotoxic activities. However, Sapium glandulosum, Sapium indicum and Sapium sebiferum were reported to possess toxic effects and Sapium sebiferum was found to contain phorbol esters acting as a tumor-promoting agent. The genus Sapium consists of 23 accepted (high confidence) species. However, only very few of species have been phytochemically and pharmacologically studied. There is great potential to discover new chemical constituents from this genus because only a

  14. Traditional usages, botany, phytochemistry, pharmacology and toxicology of Polygonum multiflorum Thunb.: a review.

    Science.gov (United States)

    Lin, Longfei; Ni, Boran; Lin, Hongmei; Zhang, Miao; Li, Xuechun; Yin, Xingbin; Qu, Changhai; Ni, Jian

    2015-01-15

    Polygonum multiflorum Thunb., which is known as Heshouwu ( in Chinese) in China. It is traditionally valued and reported for hair-blacking, liver and kidney-tonifying and anti-aging effects as well as low toxicity. The aim of this review is to provide comprehensive information on the botany, traditional uses, phytochemistry, pharmacological research and toxicology of Polygonum multiflorum, based on the scientific literature. Moreover, trends and perspectives for future investigation of this plant are discussed. It will build up a new foundation for further study on Polygonum multiflorum. A systematic review of the literature on Polygonum multiflorum was performed using several resources, including classic books on Chinese herbal medicine and various scientific databases, such as PubMed, SciFinder, the Web of Science, Science Direct, China Knowledge Resource Integrated (CNKI). Polygonum multiflorum is widely distributed throughout the world and has been used as a traditional medicine for centuries in China. The ethnomedical uses of Polygonum multiflorum have been recorded in many provinces of China and Japan for nine species of adulterants in six families. More than 100 chemical compounds have been isolated from this plant, and the major components have been determined to be stilbenes, quinones, flavonoids and others. Crude extracts and pure compounds of this plant are used as effective agents in pre-clinical and clinical practice due to their anti-aging, anti-hyperlipidaemia, anti-cancer and anti-inflammatory effects and to promote immunomodulation, neuroprotection, and the curing of other diseases. However, these extracts can also lead to hepatotoxicity, nephrotoxicity and embryonic toxicity. Pharmacokinetic studies have demonstrated that the main components of Polygonum multiflorum, such as 2,3,5,4'-tetrahydroxystilbene-2-O-β-d-glucopyranoside and emodin are distributed among many organs and tissues. Therapeutic potential of Polygonum multiflorum has been

  15. Areca catechu L. (Arecaceae): a review of its traditional uses, botany, phytochemistry, pharmacology and toxicology.

    Science.gov (United States)

    Peng, Wei; Liu, Yu-Jie; Wu, Na; Sun, Tao; He, Xiao-Yan; Gao, Yong-Xiang; Wu, Chun-Jie

    2015-04-22

    Areca catechu L. (Arecaceae), widely distributed in South and Southeast Asia, is a popular traditional herbal medicine that can be chewed for the purpose of dispersing accumulated fluid in the abdominal cavity and killing worms. The present paper aims to provide an up-to-date review on the traditional uses and advances in the botany, phytochemistry, pharmacology and toxicology of this plant. Furthermore, the possible trends and a perspective for future research of this plant are also discussed. A literature search was performed on A. catechu based on classic books of herbal medicine, PhD. and MSc. dissertations, government reports, the state and local drug standards, scientific databases including Pubmed, SciFinder, Scopus, the Web of Science, Google Scholar, and others. Various types of information regarding this plant are discussed in corresponding parts of this paper. In addition, perspectives for possible future studies of A. catechu are discussed. The seeds of A. catechu (areca nut) have been widely used in clinical practice in China, India and other South and Southeast Asian Countries. Currently, over 59 compounds have been isolated and identified from A. catechu, including alkaloids, tannins, flavones, triterpenes, steroids, and fatty acids. The extracts and compounds isolated from A. catechu have many pharmacological activities. These include antiparasitic effects, anti-depressive effects, anti-fatigue effects, antioxidant effects, antibacterial and antifungal effects, antihypertensive effects, anti-inflammatory and analgesic effects, anti-allergic effects, the promotion of digestive functions, suppression of platelet aggregation, regulatory effects on blood glucose and lipids, etc. Although arecoline is the primary active constituent of A. catechu, it is also the primary toxic compound. The main toxicities of arecoline are the promotion of oral submucosal fibrosis (OSF) and cytotoxic effects on normal human cells, which involve inducing apoptosis. As an

  16. Botany, phytochemistry, pharmacology, and potential application of Polygonum cuspidatum Sieb.et Zucc.: a review.

    Science.gov (United States)

    Peng, Wei; Qin, Rongxin; Li, Xiaoli; Zhou, Hong

    2013-07-30

    Polygonum cuspidatum Sieb. et Zucc. (Polygonum cuspidatum), also known as Reynoutria japonica Houtt and Huzhang in China, is a traditional and popular Chinese medicinal herb. Polygonum cuspidatum with a wide spectrum of pharmacological effects has been used for treatment of inflammation, favus, jaundice, scald, and hyperlipemia, etc. The present paper reviews the traditional applications as well as advances in botany, phytochemistry, pharmacodynamics, pharmacokinetics and toxicology of this plant. Finally, the tendency and perspective for future investigation of this plant are discussed, too. A systematic review of literature about Polygonum cuspidatum is carried out using resources including classic books about Chinese herbal medicine, and scientific databases including Pubmed, SciFinder, Scopus, the Web of Science and others. Polygonum cuspidatum is widely distributed in the world and has been used as a traditional medicine for a long history in China. Over 67 compounds including quinones, stilbenes, flavonoids, counmarins and ligans have been isolated and identified from this plant. The root of this plant is used as the effective agent in pre-clinical and clinical practice for regulating lipids, anti-endotoxic shock, anti-infection and anti-inflammation, anti-cancer and other diseases in China and Japan. As an important traditional Chinese medicine, Polygonum cuspidatum has been used for treatment of hyperlipemia, inflammation, infection and cancer, etc. Because there is no enough systemic data about the chemical constituents and their pharmacological effects or toxicities, it is important to investigate the pharmacological effects and molecular mechanisms of this plant based on modern realization of diseases' pathophysiology. Drug target-guided and bioactivity-guided isolation and purification of the chemical constituents from this plant and subsequent evaluation of their pharmacologic effects will promote the development of new drug and make sure which

  17. Do stage-specific functional responses of consumers dampen the effects of subsidies on trophic cascades in streams?

    Science.gov (United States)

    Sato, Takuya; Watanabe, Katsutoshi

    2014-07-01

    Resource subsidies often weaken trophic cascades in recipient communities via consumers' functional response to the subsidies. Consumer populations are commonly stage-structured and may respond to the subsidies differently among the stages yet less is known about how this might impact the subsidy effects on the strength of trophic cascades in recipient systems. We show here, using a large-scale field experiment, that the stage structure of a recipient consumer would dampen the effects of terrestrial invertebrate subsidies on the strength of trophic cascade in streams. When a high input rate of the terrestrial invertebrates was available, both large and small fish stages switched their diet to the terrestrial subsidy, which weakened the trophic cascade in streams. However, when the input rate of the terrestrial invertebrates was at a moderate level, the terrestrial subsidy did not weaken the trophic cascade. This discrepancy was likely due to small fish stages being competitively excluded from feeding on the subsidy by larger stages of fish and primarily foraging on benthic invertebrates under the moderate input level. Although previous studies using single fish stages have clearly demonstrated that the terrestrial invertebrate input equivalent to our moderate input rate weakened the trophic cascade in streams, this subsidy effect might be overestimated given small fish stage may not switch their diet to the subsidy under competition with large fish stage. Given the ubiquity of consumer stage structure and interaction among consumer stages, the effects we saw might be widespread in nature, requiring future studies that explicitly involve consumer's stage structure into community ecology. © 2013 The Authors. Journal of Animal Ecology © 2013 British Ecological Society.

  18. Trophic structure of a coastal fish community determined with diet and stable isotope analyses.

    Science.gov (United States)

    Malek, A J; Collie, J S; Taylor, D L

    2016-09-01

    A combination of dietary guild analysis and nitrogen (δ(15) N) and carbon (δ(13) C) stable-isotope analysis was used to assess the trophic structure of the fish community in Rhode Island and Block Island Sounds, an area off southern New England identified for offshore wind energy development. In the autumn of 2009, 2010 and 2011, stomach and tissue samples were taken from 20 fish and invertebrate species for analysis of diet composition and δ(15) N and δ(13) C signatures. The food chain in Rhode Island and Block Island Sounds comprises approximately four trophic levels within which the fish community is divided into distinct dietary guilds, including planktivores, benthivores, crustacivores and piscivores. Within these guilds, inter-species isotopic and dietary overlap is high, suggesting that resource partitioning or competitive interactions play a major role in structuring the fish community. Carbon isotopes indicate that most fishes are supported by pelagic phytoplankton, although there is evidence that benthic production also plays a role, particularly for obligate benthivores such as skates Leucoraja spp. This type of analysis is useful for developing an ecosystem-based approach to management, as it identifies species that act as direct links to basal resources as well as species groups that share trophic roles. © 2016 The Fisheries Society of the British Isles.

  19. Trophic complexity and the adaptive value of damage-induced plant volatiles.

    Directory of Open Access Journals (Sweden)

    Ian Kaplan

    Full Text Available Indirect plant defenses are those facilitating the action of carnivores in ridding plants of their herbivorous consumers, as opposed to directly poisoning or repelling them. Of the numerous and diverse indirect defensive strategies employed by plants, inducible volatile production has garnered the most fascination among plant-insect ecologists. These volatile chemicals are emitted in response to feeding by herbivorous arthropods and serve to guide predators and parasitic wasps to their prey. Implicit in virtually all discussions of plant volatile-carnivore interactions is the premise that plants "call for help" to bodyguards that serve to boost plant fitness by limiting herbivore damage. This, by necessity, assumes a three-trophic level food chain where carnivores benefit plants, a theoretical framework that is conceptually tractable and convenient, but poorly depicts the complexity of food-web dynamics occurring in real communities. Recent work suggests that hyperparasitoids, top consumers acting from the fourth trophic level, exploit the same plant volatile cues used by third trophic level carnivores. Further, hyperparasitoids shift their foraging preferences, specifically cueing in to the odor profile of a plant being damaged by a parasitized herbivore that contains their host compared with damage from an unparasitized herbivore. If this outcome is broadly representative of plant-insect food webs at large, it suggests that damage-induced volatiles may not always be beneficial to plants with major implications for the evolution of anti-herbivore defense and manipulating plant traits to improve biological control in agricultural crops.

  20. Landscape variation influences trophic cascades in dengue vector food webs.

    Science.gov (United States)

    Weterings, Robbie; Umponstira, Chanin; Buckley, Hannah L

    2018-02-01

    The epidemiology of vector-borne diseases is governed by a structured array of correlative and causative factors, including landscape (for example, rural versus urban), abiotic (for example, weather), and biotic (for example, food web) factors. Studies of mosquito-borne diseases rarely address these multiple factors at large spatial scales, which limits insights into how human alterations of landscapes and food webs alter mosquito abundance. We used structural equation modeling to identify the relative magnitude and direction of landscape, abiotic, and food web factors on Aedes larvae and adults across 70 sites in northern Thailand. Food web factors were modeled as mosquito-predator trophic cascades. Landscape context affected mosquito-predator communities in aquatic and terrestrial environments via cascading food web interactions. Several mosquito predators within these food webs showed potential as biocontrol agents in mosquito population control, but their potentials for control were landscape-dependent. In terrestrial food webs, the habitat-sensitive tokay gecko structured mosquito-predator communities, indicating that a conservation approach to vector control could be a useful addition to existing control efforts.

  1. [Strengths, weaknesses, and opportunities of French research in trophic ecology].

    Science.gov (United States)

    Perga, Marie-Élodie; Danger, Michael; Dubois, Stanislas; Fritch, Clémentine; Gaucherel, Cédric; Hubas, Cedric; Jabot, Franck; Lacroix, Gérard; Lefebvre, Sébastien; Marmonier, Pierre; Bec, Alexandre

    2018-05-30

    The French National Institute of Ecology and Environment (INEE) aims at fostering pluridisciplinarity in Environmental Science and, for that purpose, funds ex muros research groups (GDR) on thematic topics. Trophic ecology has been identified as a scientific field in ecology that would greatly benefit from such networking activity, as being profoundly scattered. This has motivated the seeding of a GDR, entitled "GRET". The contours of the GRET's action, and its ability to fill these gaps within trophic ecology at the French national scale, will depend on the causes of this relative scattering. This study relied on a nationally broadcasted poll aiming at characterizing the field of trophic ecology in France. Amongst all the unique individuals that fulfilled the poll, over 300 belonged at least partly to the field of trophic ecology. The sample included all French public research institutes and career stages. Three main disruptions within the community of scientist in trophic ecology were identified. The first highlighted the lack of interfaces between microbial and trophic ecology. The second evidenced that research questions were strongly linked to single study fields or ecosystem type. Last, research activities are still quite restricted to the ecosystem boundaries. All three rupture points limit the conceptual and applied progression in the field of trophic ecology. Here we show that most of the disruptions within French Trophic Ecology are culturally inherited, rather than motivated by scientific reasons or justified by socio-economic stakes. Comparison with the current literature confirms that these disruptions are not necessarily typical of the French research landscape, but instead echo the general weaknesses of the international research in ecology. Thereby, communication and networking actions within and toward the community of trophic ecologists, as planned within the GRET's objectives, should contribute to fill these gaps, by reintegrating microbes within

  2. Disruption of Trophic Inhibitory Signaling in Autism Sepctrum Disorders

    Science.gov (United States)

    2016-12-01

    1 AWARD NUMBER: W81XWH-14-1-0433 TITLE: Disruption of Trophic Inhibitory Signaling in Autism Sepctrum Disorders PRINCIPAL INVESTIGATOR: Anis...SUBTITLE 5a. CONTRACT NUMBER Disruption of Trophic Inhibitory Signaling in Autism Sepctrum Disorders 5b. GRANT NUMBER W81XWH-14-1-0433 5c. PROGRAM...chloride co-transporters that control EGABA could be used as a corrective strategy for the synaptic and circuit disruptions demonstrated in the

  3. Drivers of trophic amplification of ocean productivity trends in a changing climate

    Science.gov (United States)

    Stock, C. A.; Dunne, J. P.; John, J. G.

    2014-07-01

    . Improved understanding of the complex interactions governing these food web properties is essential to further refine estimates of climate-driven productivity changes across trophic levels.

  4. Trophic transfer of gold nanoparticles from Euglena gracilis or Chlamydomonas reinhardtii to Daphnia magna

    International Nuclear Information System (INIS)

    Lee, Woo-Mi; Yoon, Sung-Ji; Shin, Yu-Jin; An, Youn-Joo

    2015-01-01

    Understanding the trophic transfer of nanoparticles (NPs) is important because NPs are small enough to easily penetrate into organisms. In this study, we evaluated the trophic transfer of gold NPs (AuNPs) within the aquatic food chain. We observed AuNPs transfer from 2 species of primary producers (Chlamydomonas reinhardtii or Euglena gracilis) to the primary consumer (Daphnia magna). Also, bioaccumulation of AuNPs in E. gracilis was higher than that in C. reinhardtii. The reasons for the difference in Au accumulation may be the physical structure of these organisms, and the surface area that is available for interaction with NPs. C. reinhardtii has a cell wall that may act as a barrier to the penetration of NPs. The size of E. gracilis is larger than that of C. reinhardtii. This study demonstrates the trophic transfer of AuNPs from a general producer to a consumer in an aquatic environment. - Highlights: • This study evaluated the trophic transfer of AuNPs in an aquatic food chain. • Chlamydomonas reinhardtii and Euglena gracilis were selected as the primary producers. • Daphnia magna was used as the primary consumer. • The bioaccumulation of AuNPs in E. gracilis was higher than that in C. reinhardtii. • AuNPs were transferred from C. reinhardtii and E. gracilis to D. magna. - Gold nanoparticles can transfer from primary producers (Chlamydomonas reinhardtii or Euglena gracilis) to the primary consumer (Daphnia magna) in an aquatic environment

  5. Enhanced understanding of ectoparasite: host trophic linkages on coral reefs through stable isotope analysis

    Science.gov (United States)

    Demopoulos, Amanda W. J.; Sikkel, Paul C.

    2015-01-01

    Parasitism, although the most common type of ecological interaction, is usually ignored in food web models and studies of trophic connectivity. Stable isotope analysis is widely used in assessing the flow of energy in ecological communities and thus is a potentially valuable tool in understanding the cryptic trophic relationships mediated by parasites. In an effort to assess the utility of stable isotope analysis in understanding the role of parasites in complex coral-reef trophic systems, we performed stable isotope analysis on three common Caribbean reef fish hosts and two kinds of ectoparasitic isopods: temporarily parasitic gnathiids (Gnathia marleyi) and permanently parasitic cymothoids (Anilocra). To further track the transfer of fish-derived carbon (energy) from parasites to parasite consumers, gnathiids from host fish were also fed to captive Pederson shrimp (Ancylomenes pedersoni) for at least 1 month. Parasitic isopods had δ13C and δ15N values similar to their host, comparable with results from the small number of other host–parasite studies that have employed stable isotopes. Adult gnathiids were enriched in 15N and depleted in13C relative to juvenile gnathiids, providing insights into the potential isotopic fractionation associated with blood-meal assimilation and subsequent metamorphosis. Gnathiid-fed Pedersen shrimp also had δ13C values consistent with their food source and enriched in 15N as predicted due to trophic fractionation. These results further indicate that stable isotopes can be an effective tool in deciphering cryptic feeding relationships involving parasites and their consumers, and the role of parasites and cleaners in carbon transfer in coral-reef ecosystems specifically.

  6. Enhanced understanding of ectoparasite–host trophic linkages on coral reefs through stable isotope analysis

    Directory of Open Access Journals (Sweden)

    Amanda W.J. Demopoulos

    2015-04-01

    Full Text Available Parasitism, although the most common type of ecological interaction, is usually ignored in food web models and studies of trophic connectivity. Stable isotope analysis is widely used in assessing the flow of energy in ecological communities and thus is a potentially valuable tool in understanding the cryptic trophic relationships mediated by parasites. In an effort to assess the utility of stable isotope analysis in understanding the role of parasites in complex coral-reef trophic systems, we performed stable isotope analysis on three common Caribbean reef fish hosts and two kinds of ectoparasitic isopods: temporarily parasitic gnathiids (Gnathia marleyi and permanently parasitic cymothoids (Anilocra. To further track the transfer of fish-derived carbon (energy from parasites to parasite consumers, gnathiids from host fish were also fed to captive Pederson shrimp (Ancylomenes pedersoni for at least 1 month. Parasitic isopods had δ13C and δ15N values similar to their host, comparable with results from the small number of other host–parasite studies that have employed stable isotopes. Adult gnathiids were enriched in 15N and depleted in 13C relative to juvenile gnathiids, providing insights into the potential isotopic fractionation associated with blood-meal assimilation and subsequent metamorphosis. Gnathiid-fed Pedersen shrimp also had δ13C values consistent with their food source and enriched in 15N as predicted due to trophic fractionation. These results further indicate that stable isotopes can be an effective tool in deciphering cryptic feeding relationships involving parasites and their consumers, and the role of parasites and cleaners in carbon transfer in coral-reef ecosystems specifically.

  7. Trophic signatures of seabirds suggest shifts in oceanic ecosystems

    Science.gov (United States)

    Gagne, Tyler O.; Hyrenbach, K. David; Hagemann, Molly E.; Van Houtan, Kyle S.

    2018-01-01

    Pelagic ecosystems are dynamic ocean regions whose immense natural capital is affected by climate change, pollution, and commercial fisheries. Trophic level–based indicators derived from fishery catch data may reveal the food web status of these systems, but the utility of these metrics has been debated because of targeting bias in fisheries catch. We analyze a unique, fishery-independent data set of North Pacific seabird tissues to inform ecosystem trends over 13 decades (1890s to 2010s). Trophic position declined broadly in five of eight species sampled, indicating a long-term shift from higher–trophic level to lower–trophic level prey. No species increased their trophic position. Given species prey preferences, Bayesian diet reconstructions suggest a shift from fishes to squids, a result consistent with both catch reports and ecosystem models. Machine learning models further reveal that trophic position trends have a complex set of drivers including climate, commercial fisheries, and ecomorphology. Our results show that multiple species of fish-consuming seabirds may track the complex changes occurring in marine ecosystems. PMID:29457134

  8. Trophic transfer of pyrene metabolites between aquatic invertebrates

    International Nuclear Information System (INIS)

    Carrasco Navarro, V.; Leppänen, M.T.; Kukkonen, J.V.K.; Godoy Olmos, S.

    2013-01-01

    The trophic transfer of pyrene metabolites was studied using Gammarus setosus as a predator and the invertebrates Lumbriculus variegatus and Chironomus riparius as prey. The results obtained by liquid scintillation counting confirmed that the pyrene metabolites produced by the aquatic invertebrates L. variegatus and C. riparius were transferred to G. setosus through the diet. More detailed analyses by liquid chromatography discovered that two of the metabolites produced by C. riparius appeared in the chromatograms of G. setosus tissue extracts, proving their trophic transfer. These metabolites were not present in chromatograms of G. setosus exclusively exposed to pyrene. The present study supports the trophic transfer of PAH metabolites between benthic macroinvertebrates and common species of an arctic amphipod. As some PAH metabolites are more toxic than the parent compounds, the present study raises concerns about the consequences of their trophic transfer and the fate and effects of PAHs in natural environments. - Highlights: ► The trophic transfer of pyrene metabolites between invertebrates was evaluated. ► Biotransformation of pyrene by L. variegatus and C. riparius is different. ► Metabolites produced by L. variegatus and C. riparius are transferred to G. setosus. ► Specifically, two metabolites produced by C. riparius were transferred. - Some of the pyrene metabolites produced by the model invertebrates L. variegatus and C. riparius are transferred to G. setosus through the diet, proving their trophic transfer.

  9. Critical assessment and ramifications of a purported marine trophic cascade

    Science.gov (United States)

    Grubbs, R. Dean; Carlson, John K; Romine, Jason G.; Curtis, Tobey H; McElroy, W. David; McCandless, Camilla T; Cotton, Charles F; Musick, John A.

    2016-01-01

    When identifying potential trophic cascades, it is important to clearly establish the trophic linkages between predators and prey with respect to temporal abundance, demographics, distribution, and diet. In the northwest Atlantic Ocean, the depletion of large coastal sharks was thought to trigger a trophic cascade whereby predation release resulted in increased cownose ray abundance, which then caused increased predation on and subsequent collapse of commercial bivalve stocks. These claims were used to justify the development of a predator-control fishery for cownose rays, the “Save the Bay, Eat a Ray” fishery, to reduce predation on commercial bivalves. A reexamination of data suggests declines in large coastal sharks did not coincide with purported rapid increases in cownose ray abundance. Likewise, the increase in cownose ray abundance did not coincide with declines in commercial bivalves. The lack of temporal correlations coupled with published diet data suggest the purported trophic cascade is lacking the empirical linkages required of a trophic cascade. Furthermore, the life history parameters of cownose rays suggest they have low reproductive potential and their populations are incapable of rapid increases. Hypothesized trophic cascades should be closely scrutinized as spurious conclusions may negatively influence conservation and management decisions.

  10. A guideline to study the feasibility domain of multi-trophic and changing ecological communities.

    Science.gov (United States)

    Song, Chuliang; Rohr, Rudolf P; Saavedra, Serguei

    2018-04-24

    The feasibility domain of an ecological community can be described by the set of environmental abiotic and biotic conditions under which all co-occurring and interacting species in a given site and time can have positive abundances. Mathematically, the feasibility domain corresponds to the parameter space compatible with positive (feasible) solutions at equilibrium for all the state variables in a system under a given model of population dynamics. Under specific dynamics, the existence of a feasible equilibrium is a necessary condition for species persistence regardless of whether the feasible equilibrium is dynamically stable or not. Thus, the size of the feasibility domain can also be used as an indicator of the tolerance of a community to random environmental variations. This has motivated a rich research agenda to estimate the feasibility domain of ecological communities. However, these methodologies typically assume that species interactions are static, or that input and output energy flows on each trophic level are unconstrained. Yet, this is different to how communities behave in nature. Here, we present a step-by-step quantitative guideline providing illustrative examples, computational code, and mathematical proofs to study systematically the feasibility domain of ecological communities under changes of interspecific interactions and subject to different constraints on the trophic energy flows. This guideline covers multi-trophic communities that can be formed by any type of interspecific interactions. Importantly, we show that the relative size of the feasibility domain can significantly change as a function of the biological information taken into consideration. We believe that the availability of these methods can allow us to increase our understanding about the limits at which ecological communities may no longer tolerate further environmental perturbations, and can facilitate a stronger integration of theoretical and empirical research. Copyright

  11. Medicinal plants from the genus Acalypha (Euphorbiaceae)--a review of their ethnopharmacology and phytochemistry.

    Science.gov (United States)

    Seebaluck, R; Gurib-Fakim, A; Mahomoodally, F

    2015-01-15

    Acalypha is the fourth largest genus of the Euphorbiaceae family with approximately 450-570 species. Several Acalypha species are used as medicinal plants in Africa and in the Mascarene Islands. Almost every part of the plant including the leaves, stem and roots are used as traditional remedies to treat and manage a panoply of ailments. However, there is no updated compilation of traditionally important medicinal plants from the Acalypha genus. The present review therefore, endeavors to provide for the first time an updated compilation of documented ethnopharmacological information in relation to the ethnomedicinal, ethnoveterinary, zoopharmacognosy, phytochemistry and biological activities of medicinal plants from the Acalypha genus which can subsequently open new perspectives for further pharmacological research. A literature search was performed on Acalypha species using ethnobotanical text books and scientific databases such as Pubmed, Scopus, EBSCO, Google Scholar and other web sources such as records from PROTA, PROSEA, and Botanical Dermatology Database. The Plant List, International Plant Name index and Kew Botanical Garden Plant name databases were used to validate scientific names. Plants from Acalypha genus are traditionally used in the treatment and/or management of diverse ailments such as diabetes, jaundice, hypertension, fever, liver inflammation, schistosomiasis, dysentery, respiratory problems including bronchitis, asthma and pheumonia as well as skin conditions such as scabies, eczema and mycoses. Approximately 124 species were listed in ethnobotanical studies with some botanical description and others mentioned from different web sources. However, only 40 species have been included in the present review due to the unavailability of ethnopharmacological data on the remaining species. Among the 40 cited species, 30 were traditionally used for the treatment and/or management of approximately 70 human diseases or health conditions. Two species

  12. Traditional uses, phytochemistry, pharmacology and toxicology of the genus Cimicifuga: A review.

    Science.gov (United States)

    Guo, Yaqing; Yin, Tong; Wang, Xiaoming; Zhang, Fan; Pan, Guixiang; Lv, Hong; Wang, Xianrui; Owoicho Orgah, John; Zhu, Yan; Wu, Honghua

    2017-09-14

    Plants of the genus Cimicifuga have long been used as an ethnomedicine in China, Europe, and North America for its high medicinal value and health benefits. Their dried rhizomes are widely used for treating wind-heat headache, toothache, aphtha, sore throat, measles, spot poison, archoptosis, and uterine prolapse. In addition, it is used as a dietary supplement for preventing women menopausal symptoms and osteoporosis. This paper aims to provide up-to-date information on the genus Cimicifuga, including botanical characterization, medicinal resources, traditional medicinal uses, phytochemistry, quality control, pharmacological research as well as the toxicology. The possible structural-activity relationships and molecular mechanisms of the bioactive constituents are discussed in ways that contribute to the structural optimization and preclinical safety assessment for further drug design. The relevant information on Cimicifuga was collected from scientific databases (such as Google Scholar, PubMed, SciFinder Scholar, Science Direct, CNKI, Baidu Scholar, Web of Science, China Knowledge Resource Integrated Database), Chinese herbal classics, ethnobotanical books, PhD and MSc dissertations, Chinese Pharmacopoeia, published articles in peer-reviewed journals, local magazines, and unpublished materials. In addition, the Plant List (TPL, www.theplantlist.org) was also used to validate the scientific names and synonyms of this plant. The literature cited in this review dated from 1953 to 2017. The majority of chemical constituents of this plant include triterpenoid glycosides, phenylpropanoids, nitrogenous compounds, chromones, flavonoids and 4α-methyl steroid. Among them, the primary bioactive constituents are believed to be present in the triterpene glycoside fraction. To date, investigation of seven Cimicifuga spp. plants led to the identification of more than 457 compounds. Years of pharmacological research proved that the crude extracts and certain pure compounds

  13. Marine snow, zooplankton and thin layers: indications of a trophic link from small-scale sampling with the Video Plankton Recorder

    DEFF Research Database (Denmark)

    Möller, Klas O.; St. John, Michael; Temming, Axel

    2012-01-01

    Marine aggregates of biogenic origin, known as marine snow, are considered to play a major role in the ocean’s particle flux and may represent a concentrated food source for zooplankton. However, observing the marine snow−zooplankton interaction in the field is difficult since conventional net sa...... to aggregates and demonstrating feeding behaviour, which also suggests a trophic interaction. Our observations highlight the potential significance of marine snow in marine ecosystems and its potential as a food resource for various trophic levels, from bacteria up to fish...

  14. Time- and depth-wise trophic niche shifts in Antarctic benthos.

    Directory of Open Access Journals (Sweden)

    Edoardo Calizza

    Full Text Available Climate change is expected to affect resource-consumer interactions underlying stability in polar food webs. Polar benthic organisms have adapted to the marked seasonality characterising their habitats by concentrating foraging and reproductive activity in summer months, when inputs from sympagic and pelagic producers increase. While this enables the persistence of biodiverse food webs, the mechanisms underlying changes in resource use and nutrient transfer are poorly understood. Thus, our understanding of how temporal and spatial variations in the supply of resources may affect food web structure and functioning is limited. By means of C and N isotopic analyses of two key Antarctic benthic consumers (Adamussium colbecki, Bivalvia, and Sterechinus neumayeri, Echinoidea and Bayesian mixing models, we describe changes in trophic niche and nutrient transfer across trophic levels associated with the long- and short-term diet and body size of specimens sampled in midsummer in both shallow and deep waters. Samplings occurred soon after the sea-ice broke up at Tethys Bay, an area characterised by extreme seasonality in sea-ice coverage and productivity in the Ross Sea. In the long term, the trophic niche was broader and variation between specimens was greater, with intermediate-size specimens generally consuming a higher number of resources than small and large specimens. The coupling of energy channels in the food web was consequently more direct than in the short term. Sediment and benthic algae were more frequently consumed in the long term, before the sea-ice broke up, while consumers specialised on sympagic algae and plankton in the short term. Regardless of the time scale, sympagic algae were more frequently consumed in shallow waters, while plankton was more frequently consumed in deep waters. Our results suggest a strong temporal relationship between resource availability and the trophic niche of benthic consumers in Antarctica. Potential

  15. Time- and depth-wise trophic niche shifts in Antarctic benthos.

    Science.gov (United States)

    Calizza, Edoardo; Careddu, Giulio; Sporta Caputi, Simona; Rossi, Loreto; Costantini, Maria Letizia

    2018-01-01

    Climate change is expected to affect resource-consumer interactions underlying stability in polar food webs. Polar benthic organisms have adapted to the marked seasonality characterising their habitats by concentrating foraging and reproductive activity in summer months, when inputs from sympagic and pelagic producers increase. While this enables the persistence of biodiverse food webs, the mechanisms underlying changes in resource use and nutrient transfer are poorly understood. Thus, our understanding of how temporal and spatial variations in the supply of resources may affect food web structure and functioning is limited. By means of C and N isotopic analyses of two key Antarctic benthic consumers (Adamussium colbecki, Bivalvia, and Sterechinus neumayeri, Echinoidea) and Bayesian mixing models, we describe changes in trophic niche and nutrient transfer across trophic levels associated with the long- and short-term diet and body size of specimens sampled in midsummer in both shallow and deep waters. Samplings occurred soon after the sea-ice broke up at Tethys Bay, an area characterised by extreme seasonality in sea-ice coverage and productivity in the Ross Sea. In the long term, the trophic niche was broader and variation between specimens was greater, with intermediate-size specimens generally consuming a higher number of resources than small and large specimens. The coupling of energy channels in the food web was consequently more direct than in the short term. Sediment and benthic algae were more frequently consumed in the long term, before the sea-ice broke up, while consumers specialised on sympagic algae and plankton in the short term. Regardless of the time scale, sympagic algae were more frequently consumed in shallow waters, while plankton was more frequently consumed in deep waters. Our results suggest a strong temporal relationship between resource availability and the trophic niche of benthic consumers in Antarctica. Potential climate-driven changes

  16. From neurons to epidemics: How trophic coherence affects spreading processes

    Science.gov (United States)

    Klaise, Janis; Johnson, Samuel

    2016-06-01

    Trophic coherence, a measure of the extent to which the nodes of a directed network are organised in levels, has recently been shown to be closely related to many structural and dynamical aspects of complex systems, including graph eigenspectra, the prevalence or absence of feedback cycles, and linear stability. Furthermore, non-trivial trophic structures have been observed in networks of neurons, species, genes, metabolites, cellular signalling, concatenated words, P2P users, and world trade. Here, we consider two simple yet apparently quite different dynamical models—one a susceptible-infected-susceptible epidemic model adapted to include complex contagion and the other an Amari-Hopfield neural network—and show that in both cases the related spreading processes are modulated in similar ways by the trophic coherence of the underlying networks. To do this, we propose a network assembly model which can generate structures with tunable trophic coherence, limiting in either perfectly stratified networks or random graphs. We find that trophic coherence can exert a qualitative change in spreading behaviour, determining whether a pulse of activity will percolate through the entire network or remain confined to a subset of nodes, and whether such activity will quickly die out or endure indefinitely. These results could be important for our understanding of phenomena such as epidemics, rumours, shocks to ecosystems, neuronal avalanches, and many other spreading processes.

  17. A Lota lota consumption: Trophic dynamics of nonnative Burbot in a valuable sport fishery

    Science.gov (United States)

    Klobucar, Stephen L.; Saunders, W. Carl; Budy, Phaedra

    2016-01-01

    Unintentional and illegal introductions of species disrupt food webs and threaten the success of managed sport fisheries. Although many populations of Burbot Lota lota are declining in the species’ native range, a nonnative population recently expanded into Flaming Gorge Reservoir (FGR), Wyoming–Utah, and threatens to disrupt predator–prey interactions within this popular sport fishery. To determine potential impacts on sport fishes, especially trophy Lake Trout Salvelinus namaycush, we assessed the relative abundance of Burbot and quantified the potential trophic or food web impacts of this population by using diet, stable isotope, and bioenergetic analyses. We did not detect a significant potential for food resource competition between Burbot and Lake Trout (Schoener’s overlap index = 0.13), but overall consumption by Burbot likely affects other sport fishes, as indicated by our analyses of trophic niche space. Diet analyses suggested that crayfish were important diet items across time (89.3% of prey by weight in autumn; 49.4% in winter) and across Burbot size-classes (small: 77.5% of prey by weight; medium: 76.6%; large: 39.7%). However, overall consumption by Burbot increases as water temperatures cool, and fish consumption by Burbot in FGR was observed to increase during winter. Specifically, large Burbot consumed more salmonids, and we estimated (bioenergetically) that up to 70% of growth occurred in late autumn and winter. Further, our population-wide consumption estimates indicated that Burbot could consume up to double the biomass of Rainbow Trout Oncorhynchus mykiss stocked annually (>1.3 × 105 kg; >1 million individuals) into FGR. Overall, we provide some of the first information regarding Burbot trophic interactions outside of the species’ native range; these findings can help to inform the management of sport fisheries if Burbot range expansion occurs elsewhere.

  18. Highly resolved early Eocene food webs show development of modern trophic structure after the end-Cretaceous extinction

    OpenAIRE

    Dunne, Jennifer A.; Labandeira, Conrad C.; Williams, Richard J.

    2014-01-01

    Generalities of food web structure have been identified for extant ecosystems. However, the trophic organization of ancient ecosystems is unresolved, as prior studies of fossil webs have been limited by low-resolution, high-uncertainty data. We compiled highly resolved, well-documented feeding interaction data for 700 taxa from the 48 million-year-old latest early Eocene Messel Shale, which contains a species assemblage that developed after an interval of protracted environmental and biotal c...

  19. Trophic transfer of metal nanoparticles in freshwater ecosystems

    DEFF Research Database (Denmark)

    Tangaa, Stine Rosendal

    freshwater ecosystems range from a few ng/L in surface waters and up to mg/kg in sediments. Several studies have shown Ag ENPs to be toxic, bioaccumulative and harmful to aquatic biota within these concentration ranges. However, research on potential trophic transfer of Ag ENPs is limited. To investigate...... the aquatic ecosystems, Ag ENPs will undergo several transformation processes, ultimately leading to particles settling out of the water column. This will likely result in an increased concentration of ENPs in the sediment. In fact, predicted environmental concentrations of Ag ENPs in Danish and European...... freshwater food web. Future studies should concentrate on the internal distribution of Me-ENPs after uptake in both prey and predator, as this will increase the understanding of fate and effects of Me-ENPs on aquatic biota. Trophic transfer studies including more trophic levels, and higher pelagic organisms...

  20. Trophic flow structure of a neotropical estuary in northeastern Brazil and the comparison of ecosystem model indicators of estuaries

    Science.gov (United States)

    Lira, Alex; Angelini, Ronaldo; Le Loc'h, François; Ménard, Frédéric; Lacerda, Carlos; Frédou, Thierry; Lucena Frédou, Flávia

    2018-06-01

    We developed an Ecopath model for the Estuary of Sirinhaém River (SIR), a small-sized system surrounded by mangroves, subject to high impact, mainly by the sugar cane and other farming industries in order to describe the food web structure and trophic interactions. In addition, we compared our findings with those of 20 available Ecopath estuarine models for tropical, subtropical and temperate regions, aiming to synthesize the knowledge on trophic dynamics and provide a comprehensive analysis of the structures and functioning of estuaries. Our model consisted of 25 compartments and its indicators were within the expected range for estuarine areas around the world. The average trophic transfer efficiency for the entire system was 11.8%, similar to the theoretical value of 10%. The Keystone Index and MTI (Mixed Trophic Impact) analysis indicated that the snook (Centropomus undecimalis and Centropomus parallelus) and jack (Caranx latus and Caranx hippos) are considered as key resources in the system, revealing their high impact in the food web. Both groups have a high ecological and commercial relevance, despite the unregulated fisheries. As result of the comparison of ecosystem model indicators in estuaries, differences in the ecosystem structure from the low latitude zones (tropical estuaries) to the high latitude zones (temperate system) were noticed. The structure of temperate and sub-tropical estuaries is based on high flows of detritus and export, while tropical systems have high biomass, respiration and consumption rates. Higher values of System Omnivory Index (SOI) and Overhead (SO) were observed in the tropical and subtropical estuaries, denoting a more complex food chain. Globally, none of the estuarine models were classified as fully mature ecosystems, although the tropical ecosystems were considered more mature than the subtropical and temperate ecosystems. This study is an important contribution to the trophic modeling of estuaries, which may also help

  1. Harnessing the medicinal properties of Andrographis paniculata for diseases and beyond: a review of its phytochemistry and pharmacology

    Directory of Open Access Journals (Sweden)

    Agbonlahor Okhuarobo

    2014-06-01

    Full Text Available Andrographis paniculata Wall (family Acanthaceae is one of the most popular medicinal plants used traditionally for the treatment of array of diseases such as cancer, diabetes, high blood pressure, ulcer, leprosy, bronchitis, skin diseases, flatulence, colic, influenza, dysentery, dyspepsia and malaria for centuries in Asia, America and Africa continents. It possesses several photochemical constituents with unique and interesting biological properties. This review describes the past and present state of research on Andrographis paniculata with respect to the medicinal usage, phytochemistry, pharmacological activities, toxicity profile and therapeutic usage, in order to bridge the gap requiring future research opportunities. This review is based on literature study on scientific journals and books from library and electronic sources. Diterpenes, flavonoids, xanthones, noriridoides and other miscellaneous compounds have been isolated from the plant. Extract and pure compounds of the plant have been reported for their antimicrobial, cytotoxicity, anti-protozoan, anti-inflammatory, anti-oxidant, immunostimulant, anti-diabetic, anti-infective, anti-angiogenic, hepato-renal protective, sex hormone/sexual function modulation, liver enzymes modulation insecticidal and toxicity activities. The results of numerous toxicity evaluations of extracts and metabolites isolated from this plant did not show any significant acute toxicity in experimental animals. Detailed and more comprehensive toxicity profile on mammalian tissues and organs is needed in future studies.

  2. Harnessing the medicinal properties of Andrographis paniculata for diseases and beyond: a review of its phytochemistry and pharmacology

    Science.gov (United States)

    Okhuarobo, Agbonlahor; Falodun, Joyce Ehizogie; Erharuyi, Osayemwenre; Imieje, Vincent; Falodun, Abiodun; Langer, Peter

    2014-01-01

    Andrographis paniculata Wall (family Acanthaceae) is one of the most popular medicinal plants used traditionally for the treatment of array of diseases such as cancer, diabetes, high blood pressure, ulcer, leprosy, bronchitis, skin diseases, flatulence, colic, influenza, dysentery, dyspepsia and malaria for centuries in Asia, America and Africa continents. It possesses several photochemical constituents with unique and interesting biological properties. This review describes the past and present state of research on Andrographis paniculata with respect to the medicinal usage, phytochemistry, pharmacological activities, toxicity profile and therapeutic usage, in order to bridge the gap requiring future research opportunities. This review is based on literature study on scientific journals and books from library and electronic sources. Diterpenes, flavonoids, xanthones, noriridoides and other miscellaneous compounds have been isolated from the plant. Extract and pure compounds of the plant have been reported for their anti-microbial, cytotoxicity, anti-protozoan, anti-inflammatory, anti-oxidant, immunostimulant, anti-diabetic, anti-infective, anti-angiogenic, hepato-renal protective, sex hormone/sexual function modulation, liver enzymes modulation insecticidal and toxicity activities. The results of numerous toxicity evaluations of extracts and metabolites isolated from this plant did not show any significant acute toxicity in experimental animals. Detailed and more comprehensive toxicity profile on mammalian tissues and organs is needed in future studies.

  3. Zanthoxylum bungeanum Maxim. (Rutaceae: A Systematic Review of Its Traditional Uses, Botany, Phytochemistry, Pharmacology, Pharmacokinetics, and Toxicology

    Directory of Open Access Journals (Sweden)

    Mengmeng Zhang

    2017-10-01

    Full Text Available Zanthoxylum bungeanum Maxim. (Rutaceae is a popular food additive and traditional Chinese herbal medicine commonly named HuaJiao in China. This plant is widely distributed in Asian countries. The aim of this paper is to provide a systematic review on the traditional usages, botany, phytochemistry, pharmacology, pharmacokinetics, and toxicology of this plant. Furthermore, the possible development and perspectives for future research on this plant are also discussed. To date, over 140 compounds have been isolated and identified from Z. bungeanum, including alkaloids, terpenoids, flavonoids, and free fatty acids. The extracts and compounds have been shown to possess wide-ranging biological activity, such as anti-inflammatory and analgesic effects, antioxidant and anti-tumor effects, antibacterial and antifungal effects, as well as regulatory effects on the gastrointestinal system and nervous system, and other effects. As a traditional herbal medicine, Z. bungeanum has been widely used to treat many diseases, especially digestive disorders, toothache, stomach ache, and diarrhea. Many traditional usages of this plant have been validated by present investigations. However, further research elucidating the structure-function relationship among chemical compounds, understanding the mechanism of unique sensation, as well as exploring new clinical effects and establishing criteria for quality control for Z. bungeanum should be further studied.

  4. Jatropha gossypiifolia L. (Euphorbiaceae: A Review of Traditional Uses, Phytochemistry, Pharmacology, and Toxicology of This Medicinal Plant

    Directory of Open Access Journals (Sweden)

    Juliana Félix-Silva

    2014-01-01

    Full Text Available Jatropha gossypiifolia L. (Euphorbiaceae, widely known as “bellyache bush,” is a medicinal plant largely used throughout Africa and America. Several human and veterinary uses in traditional medicine are described for different parts and preparations based on this plant. However, critical reviews discussing emphatically its medicinal value are missing. This review aims to provide an up-to-date overview of the traditional uses, as well as the phytochemistry, pharmacology, and toxicity data of J. gossypiifolia species, in view of discussing its medicinal value and potential application in complementary and alternative medicine. Pharmacological studies have demonstrated significant action of different extracts and/or isolated compounds as antimicrobial, anti-inflammatory, antidiarrheal, antihypertensive, and anticancer agents, among others, supporting some of its popular uses. No clinical trial has been detected to date. Further studies are necessary to assay important folk uses, as well as to find new bioactive molecules with pharmacological relevance based on the popular claims. Toxicological studies associated with phytochemical analysis are important to understand the eventual toxic effects that could reduce its medicinal value. The present review provides insights for future research aiming for both ethnopharmacological validation of its popular use and its exploration as a new source of herbal drugs and/or bioactive natural products.

  5. Zanthoxylum bungeanum Maxim. (Rutaceae): A Systematic Review of Its Traditional Uses, Botany, Phytochemistry, Pharmacology, Pharmacokinetics, and Toxicology.

    Science.gov (United States)

    Zhang, Mengmeng; Wang, Jiaolong; Zhu, Lei; Li, Tao; Jiang, Weidong; Zhou, Juan; Peng, Wei; Wu, Chunjie

    2017-10-18

    Zanthoxylum bungeanum Maxim. (Rutaceae) is a popular food additive and traditional Chinese herbal medicine commonly named HuaJiao in China. This plant is widely distributed in Asian countries. The aim of this paper is to provide a systematic review on the traditional usages, botany, phytochemistry, pharmacology, pharmacokinetics, and toxicology of this plant. Furthermore, the possible development and perspectives for future research on this plant are also discussed. To date, over 140 compounds have been isolated and identified from Z. bungeanum , including alkaloids, terpenoids, flavonoids, and free fatty acids. The extracts and compounds have been shown to possess wide-ranging biological activity, such as anti-inflammatory and analgesic effects, antioxidant and anti-tumor effects, antibacterial and antifungal effects, as well as regulatory effects on the gastrointestinal system and nervous system, and other effects. As a traditional herbal medicine, Z. bungeanum has been widely used to treat many diseases, especially digestive disorders, toothache, stomach ache, and diarrhea. Many traditional usages of this plant have been validated by present investigations. However, further research elucidating the structure-function relationship among chemical compounds, understanding the mechanism of unique sensation, as well as exploring new clinical effects and establishing criteria for quality control for Z. bungeanum should be further studied.

  6. Emergence of a new predator in the North Sea: evaluation of potential trophic impacts focused on hake, saithe, and Norway pout

    DEFF Research Database (Denmark)

    Cormon, Xochitl; Kempf, Alexander; Vermard, Youen

    2016-01-01

    During the last 15 years, northern European hake (Merluccius merluccius) has increased in abundance, and its spatial distribution has expanded in the North Sea region in correlation with temperature. In a context of global warming, this spatial shift could impact local trophic interactions: direc...

  7. Trophic structure of macroinvertebrates in tropical pasture streams

    Directory of Open Access Journals (Sweden)

    Bruna Neves da Silveira-Manzotti

    Full Text Available Abstract: Aim The aim of this study was to describe the diet of stream macroinvertebrates and to determine their trophic groups. Methods Invertebrates were sampled with D nets in three pasture streams. They were identified to genus level and submitted to gut content analysis, except for fluid feeders such as hemipterans, to which diet data was obtained from the literature. Trophic groups were determined based on a similarity analysis using the Bray-Curtis similarity coefficient. Results Five trophic groups were defined: fine-detritivores (feed mostly on fine particulate organic matter - FPOM, coarse-detritivores/herbivores (feed mostly on coarse particulate organic matter - CPOM - and plant material, omnivores, specialist-predators (prey upon aquatic insects only, and generalist-predators. Ephemeroptera, Diptera (except Tanypodinae, Coleoptera, and Trichoptera (except Smicridea were detritivores. The caddis Macronema (Trichoptera fed exclusively on plant detritus and Tanypodinae and Smicridea were classified as omnivores. The odonate families Calopterygidae and Gomphidae were classified as specialist-predators, while Macrobrachium (Decapoda, Belostoma, and Limnocoris (Hemiptera were generalist-predators. Conclusions The great quantity and frequency of occurrence of FPOM consumed by most taxa highlight the importance of this food resource for macroinvertebrate communities from tropical streams. Furthermore, observed variations on trophic group assignment for some taxa indicate the generalist and opportunistic nature of these aquatic invertebrates. Such findings reinforce the importance of conducting gut content analysis on macroinvertebrates to understand their role in the structure and functioning of tropical streams.

  8. Assessing Trophic Position and Mercury Accumulation in Sanpping Turtles

    Science.gov (United States)

    This study determined the trophic position and the total mercury concentrations of snapping turtles (Chelydra serpentina) captured from 26 freshwater sites in Rhode Island. Turtles were captured in baited wire cages, and a non-lethal sampling technique was used in which tips of ...

  9. Trophic relationships of hake ( Merluccius capensis and M ...

    African Journals Online (AJOL)

    The trophic relationships of two hake species (Merluccius capensis and M. paradoxus) and three shark species (Centrophorus squamosus, Deania calcea and D. profundorum) were investigated using nitrogen and carbon stable isotope signatures (δ15N and δ13C) of their muscle tissues. The sharks were more enriched in ...

  10. Trophic structure and biomass distribution of macrobenthos on ...

    African Journals Online (AJOL)

    The trophic structure and biomass of macrobenthos on both wave-sheltered, rocky intertidal shores and semi-exposed ones at seven localities in the Tsitsikamma Marine Protected Area were compared. In the Cochlear zone and entire intertidal (Cochlear- and Balanoid zones combined) biomass values of invertebrates and ...

  11. 210Po and 210Pb in a pelagic trophic chain

    International Nuclear Information System (INIS)

    Radakovitch, O.; Strady, E.; Veron, A.; Chiffoleau, J.F.; Tronczynski, J.; Harmelin-Vivien, M.

    2013-01-01

    The ANR-COSTAS program studied the bioaccumulation and biomagnification of organic and inorganic contaminants through the trophic chains of two small pelagic fish, anchovy and sardine, on the continental shelf of the Gulf of Lion (Northwestern Mediterranean Sea). 210 Po and 210 Pb were analysed at various levels of this trophic chain, as well as trace metal elements, lead isotopes and C and N isotopes which provide additional information on both biogeochemical cycles and trophic transfer. To our knowledge, this is the first time that an entire trophic chain is analysed for these two radionuclides. Water, suspended particles, phytoplankton and zooplankton were collected at 7 stations during two contrast seasons. Phyto and zooplankton were separated in 6 classes through size-sieving: 6-60 μm; 60-200; 200-500; 500-1000; 1000-2000 and > 2000 μm. Anchovy and sardine were collected also two times and analyses were performed on muscle and liver independently for both sexes

  12. Trophic position of coexisting krill species: a stable isotope approach

    DEFF Research Database (Denmark)

    Agersted, Mette Dalgaard; Bode, Antonio; Nielsen, Torkel Gissel

    2014-01-01

    Four krill species with overlapping functional biology coexist in Greenland waters. Here, we used stable isotopes to investigate and discuss their trophic role and mode of coexistence. Bulk carbon (δ13C) and nitrogen (δ15N) stable isotope analyses of Thysanoessa longicaudata, T. inermis, T. raschii...

  13. Predator-prey dynamics driven by feedback between functionally diverse trophic levels.

    Directory of Open Access Journals (Sweden)

    Katrin Tirok

    Full Text Available Neglecting the naturally existing functional diversity of communities and the resulting potential to respond to altered conditions may strongly reduce the realism and predictive power of ecological models. We therefore propose and study a predator-prey model that describes mutual feedback via species shifts in both predator and prey, using a dynamic trait approach. Species compositions of the two trophic levels were described by mean functional traits--prey edibility and predator food-selectivity--and functional diversities by the variances. Altered edibility triggered shifts in food-selectivity so that consumers continuously respond to the present prey composition, and vice versa. This trait-mediated feedback mechanism resulted in a complex dynamic behavior with ongoing oscillations in the mean trait values, reflecting continuous reorganization of the trophic levels. The feedback was only possible if sufficient functional diversity was present in both trophic levels. Functional diversity was internally maintained on the prey level as no niche existed in our system, which was ideal under any composition of the predator level due to the trade-offs between edibility, growth and carrying capacity. The predators were only subject to one trade-off between food-selectivity and grazing ability and in the absence of immigration, one predator type became abundant, i.e., functional diversity declined to zero. In the lack of functional diversity the system showed the same dynamics as conventional models of predator-prey interactions ignoring the potential for shifts in species composition. This way, our study identified the crucial role of trade-offs and their shape in physiological and ecological traits for preserving diversity.

  14. Trophic ecomorphology of Siluriformes (Pisces, Osteichthyes) from a tropical stream.

    Science.gov (United States)

    Pagotto, J P A; Goulart, E; Oliveira, E F; Yamamura, C B

    2011-05-01

    The present study analysed the relationship between morphology and trophic structure of Siluriformes (Pisces, Osteichthyes) from the Caracu Stream (22º 45' S and 53º 15' W), a tributary of the Paraná River (Brazil). Sampling was carried out at three sites using electrofishing, and two species of Loricariidae and four of Heptapteridae were obtained. A cluster analysis revealed the presence of three trophic guilds (detritivores, insectivores and omnivores). Principal components analysis demonstrated the segregation of two ecomorphotypes: at one extreme there were the detritivores (Loricariidae) with morphological structures that are fundamental in allowing them to fix themselves to substrates characterised by rushing torrents, thus permitting them to graze on the detritus and organic materials encrusted on the substrate; at the other extreme of the gradient there were the insectivores and omnivores (Heptapteridae), with morphological characteristics that promote superior performance in the exploitation of structurally complex habitats with low current velocity, colonised by insects and plants. Canonical discriminant analysis revealed an ecomorphological divergence between insectivores, which have morphological structures that permit them to capture prey in small spaces among rocks, and omnivores, which have a more compressed body and tend to explore food items deposited in marginal backwater zones. Mantel tests showed that trophic structure was significantly related to the body shape of a species, independently of the phylogenetic history, indicating that, in this case, there was an ecomorphotype for each trophic guild. Therefore, the present study demonstrated that the Siluriformes of the Caracu Stream were ecomorphologically structured and that morphology can be applied as an additional tool in predicting the trophic structure of this group.

  15. Trophic ecomorphology of Siluriformes (Pisces, Osteichthyes from a tropical stream

    Directory of Open Access Journals (Sweden)

    JPA Pagotto

    Full Text Available The present study analysed the relationship between morphology and trophic structure of Siluriformes (Pisces, Osteichthyes from the Caracu Stream (22º 45' S and 53º 15' W, a tributary of the Paraná River (Brazil. Sampling was carried out at three sites using electrofishing, and two species of Loricariidae and four of Heptapteridae were obtained. A cluster analysis revealed the presence of three trophic guilds (detritivores, insectivores and omnivores. Principal components analysis demonstrated the segregation of two ecomorphotypes: at one extreme there were the detritivores (Loricariidae with morphological structures that are fundamental in allowing them to fix themselves to substrates characterised by rushing torrents, thus permitting them to graze on the detritus and organic materials encrusted on the substrate; at the other extreme of the gradient there were the insectivores and omnivores (Heptapteridae, with morphological characteristics that promote superior performance in the exploitation of structurally complex habitats with low current velocity, colonised by insects and plants. Canonical discriminant analysis revealed an ecomorphological divergence between insectivores, which have morphological structures that permit them to capture prey in small spaces among rocks, and omnivores, which have a more compressed body and tend to explore food items deposited in marginal backwater zones. Mantel tests showed that trophic structure was significantly related to the body shape of a species, independently of the phylogenetic history, indicating that, in this case, there was an ecomorphotype for each trophic guild. Therefore, the present study demonstrated that the Siluriformes of the Caracu Stream were ecomorphologically structured and that morphology can be applied as an additional tool in predicting the trophic structure of this group.

  16. The hormone prolactin is a novel, endogenous trophic factor able to regulate reactive glia and to limit retinal degeneration.

    Science.gov (United States)

    Arnold, Edith; Thebault, Stéphanie; Baeza-Cruz, German; Arredondo Zamarripa, David; Adán, Norma; Quintanar-Stéphano, Andrés; Condés-Lara, Miguel; Rojas-Piloni, Gerardo; Binart, Nadine; Martínez de la Escalera, Gonzalo; Clapp, Carmen

    2014-01-29

    Retinal degeneration is characterized by the progressive destruction of retinal cells, causing the deterioration and eventual loss of vision. We explored whether the hormone prolactin provides trophic support to retinal cells, thus protecting the retina from degenerative pressure. Inducing hyperprolactinemia limited photoreceptor apoptosis, gliosis, and changes in neurotrophin expression, and it preserved the photoresponse in the phototoxicity model of retinal degeneration, in which continuous exposure of rats to bright light leads to retinal cell death and retinal dysfunction. In this model, the expression levels of prolactin receptors in the retina were upregulated. Moreover, retinas from prolactin receptor-deficient mice exhibited photoresponsive dysfunction and gliosis that correlated with decreased levels of retinal bFGF, GDNF, and BDNF. Collectively, these data unveiled prolactin as a retinal trophic factor that may regulate glial-neuronal cell interactions and is a potential therapeutic molecule against retinal degeneration.

  17. Modelling impacts of offshore wind farms on trophic web: the Courseulles-sur-Mer case study

    Science.gov (United States)

    Raoux, Aurore; Pezy, Jean-Philippe; Dauvin, Jean-Claude; Tecchio, samuele; Degraer, Steven; Wilhelmsson, Dan; Niquil, Nathalie

    2016-04-01

    The French government is planning the construction of three offshore wind farms in Normandy. These offshore wind farms will integrate into an ecosystem already subject to a growing number of anthropogenic disturbances such as transportation, fishing, sediment deposit, and sediment extraction. The possible effects of this cumulative stressors on ecosystem functioning are still unknown, but they could impact their resilience, making them susceptible to changes from one stable state to another. Understanding the behaviour of these marine coastal complex systems is essential in order to anticipate potential state changes, and to implement conservation actions in a sustainable manner. Currently, there are no global and integrated studies on the effects of construction and exploitation of offshore wind farms. Moreover, approaches are generally focused on the conservation of some species or groups of species. Here, we develop a holistic and integrated view of ecosystem impacts through the use of trophic webs modelling tools. Trophic models describe the interaction between biological compartments at different trophic levels and are based on the quantification of flow of energy and matter in ecosystems. They allow the application of numerical methods for the characterization of emergent properties of the ecosystem, also called Ecological Network Analysis (ENA). These indices have been proposed as ecosystem health indicators as they have been demonstrated to be sensitive to different impacts on marine ecosystems. We present here in detail the strategy for analysing the potential environmental impacts of the construction of the Courseulles-sur-Mer offshore wind farm (Bay of Seine) such as the reef effect through the use of the Ecopath with Ecosim software. Similar Ecopath simulations will be made in the future on the Le Tréport offshore wind farm site. Results will contribute to a better knowledge of the impacts of the offshore wind farms on ecosystems. They also allow to

  18. Trophic web structure and ecosystem attributes of a temperate estuarine system (Ria de Aveiro, Portugal

    Directory of Open Access Journals (Sweden)

    Eva García-Seoane

    2015-11-01

    Full Text Available Estuaries are among the most productive ecosystems and simultaneously among the most threatened by conflicting human activities, which damage their ecological functions. Describing and attempting to understand the structure and functioning of estuaries is an essential step for maintaining and restoring the quality of estuarine ecosystems. The objective of this study was to obtain insights into the ecosystem structure and functioning of Ria de Aveiro. The study area is a coastal lagoon located on the Northwest Atlantic coast of Portugal, which is connected to the sea through an artificial channel. The ECOPATH software was used to create a static balanced trophic food web model of the tidal part of Ria de Aveiro. The model considers 26 functional groups, including birds, fish, invertebrates, seagrasses, zooplankton, phytoplankton and detritus. Few adjustments were necessary for the input parameters because most of the data were based on direct observations or compiled from literature based on the study site. The trophic interactions within the food web of Riade Aveiro and the transference of energy between functional groups were quantitatively represented. Finally, the keystone index was defined for each functional group.

  19. Intraguild interactions between the predatory mites Neoseiulus californicus and Phytoseiulus persimilis

    NARCIS (Netherlands)

    Cakmak, I.; Janssen, A.; Sabelis, M.W.

    2006-01-01

    Abstract. Species at the same trophic level may interact through competition for food, but can also interact through intraguild predation. Intraguild predation is widespread at the second and third trophic level and the effects may cascade down to the plant level. The effects of intraguild predation

  20. Ethnopharmacological uses, phytochemistry, biological activities, and therapeutic applications of Clinacanthus nutans (Burm. f.) Lindau: A comprehensive review.

    Science.gov (United States)

    Kamarudin, Muhamad Noor Alfarizal; Sarker, Md Moklesur Rahman; Kadir, Habsah Abdul; Ming, Long Chiau

    2017-07-12

    Clinacanthus nutans (Burm. f.) Lindau, a widely used medicinal plant, is extensively grown in tropical Asia and Southeast Asian countries. C. nutans, with its broad spectrum of pharmacological activities, has been traditionally used to treat cancer, inflammatory disorders, diabetes, insect bites, and skin problems, consumed as a vegetable, mixed with fresh juices, in concoctions, and as a whole plant. The present review analyzes the advances in the ethnopharmacology, phytochemistry, pharmacology, and toxicology of C. nutans. In addition, the needs and perspectives for future investigation of this plant are addressed. This review aims to provide a comprehensive report on the ethnomedicinal use, phytochemistry, pharmacological activities, molecular mechanisms, and nutritional values of C. nutans. The present review will open new avenues for further in-depth pharmacological studies of C. nutans for it to be developed as a potential nutraceutical and to improve the available products in the market. All the available information on C. nutans was collected using the key words "Clinacanthus nutans" and/or "ethnomedicine" and/or "phytochemicals" and/or "anticancer" and/or "anti-inflammatory" and/or "antiviral" through an electronic search of the following databases: PubMed, Web of Science, EMBASE, Cochrane Library, Clinical Trials.org, SciFinder Scholar, Scopus, and Google Scholar. In addition, unpublished materials, Ph.D. and M.Sc. dissertations, conference papers, and ethnobotanical textbooks were used. The Plant List (www.theplantlist.org) and International Plant Name Index databases were used to validate the scientific name of the plant. The literature supported the ethnomedicinal uses of C. nutans as recorded in Thailand, Indonesia, and Malaysia for various purposes. Bioactivities experimentally proven for C. nutans include cytotoxic, anticancer, antiviral, anti-inflammatory, immunomodulatory, antidiabetic, antioxidant, antihyperlipidemic, antimicrobial, and

  1. Phytochemistry, Antioxidant, and Hepatoprotective Potential of Acanthospermum hispidum DC Extracts against Diethylnitrosamine-Induced Hepatotoxicity in Rats

    Directory of Open Access Journals (Sweden)

    Jotham Yhi-pênê N’DO

    2018-05-01

    Full Text Available Background: Burkina Faso is classified among the countries with a high prevalence (˃12% of hepatitis. Hepatic diseases, such as cirrhosis—related to alcoholism—and hepatitis B and C, are the cause of the increase in cases of liver cancer. They promote the development of cancer by decreasing the natural cell death, causing problems with DNA repair, or by increasing the production of free radical toxins to the cell. According to the World Health Organization (WHO, there were nearly 639,000 deaths from liver cancer worldwide in 2014, hence the need to search for natural hepatoprotective molecules. Objective: To evaluate the hepatoprotective potential of Acanthospermum hispidum extracts on rats and the antioxidant capacity of extracts in vitro and in vivo, and to perform phytochemistry. Methods: The ethanolic and aqueous extracts of the whole Acanthospermum hispidum plant were used to evaluate hepatoprotection. The hepatotoxin used in our case was diethylenitrosamine. The animals were divided into groups of six. The sera of the treated animals were used for the determination of transaminases, and the liver homogenates were used for the determination of antioxidant. The total phenol and flavonoid contents, and the antioxidant properties of the extracts, were evaluated in vitro. Results: The results of the in vitro antioxidant tests showed good antioxidant activity of the ethanolic extract, using the 2,2-diphenyl-1-picrylhydrazyl (DPPH test (0.08 ± 0.0018 μg/mL and 2,2′-azinobis (3-ethylbenzolin-6-sulphonate (ABTS (246.05 ± 1.55 mmol TE/g. The in vivo tests showed, through the evaluation of the antioxidant in vivo and the biochemical parameters, that the ethanolic extract with the highest phenolic content had a good hepatoprotective capacity. Conclusions: The antioxidant activity of Acanthopermum hispidum extracts would justify the observed hepatoprotective activity. These results confirmed that the plant is used in the treatment of liver

  2. Cuscuta chinensis Lam.: A systematic review on ethnopharmacology, phytochemistry and pharmacology of an important traditional herbal medicine.

    Science.gov (United States)

    Donnapee, Sineeporn; Li, Jin; Yang, Xi; Ge, Ai-hua; Donkor, Paul Owusu; Gao, Xiu-mei; Chang, Yan-xu

    2014-11-18

    Cuscuta chinensis Lam. has found its use as a traditional medicine in China, Korea, Pakistan, Vietnam, India and Thailand. It is commonly used as an anti-aging agent, anti-inflammatory agent, pain reliever and aphrodisiac. To provide an overview of the ethnopharmacology, phytochemistry, pharmacokinetics, pharmacology and clinical applications of Cuscuta chinensis, as well as being an evidence base for further research works of the plant. The present review covers the literature available from 1985 to 2014. The information was collected from journals, books, theses and electronic search (Google Scholar, PubMed, ScienceDirect, ESBCO, Springerlink and CNKI). Literature abstracts and full-text articles were analyzed and included in the review. Many phytochemicals have been isolated, identified and published to date, including: at least 18 flavonoids; 13 phenolic acids; 2 steroids; 1 hydroquinone; 10 volatile oils; 22 lignans; 9 polysaccharides; 2 resin glycosides; 16 fatty acids. These phytochemicals and plant extracts exhibit a range of pharmacological activities that include hepatoprotective, renoprotective, antiosteoporotic, antioxidant, anti-aging, antimutagenic, antidepressant, improve sexual function, abortifacient effects, etc. This present review offers primary information for further studies of Cuscuta chinensis. The in vitro studies and in vivo models have provided a bioscientific explanation for its various ethnopharmacological uses and pharmacological activities (most notably antioxidant effects) especially in the prevention of hepatic disease and renal failure. It is necessary and important to do more pharmacokinetic and toxicological research works on human subjects in order to inform the possible active compounds in the body and validate its safety in clinical uses. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  3. Medicinal plants of the genus Gelsemium (Gelsemiaceae, Gentianales)--a review of their phytochemistry, pharmacology, toxicology and traditional use.

    Science.gov (United States)

    Jin, Gui-Lin; Su, Yan-Ping; Liu, Ming; Xu, Ying; Yang, Jian; Liao, Kai-Jun; Yu, Chang-Xi

    2014-02-27

    In the genus Gelsemium, Gelsemium elegans (Gardn. & Champ.) Benth. has been recognized as a toxic plant that is widely distributed in Southeast Asia and has been used as traditional Chinese medicine for the treatment of rheumatoid pain, neuropathic pain, spasticity, skin ulcers and cancers for many years. Gelsemium sempervirens (L.) J.St.-Hil. has been used since the nineteenth century in homeopathy for treating anxiety, neuralgia, migraine and spasmodic disorders, such as asthma and whooping cough in North America. This review aims to provide comprehensive information on the botany, traditional uses, phytochemistry, pharmacological research and toxicology of medicinal plants in the genus Gelsemium. The overall objective is to explore the evidence supporting its ethnopharmacological effectiveness. A literature survey was performed by searching the scientific databases Pubmed, Google Scholar, SciFinder, Scopus, Web of Science and the Chinese CNKI, in addition to traditional Chinese medicine and homeopathic texts for information on Gelsemium. Plants of the genus Gelsemium have been used in traditional medicine for the treatment of migraines, neuralgia, sciatica, cancer and various types of sores. Studies into the phytochemical composition of this genus have shown that all of the species are rich sources of monoterpene indole alkaloids and that they have attracted the attention of many researchers due to their markedly diverse and complex architecture. To date, a total of 121 alkaloids have been isolated and identified from the genus. The crude extracts, as well as the monomeric compounds, from the genus possess anti-tumor, analgesic, anxiolytic, anti-inflammatory and immunomodulating pharmacological activities. It is evident from the available literature that Gelsemium species possess potential for use as a beneficial therapeutic remedy. However, the analysis of previous pharmacological research suggests that a clear assignment of active molecules and mechanisms of

  4. Divergent trophic levels in two cryptic sibling bat species.

    Science.gov (United States)

    Siemers, Björn M; Greif, Stefan; Borissov, Ivailo; Voigt-Heucke, Silke L; Voigt, Christian C

    2011-05-01

    Changes in dietary preferences in animal species play a pivotal role in niche specialization. Here, we investigate how divergence of foraging behaviour affects the trophic position of animals and thereby their role for ecosystem processes. As a model, we used two closely related bat species, Myotis myotis and M. blythii oxygnathus, that are morphologically very similar and share the same roosts, but show clear behavioural divergence in habitat selection and foraging. Based on previous dietary studies on synanthropic populations in Central Europe, we hypothesised that M. myotis would mainly prey on predatory arthropods (i.e., secondary consumers) while M. blythii oxygnathus would eat herbivorous insects (i.e., primary consumers). We thus expected that the sibling bats would be at different trophic levels. We first conducted a validation experiment with captive bats in the laboratory and measured isotopic discrimination, i.e., the stepwise enrichment of heavy in relation to light isotopes between consumer and diet, in insectivorous bats for the first time. We then tested our trophic level hypothesis in the field at an ancient site of natural coexistence for the two species (Bulgaria, south-eastern Europe) using stable isotope analyses. As predicted, secondary consumer arthropods (carabid beetles; Coleoptera) were more enriched in (15)N than primary consumer arthropods (tettigoniids; Orthoptera), and accordingly wing tissue of M. myotis was more enriched in (15)N than tissue of M. blythii oxygnathus. According to a Bayesian mixing model, M. blythii oxygnathus indeed fed almost exclusively on primary consumers (98%), while M. myotis ate a mix of secondary (50%), but also, and to a considerable extent, primary consumers (50%). Our study highlights that morphologically almost identical, sympatric sibling species may forage at divergent trophic levels, and, thus may have different effects on ecosystem processes.

  5. Trophic modeling of Eastern Boundary Current Systems: a review and prospectus for solving the “Peruvian Puzzle”

    Directory of Open Access Journals (Sweden)

    Marc H. Taylor

    2013-04-01

    Full Text Available Eastern Boundary Current systems (EBCSs are among the most productive fishing areas in the world. High primary and secondary productivity supports a large biomass of small planktivorous pelagic fish, “small pelagics”, which are important drivers of production to the entire system whereby they can influence both higher and lower trophic levels. Environmental variability causes changes in plankton (food quality and quantity, which can affect population sizes, distribution and domi-nance among small pelagics. This variability combined with impacts from the fishery complicate the development of management strategies. Consequently, much recent work has been in the development of multispecies trophic models to better understand interdependencies and system dynamics. Despite similarities in extent, structure and primary productivity between EBCSs, the Peruvian system greatly differs from the others in the magnitude of fish catches, due mainly to the incredible production of the anchovy Engraulis ringens. This paper reviews literature concerning EBCSs dynamics and the state-of-the-art in the trophic modeling of EBCSs. The objective is to critically analyze the potential of this approach for system understanding and management and to adapt existing steady-state models of the Peruvian system for use in (future dynamic simulations. A guideline for the construction of trophodynamic models is presented taking into account the important trophic and environmental interactions. In consideration of the importance of small pelagics for the system dynamics, emphasis is placed on developing appropriate model compartmentalization and spatial delineation that facilitates dynamic simulations. Methods of model validation to historical changes are presented to support hypotheses concerning EBCS dynamics and as a critical step to the development of predictive models. Finally, the identification of direct model links to easily obtainable abiotic parameters is

  6. Willow on Yellowstone's northern range: evidence for a trophic cascade?

    Science.gov (United States)

    Beyer, Hawthorne L; Merrill, Evelyn H; Varley, Nathan; Boyce, Mark S

    2007-09-01

    Reintroduction of wolves (Canis lupus) to Yellowstone National Park in 1995-1996 has been argued to promote a trophic cascade by altering elk (Cervus elaphus) density, habitat-selection patterns, and behavior that, in turn, could lead to changes within the plant communities used by elk. We sampled two species of willow (Salix boothii and S. geyeriana) on the northern winter range to determine whether (1) there was quantitative evidence of increased willow growth following wolf reintroduction, (2) browsing by elk affected willow growth, and (3) any increase in growth observed was greater than that expected by climatic and hydrological factors alone, thereby indicating a trophic cascade caused by wolves. Using stem sectioning techniques to quantify historical growth patterns we found an approximately twofold increase in stem growth-ring area following wolf reintroduction for both species of willow. This increase could not be explained by climate and hydrological factors alone; the presence of wolves on the landscape was a significant predictor of stem growth above and beyond these abiotic factors. Growth-ring area was positively correlated with the previous year's ring area and negatively correlated with the percentage of twigs browsed from the stem during the winter preceding growth, indicating that elk browse impeded stem growth. Our results are consistent with the hypothesis of a behaviorally mediated trophic cascade on Yellowstone's northern winter range following wolf reintroduction. We suggest that the community-altering effects of wolf restoration are an endorsement of ecological-process management in Yellowstone National Park.

  7. Trophic transfer of metal-based nanoparticles in aquatic environments

    DEFF Research Database (Denmark)

    Tangaa, Stine Rosendal; Selck, Henriette; Winther-Nielsen, Margrethe

    2016-01-01

    Metal-containing engineered nanoparticles (Me-ENPs) are used in a wide range of products including inks, plastics, personal care products, clothing and electronic devices. The release of Me-ENPs has been demonstrated from some products, and thus, particles are likely to enter the aquatic environm......Metal-containing engineered nanoparticles (Me-ENPs) are used in a wide range of products including inks, plastics, personal care products, clothing and electronic devices. The release of Me-ENPs has been demonstrated from some products, and thus, particles are likely to enter the aquatic...... environment where they have been shown to be taken up by a variety of species. Therefore, there is a possibility that Me-ENPs will enter and pass through aquatic food webs, but research on this topic is limited. In this tutorial review, we discuss the factors contributing to trophic transfer of Me......-ENPs, and where this information is scarce, we utilize the existing literature on aqueous metal trophic transfer as a potential starting point for greater mechanistic insight and for setting directions for future studies. We identify four key factors affecting trophic transfer of Me-ENPs: (1) environmental...

  8. Subcellular controls of mercury trophic transfer to a marine fish

    International Nuclear Information System (INIS)

    Dang Fei; Wang Wenxiong

    2010-01-01

    Different behaviors of inorganic mercury [Hg(II)] and methylmercury (MeHg) during trophic transfer along the marine food chain have been widely reported, but the mechanisms are not fully understood. The bioavailability of ingested mercury, quantified by assimilation efficiency (AE), was investigated in a marine fish, the grunt Terapon jarbua, based on mercury subcellular partitioning in prey and purified subcellular fractions of prey tissues. The subcellular distribution of Hg(II) differed substantially among prey types, with cellular debris being a major (49-57% in bivalves) or secondary (14-19% in other prey) binding pool. However, MeHg distribution varied little among prey types, with most MeHg (43-79%) in heat-stable protein (HSP) fraction. The greater AEs measured for MeHg (90-94%) than for Hg(II) (23-43%) confirmed the findings of previous studies. Bioavailability of each purified subcellular fraction rather than the proposed trophically available metal (TAM) fraction could better elucidate mercury assimilation difference. Hg(II) associated with insoluble fraction (e.g. cellular debris) was less bioavailable than that in soluble fraction (e.g. HSP). However, subcellular distribution was shown to be less important for MeHg, with each fraction having comparable MeHg bioavailability. Subcellular distribution in prey should be an important consideration in mercury trophic transfer studies.

  9. Subcellular controls of mercury trophic transfer to a marine fish

    Energy Technology Data Exchange (ETDEWEB)

    Dang Fei [Department of Biology, Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon (Hong Kong); Wang Wenxiong, E-mail: wwang@ust.hk [Department of Biology, Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon (Hong Kong)

    2010-09-15

    Different behaviors of inorganic mercury [Hg(II)] and methylmercury (MeHg) during trophic transfer along the marine food chain have been widely reported, but the mechanisms are not fully understood. The bioavailability of ingested mercury, quantified by assimilation efficiency (AE), was investigated in a marine fish, the grunt Terapon jarbua, based on mercury subcellular partitioning in prey and purified subcellular fractions of prey tissues. The subcellular distribution of Hg(II) differed substantially among prey types, with cellular debris being a major (49-57% in bivalves) or secondary (14-19% in other prey) binding pool. However, MeHg distribution varied little among prey types, with most MeHg (43-79%) in heat-stable protein (HSP) fraction. The greater AEs measured for MeHg (90-94%) than for Hg(II) (23-43%) confirmed the findings of previous studies. Bioavailability of each purified subcellular fraction rather than the proposed trophically available metal (TAM) fraction could better elucidate mercury assimilation difference. Hg(II) associated with insoluble fraction (e.g. cellular debris) was less bioavailable than that in soluble fraction (e.g. HSP). However, subcellular distribution was shown to be less important for MeHg, with each fraction having comparable MeHg bioavailability. Subcellular distribution in prey should be an important consideration in mercury trophic transfer studies.

  10. Tempo of trophic evolution and its impact on mammalian diversification.

    Science.gov (United States)

    Price, Samantha A; Hopkins, Samantha S B; Smith, Kathleen K; Roth, V Louise

    2012-05-01

    Mammals are characterized by the complex adaptations of their dentition, which are an indication that diet has played a critical role in their evolutionary history. Although much attention has focused on diet and the adaptations of specific taxa, the role of diet in large-scale diversification patterns remains unresolved. Contradictory hypotheses have been proposed, making prediction of the expected relationship difficult. We show that net diversification rate (the cumulative effect of speciation and extinction), differs significantly among living mammals, depending upon trophic strategy. Herbivores diversify fastest, carnivores are intermediate, and omnivores are slowest. The tempo of transitions between the trophic strategies is also highly biased: the fastest rates occur into omnivory from herbivory and carnivory and the lowest transition rates are between herbivory and carnivory. Extant herbivore and carnivore diversity arose primarily through diversification within lineages, whereas omnivore diversity evolved by transitions into the strategy. The ability to specialize and subdivide the trophic niche allowed herbivores and carnivores to evolve greater diversity than omnivores.

  11. Trophic structure and feeding rates of forest soil invertebrate populations

    Energy Technology Data Exchange (ETDEWEB)

    McBrayer, J F; Reichle, D E

    1971-01-01

    Trophic level relationships of a soil invertebrate community were determined using the transient behavior of cesium-137 in experimental soil microcosms. Feeding rates were estimated from radionuclide mass balance equations using radiocesium uptake coefficients, equilibrium concentrations of /sup 137/Cs in consumers, and /sup 137/Cs composition of food bases. The fungivore trophic level included Scatopsidae larvae (Diptera), Enchytraeida (Annelida), Entomobryidae and Onychiuridae (Collembola), Rhodacaridae (Mesostigmata), and Oribatulidae, Camasiidae, Carabodidae, and Cymbaeremaeidae (Oribatei). Approximately 60% of the total faunal biomass occurred in the fungivore trophic level. Fungivores averaged 7.0 +/- 2.4% dry body weight ingested per day. Cecidomyiidae larvae (Diptera), Diplopoda, Isotomidae (Collembola), Uropodina, and Phthiracaridae (Oribatei) were determined to be surface-feeding saprophages. Subsurface-feeding saprophages included Symphyla, Cillibidae (Uropidina), and Palaeacaridae and Epilohmannidae (Oribatei). Surface-feeding saprophages averaged 1.0 +/- 0.4% dry body weight ingested per day. Feeding rates were not calculated for saprophages feeding within the mineral soil horizon. Predators included Dolichopodidae larvae (Diptera), gamasine mites, and the Scutacaridae and other prostigmatid mites. Predators averaged 2.5 +/- 1.0% dry body weight ingested per day. 15 references, 3 figures, 3 tables.

  12. Trophic and neurotrophic factors in human pituitary adenomas (Review).

    Science.gov (United States)

    Spoletini, Marialuisa; Taurone, Samanta; Tombolini, Mario; Minni, Antonio; Altissimi, Giancarlo; Wierzbicki, Venceslao; Giangaspero, Felice; Parnigotto, Pier Paolo; Artico, Marco; Bardella, Lia; Agostinelli, Enzo; Pastore, Francesco Saverio

    2017-10-01

    The pituitary gland is an organ that functionally connects the hypothalamus with the peripheral organs. The pituitary gland is an important regulator of body homeostasis during development, stress, and other processes. Pituitary adenomas are a group of tumors arising from the pituitary gland: they may be subdivided in functional or non-functional, depending on their hormonal activity. Some trophic and neurotrophic factors seem to play a key role in the development and maintenance of the pituitary function and in the regulation of hypothalamo-pituitary-adrenocortical axis activity. Several lines of evidence suggest that trophic and neurotrophic factors may be involved in pituitary function, thus suggesting a possible role of the trophic and neurotrophic factors in the normal development of pituitary gland and in the progression of pituitary adenomas. Additional studies might be necessary to better explain the biological role of these molecules in the development and progression of this type of tumor. In this review, in light of the available literature, data on the following neurotrophic factors are discussed: ciliary neurotrophic factor (CNTF), transforming growth factors β (TGF‑β), glial cell line-derived neurotrophic factor (GDNF), nerve growth factor (NGF), vascular endothelial growth factor (VEGF), vascular endothelial growth inhibitor (VEGI), fibroblast growth factors (FGFs) and epidermal growth factor (EGF) which influence the proliferation and growth of pituitary adenomas.

  13. Trophic niche shifts driven by phytoplankton in sandy beach ecosystems

    Science.gov (United States)

    Bergamino, Leandro; Martínez, Ana; Han, Eunah; Lercari, Diego; Defeo, Omar

    2016-10-01

    Stable isotopes (δ13C and δ15N) together with chlorophyll a and densities of surf diatoms were used to analyze changes in trophic niches of species in two sandy beaches of Uruguay with contrasting morphodynamics (i.e. dissipative vs. reflective). Consumers and food sources were collected over four seasons, including sediment organic matter (SOM), suspended particulate organic matter (POM) and the surf zone diatom Asterionellopsis guyunusae. Circular statistics and a Bayesian isotope mixing model were used to quantify food web differences between beaches. Consumers changed their trophic niche between beaches in the same direction of the food web space towards higher reliance on surf diatoms in the dissipative beach. Mixing models indicated that A. guyunusae was the primary nutrition source for suspension feeders in the dissipative beach, explaining their change in dietary niche compared to the reflective beach where the proportional contribution of surf diatoms was low. The high C/N ratios in A. guyunusae indicated its high nutritional value and N content, and may help to explain the high assimilation by suspension feeders at the dissipative beach. Furthermore, density of A. guyunusae was higher in the dissipative than in the reflective beach, and cell density was positively correlated with chlorophyll a only in the dissipative beach. Therefore, surf diatoms are important drivers in the dynamics of sandy beach food webs, determining the trophic niche space and productivity. Our study provides valuable insights on shifting foraging behavior by beach fauna in response to changes in resource availability.

  14. Reef Fishes at All Trophic Levels Respond Positively to Effective Marine Protected Areas

    Science.gov (United States)

    Soler, German A.; Edgar, Graham J.; Thomson, Russell J.; Kininmonth, Stuart; Campbell, Stuart J.; Dawson, Terence P.; Barrett, Neville S.; Bernard, Anthony T. F.; Galván, David E.; Willis, Trevor J.; Alexander, Timothy J.; Stuart-Smith, Rick D.

    2015-01-01

    Marine Protected Areas (MPAs) offer a unique opportunity to test the assumption that fishing pressure affects some trophic groups more than others. Removal of larger predators through fishing is often suggested to have positive flow-on effects for some lower trophic groups, in which case protection from fishing should result in suppression of lower trophic groups as predator populations recover. We tested this by assessing differences in the trophic structure of reef fish communities associated with 79 MPAs and open-access sites worldwide, using a standardised quantitative dataset on reef fish community structure. The biomass of all major trophic groups (higher carnivores, benthic carnivores, planktivores and herbivores) was significantly greater (by 40% - 200%) in effective no-take MPAs relative to fished open-access areas. This effect was most pronounced for individuals in large size classes, but with no size class of any trophic group showing signs of depressed biomass in MPAs, as predicted from higher predator abundance. Thus, greater biomass in effective MPAs implies that exploitation on shallow rocky and coral reefs negatively affects biomass of all fish trophic groups and size classes. These direct effects of fishing on trophic structure appear stronger than any top down effects on lower trophic levels that would be imposed by intact predator populations. We propose that exploitation affects fish assemblages at all trophic levels, and that local ecosystem function is generally modified by fishing. PMID:26461104

  15. Reef Fishes at All Trophic Levels Respond Positively to Effective Marine Protected Areas.

    Directory of Open Access Journals (Sweden)

    German A Soler

    Full Text Available Marine Protected Areas (MPAs offer a unique opportunity to test the assumption that fishing pressure affects some trophic groups more than others. Removal of larger predators through fishing is often suggested to have positive flow-on effects for some lower trophic groups, in which case protection from fishing should result in suppression of lower trophic groups as predator populations recover. We tested this by assessing differences in the trophic structure of reef fish communities associated with 79 MPAs and open-access sites worldwide, using a standardised quantitative dataset on reef fish community structure. The biomass of all major trophic groups (higher carnivores, benthic carnivores, planktivores and herbivores was significantly greater (by 40% - 200% in effective no-take MPAs relative to fished open-access areas. This effect was most pronounced for individuals in large size classes, but with no size class of any trophic group showing signs of depressed biomass in MPAs, as predicted from higher predator abundance. Thus, greater biomass in effective MPAs implies that exploitation on shallow rocky and coral reefs negatively affects biomass of all fish trophic groups and size classes. These direct effects of fishing on trophic structure appear stronger than any top down effects on lower trophic levels that would be imposed by intact predator populations. We propose that exploitation affects fish assemblages at all trophic levels, and that local ecosystem function is generally modified by fishing.

  16. INTERACT

    DEFF Research Database (Denmark)

    Jochum, Elizabeth; Borggreen, Gunhild; Murphey, TD

    This paper considers the impact of visual art and performance on robotics and human-computer interaction and outlines a research project that combines puppetry and live performance with robotics. Kinesics—communication through movement—is the foundation of many theatre and performance traditions ...

  17. Trophic cascades triggered by overfishing reveal possible mechanisms of ecosystem regime shifts.

    Science.gov (United States)

    Daskalov, Georgi M; Grishin, Alexander N; Rodionov, Sergei; Mihneva, Vesselina

    2007-06-19

    Large-scale transitions between alternative states in ecosystems are known as regime shifts. Once described as healthy and dominated by various marine predators, the Black Sea ecosystem by the late 20th century had experienced anthropogenic impacts such as heavy fishing, cultural eutrophication, and invasions by alien species. We studied changes related to these "natural experiments" to reveal the mechanisms of regime shifts. Two major shifts were detected, the first related to a depletion of marine predators and the second to an outburst of the alien comb jelly Mnemiopsis leidyi; both shifts were triggered by intense fishing resulting in system-wide trophic cascades. The complex nature of ecosystem responses to human activities calls for more elaborate approaches than currently provided by traditional environmental and fisheries management. This implies challenging existing practices and implementing explanatory models of ecosystem interactions that can better reconcile conservation and ecosystem management ideals.

  18. Trophic compensation reinforces resistance: herbivory absorbs the increasing effects of multiple disturbances.

    Science.gov (United States)

    Ghedini, Giulia; Russell, Bayden D; Connell, Sean D

    2015-02-01

    Disturbance often results in small changes in community structure, but the probability of transitioning to contrasting states increases when multiple disturbances combine. Nevertheless, we have limited insights into the mechanisms that stabilise communities, particularly how perturbations can be absorbed without restructuring (i.e. resistance). Here, we expand the concept of compensatory dynamics to include countervailing mechanisms that absorb disturbances through trophic interactions. By definition, 'compensation' occurs if a specific disturbance stimulates a proportional countervailing response that eliminates its otherwise unchecked effect. We show that the compounding effects of disturbances from local to global scales (i.e. local canopy-loss, eutrophication, ocean acidification) increasingly promote the expansion of weedy species, but that this response is countered by a proportional increase in grazing. Finally, we explore the relatively unrecognised role of compensatory effects, which are likely to maintain the resistance of communities to disturbance more deeply than current thinking allows. © 2015 John Wiley & Sons Ltd/CNRS.

  19. Trophic levels of fish species of commercial importance in the Colombian Caribbean

    Directory of Open Access Journals (Sweden)

    Camilo B García

    2011-09-01

    Full Text Available Ecological studies on commercial important fish species are of great value to support resource management issues. This study calculated trophic levels of those Colombian Caribbean fish species whose diet has been locally described. Usable diet data of 119 species resulted in 164 trophic level estimates. An ordinary regression model relating trophic level and fish size was formulated. The regression slope was positive and significantly different from zero (p<0.05 suggesting a scaling of trophic level with fish size. Both the list of trophic levels and the regression model should be of help in the formulation of trophic indicators and models of neotropical ecosystems. Rev. Biol. Trop. 59 (3: 1195-1203. Epub 2011 September 01.

  20. Baseline identification in stable -isotope studies of temperate lotic systems and implications for calculated trophic positions

    DEFF Research Database (Denmark)

    Kristensen, Peter Brinkmann; Riis, Tenna; Dylmer, Hans Erik

    2016-01-01

    of two common fish species (three-spined stickleback, Gasterosteus aculeatus, and brown trout Salmo trutta) differed markedly depending on the baseline chosen. The estimated trophic position was lowest when based on Baetidae and highest when using Simuliidae. The trophic position of Gasterosteus...... aculeatus was independent of land use (proxy used=%nature) when based on Gammarus pulex and Simuliidae, and the trophic position of Salmo trutta was independent of land use when based on Simuliidae only. The trophic position estimates based on Baetidae and mean primary consumers correlated with %nature...

  1. Ekologi Trofik Komunitas Ikan di Perairan Segara Menyan, Subang, Jawa Barat (Trophic Ecology of the Fish Community in Segara Menyan Coastal Lagoon, Subang, West Java

    Directory of Open Access Journals (Sweden)

    Ahmad Zahid

    2015-09-01

    monthly for one year at three zones. Fish samples were placed in separate labelled plastic bags according to the time scale and location sampling, then gut contents were analyzed. The data of vacuity index, number of prey, prey dominant, diet breadth, and trophic level were analyzed. For each of 106 fish species, between 1 and 380 stomachs, were examined. The vacuity index was also different among species. Five of 106 species had a vacuity index of “0” and total number of food items consumed varied between fish species, ranging from three items to 27 items. The overall diet breadth (Bi was relatively low among species, ranging from 0.20 to 0.78, with most of them between 0.20 and 0.48. Calanoid copepods comprised the most common food item consumed by all the fishes examined. Fishes occurring can be broadly categorized into seven different trophic guilds. The trophic level of fish communities ranged from 2.05 to 4.73. Spatio-temporal variation of food web was influenced of ontogenetic shift, food availability, habitat characteristic, and migration of some species in Segara Menyan coastal lagoon. Keywords: trophic interaction, lagoon, fishes, spatio-temporal variation, trophic guild

  2. Diet and trophic niche of Lithobates catesbeianus (Amphibia: Anura

    Directory of Open Access Journals (Sweden)

    Peterson T. Leivas

    2012-10-01

    Full Text Available Lithobates catesbeianus (Shaw, 1802 is an invasive anuran introduced in Brazil that is associated with the displacement and the decline of populations of native species worldwide. There is evidence that biological invasions are facilitated by certain attributes of the invading species, for instance niche breath, and that invasive species have a broader ecological niche with respect to native ones. We designed a study to ascertain the temporal, ontogenetic, and sex differences in the niche dynamics of the American bullfrog. We sampled monthly from June 2008 to May 2009 in the state of Paraná, southern Brazil. For each individual, we gathered biometric and stomach content data. We then estimated the niche breath of the juveniles and adults, and compared it between the sexes. A total of 104 females and 77 males were sampled. Lithobates catesbeianus has a generalist diet, preying upon invertebrates and vertebrates. Even though the diet of the studied population varied seasonally, it did not differ between the sexes nor did it respond to biometric variables. Niche breadth was more restricted in the winter than in the autumn. The trophic niche of juveniles and adults did not overlap much when compared with the trophic niche overlap between males and females. Adult males and females had a considerable niche overlap, but females had a broader trophic niche than males in the winter and in the spring. These niche characteristics point to an opportunistic predation strategy that may have facilitated the process of invasion and establishment of this species in the study area.

  3. Comparison of contaminants from different trophic levels and ecosystems

    DEFF Research Database (Denmark)

    Dietz, R.; Riget, F.; Cleemann, M.

    2000-01-01

    The present paper provides an overview of the priority contaminants and media from the Greenland part of the Arctic Monitoring and Assessment Program. Levels and accumulation patterns of heavy metals, POPs and a radionuclide (Cs-137) are compared from the terrestrial, freshwater and marine...... ecosystems. Of the nine compounds presented, seven (Cd, Hg, Se, Sigma PCB, Sigma DDT, Sigma HCH, HCB) increased in concentration towards higher trophic levels. For these contaminants the concentrations in soil and aquatic sediment were in the same order of magnitude, whereas the concentrations in marine...

  4. TROPHIC RELATIONS OF LADY BEETLES (COLEOPTERA, COCCINELLIDAE OF THE URALS

    Directory of Open Access Journals (Sweden)

    Z. I. Tyumaseva

    2016-05-01

    Full Text Available The article contains the study of the trophic relations of the lady beetles living in the Urals. The study allocates three ecological groups depending on the peculiarities of the beetles and larvae nutrition: phytophages, micetophages, and entomophages-predators. We have revealed 66 species of lady birds-predators and two species-phytophages: Subcoccinella vigintiquatuorpunctata (Linnaeus, 1758 and Bulaea lichatschovii (Hummel, 1827. In the group of obligatory micetophages in the Urals we registered the representatives of the tribe Halyziini, it is Halyzia sedecimguttata (Linnaeus, 1758 and Psyllobora vigintiduopunctata (Linnaeus, 1758.

  5. Five Pistacia species (P. vera, P. atlantica, P. terebinthus, P. khinjuk, and P. lentiscus: A Review of Their Traditional Uses, Phytochemistry, and Pharmacology

    Directory of Open Access Journals (Sweden)

    Mahbubeh Bozorgi

    2013-01-01

    Full Text Available Pistacia, a genus of flowering plants from the family Anacardiaceae, contains about twenty species, among them five are more popular including P. vera, P. atlantica, P. terebinthus, P. khinjuk, and P. lentiscus. Different parts of these species have been used in traditional medicine for various purposes like tonic, aphrodisiac, antiseptic, antihypertensive and management of dental, gastrointestinal, liver, urinary tract, and respiratory tract disorders. Scientific findings also revealed the wide pharmacological activities from various parts of these species, such as antioxidant, antimicrobial, antiviral, anticholinesterase, anti-inflammatory, antinociceptive, antidiabetic, antitumor, antihyperlipidemic, antiatherosclerotic, and hepatoprotective activities and also their beneficial effects in gastrointestinal disorders. Various types of phytochemical constituents like terpenoids, phenolic compounds, fatty acids, and sterols have also been isolated and identified from different parts of Pistacia species. The present review summarizes comprehensive information concerning ethnomedicinal uses, phytochemistry, and pharmacological activities of the five mentioned Pistacia species.

  6. Trophic relationships in an Arctic food web and implications for trace metal transfer

    Energy Technology Data Exchange (ETDEWEB)

    Dehn, Larissa-A. [Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska, 99775-7000 (United States)]. E-mail: ftld@uaf.edu; Follmann, Erich H. [Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska, 99775-7000 (United States); Thomas, Dana L. [Department of Mathematical Sciences, University of Alaska Fairbanks, Fairbanks, Alaska, 99775-6660 (United States); Sheffield, Gay G. [Alaska Department of Fish and Game, Fairbanks, Division of Wildlife Conservation, Fairbanks, Alaska, 99701-1599 (United States); Rosa, Cheryl [Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska, 99775-7000 (United States); Duffy, Lawrence K. [Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska, 99775-7000 (United States); O' Hara, Todd M. [Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska, 99775-7000 (United States)

    2006-06-01

    Tissues of subsistence-harvested Arctic mammals were analyzed for silver (Ag), cadmium (Cd), and total mercury (THg). Muscle (or total body homogenates of potential fish and invertebrate prey) was analyzed for stable carbon ({delta} {sup 13}C) and nitrogen ({delta} {sup 15}N) isotopes to establish trophic interactions within the Arctic food chain. Food web magnification factors (FWMFs) and biomagnification factors for selected predator-prey scenarios (BMFs) were calculated to describe pathways of heavy metals in the Alaskan Arctic. FWMFs in this study indicate that magnification of selected heavy metals in the Arctic food web is not significant. Biomagnification of Cd occurs mainly in kidneys; calculated BMFs are higher for hepatic THg than renal THg for all predator-prey scenarios with the exception of polar bears (Ursus maritimus). In bears, the accumulation of renal THg is approximately 6 times higher than in liver. Magnification of hepatic Ag is minimal for all selected predator-prey scenarios. Though polar bears occupy a higher trophic level than belugas (Delphinapterus leucas), based on {delta} {sup 15}N, the metal concentrations are either not statistically different between the two species or lower for bears. Similarly, concentrations of renal and hepatic Cd are significantly lower or not statistically different in polar bears compared to ringed (Phoca hispida) and bearded seals (Erignathus barbatus), their primary prey. THg, on the other hand, increased significantly from seal to polar bear tissues. Mean {delta} {sup 15}N was lowest in muscle of Arctic fox (Alopex lagopus) and foxes also show the lowest levels of Hg, Cd and Ag in liver and kidney compared to the other species analyzed. These values are in good agreement with a diet dominated by terrestrial prey. Metal deposition in animal tissues is strongly dependent on biological factors such as diet, age, sex, body condition and health, and caution should be taken when interpreting magnification of

  7. Reappraisal of the Trophic Ecology of One of the World's Most Threatened Spheniscids, the African Penguin.

    Directory of Open Access Journals (Sweden)

    Maëlle Connan

    Full Text Available Many species of seabirds, including the only penguin species breeding on the African continent, are threatened with extinction. The world population of the endangered African penguin Spheniscus demersus has decreased from more than 1.5 million individuals in the early 1900s to c.a. 23 000 pairs in 2013. Determining the trophic interactions of species, especially those of conservation concern, is important when declining numbers are thought to be driven by food limitation. By and large, African penguin dietary studies have relied on the identification of prey remains from stomach contents. Despite all the advantages of this method, it has well known biases. We therefore assessed the African penguin's diet, using stable isotopes, at two colonies in Algoa Bay (south-east coast of South Africa. These represent over 50% of the world population. Various samples (blood, feathers, egg membranes were collected for carbon and nitrogen stable isotope analyses. Results indicate that the trophic ecology of African penguins is influenced by colony, season and age class, but not adult sex. Isotopic niches identified by standard Bayesian ellipse areas and convex hulls, highlighted differences among groups and variability among individual penguins. Using Bayesian mixing models it was for the first time shown that adults target chokka squid Loligo reynaudii for self-provisioning during particular stages of their annual cycle, while concurrently feeding their chicks primarily with small pelagic fish. This has important ramifications and means that not only pelagic fish, but also squid stocks, need to be carefully managed in order to allow population recovery of African penguin.

  8. Reconstruction of trophic pathways between plankton and the North Iberian sardine (Sardina pilchardus using stable isotopes

    Directory of Open Access Journals (Sweden)

    Antonio Bode

    2004-03-01

    Full Text Available Feeding on phyto- and zooplankton by juvenile (< 1 year old and adult sardines (Sardina pilchardus was inferred from analyses of natural abundance of stable carbon and nitrogen isotopes in samples from the northwestern Iberian Peninsula (Spain collected at the beginning of the upwelling season and peak spawning period of sardine. Plankton samples were fractionated through nets of 20, 200, 500, 1000 and 2000 ?m mesh-size and the muscle protein of individual sardines was isolated before isotopic determinations. Up to six planktonic components and two sardine feeding types were identified from the modes in the frequency distributions of isotope abundance values. Also, the most probable pathways for carbon and nitrogen flows between compartments were analysed. The resulting food web revealed a relatively large degree of omnivory, both in plankton and sardine components, which confirms that complex trophic interactions could also occur in pelagic upwelling ecosystems. Young sardines had isotope abundance values clustered around a single mode in the frequency distribution, while adult sardines displayed two main modes. These modes are interpreted as representative of two extreme feeding types: one related to the individual capture of zooplankton prey and the other to unselective filter-feeding. Although both types of feeding could include micro- (20-200 ?m and mesozooplankton (200-2000 ?m prey, phytoplankton appears to be ingested mainly by filter-feeding. However, even adult sardines must be mainly zoophagous to achieve the observed isotopic abundance values, taking into account current assumptions on stable isotope enrichment through trophic levels. From the differences in the resulting pathways using either carbon or nitrogen isotopes, we interpreted that sardines acquire most of the protein nitrogen from zooplankton while a substantial fraction of their carbon would derive from phytoplankton. These interpretations agree with the information

  9. Trophic relationships in an Arctic food web and implications for trace metal transfer

    International Nuclear Information System (INIS)

    Dehn, Larissa-A.; Follmann, Erich H.; Thomas, Dana L.; Sheffield, Gay G.; Rosa, Cheryl; Duffy, Lawrence K.; O'Hara, Todd M.

    2006-01-01

    Tissues of subsistence-harvested Arctic mammals were analyzed for silver (Ag), cadmium (Cd), and total mercury (THg). Muscle (or total body homogenates of potential fish and invertebrate prey) was analyzed for stable carbon (δ 13 C) and nitrogen (δ 15 N) isotopes to establish trophic interactions within the Arctic food chain. Food web magnification factors (FWMFs) and biomagnification factors for selected predator-prey scenarios (BMFs) were calculated to describe pathways of heavy metals in the Alaskan Arctic. FWMFs in this study indicate that magnification of selected heavy metals in the Arctic food web is not significant. Biomagnification of Cd occurs mainly in kidneys; calculated BMFs are higher for hepatic THg than renal THg for all predator-prey scenarios with the exception of polar bears (Ursus maritimus). In bears, the accumulation of renal THg is approximately 6 times higher than in liver. Magnification of hepatic Ag is minimal for all selected predator-prey scenarios. Though polar bears occupy a higher trophic level than belugas (Delphinapterus leucas), based on δ 15 N, the metal concentrations are either not statistically different between the two species or lower for bears. Similarly, concentrations of renal and hepatic Cd are significantly lower or not statistically different in polar bears compared to ringed (Phoca hispida) and bearded seals (Erignathus barbatus), their primary prey. THg, on the other hand, increased significantly from seal to polar bear tissues. Mean δ 15 N was lowest in muscle of Arctic fox (Alopex lagopus) and foxes also show the lowest levels of Hg, Cd and Ag in liver and kidney compared to the other species analyzed. These values are in good agreement with a diet dominated by terrestrial prey. Metal deposition in animal tissues is strongly dependent on biological factors such as diet, age, sex, body condition and health, and caution should be taken when interpreting magnification of dynamic and actively regulated trace metals

  10. Is Bocourt’s Terrific Skink Really So Terrific? Trophic Myth and Reality

    Science.gov (United States)

    Jowers, Michael J.; Boistel, Renaud; Ineich, Ivan

    2013-01-01

    Many scientists argue that our planet is undergoing a mass extinction event that is largely due to human influences. In this context, rediscoveries of species presumed to be extinct are encouraging and of great potential interest. During a 2003 expedition to New Caledonia, Bocourt’s terrific skink, Phoboscincus bocourti, was unexpectedly rediscovered on a small islet by one of us. This skink species had been described from a single specimen collected around 1872 in New Caledonia. Since that time, however, no data on the species’ biology, trophic interactions, or role in the ecosystem have been collected, making it difficult to follow the established conservation plan. In this study, we used a multidisciplinary approach involving natural history, anatomy, morphology, genetics, and stable isotopes to elucidate the ecology of Bocourt’s terrific skink. Over the course of three different expeditions to the islet (total of 55 days across 2005 and 2012), we captured 4 individuals and observed another 4 individuals. The species’ dentition and trophic ecology suggest that it is a top predator in its ecosystem and a major consumer of small terrestrial reptiles. Its high degree of genetic relatedness to another New Caledonian skink, which has a broad distribution, suggests that P. bocourti underwent genetic isolation at a geographical remote location, where dispersal or colonization was highly improbable. Moreover, the lack of genetic variation among the four individuals we captured may imply that a unique lineage, characterized by few inter-island exchanges, exists on the islet. Bocourt’s terrific skink may be the largest terrestrial squamate predator alive in New Caledonia today. As a result, it is likely vulnerable to habitat modifications and especially the invasive rodents found on this islet. Further information is necessary to assess the conservation plans and practices in place as no concrete changes have been made since the species’ rediscovery almost 10

  11. Reappraisal of the Trophic Ecology of One of the World's Most Threatened Spheniscids, the African Penguin.

    Science.gov (United States)

    Connan, Maëlle; Hofmeyr, G J Greg; Pistorius, Pierre A

    2016-01-01

    Many species of seabirds, including the only penguin species breeding on the African continent, are threatened with extinction. The world population of the endangered African penguin Spheniscus demersus has decreased from more than 1.5 million individuals in the early 1900s to c.a. 23 000 pairs in 2013. Determining the trophic interactions of species, especially those of conservation concern, is important when declining numbers are thought to be driven by food limitation. By and large, African penguin dietary studies have relied on the identification of prey remains from stomach contents. Despite all the advantages of this method, it has well known biases. We therefore assessed the African penguin's diet, using stable isotopes, at two colonies in Algoa Bay (south-east coast of South Africa). These represent over 50% of the world population. Various samples (blood, feathers, egg membranes) were collected for carbon and nitrogen stable isotope analyses. Results indicate that the trophic ecology of African penguins is influenced by colony, season and age class, but not adult sex. Isotopic niches identified by standard Bayesian ellipse areas and convex hulls, highlighted differences among groups and variability among individual penguins. Using Bayesian mixing models it was for the first time shown that adults target chokka squid Loligo reynaudii for self-provisioning during particular stages of their annual cycle, while concurrently feeding their chicks primarily with small pelagic fish. This has important ramifications and means that not only pelagic fish, but also squid stocks, need to be carefully managed in order to allow population recovery of African penguin.

  12. From the epipelagic zone to the abyss: Trophic structure at two seamounts in the subtropical and tropical Eastern Atlantic - Part I zooplankton and micronekton

    Science.gov (United States)

    Denda, Anneke; Stefanowitsch, Benjamin; Christiansen, Bernd

    2017-12-01

    Specific mechanisms, driving trophic interactions within the pelagic community may be highly variable in different seamount systems. This study investigated the trophic structure of zooplankton and micronekton above and around Ampère and Senghor, two shallow seamounts in the subtropical and tropical Eastern Atlantic, and over the adjacent abyssal plains. For the identification of food sources and trophic positions stable isotope ratios (δ13C and δ15N) were used. δ13C ranged from -24.7‰ to -15.0‰ and δ15N covered a total range of 0.9-15.9‰. Based on epipelagic particulate organic matter, zooplankton and micronekton usually occupied the 1st-3rd trophic level, including herbivorous, omnivorous and carnivorous taxa. δ13C and δ15N values were generally lower in zooplankton and micronekton of the subtropical waters as compared to the tropical region, due to the differing nutrient availability and phytoplankton communities. Correlations between δ13C and δ15N values of particulate organic matter, zooplankton, micronekton and benthopelagic fishes suggest a linear food chain based on a single energy source from primary production for Ampère Seamount, but no evidence was found for an autochthonus seamount production as compared to the open ocean reference site. Between Senghor Seamount and the open ocean δ13C signatures indicate that hydrodynamic effects at seamounts may modify the energy supply at times, but evidence for a seamount effect on the trophic structure of the pelagic communities was weak, which supports the assumption that seamount communities rely to a large extent on advected food sources.

  13. Looplessness in networks is linked to trophic coherence.

    Science.gov (United States)

    Johnson, Samuel; Jones, Nick S

    2017-05-30

    Many natural, complex systems are remarkably stable thanks to an absence of feedback acting on their elements. When described as networks these exhibit few or no cycles, and associated matrices have small leading eigenvalues. It has been suggested that this architecture can confer advantages to the system as a whole, such as "qualitative stability," but this observation does not in itself explain how a loopless structure might arise. We show here that the number of feedback loops in a network, as well as the eigenvalues of associated matrices, is determined by a structural property called trophic coherence, a measure of how neatly nodes fall into distinct levels. Our theory correctly classifies a variety of networks-including those derived from genes, metabolites, species, neurons, words, computers, and trading nations-into two distinct regimes of high and low feedback and provides a null model to gauge the significance of related magnitudes. Because trophic coherence suppresses feedback, whereas an absence of feedback alone does not lead to coherence, our work suggests that the reasons for "looplessness" in nature should be sought in coherence-inducing mechanisms.

  14. Trophic specialization drives morphological evolution in sea snakes.

    Science.gov (United States)

    Sherratt, Emma; Rasmussen, Arne R; Sanders, Kate L

    2018-03-01

    Viviparous sea snakes are the most rapidly speciating reptiles known, yet the ecological factors underlying this radiation are poorly understood. Here, we reconstructed dated trees for 75% of sea snake species and quantified body shape (forebody relative to hindbody girth), maximum body length and trophic diversity to examine how dietary specialization has influenced morphological diversification in this rapid radiation. We show that sea snake body shape and size are strongly correlated with the proportion of burrowing prey in the diet. Specialist predators of burrowing eels have convergently evolved a 'microcephalic' morphotype with dramatically reduced forebody relative to hindbody girth and intermediate body length. By comparison, snakes that predominantly feed on burrowing gobies are generally short-bodied and small-headed, but there is no evidence of convergent evolution. The eel specialists also exhibit faster rates of size and shape evolution compared to all other sea snakes, including those that feed on gobies. Our results suggest that trophic specialization to particular burrowing prey (eels) has invoked strong selective pressures that manifest as predictable and rapid morphological changes. Further studies are needed to examine the genetic and developmental mechanisms underlying these dramatic morphological changes and assess their role in sea snake speciation.

  15. Ecosystem structure and trophic analysis of Angolan fishery landings

    Directory of Open Access Journals (Sweden)

    Ronaldo Angelini

    2011-06-01

    Full Text Available Information on the mean trophic level of fishery landings in Angola and the output from a preliminary Ecopath with Ecosim (EwE model were used to examine the dynamics of the Angolan marine ecosystem. Results were compared with the nearby Namibian and South African ecosystems, which share some of the exploited fish populations. The results show that: (i The mean trophic level of Angola’s fish landings has not decreased over the years; (ii There are significant correlations between the landings of Angola, Namibia and South Africa; (iii The ecosystem attributes calculated by the EwE models for the three ecosystems were similar, and the main differences were related to the magnitude of flows and biomass; (iv The similarity among ecosystem trends for Namibia, South Africa and Angola re-emphasizes the need to continue collaborative regional studies on the fish stocks and their ecosystems. To improve the Angolan model it is necessary to gain a better understanding of plankton dynamics because plankton are essential for Sardinella spp. An expanded analysis of the gut contents of the fish species occupying Angola’s coastline is also necessary.

  16. Fish mitigate trophic depletion in marine cave ecosystems.

    Science.gov (United States)

    Bussotti, Simona; Di Franco, Antonio; Bianchi, Carlo Nike; Chevaldonné, Pierre; Egea, Lea; Fanelli, Emanuela; Lejeusne, Christophe; Musco, Luigi; Navarro-Barranco, Carlos; Pey, Alexis; Planes, Serge; Vieux-Ingrassia, Jean Vincent; Guidetti, Paolo

    2018-06-15

    Dark marine habitats are often characterized by a food-limited condition. Peculiar dark habitats include marine caves, characterized by the absence of light and limited water flow, which lead to reduced fluxes of organic matter for cave-dwelling organisms. We investigated whether the most abundant and common cave-dwelling fish Apogon imberbis has the potential to play the role of trophic vector in Mediterranean marine caves. We first analysed stomach contents to check whether repletion changes according to a nycthemeral cycle. We then identified the prey items, to see whether they belong to species associated with cave habitats or not. Finally, we assessed whether A. imberbis moves outside marine caves at night to feed, by collecting visual census data on A. imberbis density both inside and outside caves, by day and by night. The stomach repletion of individuals sampled early in the morning was significantly higher than later in the day. Most prey were typical of habitats other than caves. A. imberbis was on average more abundant within caves during the day and outside during the night. Our study supports the hypothesis regarding the crucial trophic role of A. imberbis in connecting Mediterranean marine caves with external habitats.

  17. Bioenergetics, Trophic Ecology, and Niche Separation of Tunas.

    Science.gov (United States)

    Olson, R J; Young, J W; Ménard, F; Potier, M; Allain, V; Goñi, N; Logan, J M; Galván-Magaña, F

    Tunas are highly specialized predators that have evolved numerous adaptations for a lifestyle that requires large amounts of energy consumption. Here we review our understanding of the bioenergetics and feeding dynamics of tunas on a global scale, with an emphasis on yellowfin, bigeye, skipjack, albacore, and Atlantic bluefin tunas. Food consumption balances bioenergetics expenditures for respiration, growth (including gonad production), specific dynamic action, egestion, and excretion. Tunas feed across the micronekton and some large zooplankton. Some tunas appear to time their life history to take advantage of ephemeral aggregations of crustacean, fish, and molluscan prey. Ontogenetic and spatial diet differences are substantial, and significant interdecadal changes in prey composition have been observed. Diet shifts from larger to smaller prey taxa highlight ecosystem-wide changes in prey availability and diversity and provide implications for changing bioenergetics requirements into the future. Where tunas overlap, we show evidence of niche separation between them; resources are divided largely by differences in diet percentages and size ranges of prey taxa. The lack of long-term data limits the ability to predict impacts of climate change on tuna feeding behaviour. We note the need for systematic collection of feeding data as part of routine monitoring of these species, and we highlight the advantages of using biochemical techniques for broad-scale analyses of trophic relations. We support the continued development of ecosystem models, which all too often lack the regional-specific trophic data needed to adequately investigate climate and fishing impacts. © 2016 Elsevier Ltd. All rights reserved.

  18. Comparison of contaminants from different trophic levels and ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Dietz, R.; Riget, F. [Department of Arctic Environment, Ministry of Environment and Energy, National Environmental Research Institute, Tagensvej 135, 4 floor, DK-2200 Copenhagen (Denmark); Cleemann, M. [Department of Environmental Chemistry, Ministry of Environment and Energy, National Environmental Research Institute, Frederiksborgvej 399, DK-4000 Roskilde (Denmark); Aarkrog, A. [Risoe National Laboratory, Frederiksborgvej 399, DK-4000 Roskilde (Denmark); Johansen, P. [Department of Arctic Environment, Ministry of Environment and Energy, National Environmental Research Institute, Tagensvej 135, 4 floor, DK-2200 Copenhagen (Denmark); Hansen, J.C. [Risoe National Laboratory, Frederiksborgvej 399, DK-4000 Roskilde (Denmark)

    2000-01-17

    The present paper provides an overview of the priority contaminants and media from the Greenland part of the Arctic Monitoring and Assessment Program. Levels and accumulation patterns of heavy metals, POPs and a radionuclide (137Cs) are compared from the terrestrial, freshwater and marine ecosystems. Of the nine compounds presented, seven (Cd, Hg, Se, {sigma}PCB, {sigma}DDT, {sigma}HCH, HCB) increased in concentration towards higher trophic levels. For these contaminants the concentrations in soil and aquatic sediment were in the same order of magnitude, whereas the concentrations in marine biota were higher than found in the freshwater and terrestrial ecosystems probably due to the presence of longer food chains. Pb and 137Cs showed the reverse pattern compared with the other compounds. The concentrations in soil and aquatic sediments decreased in the order terrestrial, freshwater and marine ecosystems, which was reflected in the biota as well. Reindeer had similar or lower levels of Pb and 137Cs than lichens. Levels of Pb and 137Cs in marine biota did not show the same clear increase towards higher trophic as found for the other analysed compounds. Greenland Inuit contains considerably less mercury but higher levels of {sigma}PCB, {sigma}DDT and HCB than other Arctic marine top consumers.

  19. A Review of the Phytochemistry and Pharmacological Activities of Raphani Semen

    Directory of Open Access Journals (Sweden)

    Tung-Ting Sham

    2013-01-01

    Full Text Available The dried ripe seed of Raphanus sativus L., commonly known as radish seed (or Raphani Semen, is used as traditional Chinese medicine (TCM to treat constipation, chronic tracheitis, and hypertension. The major active compounds in Raphani Semen are alkaloids, glucosinolates, brassinosteroids, and flavonoids. Fatty acids are its main nutritional contents. Raphani Semen has been demonstrated to have beneficial effects on hypertension, obesity, diabetes mellitus, constipation, and cough. So far, there is no report about the adverse/toxic effects of this herb on humans. However, Raphani Semen processed by roasting was reported to exhibit some adverse effects on mice. Additionally, erucic acid, the main fatty acid in Raphani Semen, was shown to enhance the toxicity of doxorubicin. Thus, Raphani Semen has a potential risk of causing toxicity and drug interaction. In summary, Raphani Semen is a valuable TCM herb with multiple pharmacological effects. More studies on Raphani Semen could help better understand its pharmacological mechanisms so as to provide clear scientific evidence to explain its traditional uses, to identify its therapeutic potential on other diseases, and to understand its possible harmful effects.

  20. Pro-survival role for Parkinson's associated gene DJ-1 revealed in trophically impaired dopaminergic neurons.

    Directory of Open Access Journals (Sweden)

    Liviu Aron

    2010-04-01

    Full Text Available The mechanisms underlying the selective death of substantia nigra (SN neurons in Parkinson disease (PD remain elusive. While inactivation of DJ-1, an oxidative stress suppressor, causes PD, animal models lacking DJ-1 show no overt dopaminergic (DA neuron degeneration in the SN. Here, we show that aging mice lacking DJ-1 and the GDNF-receptor Ret in the DA system display an accelerated loss of SN cell bodies, but not axons, compared to mice that only lack Ret signaling. The survival requirement for DJ-1 is specific for the GIRK2-positive subpopulation in the SN which projects exclusively to the striatum and is more vulnerable in PD. Using Drosophila genetics, we show that constitutively active Ret and associated Ras/ERK, but not PI3K/Akt, signaling components interact genetically with DJ-1. Double loss-of-function experiments indicate that DJ-1 interacts with ERK signaling to control eye and wing development. Our study uncovers a conserved interaction between DJ-1 and Ret-mediated signaling and a novel cell survival role for DJ-1 in the mouse. A better understanding of the molecular connections between trophic signaling, cellular stress and aging could uncover new targets for drug development in PD.

  1. Phytochemistry and pharmacology of anti-depressant medicinal plants: A review.

    Science.gov (United States)

    Martins, Jeanette; S, Brijesh

    2018-05-16

    Stress renders an individual to experience mental pressure and exhaustion which brings about feelings of anxiety, depression, anger and/or other negative emotions. Depression affects a person's state of mind, behaviour, health and is often associated with suicide. The use of anti-depressant drugs as therapeutic agents is associated with symptoms such as, delayed onset of action, side-effects, drug-drug and dietary interactions, sexual dysfunction, cardiac toxicity, etc. Thus, there is need to target these issues and improve current treatment options. Medicinal plants have long been used in discovering novel treatment strategies and compounds with promising roles in treating various disease conditions. There has been an increase, worldwide, in the use of medicinal plants and herbs for developing nutraceuticals for treatment of depression and other psychiatric disorders. Medicinal plants in their natural forms are valuable as they are rich in various phytochemical compounds. These phytochemical compounds have pharmacological roles in treating various diseases conditions; apart from being widely available in nature and commercially beneficial. The phytochemical compounds in plants are constantly being explored through various experimental studies to determine the molecular basis of how medicinal plants work in relation to drugs and diseases and to develop neutraceuticals for improving conditions. This review summarizes 110 medicinal plants and their phytochemical constituents that have been shown to possess anti-depressant activity. This review also highlights the various mechanisms of anti-depressant action of some of these plants and their plant parts like roots, stem, leaves, flowers, fruit or whole plant; phytochemical compounds showing anti-depressant activity such flavanoids, steroids, saponins, sugars, lectins, alkaloids, etc.; and various anti-depressant screening models used such as tail suspension test, forced swim test, chronic unpredictable stress test

  2. Trophic niche of squids: Insights from isotopic data in marine systems worldwide

    Science.gov (United States)

    Navarro, Joan; Coll, Marta; Somes, Christoper J.; Olson, Robert J.

    2013-10-01

    Cephalopods are an important prey resource for fishes, seabirds, and marine mammals, and are also voracious predators on crustaceans, fishes, squid and zooplankton. Because of their high feeding rates and abundance, squids have the potential to exert control on the recruitment of commercially important fishes. In this review, we synthesize the available information for two intrinsic markers (δ15N and δ13C isotopic values) in squids for all oceans and several types of ecosystems to obtain a global view of the trophic niches of squids in marine ecosystems. In particular, we aimed to examine whether the trophic positions and trophic widths of squid species vary among oceans and ecosystem types. To correctly compare across systems, we adjusted squid δ15N values for the isotopic variability of phytoplankton at the base of the food web provided by an ocean circulation-biogeochemistry-isotope model. Studies that focused on the trophic ecology of squids using isotopic techniques were few, and most of the information on squids was from studies on their predators. Our results showed that squids occupy a large range of trophic positions and exploit a large range of trophic resources, reflecting the versatility of their feeding behavior and confirming conclusions from food-web models. Clear differences in both trophic position and trophic width were found among oceans and ecosystem types. The study also reinforces the importance of considering the natural variation in isotopic values when comparing the isotopic values of consumers inhabiting different ecosystems.

  3. Multiple attractors and boundary crises in a tri-trophic food chain.

    NARCIS (Netherlands)

    Boer, M.P.; Kooi, B.W.; Kooijman, S.A.L.M.

    2001-01-01

    The asymptotic behaviour of a model of a tri-trophic food chain in the chemostat is analysed in detail. The Monod growth model is used for all trophic levels, yielding a non-linear dynamical system of four ordinary differential equations. Mass conservation makes it possible to reduce the dimension

  4. Intersexual Trophic Niche Partitioning in an Ant-Eating spider (Araneae: Zodariidae)

    DEFF Research Database (Denmark)

    Pekár, Stanislav; Martisová, Martina; Bilde, T.

    2011-01-01

    lead to higher energy demands in females driven by fecundity selection, while males invest in mate searching. We tested predictions of the two hypotheses underlying intersexual trophic niche partitioning in a natural population of spiders. Zodarion jozefienae spiders specialize on Messor barbarus ants...... that are polymorphic in body size and hence comprise potential trophic niches for the spider, making this system well-suited to study intersexual trophic niche partitioning. Methodology/Principal Findings Comparative analysis of trophic morphology (the chelicerae) and body size of males, females and juveniles...... demonstrated highly female biased SSD (Sexual Size Dimorphism) in body size, body weight, and in the size of chelicerae, the latter arising from sex-specific growth patterns in trophic morphology. In the field, female spiders actively selected ant sub-castes that were larger than the average prey size...

  5. Animal water balance drives top-down effects in a riparian forest-implications for terrestrial trophic cascades.

    Science.gov (United States)

    McCluney, Kevin E; Sabo, John L

    2016-08-17

    Despite the clear importance of water balance to the evolution of terrestrial life, much remains unknown about the effects of animal water balance on food webs. Based on recent research suggesting animal water imbalance can increase trophic interaction strengths in cages, we hypothesized that water availability could drive top-down effects in open environments, influencing the occurrence of trophic cascades. We manipulated large spider abundance and water availability in 20 × 20 m open-air plots in a streamside forest in Arizona, USA, and measured changes in cricket and small spider abundance and leaf damage. As expected, large spiders reduced both cricket abundance and herbivory under ambient, dry conditions, but not where free water was added. When water was added (free or within moist leaves), cricket abundance was unaffected by large spiders, but spiders still altered herbivory, suggesting behavioural effects. Moreover, we found threshold-type increases in herbivory at moderately low soil moisture (between 5.5% and 7% by volume), suggesting the possibility that water balance may commonly influence top-down effects. Overall, our results point towards animal water balance as an important driver of direct and indirect species interactions and food web dynamics in terrestrial ecosystems. © 2016 The Author(s).

  6. Highly resolved early Eocene food webs show development of modern trophic structure after the end-Cretaceous extinction.

    Science.gov (United States)

    Dunne, Jennifer A; Labandeira, Conrad C; Williams, Richard J

    2014-05-07

    Generalities of food web structure have been identified for extant ecosystems. However, the trophic organization of ancient ecosystems is unresolved, as prior studies of fossil webs have been limited by low-resolution, high-uncertainty data. We compiled highly resolved, well-documented feeding interaction data for 700 taxa from the 48 million-year-old latest early Eocene Messel Shale, which contains a species assemblage that developed after an interval of protracted environmental and biotal change during and following the end-Cretaceous extinction. We compared the network structure of Messel lake and forest food webs to extant webs using analyses that account for scale dependence of structure with diversity and complexity. The Messel lake web, with 94 taxa, displays unambiguous similarities in structure to extant webs. While the Messel forest web, with 630 taxa, displays differences compared to extant webs, they appear to result from high diversity and resolution of insect-plant interactions, rather than substantive differences in structure. The evidence presented here suggests that modern trophic organization developed along with the modern Messel biota during an 18 Myr interval of dramatic post-extinction change. Our study also has methodological implications, as the Messel forest web analysis highlights limitations of current food web data and models.

  7. Diet Composition and Trophic Ecology of Northeast Pacific Ocean Sharks.

    Science.gov (United States)

    Bizzarro, Joseph J; Carlisle, Aaron B; Smith, Wade D; Cortés, Enric

    Although there is a general perception of sharks as large pelagic, apex predators, most sharks are smaller, meso- and upper-trophic level predators that are associated with the seafloor. Among 73 shark species documented in the eastern North Pacific (ENP), less than half reach maximum lengths >200cm, and 78% occur in demersal or benthic regions of the continental shelf or slope. Most small (≤200cm) species (e.g., houndsharks) and demersal, nearshore juveniles of larger species (e.g., requiem sharks) consume small teleosts and decapod crustaceans, whereas large species in pelagic coastal and oceanic environments feed on large teleosts and squids. Several large, pelagic apex predator species occur in the ENP, but the largest species (i.e., Basking Shark, Whale Shark) consume zooplankton or small nekton. Size-based dietary variability is substantial for many species, and segregation of juvenile and adult foraging habitats also is common (e.g., Horn Shark, Shortfin Mako). Temporal dietary differences are most pronounced for temperate, nearshore species with wide size ranges, and least pronounced for smaller species in extreme latitudes and deep-water regions. Sympatric sharks often occupy various trophic positions, with resource overlap differing by space and time and some sharks serving as prey to other species. Most coastal species remain in the same general region over time and feed opportunistically on variable prey inputs (e.g., season migrations, spawning, or recruitment events), whereas pelagic, oceanic species actively seek hot spots of prey abundance that are spatiotemporally variable. The influence of sharks on ecosystem structure and regulation has been downplayed compared to that of large teleosts species with higher per capita consumption rates (e.g., tunas, billfishes). However, sharks also exert indirect influences on prey populations by causing behavioural changes that may result in restricted ranges and reduced fitness. Except for food web modelling

  8. Pollutant Dehalogenation Capability May Depend on the Trophic Evolutionary History of the Organism: PBDEs in Freshwater Food Webs

    Science.gov (United States)

    Bartrons, Mireia; Grimalt, Joan O.; de Mendoza, Guillermo; Catalan, Jordi

    2012-01-01

    Organohalogen compounds are some of the most notorious persistent pollutants disturbing the Earth biosphere. Although human-made, these chemicals are not completely alien to living systems. A large number of natural organohalogens, part of the secondary metabolism, are involved in chemical trophic interactions. Surprisingly, the relationship between organisms’ trophic position and synthetic organohalogen biotransformation capability has not been investigated. We studied the case for polybromodiphenyl ethers (PBDE), a group of flame-retardants of widespread use in the recent years, in aquatic food webs from remote mountain lakes. These relatively simple ecosystems only receive pollution by atmospheric transport. A large predominance of the PBDE congener currently in use in Europe, BDE-209, largely dominated the PBDE composition of the basal resources of the food web. In contrast, primary consumers (herbivores and detritivores) showed a low proportion of BDE-209, and dominance of several less brominated congeners (e.g. BDE-100, BDE47). Secondary consumers (predators) showed large biomagnification of BDE-209 compare to other congeners. Finally, top predator fish characterized by low total PBDE concentrations. Examination of the bromine stable isotopic composition indicates that primary consumers showed higher PBDE biotransformation capability than secondary consumers. We suggest that the evolutionary response of primary consumers to feeding deterrents would have pre-adapted them for PBDE biotransformation. The observed few exceptions, some insect taxa, can be interpreted in the light of the trophic history of the evolutionary lineage of the organisms. Bromine isotopic composition in fish indicates that low PBDE values are due to not only biotransformation but also to some other process likely related to transport. Our finding illustrates that organohalogen compounds may strongly disturb ecosystems even at low concentrations, since the species lacking or having

  9. Pollutant dehalogenation capability may depend on the trophic evolutionary history of the organism: PBDEs in freshwater food webs.

    Directory of Open Access Journals (Sweden)

    Mireia Bartrons

    Full Text Available Organohalogen compounds are some of the most notorious persistent pollutants disturbing the Earth biosphere. Although human-made, these chemicals are not completely alien to living systems. A large number of natural organohalogens, part of the secondary metabolism, are involved in chemical trophic interactions. Surprisingly, the relationship between organisms' trophic position and synthetic organohalogen biotransformation capability has not been investigated. We studied the case for polybromodiphenyl ethers (PBDE, a group of flame-retardants of widespread use in the recent years, in aquatic food webs from remote mountain lakes. These relatively simple ecosystems only receive pollution by atmospheric transport. A large predominance of the PBDE congener currently in use in Europe, BDE-209, largely dominated the PBDE composition of the basal resources of the food web. In contrast, primary consumers (herbivores and detritivores showed a low proportion of BDE-209, and dominance of several less brominated congeners (e.g. BDE-100, BDE47. Secondary consumers (predators showed large biomagnification of BDE-209 compare to other congeners. Finally, top predator fish characterized by low total PBDE concentrations. Examination of the bromine stable isotopic composition indicates that primary consumers showed higher PBDE biotransformation capability than secondary consumers. We suggest that the evolutionary response of primary consumers to feeding deterrents would have pre-adapted them for PBDE biotransformation. The observed few exceptions, some insect taxa, can be interpreted in the light of the trophic history of the evolutionary lineage of the organisms. Bromine isotopic composition in fish indicates that low PBDE values are due to not only biotransformation but also to some other process likely related to transport. Our finding illustrates that organohalogen compounds may strongly disturb ecosystems even at low concentrations, since the species lacking

  10. Trophic niches of sympatric tropical tuna in the Western Indian Ocean inferred by stable isotopes and neutral fatty acids

    Science.gov (United States)

    Sardenne, Fany; Bodin, Nathalie; Chassot, Emmanuel; Amiel, Aurélien; Fouché, Edwin; Degroote, Maxime; Hollanda, Stéphanie; Pethybridge, Heidi; Lebreton, Benoit; Guillou, Gaël; Ménard, Frédéric

    2016-08-01

    This study examined the trophic ecology of three sympatric tropical tuna species (bigeye BET, skipjack SKJ, and yellowfin YFT) sampled in the Western Indian Ocean throughout 2013. Specifically we explored inter-specific resource partitioning and ontogenetic variability using neutral fatty acids and stable isotope analysis of liver and muscle from small (⩽100 cm fork length, FL) and large (>100 cm FL) tuna collected in mixed schools at the surface by purse-seine. Both biochemical tracers were used to calculate trophic niche indices that collectively revealed high potential for resource overlap, especially among small tuna. Resource overlap appeared strongest between BET and YFT, with SKJ tissues having high carbon isotope (δ13C) values (-17 ± 0.3‰), lower nitrogen isotope (δ15N) values (11.4 ± 0.6‰), and higher relative proportion of poly-unsaturated fatty acids (PUFA) than the two other species, indicating a different diet. Size was found to be a strong predictor for most biochemical tracers in the three species with δ13C, δ15N and total lipid content in the liver. In the larger species (YFT and BET), proportions of mono-unsaturated fatty acids typically increased with size, while quantities of PUFA decreased. In addition to ontogenetic variability, trophic markers were shown to vary between sampling area and season: higher lipid reserves and δ15N values, and lower δ13C values occurred during monsoon periods around Seychelles than in the Mozambique Channel (parted from about 1500 km). Our multi-tracer approach reveals the magnitude of potential competitive interactions in mixed tropical tuna schools at both small and large sizes and demonstrates that ontogenetic niche differentiation acts as a major factor of coexistence in tropical tuna.

  11. Biodiversity enhances ecosystem multifunctionality across trophic levels and habitats

    Science.gov (United States)

    Lefcheck, Jonathan S.; Byrnes, Jarrett E. K.; Isbell, Forest; Gamfeldt, Lars; Griffin, John N.; Eisenhauer, Nico; Hensel, Marc J. S.; Hector, Andy; Cardinale, Bradley J.; Duffy, J. Emmett

    2015-01-01

    The importance of biodiversity for the integrated functioning of ecosystems remains unclear because most evidence comes from analyses of biodiversity's effect on individual functions. Here we show that the effects of biodiversity on ecosystem function become more important as more functions are considered. We present the first systematic investigation of biodiversity's effect on ecosystem multifunctionality across multiple taxa, trophic levels and habitats using a comprehensive database of 94 manipulations of species richness. We show that species-rich communities maintained multiple functions at higher levels than depauperate ones. These effects were stronger for herbivore biodiversity than for plant biodiversity, and were remarkably consistent across aquatic and terrestrial habitats. Despite observed tradeoffs, the overall effect of biodiversity on multifunctionality grew stronger as more functions were considered. These results indicate that prior research has underestimated the importance of biodiversity for ecosystem functioning by focusing on individual functions and taxonomic groups. PMID:25907115

  12. Trophic convergence drives morphological convergence in marine tetrapods.

    Science.gov (United States)

    Kelley, Neil P; Motani, Ryosuke

    2015-01-01

    Marine tetrapod clades (e.g. seals, whales) independently adapted to marine life through the Mesozoic and Caenozoic, and provide iconic examples of convergent evolution. Apparent morphological convergence is often explained as the result of adaptation to similar ecological niches. However, quantitative tests of this hypothesis are uncommon. We use dietary data to classify the feeding ecology of extant marine tetrapods and identify patterns in skull and tooth morphology that discriminate trophic groups across clades. Mapping these patterns onto phylogeny reveals coordinated evolutionary shifts in diet and morphology in different marine tetrapod lineages. Similarities in morphology between species with similar diets-even across large phylogenetic distances-are consistent with previous hypotheses that shared functional constraints drive convergent evolution in marine tetrapods.

  13. Evaluation on Biofilter in Recirculating Integrated Multi-Trophic Aquaculture

    Directory of Open Access Journals (Sweden)

    S. Sumoharjo

    2013-06-01

    Full Text Available Integrated multi-trophic aquaculture pays more attention as a bio-integrated food production system that serves as a model of sustainable aquaculture, minimizes waste discharge, increases diversity and yields multiple products. The objectives of this research were to analyze the efficiency of total ammonia nitrogen biofiltration and its effect on carrying capacity of fish rearing units. Pilot-scale bioreactor was designed with eight run-raceways (two meters of each that assembled in series. Race 1-3 were used to stock silky worm (Tubifex sp as detrivorous converter, then race 4-8 were used to plant three species of leaf-vegetable as photoautotrophic converters, i.e; spinach (Ipomoea reptana, green mustard (Brassica juncea and basil (Ocimum basilicum. The three plants were placed in randomized block design based on water flow direction. Mass balance of nutrient analysis, was applied to figure out the efficiency of bio-filtration and its effect on carrying capacity of rearing units. The result of the experiment showed that 86.5 % of total ammonia nitrogen removal was achieved in 32 days of culturing period. This efficiency able to support the carrying capacity of the fish tank up to 25.95 kg/lpm with maximum density was 62.69 kg/m3 of fish biomass productionDoi: http://dx.doi.org/10.12777/ijse.4.2.2013.80-85 [How to cite this article: Sumoharjo, S.  and Maidie, A. (2013. Evaluation on Biofilter in Recirculating Integrated Multi-Trophic Aquaculture.  International Journal of  Science and Engineering, 4(2,80-85. Doi: http://dx.doi.org/10.12777/ijse.4.2.2013.80-85

  14. Ammonium Transformation in 14 Lakes along a Trophic Gradient

    Directory of Open Access Journals (Sweden)

    Barbara Leoni

    2018-03-01

    Full Text Available Ammonia is a widespread pollutant in aquatic ecosystems originating directly and indirectly from human activities, which can strongly affect the structure and functioning of the aquatic foodweb. The biological oxidation of NH4+ to nitrite, and then nitrate is a key part of the complex nitrogen cycle and a fundamental process in aquatic environments, having a profound influence on ecosystem stability and functionality. Environmental studies have shown that our current knowledge of physical and chemical factors that control this process and the abundance and function of involved microorganisms are not entirely understood. In this paper, the efficiency and the transformation velocity of ammonium into oxidised compounds in 14 south-alpine lakes in northern Italy, with a similar origin, but different trophic levels, are compared with lab-scale experimentations (20 °C, dark, oxygen saturation that are performed in artificial microcosms (4 L. The water samples were collected in different months to highlight the possible effect of seasonality on the development of the ammonium oxidation process. In four-liter microcosms, concentrations were increased by 1 mg/L NH4+ and the process of ammonium oxidation was constantly monitored. The time elapsed for the decrease of 25% and 95% of the initial ion ammonium concentration and the rate for that ammonium oxidation were evaluated. Principal Component Analysis and General Linear Model, performed on 56 observations and several chemical and physical parameters, highlighted the important roles of total phosphorus and nitrogen concentrations on the commencement of the oxidation process. Meanwhile, the natural concentration of ammonium influenced the rate of nitrification (µg NH4+/L day. Seasonality did not seem to significantly affect the ammonium transformation. The results highlight the different vulnerabilities of lakes with different trophic statuses.

  15. Macrophytes shape trophic niche variation among generalist fishes.

    Directory of Open Access Journals (Sweden)

    Ivana Vejříková

    Full Text Available Generalist species commonly have a fundamental role in ecosystems as they can integrate spatially distinct habitats and food-web compartments, as well as control the composition, abundance and behavior of organisms at different trophic levels. Generalist populations typically consist of specialized individuals, but the potential for and hence degree of individual niche variation can be largely determined by habitat complexity. We compared individual niche variation within three generalist fishes between two comparable lakes in the Czech Republic differing in macrophyte cover, i.e. macrophyte-rich Milada and macrophyte-poor Most. We tested the hypothesis that large individual niche variation among generalist fishes is facilitated by the presence of macrophytes, which provides niches and predation shelter for fish and their prey items. Based on results from stable nitrogen (δ15N and carbon (δ13C isotopic mixing models, perch (Perca fluviatilis L. and rudd (Scardinius erythrophthalmus (L. showed larger individual variation (i.e., variance in trophic position in Milada as compared to Most, whereas no significant between-lake differences were observed for roach (Rutilus rutilus (L.. Contrary to our hypothesis, all the three species showed significantly lower individual variation in the relative reliance on littoral food resources in Milada than in Most. Rudd relied significantly more whereas perch and roach relied less on littoral food resources in Milada than in Most, likely due to prevalent herbivory by rudd and prevalent zooplanktivory by perch and roach in the macrophyte-rich Milada as compared to macrophyte-poor Most. Our study demonstrates how the succession of macrophyte vegetation, via its effects on the physical and biological complexity of the littoral zone and on the availability of small prey fish and zooplankton, can strongly influence individual niche variation among generalist fishes with different ontogenetic trajectories, and hence

  16. Macrophytes shape trophic niche variation among generalist fishes

    Science.gov (United States)

    Vejřík, Lukáš; Šmejkal, Marek; Čech, Martin; Sajdlová, Zuzana; Frouzová, Jaroslava; Kiljunen, Mikko; Peterka, Jiří

    2017-01-01

    Generalist species commonly have a fundamental role in ecosystems as they can integrate spatially distinct habitats and food-web compartments, as well as control the composition, abundance and behavior of organisms at different trophic levels. Generalist populations typically consist of specialized individuals, but the potential for and hence degree of individual niche variation can be largely determined by habitat complexity. We compared individual niche variation within three generalist fishes between two comparable lakes in the Czech Republic differing in macrophyte cover, i.e. macrophyte-rich Milada and macrophyte-poor Most. We tested the hypothesis that large individual niche variation among generalist fishes is facilitated by the presence of macrophytes, which provides niches and predation shelter for fish and their prey items. Based on results from stable nitrogen (δ15N) and carbon (δ13C) isotopic mixing models, perch (Perca fluviatilis L.) and rudd (Scardinius erythrophthalmus (L.)) showed larger individual variation (i.e., variance) in trophic position in Milada as compared to Most, whereas no significant between-lake differences were observed for roach (Rutilus rutilus (L.)). Contrary to our hypothesis, all the three species showed significantly lower individual variation in the relative reliance on littoral food resources in Milada than in Most. Rudd relied significantly more whereas perch and roach relied less on littoral food resources in Milada than in Most, likely due to prevalent herbivory by rudd and prevalent zooplanktivory by perch and roach in the macrophyte-rich Milada as compared to macrophyte-poor Most. Our study demonstrates how the succession of macrophyte vegetation, via its effects on the physical and biological complexity of the littoral zone and on the availability of small prey fish and zooplankton, can strongly influence individual niche variation among generalist fishes with different ontogenetic trajectories, and hence the overall

  17. Ecosystem Responses To Plant Phenology Across Scales And Trophic Levels

    Science.gov (United States)

    Stoner, D.; Sexton, J. O.; Nagol, J. R.; Ironside, K.; Choate, D.; Longshore, K.; Edwards, T., Jr.

    2015-12-01

    Plant phenology in arid and semi-arid ecoregions is constrained by water availability and governs the life history characteristics of primary and secondary consumers. We related the behavior, demography, and distribution of mammalian herbivores and their principal predator to remotely sensed vegetation and climatological indices across the western United States for the period 2000-2014. Across scales, terrain and topographic position moderates the effects of climatological drought on primary productivity, resulting in differential susceptibility among plant functional types to water stress. At broad scales, herbivores tie parturition to moist sites during the period of maximum increase in local forage production. Consequently, juvenile mortality is highest in regions of extreme phenological variability. Although decoupled from primary production by one or more trophic levels, carnivore home range size and density is negatively correlated to plant productivity and growing season length. At the finest scales, predation influences the behavior of herbivore prey through compromised habitat selection, in which maternal females trade nutritional benefits of high plant biomass for reduced mortality risk associated with increased visibility. Climate projections for the western United States predict warming combined with shifts in the timing and form of precipitation. Our analyses suggest that these changes will propagate through trophic levels as increased phenological variability and shifts in plant distributions, larger consumer home ranges, altered migration behavior, and generally higher volatility in wildlife populations. Combined with expansion and intensification of human land use across the region, these changes will likely have economic implications stemming from increased human-wildlife conflict (e.g., crop damage, vehicle collisions) and changes in wildlife-related tourism.

  18. Disease-mediated bottom-up regulation: An emergent virus affects a keystone prey, and alters the dynamics of trophic webs.

    Science.gov (United States)

    Monterroso, Pedro; Garrote, Germán; Serronha, Ana; Santos, Emídio; Delibes-Mateos, Miguel; Abrantes, Joana; Perez de Ayala, Ramón; Silvestre, Fernando; Carvalho, João; Vasco, Inês; Lopes, Ana M; Maio, Elisa; Magalhães, Maria J; Mills, L Scott; Esteves, Pedro J; Simón, Miguel Ángel; Alves, Paulo C

    2016-10-31

    Emergent diseases may alter the structure and functioning of ecosystems by creating new biotic interactions and modifying existing ones, producing cascading processes along trophic webs. Recently, a new variant of the rabbit haemorrhagic disease virus (RHDV2 or RHDVb) arguably caused widespread declines in a keystone prey in Mediterranean ecosystems - the European rabbit (Oryctolagus cuniculus). We quantitatively assess the impact of RHDV2 on natural rabbit populations and in two endangered apex predator populations: the Iberian lynx (Lynx pardinus) and the Spanish Imperial eagle (Aquila adalberti). We found 60-70% declines in rabbit populations, followed by decreases of 65.7% in Iberian lynx and 45.5% in Spanish Imperial eagle fecundities. A revision of the web of trophic interactions among rabbits and their dependent predators suggests that RHDV2 acts as a keystone species, and may steer Mediterranean ecosystems to management-dependent alternative states, dominated by simplified mesopredator communities. This model system stresses the importance of diseases as functional players in the dynamics of trophic webs.

  19. Feeding ecology and trophic relationships of fish species in the lower Guadiana River Estuary and Castro Marim e Vila Real de Santo António Salt Marsh

    Science.gov (United States)

    Sá, Rita; Bexiga, Constança; Veiga, Pedro; Vieira, Lina; Erzini, Karim

    2006-10-01

    In this study we analyze the feeding ecology and trophic relationships of some of the main fish species (Soleidae, Moronidae, Mullidae, Sparidae, Mugilidae, and Batrachoididae) of the lower Estuary of the Guadiana River and the Castro Marim e Vila Real de Santo António Salt Marsh. We examined the stomachs of 1415 fish caught monthly between September 2000 and August 2001. Feeding indices and coefficients were determined and used along with the results of multivariate analysis to develop diagrams of trophic interactions (food webs). Results show that these species are largely opportunistic predators. The most important prey items are amphipods, gobies (Gobiidae), shrimps ( Palaemon serratus and Crangon crangon), and polychaete worms. The lower Estuary and associated salt marshes are important nurseries and feeding grounds for the species studied. In this area, it is therefore important to monitor the effects of changes in river runoff, nutrient input, and temperature that result from construction of the Alqueva Dam upstream.

  20. Trophic factors as modulators of motor neuron physiology and survival: implications for ALS therapy

    Directory of Open Access Journals (Sweden)

    Luis B Tovar-y-Romo

    2014-02-01

    Full Text Available Motor neuron physiology and development depend on a continuous and tightly regulated trophic support from a variety of cellular sources. Trophic factors guide the generation and positioning of motor neurons during every stage of the developmental process. As well, they are involved in axon guidance and synapse formation. Even in the adult spinal cord an uninterrupted trophic input is required to maintain neuronal functioning and protection from noxious stimuli. Among the trophic factors that have been demonstrated to participate in motor neuron physiology are vascular endothelial growth factor (VEGF, glial-derived neurotrophic factor (GDNF, ciliary neurotrophic factor (CNTF and insulin-like growth factor 1 (IGF-1. Upon binding to membrane receptors expressed in motor neurons or neighboring glia, these trophic factors activate intracellular signaling pathways that promote cell survival and have protective action on motor neurons, in both in vivo and in vitro models of neuronal degeneration. For these reasons these factors have been considered a promising therapeutic method for amyotrophic lateral sclerosis (ALS and other neurodegenerative diseases, although their efficacy in human clinical trials have not yet shown the expected protection. In this review we summarize experimental data on the role of these trophic factors in motor neuron function and survival, as well as their mechanisms of action. We also briefly discuss the potential therapeutic use of the trophic factors and why these therapies may have not been yet successful in the clinical use.

  1. Wolf presence and increased willow consumption by Yellowstone elk: implications for trophic cascades.

    Science.gov (United States)

    Creel, Scott; Christianson, David

    2009-09-01

    Recent increases in the height and growth ring width of willow (Salix spp.) and other woody plants in the Greater Yellowstone Ecosystem (GYE) have been attributed to a behaviorally mediated trophic cascade from wolves (Canis lupus) to elk (Cervus elaphus) to willows. This hypothesis predicts that individual elk consume less willow in response to the presence of wolves, but this prediction has not been directly tested with data from elk. We collected 727 fecal samples from elk in the Gallatin Canyon portion of the GYE over three winters and used microhistological methods to quantify the proportion of willow in each sample. We then tested the effect of wolf presence on willow consumption by elk, controlling for the effects of snow conditions, sex, and habitat type. During the period of study, 8-17 wolves occupied the study area, and wolves were locally present on 49% of 260 sampling days, stratified at two-week intervals across three drainages. Over the three years combined, willow consumption was related to snow conditions, wolf presence, and a wolf X sex interaction. As expected, willow consumption increased with deeper and less penetrable snow, and this effect was strong. Contrary to expectation, willow consumption increased in the presence of wolves. As with other aspects of antipredator behavior, wolves had different effects on willow consumption by males and females. Finally, we aggregated the data to estimate winter-long mean willow consumption within each drainage; at this broader scale, willow consumption again increased as predation risk increased. In summary, willow consumption was more strongly affected by snow conditions than by the presence of wolves. Interactions between elk and willow were affected by wolves, but not as predicted by the hypothesis that wolf presence favors willow release through a reduction in the selection of willow by individual elk. If a trophic cascade is operating, our results suggest that a decline in the size of the elk

  2. Trophic mass-balance model of Alaska's Prince William Sound ecosystem, for the post-spill period 1994-1996

    International Nuclear Information System (INIS)

    Okey, T.A.; Pauly, D.

    1998-01-01

    The Ecopath modelling approach for the Prince William Sound (PWS) ecosystem was described. The area is the site of the 1989 Exxon Valdez oil spill (EVOS), the largest spill in U.S. history. 36,000 tonnes of crude oil spread throughout the central and southwestern PWS into the Gulf of Alaska and along the Kenai and Alaska Peninsula. The initial effects of the oil spill were catastrophic. The Ecopath modelling approach discussed in this report is aimed at providing a cohesive picture of the PWS ecosystem by constructing a mass-balanced model of food-web interactions and trophic flows using information collected since the EVOS. The model includes all biotic components of the ecosystem and provides a quantitative description of food-web interactions and relationships, as well as energy flows among components. The model can provide an understanding of how ecosystems respond to disturbances, such as oil spills. 216 refs., 74 tabs., 13 figs., 8 appendices

  3. Intersexual trophic niche partitioning in an ant-eating spider (Araneae: Zodariidae.

    Directory of Open Access Journals (Sweden)

    Stano Pekár

    2011-01-01

    Full Text Available Divergence in trophic niche between the sexes may function to reduce competition between the sexes ("intersexual niche partitioning hypothesis", or may be result from differential selection among the sexes on maximizing reproductive output ("sexual selection hypothesis". The latter may lead to higher energy demands in females driven by fecundity selection, while males invest in mate searching. We tested predictions of the two hypotheses underlying intersexual trophic niche partitioning in a natural population of spiders. Zodarion jozefienae spiders specialize on Messor barbarus ants that are polymorphic in body size and hence comprise potential trophic niches for the spider, making this system well-suited to study intersexual trophic niche partitioning.Comparative analysis of trophic morphology (the chelicerae and body size of males, females and juveniles demonstrated highly female biased SSD (Sexual Size Dimorphism in body size, body weight, and in the size of chelicerae, the latter arising from sex-specific growth patterns in trophic morphology. In the field, female spiders actively selected ant sub-castes that were larger than the average prey size, and larger than ants captured by juveniles and males. Female fecundity was highly positively correlated with female body mass, which reflects foraging success during the adult stage. Females in laboratory experiments preferred the large ant sub-castes and displayed higher capture efficiency. In contrast, males occupied a different trophic niche and showed reduced foraging effort and reduced prey capture and feeding efficiency compared with females and juveniles.Our data indicate that female-biased dimorphism in trophic morphology and body size correlate with sex-specific reproductive strategies. We propose that intersexual trophic niche partitioning is shaped primarily by fecundity selection in females, and results from sex-differences in the route to successful reproduction where females are

  4. Wolves trigger a trophic cascade to berries as alternative food for grizzly bears.

    Science.gov (United States)

    Ripple, William J; Beschta, Robert L; Fortin, Jennifer K; Robbins, Charles T

    2015-05-01

    This is a Forum article in response to: Barber-Meyer, S. (2015) Trophic cascades from wolves to grizzly bears or changing abundance of bears and alternate foods? Journal of Animal Ecology, 83, doi: 10.1111/1365-2656.12338. We used multiple data sets and study areas as well as several lines of evidence to investigate potential trophic linkages in Yellowstone National Park. Our results suggest that a trophic cascade from wolves to elk to berry production to berry consumption by grizzly bears may now be underway in the Park. © 2015 The Authors. Journal of Animal Ecology © 2015 British Ecological Society.

  5. [Applications of stable isotope analysis in the trophic ecology studies of cephalopods].

    Science.gov (United States)

    Li, Yun-Kai; Gong, Yi; Chen, Xin-Jun

    2014-05-01

    Cephalopods play an important role in marine food webs, however, knowledge about their complex life history, especially their feeding ecology, remains limited. With the rapidly increasing use of stable isotope analysis (SIA) in ecology, it becomes a powerful tool and complement of traditional methods for investigating the trophic ecology and migration patterns of invertebrates. Here, after summarizing the current methods for trophic ecology investigation of cephalopods, applications of SIA in studying the trophic ecology of cephalopods were reviewed, including the key issues such as standardization of available tissues for SIA analyzing, diet shift and migration patterns of cephalopods, with the aim of advancing its application in the biology of cephalopods in the future.

  6. Trophic Ecology and Movement Patters of Tiger Sharks (Galeocerdo Cuvier) off the Western North Atlantic Coastal and Continental Shelf Waters

    Science.gov (United States)

    Sancho, G.; Edman, R.; Frazier, B.; Bubley, W.

    2016-02-01

    Understanding the trophic dynamics and habitat utilization of apex predators is central to inferring their influence on different marine landscapes and to help design effective management plans for these animals. Tiger sharks (Galeocerdo cuvier) are abundant in shelf and offshore Gulf Stream waters of the western North Atlantic Ocean, and based on movements from individuals captured in Florida and Bahamas, seem to avoid coastal and shelf waters off South Carolina and Georgia. This contradicts reports of tiger sharks regularly being caught nearshore by anglers in these states, indicating that separate sub-populations may exist in the western North Atlantic. In the present study we captured Tiger Sharks in coastal waters off South Carolina in 2014 and 2015 in order to describe their movement patterns through acoustic and satellite tagging, and trophic dynamics through stable isotope analyses. Movement data show that these tiger sharks repeatedly visit particular inshore areas and mainly travel over the continental shelf, but rarely venture offshore beyond the continental shelf edge. Ongoing C and N stable isotope analyses of muscle, blood and skin tissues from adult and juvenile tiger sharks, as well as from potential prey species and primary producers, will help determine if their diets are based on inshore, shelf or offshore based food webs. Tiger sharks exploiting nearshore environments and shelf waters have much higher probabilities of interacting with humans than individuals occupying far offshore Gulf Stream habitats.

  7. Trophic structure in the Gulf of Lions marine ecosystem (north-western Mediterranean Sea) and fishing impacts

    Science.gov (United States)

    Bănaru, D.; Mellon-Duval, C.; Roos, D.; Bigot, J.-L.; Souplet, A.; Jadaud, A.; Beaubrun, P.; Fromentin, J.-M.

    2013-02-01

    The Gulf of Lions ecosystem was described using the Ecopath mass-balance model to characterise its structure and functioning and to examine the effects of the multispecific fisheries operating in this area. The model is composed of 40 compartments, including 1 group of seabirds, 2 groups of cetaceans, 18 groups of fish, 12 groups of invertebrates, 5 groups of primary producers, detritus and discards. Input data were based on several recurrent scientific surveys, two alternative datasets for fishing data, stock assessment outputs, stomach content analyses and published information. Results showed that the functional groups were organised into five trophic levels with the highest one represented by dolphins, anglerfish, Atlantic bluefin tuna, European hake and European conger. European pilchard and European anchovy dominated in terms of fish biomass and catch. Other fish with high biomass such as Atlantic mackerel and blue whiting were highly important in the food web. Seabirds, dolphins and cuttlefish-squids represented keystone species. Important coupled pelagic-demersal-benthic interactions were described. The 7 different fisheries analysed were operating at mean trophic levels situated between 2.6 for small artisanal boats, and 4.1 for purse seines (> 24 m) targeting large pelagic fish, indicating an intensively exploited ecosystem. Large trawlers (24-40 m) had the highest impact on most of the groups considered; while purse seines (12-24 m) targeting small pelagic fish had the lowest impact. Preliminary results highlighted the importance of data sources for further ecosystem and fisheries analyses and management scenarios.

  8. Trophic ecology drives contaminant concentrations within a tropical seabird community.

    Science.gov (United States)

    Sebastiano, Manrico; Bustamante, Paco; Eulaers, Igor; Malarvannan, Govindan; Mendez-Fernandez, Paula; Churlaud, Carine; Blévin, Pierre; Hauselmann, Antoine; Covaci, Adrian; Eens, Marcel; Costantini, David; Chastel, Olivier

    2017-08-01

    To support environmental management programs, there is an urgent need to know about the presence and understand the dynamics of major contaminants in seabird communities of key marine ecosystems. In this study, we investigated the concentrations and trophodynamics of trace elements in six seabird species and persistent organic pollutants (POPs) in three seabird species breeding on Grand Connétable Island (French Guiana), an area where the increase in human population and mining activities has raised concerns in recent years. Red blood cell Hg concentrations in adults were the highest in Magnificent frigatebirds Fregata magnificens (median: 5.6 μg g -1 dw; range: 3.8-7.8 μg g -1 dw) and lowest in Sooty terns Onychoprion fuscatus (median: 0.9 μg g -1 dw; range: 0.6-1.1 μg g -1 dw). Among POPs, dichlorodiphenyldichloroethylene (p,p'-DDE) was the most abundant compound in plasma of Cayenne terns Thalasseus sandvicensis (median: 1100 pg g -1 ww; range: 160 ± 5100 pg g -1 ww), while polychlorinated biphenyls (PCBs) were the most abundant compound class in plasma of Magnificent frigatebirds (median: 640 pg g -1 ww; range 330 ± 2700 pg g -1 ww). While low intensity of POP exposure does not appear to pose a health threat to this seabird community, Hg concentration in several adults Laughing gulls Leucophaeus atricilla and Royal terns Thalasseus maximus, and in all Magnificent frigatebirds was similar or higher than that of high contaminated seabird populations. Furthermore, nestling red blood cells also contained Hg concentrations of concern, and further studies should investigate its potential health impact in this seabird community. Differences in adult trophic ecology of the six species explained interspecific variation in exposure to trace element and POPs, while nestling trophic ecology provides indications about the diverse feeding strategies adopted by the six species, with the consequent variation in exposure to contaminants. Copyright

  9. A trophic model of fringing coral reefs in Nanwan Bay, southern Taiwan suggests overfishing.

    Science.gov (United States)

    Liu, Pi-Jen; Shao, Kwang-Tsao; Jan, Rong-Quen; Fan, Tung-Yung; Wong, Saou-Lien; Hwang, Jiang-Shiou; Chen, Jen-Ping; Chen, Chung-Chi; Lin, Hsing-Juh

    2009-09-01

    Several coral reefs of Nanwan Bay, Taiwan have recently undergone shifts to macroalgal or sea anemone dominance. Thus, a mass-balance trophic model was constructed to analyze the structure and functioning of the food web. The fringing reef model was comprised of 18 compartments, with the highest trophic level of 3.45 for piscivorous fish. Comparative analyses with other reef models demonstrated that Nanwan Bay was similar to reefs with high fishery catches. While coral biomass was not lower, fish biomass was lower than those of reefs with high catches. Consequently, the sums of consumption and respiratory flows and total system throughput were also decreased. The Nanwan Bay model potentially suggests an overfished status in which the mean trophic level of the catch, matter cycling, and trophic transfer efficiency are extremely reduced.

  10. Trophic Magnification of PCBs and Its Relationship to the Octanol−Water Partition Coefficient

    Science.gov (United States)

    We investigated polychlorinated biphenyl (PCB) bioaccumulation relative to octanol-water partition coefficient (KOW) and organism trophic position (TP) at the Lake Hartwell Superfund (South Carolina, USA). We measured PCBs (127 congeners) and stable isotopes (δ15...

  11. Trophic roles of scavenger beetles in relation to decomposition stages and seasons

    Directory of Open Access Journals (Sweden)

    Noelia I. Zanetti

    2015-06-01

    Full Text Available Carcasses represent a trophic and reproductive resource or shelter for arthropods, which are a representative component of the decomposition process. Four experiments, one per season, were conducted in a semi-rural area of Bahía Blanca, Argentina, to study the trophic roles of cadaveric beetles, evaluating the abundance, composition and dominance during all decomposition stages and seasons. Species of necrophagous, necrophilous and omnivorous habits were found. Abundance, composition and dominance of beetles in relation to their trophic roles changed according to seasons and decomposition stages. Guilds and patterns of succession were established in relation to those periods. Trophic roles could be an indicator of beetle associations with decomposition stages and seasons.

  12. Diet and trophic groups of an aquatic insect community in a tropical stream

    Directory of Open Access Journals (Sweden)

    R. L. Motta

    Full Text Available The diet and trophic groups of an assemblage of aquatic insects were studied in a tropical stream. Genera of the orders Ephemeroptera, Odonata, Plecoptera, Lepidoptera, and Hemiptera showed feeding specialization. Others, such as Trichoptera, Coleoptera, and Diptera, showed great diet variation with genera of different trophic groups. Seasonal variation of insect diet, evident only for some genera of the orders Trichoptera, Lepidoptera, Coleoptera, and Diptera, was due to the differences observed in community composition and to generalist habits of these genera. However, the seasonal comparison of trophic groups showed no significant statistical differences. The great importance of organic matter, a non-limited resource, in the diet of Ribeirão do Atalho aquatic insects may be the explanation for the trophic stability in this community organization.

  13. Plant species richness sustains higher trophic levels of soil nematode communities after consecutive environmental perturbations.

    Science.gov (United States)

    Cesarz, Simone; Ciobanu, Marcel; Wright, Alexandra J; Ebeling, Anne; Vogel, Anja; Weisser, Wolfgang W; Eisenhauer, Nico

    2017-07-01

    The magnitude and frequency of extreme weather events are predicted to increase in the future due to ongoing climate change. In particular, floods and droughts resulting from climate change are thought to alter the ecosystem functions and stability. However, knowledge of the effects of these weather events on soil fauna is scarce, although they are key towards functioning of terrestrial ecosystems. Plant species richness has been shown to affect the stability of ecosystem functions and food webs. Here, we used the occurrence of a natural flood in a biodiversity grassland experiment that was followed by a simulated summer drought experiment, to investigate the interactive effects of plant species richness, a natural flood, and a subsequent summer drought on nematode communities. Three and five months after the natural flooding, effects of flooding severity were still detectable in the belowground system. We found that flooding severity decreased soil nematode food-web structure (loss of K-strategists) and the abundance of plant feeding nematodes. However, high plant species richness maintained higher diversity and abundance of higher trophic levels compared to monocultures throughout the flood. The subsequent summer drought seemed to be of lower importance but reversed negative flooding effects in some cases. This probably occurred because the studied grassland system is well adapted to drought, or because drought conditions alleviated the negative impact of long-term soil waterlogging. Using soil nematodes as indicator taxa, this study suggests that high plant species richness can maintain soil food web complexity after consecutive environmental perturbations.

  14. Influence of dispersants on trophic transfer of petroleum hydrocarbons in a marine food chain

    Energy Technology Data Exchange (ETDEWEB)

    Wolfe, M.; Tjeerdema, R. [Univ. of California, Santa Cruz, CA (United States). Dept. of Chemistry and Biochemistry; Sowby, M. [California Dept. of Fish and Game, Sacramento, CA (United States)

    1995-12-31

    When crude oil is accidentally released into the ocean, it threatens many levels of marine life. Intervention, in the form of chemical dispersing agents, alters the normal behavior of petroleum hydrocarbons (PH) by increasing their functional water solubility and the extent of their exposure to sub-surface organisms. Dispersing agents may modify bioavailability as a result of altered interactions between dispersed PH droplets and organismal cell membranes.The objective of this research was to determine the impact of dispersing agents on PH bioavailability and trophic transfer in primary levels of a marine food chain. Uptake, bioaccumulation, depuration, and metabolic transformation of a model PH, {sup 14}C-naphthalene, were measured and compared for Prudhoe Bay Crude Oil (PBCO) dispersed with Corexit 9527 and undispersed preparations of the water-accommodated fractions (WAF) of PBCO at two salinities and temperatures. The model food chain consisted of Isochrysis galbana and Brachionus plicatilis. Direct aqueous exposure was compared with combined aqueous and dietary exposure. Fractionation and identification of metabolites was done by HPLC co-chromatography with analytical standards, and quantitation was done by liquid scintillation counting. GC-FID characterization of WAF and dispersed oil (DO) preparations shows higher concentrations of petroleum hydrocarbons and a greater number of individual constituents in the dispersed oil preparations.

  15. Influence of dispersants on trophic transfer of petroleum hydrocarbons in a marine food chain

    International Nuclear Information System (INIS)

    Wolfe, M.; Tjeerdema, R.

    1995-01-01

    When crude oil is accidentally released into the ocean, it threatens many levels of marine life. Intervention, in the form of chemical dispersing agents, alters the normal behavior of petroleum hydrocarbons (PH) by increasing their functional water solubility and the extent of their exposure to sub-surface organisms. Dispersing agents may modify bioavailability as a result of altered interactions between dispersed PH droplets and organismal cell membranes.The objective of this research was to determine the impact of dispersing agents on PH bioavailability and trophic transfer in primary levels of a marine food chain. Uptake, bioaccumulation, depuration, and metabolic transformation of a model PH, 14 C-naphthalene, were measured and compared for Prudhoe Bay Crude Oil (PBCO) dispersed with Corexit 9527 and undispersed preparations of the water-accommodated fractions (WAF) of PBCO at two salinities and temperatures. The model food chain consisted of Isochrysis galbana and Brachionus plicatilis. Direct aqueous exposure was compared with combined aqueous and dietary exposure. Fractionation and identification of metabolites was done by HPLC co-chromatography with analytical standards, and quantitation was done by liquid scintillation counting. GC-FID characterization of WAF and dispersed oil (DO) preparations shows higher concentrations of petroleum hydrocarbons and a greater number of individual constituents in the dispersed oil preparations

  16. Psychrophilic Biomass Producers in the Trophic Chain of the Microbial Community of Lake Untersee, Antarctica

    Science.gov (United States)

    Pikuta, Elena V.; Hoover, Richard B.

    2010-01-01

    The study of photosynthetic microorganisms from the Lake Untersee samples showed dispersed distribution of phototrophs within 80 m water column. Lake Untersee represents a unique ecosystem that experienced complete isolation: sealed by the Anuchin Glacier for many millennia. Consequently, its biocenosis has evolved over a significant period of time without exchange or external interaction with species from other environments. The major producers of organic matter in Lake Untersee are represented by phototrophic and chemolithotrophic microorganisms. This is the traditional trophic scheme for lacustrine ecosystems on Earth. Among the phototrophs, diatoms were not found, which differentiates this lake from other known ecosystems. The dominant species among phototrophs was Chlamydomonas sp. with typical morphostructure: green chloroplasts, bright red round spot, and two polar flagella near the opening. As expected, the physiology of studied phototrophs was limited by low temperature, which defined them as obligate psychrophilic microorganisms. By the quantity estimation of methanogenesis in this lake, the litho-autotrophic production of organic matter is competitive with phototrophic production. However, pure cultures of methanogens have not yet been obtained. We discuss the primary producers of organic matter and the participation of our novel psychrophilic homoacetogen into the litho-autotrophic link of biomass production in Lake Untersee.

  17. Microbial Ecophysiology of Whey Biomethanation: Characterization of Bacterial Trophic Populations and Prevalent Species in Continuous Culture

    OpenAIRE

    Chartrain, M.; Zeikus, J. G.

    1986-01-01

    The organization and species composition of bacterial trophic groups associated with lactose biomethanation were investigated in a whey-processing chemostat by enumeration, isolation, and general characterization studies. The bacteria were spatially organized as free-living forms and as self-immobilized forms appearing in flocs. Three dominant bacterial trophic group populations were present (in most probable number per milliliter) whose species numbers varied with the substrate consumed: hyd...

  18. Not all jellyfish are equal: isotopic evidence for inter- and intraspecific variation in jellyfish trophic ecology

    Directory of Open Access Journals (Sweden)

    Nicholas E.C. Fleming

    2015-07-01

    Full Text Available Jellyfish are highly topical within studies of pelagic food-webs and there is a growing realisation that their role is more complex than once thought. Efforts being made to include jellyfish within fisheries and ecosystem models are an important step forward, but our present understanding of their underlying trophic ecology can lead to their oversimplification in these models. Gelatinous zooplankton represent a polyphyletic assemblage spanning >2,000 species that inhabit coastal seas to the deep-ocean and employ a wide variety of foraging strategies. Despite this diversity, many contemporary modelling approaches include jellyfish as a single functional group feeding at one or two trophic levels at most. Recent reviews have drawn attention to this issue and highlighted the need for improved communication between biologists and theoreticians if this problem is to be overcome. We used stable isotopes to investigate the trophic ecology of three co-occurring scyphozoan jellyfish species (Aurelia aurita, Cyanea lamarckii and C. capillata within a temperate, coastal food-web in the NE Atlantic. Using information on individual size, time of year and δ13C and δ15N stable isotope values, we examined: (1 whether all jellyfish could be considered as a single functional group, or showed distinct inter-specific differences in trophic ecology; (2 Were size-based shifts in trophic position, found previously in A. aurita, a common trait across species?; (3 When considered collectively, did the trophic position of three sympatric species remain constant over time? Differences in δ15N (trophic position were evident between all three species, with size-based and temporal shifts in δ15N apparent in A. aurita and C. capillata. The isotopic niche width for all species combined increased throughout the season, reflecting temporal shifts in trophic position and seasonal succession in these gelatinous species. Taken together, these findings support previous

  19. Vacuum therapy of trophic ulcer of lower extremities, presented in patients with DFS

    Directory of Open Access Journals (Sweden)

    Yurkova R.A.

    2017-01-01

    Full Text Available the article has analyzed the results of treatment of 67 patients with diabetic foot syndrome (DFS, complicated by feet trophic ulcers, using the vacuum bandages. Patients were divided into 2 groups: the control group had a traditional treatment and the studied one had vacuum bandages applied to the trophic ulcers. The results confirmed an assured decrease in the duration of patients’ treatment and hospitalization in the hospital.

  20. Not all jellyfish are equal: isotopic evidence for inter- and intraspecific variation in jellyfish trophic ecology.

    Science.gov (United States)

    Fleming, Nicholas E C; Harrod, Chris; Newton, Jason; Houghton, Jonathan D R

    2015-01-01

    Jellyfish are highly topical within studies of pelagic food-webs and there is a growing realisation that their role is more complex than once thought. Efforts being made to include jellyfish within fisheries and ecosystem models are an important step forward, but our present understanding of their underlying trophic ecology can lead to their oversimplification in these models. Gelatinous zooplankton represent a polyphyletic assemblage spanning >2,000 species that inhabit coastal seas to the deep-ocean and employ a wide variety of foraging strategies. Despite this diversity, many contemporary modelling approaches include jellyfish as a single functional group feeding at one or two trophic levels at most. Recent reviews have drawn attention to this issue and highlighted the need for improved communication between biologists and theoreticians if this problem is to be overcome. We used stable isotopes to investigate the trophic ecology of three co-occurring scyphozoan jellyfish species (Aurelia aurita, Cyanea lamarckii and C. capillata) within a temperate, coastal food-web in the NE Atlantic. Using information on individual size, time of year and δ (13)C and δ (15)N stable isotope values, we examined: (1) whether all jellyfish could be considered as a single functional group, or showed distinct inter-specific differences in trophic ecology; (2) Were size-based shifts in trophic position, found previously in A. aurita, a common trait across species?; (3) When considered collectively, did the trophic position of three sympatric species remain constant over time? Differences in δ (15)N (trophic position) were evident between all three species, with size-based and temporal shifts in δ (15)N apparent in A. aurita and C. capillata. The isotopic niche width for all species combined increased throughout the season, reflecting temporal shifts in trophic position and seasonal succession in these gelatinous species. Taken together, these findings support previous assertions

  1. From the epipelagic zone to the abyss: Trophic structure at two seamounts in the subtropical and tropical Eastern Atlantic - Part II Benthopelagic fishes

    Science.gov (United States)

    Denda, Anneke; Stefanowitsch, Benjamin; Christiansen, Bernd

    2017-12-01

    Specific mechanisms, driving trophic interactions between seamount associated fishes and the pelagic community may be highly variable in different seamount systems. This study investigated the trophic structure and the main prey of benthopelagic fishes from the summit and slope regions of Ampère and Senghor, two shallow seamounts in the subtropical and tropical NE Atlantic, and the adjacent deep-sea plains. For the identification of food sources and nutritional links to the pelagic realm a combination of stomach content and stable isotope ratio (δ13C and δ15N) analyses was used. δ13C ranged from -22.2‰ to -15.4‰ and δ15N covered a total range of 8.0-15.9‰. Feeding types of fish species comprised mainly zooplanktivores and mixed feeders, but also benthivores, piscivores, and predator-scavengers. Based on epipelagic particulate organic matter, they occupied trophic positions between the 2nd and 4th trophic level. Differences in stomach contents and stable isotope signatures indicate a resource partitioning among the benthopelagic fish fauna through distinct habitat choice, vertical feeding positions and prey selection. Topographic trapping of vertically migrating zooplankton on the summit seemed to be of minor importance for food supply of the resident near-bottom fishes, rather horizontal current-driven advection of the planktonic prey was assumed as major factor. Vertically migrating micronekton and mesopelagic fishes show up as key players within the food webs at Ampère and Senghor Seamounts and the adjacent deep-sea plains.

  2. Coastal Upwelling Drives Intertidal Assemblage Structure and Trophic Ecology.

    Science.gov (United States)

    Reddin, Carl J; Docmac, Felipe; O'Connor, Nessa E; Bothwell, John H; Harrod, Chris

    2015-01-01

    Similar environmental driving forces can produce similarity among geographically distant ecosystems. Coastal oceanic upwelling, for example, has been associated with elevated biomass and abundance patterns of certain functional groups, e.g., corticated macroalgae. In the upwelling system of Northern Chile, we examined measures of intertidal macrobenthic composition, structure and trophic ecology across eighteen shores varying in their proximity to two coastal upwelling centres, in a hierarchical sampling design (spatial scales of >1 and >10 km). The influence of coastal upwelling on intertidal communities was confirmed by the stable isotope values (δ13C and δ15N) of consumers, including a dominant suspension feeder, grazers, and their putative resources of POM, epilithic biofilm, and macroalgae. We highlight the utility of muscle δ15N from the suspension feeding mussel, Perumytilus purpuratus, as a proxy for upwelling, supported by satellite data and previous studies. Where possible, we used corrections for broader-scale trends, spatial autocorrelation, ontogenetic dietary shifts and spatial baseline isotopic variation prior to analysis. Our results showed macroalgal assemblage composition, and benthic consumer assemblage structure, varied significantly with the intertidal influence of coastal upwelling, especially contrasting bays and coastal headlands. Coastal topography also separated differences in consumer resource use. This suggested that coastal upwelling, itself driven by coastline topography, influences intertidal communities by advecting nearshore phytoplankton populations offshore and cooling coastal water temperatures. We recommend the isotopic values of benthic organisms, specifically long-lived suspension feeders, as in situ alternatives to offshore measurements of upwelling influence.

  3. Energetic differences between bacterioplankton trophic groups and coral reef resistance.

    Science.gov (United States)

    McDole Somera, Tracey; Bailey, Barbara; Barott, Katie; Grasis, Juris; Hatay, Mark; Hilton, Brett J; Hisakawa, Nao; Nosrat, Bahador; Nulton, James; Silveira, Cynthia B; Sullivan, Chris; Brainard, Russell E; Rohwer, Forest

    2016-04-27

    Coral reefs are among the most productive and diverse marine ecosystems on the Earth. They are also particularly sensitive to changing energetic requirements by different trophic levels. Microbialization specifically refers to the increase in the energetic metabolic demands of microbes relative to macrobes and is significantly correlated with increasing human influence on coral reefs. In this study, metabolic theory of ecology is used to quantify the relative contributions of two broad bacterioplankton groups, autotrophs and heterotrophs, to energy flux on 27 Pacific coral reef ecosystems experiencing human impact to varying degrees. The effective activation energy required for photosynthesis is lower than the average energy of activation for the biochemical reactions of the Krebs cycle, and changes in the proportional abundance of these two groups can greatly affect rates of energy and materials cycling. We show that reef-water communities with a higher proportional abundance of microbial autotrophs expend more metabolic energy per gram of microbial biomass. Increased energy and materials flux through fast energy channels (i.e. water-column associated microbial autotrophs) may dampen the detrimental effects of increased heterotrophic loads (e.g. coral disease) on coral reef systems experiencing anthropogenic disturbance. © 2016 The Author(s).

  4. Trigeminal Trophic Syndrome Associated With the Use of Synthetic Marijuana.

    Science.gov (United States)

    Khan, Fawad A; Manacheril, Rinu; Ulep, Robin; Martin, Julie E; Chimakurthy, Anil

    2017-01-01

    Trigeminal trophic syndrome (TTS) is an uncommon disorder of the trigeminal nerve tract and trigeminal brainstem nucleus. The syndrome is characterized by a triad of unilateral crescentic ulcers with anesthesia and paresthesias of the involved trigeminal dermatomes. A 24-year-old right-handed black female presented to our emergency department with a 4-week history of rapidly progressive painless desquamation/denudation of skin over her right face and scalp. Four weeks prior, she had been admitted to another institution for seizures and was diagnosed with seizures provoked by synthetic marijuana use. She was afebrile during her initial presentation at our institution. Dermatologic examination revealed denudation of the epidermis and partial dermis over the right frontal, parietal, and temporal scalp with associated alopecia. To our knowledge, the association of disorders of the trigeminal nerve pathway, including TTS, with the use of synthetic marijuana has not been previously reported. The long-term neurologic effects of synthetic marijuana are difficult to predict, and the pathologic underpinnings of TTS are largely unknown. Further studies dedicated to exploring the underlying molecular and cellular mechanisms may translate into effective therapies and approaches to halt and reverse the process and prevent tissue destruction and cosmetic disfigurement.

  5. Application of Trophic Magnification Factors (TMFs) Under the ...

    Science.gov (United States)

    Directive 2013/39/EU amending and updating the Water Framework Directive (2000/60/EC) and its Daughter Directive (the so-called EQS Directive: 2008/105/EC) sets Environmental Quality Standards for biota (EQSbiota) for a number of bioaccumulative chemicals which can pose a threat to both aquatic wildlife (piscivorous birds and mammals) and human health via the consumption of contaminated prey or the intake of contaminated food originating from the aquatic environment. Member States (MS) of the European Union will need to establish programs to monitor the concentration of 11 priority substances in biota and assess compliance against these new standards for surface water classification. The biota standards essentially refer to fish and should be applied to the trophic level (TL) at which contaminant concentrations peak, so that the predator of the species at that TL is exposed to the highest contaminant levels in its food. For chemicals that are subject to biomagnification, the peak concentrations are theoretically attained at TL 3 to 4 in freshwater food webs and TL 5 in marine food webs, where the risk of secondary poisoning of top predators should also be considered. An EU-wide guidance effectively addresses the implementation of EQSbiota (EC 2014). Flexibility is allowed in the choice of target species used for monitoring because of the diversity of both habitats and aquatic community composition across Europe. According to that guidance, the consistency and co

  6. Dynamics of a Subterranean Trophic Cascade in Space and Time

    Science.gov (United States)

    Ram, Karthik; Gruner, Daniel S.; McLaughlin, John P.; Preisser, Evan L.; Strong, Donald R.

    2008-01-01

    Trophic cascades, whereby predators indirectly benefit plant biomass by reducing herbivore pressure, form the mechanistic basis for classical biological control of pest insects. Entomopathogenic nematodes (EPN) are lethal to a variety of insect hosts with soil-dwelling stages, making them promising biocontrol agents. EPN biological control programs, however, typically fail because nematodes do not establish, persist and/or recycle over multiple host generations in the field. A variety of factors such as local abiotic conditions, host quantity and quality, and rates of movement affect the probability of persistence. Here, we review results from 13 years of study on the biology and ecology of an endemic population of Heterorhabditis marelatus (Rhabditida: Heterorhabditidae) in a California coastal prairie. In a highly seasonal abiotic environment with intrinsic variation in soils, vegetation structure, and host availability, natural populations of H. marelatus persisted at high incidence at some but not all sites within our study area. Through a set of field and lab experiments, we describe mechanisms and hypotheses to understand the persistence of H. marelatus. We suggest that further ecological study of naturally occurring EPN populations can yield significant insight to improve the practice and management of biological control of soil-dwelling insect pests. PMID:19259524

  7. The disruption of the epithelial mesenchymal trophic unit in COPD.

    Science.gov (United States)

    Behzad, Ali R; McDonough, John E; Seyednejad, Nazgol; Hogg, James C; Walker, David C

    2009-12-01

    Progression of COPD is associated with a measurable increase in small airway wall thickness resulting from a repair and remodeling process that involves fibroblasts of the epithelial mesenchymal trophic unit (EMTU). The present study was designed to examine the organization of fibroblasts within the lamina propria of small airways with respect to their contacts with the epithelium and with each other in persons with COPD. Transmission electron microcopy (TEM) and three-dimensional (3D) reconstructions of serial TEM sections were used to estimate the frequency and determine the nature of the contacts between the epithelium and fibroblasts within the EMTU in small airways from 5 controls (smokers with normal lung function), from 6 persons with mild (GOLD-1) and 5 with moderate (GOLD-2) COPD. In airways from control lungs fibroblasts make frequent contact with cytoplasmic extensions of epithelial cells through apertures in the epithelial basal lamina, but the frequency of these fibroblast-epithelial contacts is reduced in both mild and moderate COPD compared to controls (p < 0.01). The 3D reconstructions showed that the cytoplasmic extensions of lamina propria fibroblasts form a reticulum with fibroblast-fibroblast contacts in an airway from a control subject but this reticulum may be reorganized in airways of COPD patients. Development of COPD is associated with significant disruption of the EMTU due to a reduction of contacts between fibroblasts and the epithelium.

  8. Trophic transfer of microplastics in aquatic ecosystems: Identifying critical research needs.

    Science.gov (United States)

    Au, Sarah Y; Lee, Cindy M; Weinstein, John E; van den Hurk, Peter; Klaine, Stephen J

    2017-05-01

    To evaluate the process of trophic transfer of microplastics, it is important to consider various abiotic and biotic factors involved in their ingestion, egestion, bioaccumulation, and biomagnification. Toward this end, a review of the literature on microplastics has been conducted to identify factors influencing their uptake and absorption; their residence times in organisms and bioaccumulation; the physical effects of their aggregation in gastrointestinal tracts; and their potential to act as vectors for the transfer of other contaminants. Limited field evidence from higher trophic level organisms in a variety of habitats suggests that trophic transfer of microplastics may be a common phenomenon and occurs concurrently with direct ingestion. Critical research needs include standardizing methods of field characterization of microplastics, quantifying uptake and depuration rates in organisms at different trophic levels, quantifying the influence that microplastics have on the uptake and/or depuration of environmental contaminants among different trophic levels, and investigating the potential for biomagnification of microplastic-associated chemicals. More integrated approaches involving computational modeling are required to fully assess trophic transfer of microplastics. Integr Environ Assess Manag 2017;13:505-509. © 2017 SETAC. © 2017 SETAC.

  9. Element patterns in albatrosses and petrels: Influence of trophic position, foraging range, and prey type

    International Nuclear Information System (INIS)

    Anderson, O.R.J.; Phillips, R.A.; Shore, R.F.; McGill, R.A.R.; McDonald, R.A.; Bearhop, S.

    2010-01-01

    We investigated the concentrations of 22 essential and non-essential elements among a community of Procellariiformes (and their prey) to identify the extent to which trophic position and foraging range governed element accumulation. Stable isotope analysis (SIA) was used to characterise trophic (δ 15 N) and spatial patterns (δ 13 C) among species. Few consistent patterns were observed in element distributions among species and diet appeared to be highly influential in some instances. Arsenic levels in seabird red blood cells correlated with δ 15 N and δ 13 C, demonstrating the importance of trophic position and foraging range for arsenic distribution. Arsenic concentrations in prey varied significantly across taxa, and in the strength of association with δ 15 N values (trophic level). In most instances, element patterns in Procellariiformes showed the clearest separation among species, indicating that a combination of prey selection and other complex species-specific characteristics (e.g. moult patterns) were generally more important determining factors than trophic level per se. - Trophic position, foraging range, and prey type were found to influence element compositions and concentrations in Procellariiformes from South Georgia.

  10. Examining predator–prey body size, trophic level and body mass across marine and terrestrial mammals

    Science.gov (United States)

    Tucker, Marlee A.; Rogers, Tracey L.

    2014-01-01

    Predator–prey relationships and trophic levels are indicators of community structure, and are important for monitoring ecosystem changes. Mammals colonized the marine environment on seven separate occasions, which resulted in differences in species' physiology, morphology and behaviour. It is likely that these changes have had a major effect upon predator–prey relationships and trophic position; however, the effect of environment is yet to be clarified. We compiled a dataset, based on the literature, to explore the relationship between body mass, trophic level and predator–prey ratio across terrestrial (n = 51) and marine (n = 56) mammals. We did not find the expected positive relationship between trophic level and body mass, but we did find that marine carnivores sit 1.3 trophic levels higher than terrestrial carnivores. Also, marine mammals are largely carnivorous and have significantly larger predator–prey ratios compared with their terrestrial counterparts. We propose that primary productivity, and its availability, is important for mammalian trophic structure and body size. Also, energy flow and community structure in the marine environment are influenced by differences in energy efficiency and increased food web stability. Enhancing our knowledge of feeding ecology in mammals has the potential to provide insights into the structure and functioning of marine and terrestrial communities. PMID:25377460

  11. Examining predator-prey body size, trophic level and body mass across marine and terrestrial mammals.

    Science.gov (United States)

    Tucker, Marlee A; Rogers, Tracey L

    2014-12-22

    Predator-prey relationships and trophic levels are indicators of community structure, and are important for monitoring ecosystem changes. Mammals colonized the marine environment on seven separate occasions, which resulted in differences in species' physiology, morphology and behaviour. It is likely that these changes have had a major effect upon predator-prey relationships and trophic position; however, the effect of environment is yet to be clarified. We compiled a dataset, based on the literature, to explore the relationship between body mass, trophic level and predator-prey ratio across terrestrial (n = 51) and marine (n = 56) mammals. We did not find the expected positive relationship between trophic level and body mass, but we did find that marine carnivores sit 1.3 trophic levels higher than terrestrial carnivores. Also, marine mammals are largely carnivorous and have significantly larger predator-prey ratios compared with their terrestrial counterparts. We propose that primary productivity, and its availability, is important for mammalian trophic structure and body size. Also, energy flow and community structure in the marine environment are influenced by differences in energy efficiency and increased food web stability. Enhancing our knowledge of feeding ecology in mammals has the potential to provide insights into the structure and functioning of marine and terrestrial communities. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  12. [Trophic niche partitioning of pelagic sharks in Central Eastern Pacific inferred from stable isotope analysis.

    Science.gov (United States)

    Li, Yun Kai; Gao, Xiao di; Wang, Lin Yu; Fang, Lin

    2018-01-01

    As the apex predators of the open ocean ecosystems, pelagic sharks play important roles in stabilizing the marine food web through top-down control. Stable isotope analysis is a powerful tool to investigate the feeding ecology. The carbon and nitrogen isotope ratios can be used to trace food source and evaluate the trophic position of marine organisms. In this study, the isotope values of 130 pelagic sharks from 8 species in Central Eastern Pacific were analyzed and their trophic position and niche were calculated to compare the intra/inter-specific resource partitioning in the Central Eastern Pacific ecosystem. The results exhibited significant differences in both carbon and nitrogen isotope values among the shark species. The trophic levels ranged from 4.3 to 5.4 in the Central Eastern Pacific shark community. The trophic niche of blue sharks and shortfin mako sharks showed no overlap with the other shark species, exhibiting unique ecological roles in the open ocean food web. These data highlighted the diverse roles among pelagic sharks, supporting previous findings that this species is not trophically redundant and the trophic niche of pelagic sharks can not be simply replaced by those of other top predator species.

  13. Evaluating trophic cascades as drivers of regime shifts in different ocean ecosystems

    Science.gov (United States)

    Pershing, Andrew J.; Mills, Katherine E.; Record, Nicholas R.; Stamieszkin, Karen; Wurtzell, Katharine V.; Byron, Carrie J.; Fitzpatrick, Dominic; Golet, Walter J.; Koob, Elise

    2015-01-01

    In ecosystems that are strongly structured by predation, reducing top predator abundance can alter several lower trophic levels—a process known as a trophic cascade. A persistent trophic cascade also fits the definition of a regime shift. Such ‘trophic cascade regime shifts' have been reported in a few pelagic marine systems—notably the Black Sea, Baltic Sea and eastern Scotian Shelf—raising the question of how common this phenomenon is in the marine environment. We provide a general methodology for distinguishing top-down and bottom-up effects and apply this methodology to time series from these three ecosystems. We found evidence for top-down forcing in the Black Sea due primarily to gelatinous zooplankton. Changes in the Baltic Sea are primarily bottom-up, strongly structured by salinity, but top-down forcing related to changes in cod abundance also shapes the ecosystem. Changes in the eastern Scotian Shelf that were originally attributed to declines in groundfish are better explained by changes in stratification. Our review suggests that trophic cascade regime shifts are rare in open ocean ecosystems and that their likelihood increases as the residence time of water in the system increases. Our work challenges the assumption that negative correlation between consecutive trophic levels implies top-down forcing.

  14. Predation risk, elk, and aspen: tests of a behaviorally mediated trophic cascade in the Greater Yellowstone Ecosystem.

    Science.gov (United States)

    Winnie, John A

    2012-12-01

    Aspen in the Greater Yellowstone Ecosystem are hypothesized to be recovering from decades of heavy browsing by elk due to a behaviorally mediated trophic cascade (BMTC). Several authors have suggested that wolves interact with certain terrain features, creating places of high predation risk at fine spatial scales, and that elk avoid these places, which creates refugia for plants. This hypothesized BMTC could release aspen from elk browsing pressure, leading to a patchy recovery in places of high risk. I tested whether four specific, hypothesized fine-scale risk factors are correlated with changes in current elk browsing pressure on aspen, or with aspen recruitment since wolf reintroduction, in the Daly Creek drainage in Yellowstone National Park, and near two aspen enclosures outside of the park boundary. Aspen were not responding to hypothesized fine-scale risk factors in ways consistent with the current BMTC hypothesis.

  15. Almost there: transmission routes of bacterial symbionts between trophic levels.

    Directory of Open Access Journals (Sweden)

    Elad Chiel

    transmission of symbionts across trophic levels. The possible mechanisms that lead to the differences in transmission of species of symbionts among species of hosts are discussed.

  16. Evaluation of the Trophic Level of Kune and Vain Lagoons in Albania, Using Phytoplankton as a Bioindicator

    Directory of Open Access Journals (Sweden)

    Anni Koci Kallfa

    2014-03-01

    Full Text Available Concentration of chlorophyll is an adequate parameter for assessing the trophic state of lagoon ecosystems. Objectives of this study are: selection of a system of bioindicators to enable a good qualitative evaluation of the trophic state of the lagoons and their dynamics; evaluation of seasonal water quality variability and comparison between lagoons. The trophic state of the lagoons is analysed every month over the year. Water samples are retrieved at four different sites (exact coordinates each month, sites that are representative of different water circulation systems at each lagoon. The trophic level in the respective lagoons is thus assessed through selection of an adequate system of bioindicators, in order to observe the oscillations of the amount of chlorophyll and therefore to determine the level of eutrophication. Based on the above parameters, the comparison of the trophic state in these two lagoons has shown that they have different trophic states.

  17. Coastal habitats as surrogates for taxonomic, functional and trophic structures of benthic faunal communities.

    Science.gov (United States)

    Törnroos, Anna; Nordström, Marie C; Bonsdorff, Erik

    2013-01-01

    Due to human impact, there is extensive degradation and loss of marine habitats, which calls for measures that incorporate taxonomic as well as functional and trophic aspects of biodiversity. Since such data is less easily quantifiable in nature, the use of habitats as surrogates or proxies for biodiversity is on the rise in marine conservation and management. However, there is a critical gap in knowledge of whether pre-defined habitat units adequately represent the functional and trophic structure of communities. We also lack comparisons of different measures of community structure in terms of both between- (β) and within-habitat (α) variability when accounting for species densities. Thus, we evaluated a priori defined coastal habitats as surrogates for traditional taxonomic, functional and trophic zoobenthic community structure. We focused on four habitats (bare sand, canopy-forming algae, seagrass above- and belowground), all easily delineated in nature and defined through classification systems. We analyzed uni- and multivariate data on species and trait diversity as well as stable isotope ratios of benthic macrofauna. A good fit between habitat types and taxonomic and functional structure was found, although habitats were more similar functionally. This was attributed to within-habitat heterogeneity so when habitat divisions matched the taxonomic structure, only bare sand was functionally distinct. The pre-defined habitats did not meet the variability of trophic structure, which also proved to differentiate on a smaller spatial scale. The quantification of trophic structure using species density only identified an epi- and an infaunal unit. To summarize the results we present a conceptual model illustrating the match between pre-defined habitat types and the taxonomic, functional and trophic community structure. Our results show the importance of including functional and trophic aspects more comprehensively in marine management and spatial planning.

  18. Measuring variability in trophic status in the Lake Waco/Bosque River Watershed

    Directory of Open Access Journals (Sweden)

    Rodriguez Angela D

    2008-01-01

    Full Text Available Abstract Background Nutrient management in rivers and streams is difficult due to the spatial and temporal variability of algal growth responses. The objectives of this project were to determine the spatial and seasonal in situ variability of trophic status in the Lake Waco/Bosque River watershed, determine the variability in the lotic ecosystem trophic status index (LETSI at each site as indicators of the system's nutrient sensitivity, and determine if passive diffusion periphytometers could provide threshold algal responses to nutrient enrichment. Methods We used the passive diffusion periphytometer to measure in-situ nutrient limitation and trophic status at eight sites in five streams in the Lake Waco/Bosque River Watershed in north-central Texas from July 1997 through October 1998. The chlorophyll a production in the periphytometers was used as an indicator of baseline chlorophyll a productivity and of maximum primary productivity (MPP in response to nutrient enrichment (nitrogen and phosphorus. We evaluated the lotic ecosystem trophic status index (LETSI using the ratio of baseline primary productivity to MPP, and evaluated the trophic class of each site. Results The rivers and streams in the Lake Waco/Bosque River Watershed exhibited varying degrees of nutrient enrichment over the 18-month sampling period. The North Bosque River at the headwaters (NB-02 located below the Stephenville, Texas wastewater treatment outfall consistently exhibited the highest degree of water quality impact due to nutrient enrichment. Sites at the outlet of the watershed (NB-04 and NB-05 were the next most enriched sites. Trophic class varied for enriched sites over seasons. Conclusion Seasonality played a significant role in the trophic class and sensitivity of each site to nutrients. Managing rivers and streams for nutrients will require methods for measuring in situ responses and sensitivities to nutrient enrichment. Nutrient enrichment periphytometers show

  19. Bioaccumulation and biomagnification of mercury in African lakes: The importance of trophic status

    Energy Technology Data Exchange (ETDEWEB)

    Poste, Amanda E., E-mail: amanda.poste@niva.no [Norwegian Institute for Water Research, Gaustadalléen 21, 0349 Oslo (Norway); Department of Biology, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1 (Canada); Muir, Derek C.G. [Aquatic Contaminants Research Division, Environment Canada, 867 Lakeshore Drive, Burlington, ON L7R 4A6 (Canada); Guildford, Stephanie J.; Hecky, Robert E. [Department of Biology, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1 (Canada); Large Lakes Observatory, University of Minnesota Duluth, 2205 East Fifth Street, Duluth, MN 55812 (United States)

    2015-02-15

    Despite the global prevalence of both mercury (Hg) contamination and anthropogenic eutrophication, relatively little is known about the behavior of Hg in eutrophic and hypereutrophic systems or the effects of lake trophic status on Hg uptake and trophodynamics. In the current study we explore Hg trophodynamics at 8 tropical East African study sites ranging from mesotrophic to hypereutrophic, in order to assess the influence of lake trophic status on Hg uptake and biomagnification. Comprehensive water, plankton and fish samples were collected for analysis of total mercury (THg) and stable carbon and nitrogen isotopic ratios. We found evidence that uptake of THg into phytoplankton tended to be lower in higher productivity systems. THg concentrations in fish were generally low, and THg trophic magnification factors (TMFs; representing the average increase in contaminant concentrations from one trophic level to the next) ranged from 1.9 to 5.6. Furthermore TMFs were significantly lower in hypereutrophic lakes than in meso- and eutrophic lakes, and were negatively related to chlorophyll a concentrations both across our study lakes, and across African lakes for which literature data were available. These observations suggest that THg concentrations were strongly influenced by trophic status, with year-round high phytoplankton and fish growth rates reducing the potential for high THg in fish in these productive tropical lakes. - Highlights: • We characterized Hg in water and biota from 8 East African study sites. • Hg concentrations in fish were low and should not pose a risk to human consumers. • Hg uptake and biomagnification rates were negatively related to trophic status. • Growth dilution in phytoplankton and consumer trophic levels led to low fish Hg.

  20. Bioaccumulation and biomagnification of mercury in African lakes: The importance of trophic status

    International Nuclear Information System (INIS)

    Poste, Amanda E.; Muir, Derek C.G.; Guildford, Stephanie J.; Hecky, Robert E.

    2015-01-01

    Despite the global prevalence of both mercury (Hg) contamination and anthropogenic eutrophication, relatively little is known about the behavior of Hg in eutrophic and hypereutrophic systems or the effects of lake trophic status on Hg uptake and trophodynamics. In the current study we explore Hg trophodynamics at 8 tropical East African study sites ranging from mesotrophic to hypereutrophic, in order to assess the influence of lake trophic status on Hg uptake and biomagnification. Comprehensive water, plankton and fish samples were collected for analysis of total mercury (THg) and stable carbon and nitrogen isotopic ratios. We found evidence that uptake of THg into phytoplankton tended to be lower in higher productivity systems. THg concentrations in fish were generally low, and THg trophic magnification factors (TMFs; representing the average increase in contaminant concentrations from one trophic level to the next) ranged from 1.9 to 5.6. Furthermore TMFs were significantly lower in hypereutrophic lakes than in meso- and eutrophic lakes, and were negatively related to chlorophyll a concentrations both across our study lakes, and across African lakes for which literature data were available. These observations suggest that THg concentrations were strongly influenced by trophic status, with year-round high phytoplankton and fish growth rates reducing the potential for high THg in fish in these productive tropical lakes. - Highlights: • We characterized Hg in water and biota from 8 East African study sites. • Hg concentrations in fish were low and should not pose a risk to human consumers. • Hg uptake and biomagnification rates were negatively related to trophic status. • Growth dilution in phytoplankton and consumer trophic levels led to low fish Hg

  1. Effect of the riparian vegetation removal on the trophic network of Neotropical stream fish assemblage

    Directory of Open Access Journals (Sweden)

    Pedro Sartori Manoel

    2018-02-01

    Full Text Available The study of the diet of fish is an important tool to assess different levels of environmental degradation, since the availability of food in the environment is a key factor for the fish occurrence. The removal of riparian vegetation usually degrades environmental quality, as this vegetation has an important role in providing energy to the ecosystem. This study investigates the effects of the removal of riparian vegetation on the fish assemblage trophic network. The study was carried out in two stretches of a southeastern Brazilian stream, one in a forest fragment and another in a pasture, during the wet and dry seasons of 2014. We analyzed the items consumed by each fish species using the frequency of occurrence and area of each item, which were combined to calculate the alimentary index, which was used to determine the food niche overlap of the fish and the specialization index of the trophic network. Aquatic Hexapoda, vegetal debris and organic matter dominated the trophic network of the two stretches. We detected higher values of food niche overlap in the forested stretch and more complex trophic networks in the pasture stretch. We found few seasonal variations in the items consumed and calculated indices in both stretches studied. The presence of grass on the banks in the pasture stretch and the importation of food resources from the upstream area may have provided a higher diversity of resources and consequently showed a more complex trophic network when compared to the forested stretch.

  2. Trophic specialization influences the rate of environmental niche evolution in damselfishes (Pomacentridae).

    Science.gov (United States)

    Litsios, Glenn; Pellissier, Loïc; Forest, Félix; Lexer, Christian; Pearman, Peter B; Zimmermann, Niklaus E; Salamin, Nicolas

    2012-09-22

    The rate of environmental niche evolution describes the capability of species to explore the available environmental space and is known to vary among species owing to lineage-specific factors. Trophic specialization is a main force driving species evolution and is responsible for classical examples of adaptive radiations in fishes. We investigate the effect of trophic specialization on the rate of environmental niche evolution in the damselfish, Pomacentridae, which is an important family of tropical reef fishes. First, phylogenetic niche conservatism is not detected in the family using a standard test of phylogenetic signal, and we demonstrate that the environmental niches of damselfishes that differ in trophic specialization are not equivalent while they still overlap at their mean values. Second, we estimate the relative rates of niche evolution on the phylogenetic tree and show the heterogeneity among rates of environmental niche evolution of the three trophic groups. We suggest that behavioural characteristics related to trophic specialization can constrain the evolution of the environmental niche and lead to conserved niches in specialist lineages. Our results show the extent of influence of several traits on the evolution of the environmental niche and shed new light on the evolution of damselfishes, which is a key lineage in current efforts to conserve biodiversity in coral reefs.

  3. Trait- and density-mediated indirect interactions initiated by an exotic invasive plant autogenic ecosystem engineer

    Science.gov (United States)

    Dean E. Pearson

    2010-01-01

    Indirect interactions are important for structuring ecological systems. However, research on indirect effects has been heavily biased toward top-down trophic interactions, and less is known about other indirect-interaction pathways. As autogenic ecosystem engineers, plants can serve as initiators of nontrophic indirect interactions that, like top-down pathways, can...

  4. Spatially Extended Habitat Modification by Intertidal Reef-Building Bivalves has Implications for Consumer-Resource Interactions

    NARCIS (Netherlands)

    van der Zee, E.M.; van der Heide, T.; Donadi, S.; Eklöf, J.S.; Eriksson, B.K.; Olff, H.; van der Veer, H.W.; Piersma, T.

    2012-01-01

    Ecosystem engineers can strongly modify habitat structure and resource availability across space. In theory, this should alter the spatial distributions of trophically interacting species. In this article, we empirically investigated the importance of spatially extended habitat modification by

  5. Spatially extended habitat modification by intertidal reef-building bivalves has implications for consumer-resource interactions

    NARCIS (Netherlands)

    van der Zee, Els M.; van der Heide, Tjisse; Donadi, Serena; Eklöf, Johan S.; Eriksson, Britas Klemens; Olff, Han; van der Veer, Henk W.; Piersma, Theunis

    Ecosystem engineers can strongly modify habitat structure and resource availability across space. In theory, this should alter the spatial distributions of trophically interacting species. In this article, we empirically investigated the importance of spatially extended habitat modification by

  6. Geographic extent and variation of a coral reef trophic cascade.

    Science.gov (United States)

    McClanahan, T R; Muthiga, N A

    2016-07-01

    Trophic cascades caused by a reduction in predators of sea urchins have been reported in Indian Ocean and Caribbean coral reefs. Previous studies have been constrained by their site-specific nature and limited spatial replication, which has produced site and species-specific understanding that can potentially preclude larger community-organization nuances and generalizations. In this study, we aimed to evaluate the extent and variability of the cascade community in response to fishing across ~23° of latitude and longitude in coral reefs in the southwestern Indian Ocean. The taxonomic composition of predators of sea urchins, the sea urchin community itself, and potential effects of changing grazer abundance on the calcifying benthic organisms were studied in 171 unique coral reef sites. We found that geography and habitat were less important than the predator-prey relationships. There were seven sea urchin community clusters that aligned with a gradient of declining fishable biomass and the abundance of a key predator, the orange-lined triggerfish (Balistapus undulatus). The orange-lined triggerfish dominated where sea urchin numbers and diversity were low but the relative abundance of wrasses and emperors increased where sea urchin numbers were high. Two-thirds of the study sites had high sea urchin biomass (>2,300 kg/ha) and could be dominated by four different sea urchin species, Echinothrix diadema, Diadema savignyi, D. setosum, and Echinometra mathaei, depending on the community of sea urchin predators, geographic location, and water depth. One-third of the sites had low sea urchin biomass and diversity and were typified by high fish biomass, predators of sea urchins, and herbivore abundance, representing lightly fished communities with generally higher cover of calcifying algae. Calcifying algal cover was associated with low urchin abundance where as noncalcifying fleshy algal cover was not clearly associated with herbivore abundance. Fishing of the orange

  7. Trophic and microhabitat niche overlap in two sympatric dendrobatids from La Selva, Costa Rica

    Directory of Open Access Journals (Sweden)

    Cajade, Rodrigo

    2010-11-01

    both dendrobatids were recorded by the analysed stomach flushing technique. Microhabitats uses were defined as the site where each individual was captured. The influence of microhabitat on diets was evaluated by the dietary (prey proportions and volume and microhabitat overlapsusing Pianka’s (Ojk overlap index calculated with EcoSim software. Diets of both dendrobatids were principally characterized by the preference of hymenopterans (ants, acarines and collembolans, resulted in a high overlapping in prey proportions and prey volume. However, diets overlaps were not significant, suggesting the absence of negative feeding interactions.Microhabitat use was low overlapped and also not significant, suggesting a differentiation on theuse of spatial resource. The absence of negative feeding interactions between Dendrobates auratus and Oophaga pumilio could be due to segregation in microhabitat use and possible by the abundance of trophic resource in the area. The great large volumes of formicids andacarines in the diet of this dendrobatids are in agreement with the hypothesis of these arthropods as a dietary source of alkaloids.

  8. Recovering aspen follow changing elk dynamics in Yellowstone: evidence of a trophic cascade?

    Science.gov (United States)

    Painter, Luke E; Beschta, Robert L; Larsen, Eric J; Ripple, William J

    2015-01-01

    To investigate the extent and causes of recent quaking aspen (Populus tremuloides) recruitment in northern Yellowstone National Park, we measured browsing intensity and height of young aspen in 87 randomly selected aspen stands in 2012, and compared our results to similar data collected in 1997-1998. We also examined the relationship between aspen recovery and the distribution of Rocky Mountain elk (Cervus elaphus) and bison (Bison bison) on the Yellowstone northern ungulate winter range, using ungulate fecal pile densities and annual elk count data. In 1998, 90% of young aspen were browsed and none were taller-than 200 cm, the height at which aspen begin to escape from elk browsing. In 2012, only 37% in the east and 63% in the west portions of the winter range were browsed, and 65% of stands in the east had young aspen taller than 200 cm. Heights of young aspen were inversely related to browsing intensity, with the least browsing and greatest heights in the eastern portion of the range, corresponding with recent changes in elk density and distribution. In contrast with historical elk distribution (1930s-1990s), the greatest densities of elk recently (2006-2012) have been north of the park boundary (approximately 5 elk/km2), and in the western part of the range (2-4 elk/km2), with relatively few elk in the eastern portion of the range (wolves (Canis lupius) in 1995-1996 played a role in these changing elk population dynamics, interacting with other influences including increased predation by bears (Ursus spp.), competition with an expanding bison population, and shifting patterns of human land use and hunting outside the park. The resulting new aspen recruitment is evidence of a landscape-scale trophic cascade in which a resurgent large carnivore community, combined with other ecological changes, has benefited aspen through effects on ungulate prey.

  9. Trophic facilitation or limitation? Comparative effects of pumas and black bears on the scavenger community.

    Science.gov (United States)

    Allen, Maximilian L; Elbroch, L Mark; Wilmers, Christopher C; Wittmer, Heiko U

    2014-01-01

    Scavenging is a widespread behaviour and an important process influencing food webs and ecological communities. Large carnivores facilitate the movement of energy across trophic levels through the scavenging and decomposition of their killed prey, but competition with large carnivores is also likely to constrain acquisition of carrion by scavengers. We used an experimental approach based on motion-triggered video cameras at black-tailed deer (Odocoileus hemionus columbianus) carcasses to measure the comparative influences of two large carnivores in the facilitation and limitation of carrion acquisition by scavengers. We found that pumas (Puma concolor) and black bears (Ursus americanus) had different effects on their ecological communities. Pumas, as a top-level predator, facilitated the consumption of carrion by scavengers, despite significantly reducing their observed sum feeding times (165.7 min ± 21.2 SE at puma kills 264.3 min ± 30.1 SE at control carcasses). In contrast, black bears, as the dominant scavenger in the system, limited consumption of carrion by scavengers as evidenced by the observed reduction of scavenger species richness recorded at carcasses where they were present (mean = 2.33 ± 0.28 SE), compared to where they were absent (mean = 3.28 ± 0.23 SE). Black bears also had large negative effects on scavenger sum feeding times (88.5 min ± 19.8 SE at carcasses where bears were present, 372.3 min ± 50.0 SE at carcasses where bears were absent). In addition, we found that pumas and black bears both increased the nestedness (a higher level of order among species present) of the scavenger community. Our results suggest that scavengers have species-specific adaptions to exploit carrion despite large carnivores, and that large carnivores influence the structure and composition of scavenger communities. The interactions between large carnivores and scavengers should be considered in future studies of food webs and ecological communities.

  10. Testing the generality of a trophic-cascade model for plague

    Science.gov (United States)

    Collinge, S.K.; Johnson, W.C.; Ray, C.; Matchett, R.; Grensten, J.; Cully, J.F.; Gage, K.L.; Kosoy, M.Y.; Loye, J.E.; Martin, A.P.

    2005-01-01

    Climate may affect the dynamics of infectious diseases by shifting pathogen, vector, or host species abundance, population dynamics, or community interactions. Black-tailed prairie dogs (Cynomys ludovicianus) are highly susceptible to plague, yet little is known about factors that influence the dynamics of plague epizootics in prairie dogs. We investigated temporal patterns of plague occurrence in black-tailed prairie dogs to assess the generality of links between climate and plague occurrence found in previous analyses of human plague cases. We examined long-term data on climate and plague occurrence in prairie dog colonies within two study areas. Multiple regression analyses revealed that plague occurrence in prairie dogs was not associated with climatic variables in our Colorado study area. In contrast, plague occurrence was strongly associated with climatic variables in our Montana study area. The models with most support included a positive association with precipitation in April-July of the previous year, in addition to a positive association with the number of "warm" days and a negative association with the number of "hot" days in the same year as reported plague events. We conclude that the timing and magnitude of precipitation and temperature may affect plague occurrence in some geographic areas. The best climatic predictors of plague occurrence in prairie dogs within our Montana study area are quite similar to the best climatic predictors of human plague cases in the southwestern United States. This correspondence across regions and species suggests support for a (temperature-modulated) trophic-cascade model for plague, including climatic effects on rodent abundance, flea abundance, and pathogen transmission, at least in regions that experience strong climatic signals. ?? 2005 EcoHealth Journal Consortium.

  11. Coastal urban lighting has ecological consequences for multiple trophic levels under the sea.

    Science.gov (United States)

    Bolton, D; Mayer-Pinto, M; Clark, G F; Dafforn, K A; Brassil, W A; Becker, A; Johnston, E L

    2017-01-15

    Urban land and seascapes are increasingly exposed to artificial lighting at night (ALAN), which is a significant source of light pollution. A broad range of ecological effects are associated with ALAN, but the changes to ecological processes remain largely unstudied. Predation is a key ecological process that structures assemblages and responds to natural cycles of light and dark. We investigated the effect of ALAN on fish predatory behaviour, and sessile invertebrate prey assemblages. Over 21days fish and sessile assemblages were exposed to 3 light treatments (Day, Night and ALAN). An array of LED spotlights was installed under a wharf to create the ALAN treatments. We used GoPro cameras to film during the day and ALAN treatments, and a Dual frequency IDentification SONar (DIDSON) to film during the night treatments. Fish were most abundant during unlit nights, but were also relatively sedentary. Predatory behaviour was greatest during the day and under ALAN than at night, suggesting that fish are using structures for non-feeding purposes (e.g. shelter) at night, but artificial light dramatically increases their predatory behaviour. Altered predator behaviour corresponded with structural changes to sessile prey assemblages among the experimental lighting treatments. We demonstrate the direct effects of artificial lighting on fish behaviour and the concomitant indirect effects on sessile assemblage structure. Current and future projected use of artificial lights has the potential to significantly affect predator-prey interactions in marine systems by altering habitat use for both predators and prey. However, developments in lighting technology are a promising avenue for mitigation. This is among the first empirical evidence from the marine system on how ALAN can directly alter predation, a fundamental ecosystem process, and have indirect trophic consequences. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Trophic facilitation or limitation? Comparative effects of pumas and black bears on the scavenger community.

    Directory of Open Access Journals (Sweden)

    Maximilian L Allen

    Full Text Available Scavenging is a widespread behaviour and an important process influencing food webs and ecological communities. Large carnivores facilitate the movement of energy across trophic levels through the scavenging and decomposition of their killed prey, but competition with large carnivores is also likely to constrain acquisition of carrion by scavengers. We used an experimental approach based on motion-triggered video cameras at black-tailed deer (Odocoileus hemionus columbianus carcasses to measure the comparative influences of two large carnivores in the facilitation and limitation of carrion acquisition by scavengers. We found that pumas (Puma concolor and black bears (Ursus americanus had different effects on their ecological communities. Pumas, as a top-level predator, facilitated the consumption of carrion by scavengers, despite significantly reducing their observed sum feeding times (165.7 min ± 21.2 SE at puma kills 264.3 min ± 30.1 SE at control carcasses. In contrast, black bears, as the dominant scavenger in the system, limited consumption of carrion by scavengers as evidenced by the observed reduction of scavenger species richness recorded at carcasses where they were present (mean = 2.33 ± 0.28 SE, compared to where they were absent (mean = 3.28 ± 0.23 SE. Black bears also had large negative effects on scavenger sum feeding times (88.5 min ± 19.8 SE at carcasses where bears were present, 372.3 min ± 50.0 SE at carcasses where bears were absent. In addition, we found that pumas and black bears both increased the nestedness (a higher level of order among species present of the scavenger community. Our results suggest that scavengers have species-specific adaptions to exploit carrion despite large carnivores, and that large carnivores influence the structure and composition of scavenger communities. The interactions between large carnivores and scavengers should be considered in future studies of food webs and ecological communities.

  13. Trophic phylogenetics: evolutionary influences on body size, feeding, and species associations in grassland arthropods.

    Science.gov (United States)

    Lind, Eric M; Vincent, John B; Weiblen, George D; Cavender-Bares, Jeannine; Borer, Elizabeth T

    2015-04-01

    Contemporary animal-plant interactions such as herbivory are widely understood to be shaped by evolutionary history. Yet questions remain about the role of plant phylogenetic diversity in generating and maintaining herbivore diversity, and whether evolutionary relatedness of producers might predict the composition of consumer communities. We tested for evidence of evolutionary associations among arthropods and the plants on which they were found, using phylogenetic analysis of naturally occurring arthropod assemblages sampled from a plant-diversity manipulation experiment. Considering phylogenetic relationships among more than 900 arthropod consumer taxa and 29 plant species in the experiment, we addressed several interrelated questions. First, our results support the hypothesis that arthropod functional traits such as body size and trophic role are phylogenetically conserved in community ecological samples. Second, herbivores tended to cooccur with closer phylogenetic relatives than would be expected at random, whereas predators and parasitoids did not show phylogenetic association patterns. Consumer specialization, as measured by association through time with monocultures of particular host plant species, showed significant phylogenetic signal, although the. strength of this association varied among plant species. Polycultures of phylogenetically dissimilar plant species supported more phylogenetically dissimilar consumer communities than did phylogenetically similar polycultures. Finally, we separated the effects of plant species richness and relatedness in predicting the phylogenetic distribution of the arthropod assemblages in this experiment. The phylogenetic diversity of plant communities predicted the phylogenetic diversity of herbivore communities even after accounting for plant species richness. The phylogenetic diversity of secondary consumers differed by guild, with predator phylogenetic diversity responding to herbivore relatedness, while parasitoid

  14. Weak trophic links between a crab-spider and the effective pollinators of a rewardless orchid

    Science.gov (United States)

    Quintero, Carolina; Corley, Juan C.; Aizen, Marcelo A.

    2015-01-01

    Sit and wait predators hunting on flowers are considered to be exploiters of plant-pollinator mutualisms. Several studies have shown that plant-pollinator interactions can be highly susceptible to the impact of a third trophic level, via consumptive (direct) and non-consumptive (indirect) effects that alter pollinator behavior and, ultimately, plant fitness. However, most flowering plants attract a wide array of flower visitors, from which only a subset will be effective pollinators. Hence, a negative effect of an ambush predator on plant fitness should be expected only when: (i) the effective pollinators are part of the predators' diet and/or (ii) the non-consumptive effects of predator presence (e.g. dead prey) alter the behavior of effective pollinators and pollen movement among individual plants. We analyzed the direct and indirect effects of a crab-spider (Misumenops pallidus), on the pollination and reproductive success of Chloraea alpina, a Patagonian rewardless orchid. Our results indicate that most of the flower visitors do not behave as effective pollinators and most effective pollinators were not observed as prey for the crab-spider. In terms of non-consumptive effects, inflorescences with and without spiders and/or dead-prey did not vary the frequency of flower visitors, nor pollinia removal or deposition. Hence, it is not surprising that M. pallidus has a neutral effect on pollinia removal and deposition as well as on fruit and seed set. Similar to other rewardless orchids, the low reproductive success of C. alpina (∼6% fruit set) was associated with the limited number of visits by effective pollinators. Negative top-down effects of a flower-visitor predator on plant pollination may not be anticipated without studying the direct and indirect effects of this predator on the effective pollinators. In pollination systems where effective pollinators visited flowers erratically, such as in deceptive orchids, we expect weak or no effect of predators on

  15. Reappraisal of the Trophic Ecology of One of the World’s Most Threatened Spheniscids, the African Penguin

    Science.gov (United States)

    Connan, Maëlle; Hofmeyr, G. J. Greg; Pistorius, Pierre A

    2016-01-01

    Many species of seabirds, including the only penguin species breeding on the African continent, are threatened with extinction. The world population of the endangered African penguin Spheniscus demersus has decreased from more than 1.5 million individuals in the early 1900s to c.a. 23 000 pairs in 2013. Determining the trophic interactions of species, especially those of conservation concern, is important when declining numbers are thought to be driven by food limitation. By and large, African penguin dietary studies have relied on the identification of prey remains from stomach contents. Despite all the advantages of this method, it has well known biases. We therefore assessed the African penguin’s diet, using stable isotopes, at two colonies in Algoa Bay (south-east coast of South Africa). These represent over 50% of the world population. Various samples (blood, feathers, egg membranes) were collected for carbon and nitrogen stable isotope analyses. Results indicate that the trophic ecology of African penguins is influenced by colony, season and age class, but not adult sex. Isotopic niches identified by standard Bayesian ellipse areas and convex hulls, highlighted differences among groups and variability among individual penguins. Using Bayesian mixing models it was for the first time shown that adults target chokka squid Loligo reynaudii for self-provisioning during particular stages of their annual cycle, while concurrently feeding their chicks primarily with small pelagic fish. This has important ramifications and means that not only pelagic fish, but also squid stocks, need to be carefully managed in order to allow population recovery of African penguin. PMID:27434061

  16. Secondary foundation species as drivers of trophic and functional diversity: evidence from a tree-epiphyte system.

    Science.gov (United States)

    Angelini, Christine; Silliman, Brian R

    2014-01-01

    Facilitation cascades arise where primary foundation species facilitate secondary (dependent) foundation species, and collectively, they increase habitat complexity and quality to enhance biodiversity. Whether such phenomena occur in nonmarine systems and if secondary foundation species enhance food web structure (e.g., support novel feeding guilds) and ecosystem function (e.g., provide nursery for juveniles) remain unclear. Here we report on field experiments designed to test whether trees improve epiphyte survival and epiphytes secondarily increase the number and diversity of adult and juvenile invertebrates in a potential live oak-Tillandsia usneoides (Spanish moss) facilitation cascade. Our results reveal that trees reduce physical stress to facilitate Tillandsia, which, in turn, reduces desiccation and predation stress to facilitate invertebrates. In experimental removals, invertebrate total density, juvenile density, species richness and H' diversity were 16, 60, 1.7, and 1.5 times higher, and feeding guild richness and H' were 5 and 11 times greater in Tillandsia-colonized relative to Tillandsia-removal limb plots. Tillandsia enhanced communities similarly in a survey across the southeastern United States. These findings reveal that a facilitation cascade organizes this widespread terrestrial assemblage and expand the role of secondary foundation species as drivers of trophic structure and ecosystem function. We conceptualize the relationship between foundation species' structural attributes and associated species abundance and composition in a Foundation Species-Biodiversity (FSB) model. Importantly, the FSB predicts that, where secondary foundation species form expansive and functionally distinct structures that increase habitat availability and complexity within primary foundation species, they generate and maintain hot spots of biodiversity and trophic interactions.

  17. Trophic ontogeny of fluvial Bull Trout and seasonal predation on Pacific Salmon in a riverine food web

    Science.gov (United States)

    Lowery, Erin D.; Beauchamp, David A.

    2015-01-01

    Bull Trout Salvelinus confluentus are typically top predators in their host ecosystems. The Skagit River in northwestern Washington State contains Bull Trout and Chinook Salmon Oncorhynchus tshawytschapopulations that are among the largest in the Puget Sound region and also contains a regionally large population of steelhead O. mykiss (anadromous Rainbow Trout). All three species are listed as threatened under the Endangered Species Act (ESA). Our objective was to determine the trophic ecology of Bull Trout, especially their role as predators and consumers in the riverine food web. We seasonally sampled distribution, diets, and growth of Bull Trout in main-stem and tributary habitats during 2007 and winter–spring 2008. Consumption rates were estimated with a bioenergetics model to (1) determine the annual and seasonal contributions of different prey types to Bull Trout energy budgets and (2) estimate the potential impacts of Bull Trout predation on juvenile Pacific salmon populations. Salmon carcasses and eggs contributed approximately 50% of the annual energy budget for large Bull Trout in main-stem habitats, whereas those prey types were largely inaccessible to smaller Bull Trout in tributary habitats. The remaining 50% of the energy budget was acquired by eating juvenile salmon, resident fishes, and immature aquatic insects. Predation on listed Chinook Salmon and steelhead/Rainbow Trout was highest during winter and spring (January–June). Predation on juvenile salmon differed between the two study years, likely due to the dominant odd-year spawning cycle for Pink Salmon O. gorbuscha. The population impact on ocean- and stream-type Chinook Salmon was negligible, whereas the impact on steelhead/Rainbow Trout was potentially very high. Due to the ESA-listed status of Bull Trout, steelhead, and Chinook Salmon, the complex trophic interactions in this drainage provide both challenges and opportunities for creative adaptive management strategies.

  18. Relationship between ecomorphology and trophic segregation in four closely related sympatric fish species (Teleostei, Sciaenidae).

    Science.gov (United States)

    Blasina, Gabriela; Molina, Juan; Lopez Cazorla, Andrea; Díaz de Astarloa, Juan

    This study explores the relationship between ecomorphology and trophic segregation in four closely related sympatric fish species (Teleostei, Sciaenidae) that are known to differ in their trophic habits. Only adult specimens were analyzed: 103 Cynoscion guatucupa, 77 Pogonias cromis, 61 Micropogonias furnieri, and 48 Menticirrhus americanus. The four species presented divergent ecomorphological traits related to swimming agility, prey spotting and capture, and the potential size of prey they were able to swallow. Results suggest that these sciaenid species can partition the food resources, even though they completely overlap in space. Differences in their ecomorphological traits appear to correlate closely with the diet and consequently could explain the trophic differentiation observed. Arguably, these ecomorphological differences play a significant role in the coexistence of the adults of these sympatric fish species. Copyright © 2016 Académie des sciences. Published by Elsevier SAS. All rights reserved.

  19. Influence of dispersants on trophic transfer of petroleum hydrocarbons in a marine food chain

    International Nuclear Information System (INIS)

    Wolfe, M. F.; Schwartz, G. J. B.; Singaram, S.; Tjeerdema, R. S.

    1997-01-01

    Experiments were conducted to determine the impact of dispersing agents on petroleum hydrocarbons (PH) bioavailability and trophic transfer in primary levels of a marine food chain. Uptake, bioaccumulation and metabolic transformation of a model PH, ( 1 4C)naphthalene, were measured and compared with Prudhoe Bay Crude Oil (PBCO) dispersed with Corexit 9527, and undispersed preparations of PBCO. The model food chain consisted of a primary algae producer and a primary rotifer consumer. Results showed that uptake of naphthalene increased significantly in the presence of a dispersant in algae. A significant increase in uptake was also recorded in rotifers via trophic transfer. Trophic transfer played a significant, sometimes even dominant, role in uptake and bioaccumulation. 27 refs., 6 figs

  20. Evolutionary trade-offs in plants mediate the strength of trophic cascades.

    Science.gov (United States)

    Mooney, Kailen A; Halitschke, Rayko; Kessler, Andre; Agrawal, Anurag A

    2010-03-26

    Predators determine herbivore and plant biomass via so-called trophic cascades, and the strength of such effects is influenced by ecosystem productivity. To determine whether evolutionary trade-offs among plant traits influence patterns of trophic control, we manipulated predators and soil fertility and measured impacts of a major herbivore (the aphid Aphis nerii) on 16 milkweed species (Asclepias spp.) in a phylogenetic field experiment. Herbivore density was determined by variation in predation and trade-offs between herbivore resistance and plant growth strategy. Neither herbivore density nor predator effects on herbivores predicted the cascading effects of predators on plant biomass. Instead, cascade strength was strongly and positively associated with milkweed response to soil fertility. Accordingly, contemporary patterns of trophic control are driven by evolutionary convergent trade-offs faced by plants.

  1. [Effects of different trophic modes on growth characteristics, metabolism and cellular components of Chlorella vulgaris].

    Science.gov (United States)

    Kong, Weibao; Wang, Yang; Yang, Hong; Xi, Yuqin; Han, Rui; Niu, Shiquan

    2015-03-04

    We studied the effects of trophic modes related to glucose and light (photoautotrophy, mixotrophy and heterotrophy) on growth, cellular components and carbon metabolic pathway of Chlorella vulgaris. The parameters about growth of algal cells were investigated by using spectroscopy and chromatography techniques. When trophic mode changed from photoautotrophy to mixotrophy and to heterotrophy successively, the concentrations of soluble sugar, lipid and saturated C16/C18 fatty acids in C. vulgaris increased, whereas the concentrations of unsaturated C16, C18 fatty acids, proteins, photosynthetic pigments and 18 relative amino acids decreased. Light and glucose affect the growth, metabolism and the biochemical components biosynthesis of C. vulgaris. Addition of glucose can promote algal biomass accumulation, stimulate the synthesis of carbonaceous components, but inhibit nitrogenous components. Under illumination cultivation, concentration and consumption level of glucose decided the main trophic modes of C. vulgaris. Mixotrophic and heterotrophic cultivation could promote the growth of algal cells.

  2. Chemical composition and trophic state of shallow saline steppe lakes in central Asia (North Kazakhstan).

    Science.gov (United States)

    Boros, Emil; Jurecska, Laura; Tatár, Enikő; Vörös, Lajos; Kolpakova, Marina

    2017-10-09

    The purpose of this study was to identify the prevailing chemical composition and trophic state of the shallow saline steppe lakes of North Kazakhstan along a wide size range (SO 4 and Na-Cl (n = 16; 64%); the Ca, Mg, HCO 3 , and SO 4 ions precipitate with increasing salinity (2-322 g L -1 ); and ion composition shifts from Na>Mg-Cl>SO 4 to Na-Cl. The most of the chemical variables positively, but chlorophyll a negatively, correlated with total dissolved solids, and the total phosphorus had no significant correlation with any variables. The trophic state of these lakes in most cases exceeded the hypertrophic level. The increase in salinity causes change in chemical composition and effects on the phytoplankton development independently from the size of water surface, and the human disturbances had negligible effect on the trophic state of shallow saline lakes in this region of Kazakhstan.

  3. Effects of trophic skewing of species richness on ecosystem functioning in a diverse marine community.

    Directory of Open Access Journals (Sweden)

    Pamela L Reynolds

    Full Text Available Widespread overharvesting of top consumers of the world's ecosystems has "skewed" food webs, in terms of biomass and species richness, towards a generally greater domination at lower trophic levels. This skewing is exacerbated in locations where exotic species are predominantly low-trophic level consumers such as benthic macrophytes, detritivores, and filter feeders. However, in some systems where numerous exotic predators have been added, sometimes purposefully as in many freshwater systems, food webs are skewed in the opposite direction toward consumer dominance. Little is known about how such modifications to food web topology, e.g., changes in the ratio of predator to prey species richness, affect ecosystem functioning. We experimentally measured the effects of trophic skew on production in an estuarine food web by manipulating ratios of species richness across three trophic levels in experimental mesocosms. After 24 days, increasing macroalgal richness promoted both plant biomass and grazer abundance, although the positive effect on plant biomass disappeared in the presence of grazers. The strongest trophic cascade on the experimentally stocked macroalgae emerged in communities with a greater ratio of prey to predator richness (bottom-rich food webs, while stronger cascades on the accumulation of naturally colonizing algae (primarily microalgae with some early successional macroalgae that recruited and grew in the mesocosms generally emerged in communities with greater predator to prey richness (the more top-rich food webs. These results suggest that trophic skewing of species richness and overall changes in food web topology can influence marine community structure and food web dynamics in complex ways, emphasizing the need for multitrophic approaches to understand the consequences of marine extinctions and invasions.

  4. Mercury cycling in stream ecosystems. 3. Trophic dynamics and methylmercury bioaccumulation

    Science.gov (United States)

    Chasar, L.C.; Scudder, B.C.; Stewart, A.R.; Bell, A.H.; Aiken, G.R.

    2009-01-01

    Trophic dynamics (community composition and feeding relationships) have been identified as important drivers of methylmercury (MeHg) bioaccumulation in lakes, reservoirs, and marine ecosystems. The relative importance of trophic dynamics and geochemical controls on MeHg bioaccumulation in streams, however, remains poorly characterized. MeHg bioaccumulation was evaluated in eight stream ecosystems across the United States (Oregon, Wisconsin, and Florida) spanning large ranges in climate, landscape characteristics, atmospheric Hg deposition, and stream chemistry. Across all geographic regions and all streams, concentrations of total Hg (THg) in top predator fish and forage fish, and MeHg in invertebrates, were strongly positively correlated to concentrations of filtered THg (FTHg), filtered MeHg (FMeHg), and dissolved organic carbon (DOC); to DOC complexity (as measured by specific ultraviolet absorbance); and to percent wetland in the stream basins. Correlations were strongest for nonurban streams. Although regressions of log[Hg] versus ??15N indicate that Hg in biota increased significantly with increasing trophic position within seven of eight individual streams, Hg concentrations in top predator fish (including cutthroat, rainbow, and brown trout; green sunfish; and largemouth bass) were not strongly influenced by differences in relative trophic position. Slopes of log[Hg] versus ??15N, an indicator of the efficiency of trophic enrichment, ranged from 0.14 to 0.27 for all streams. These data suggest that, across the large ranges in FTHg (0.14-14.2 ng L-1), FMeHg (0.023-1.03 ng L-1), and DOC (0.50-61.0 mg L-1) found in this study, Hg contamination in top predator fish in streams likely is dominated by the amount of MeHg available for uptake at the base of the food web rather than by differences in the trophic position of top predator fish. ?? 2009 American Chemical Society.

  5. Trophic structure of fish fauna along the longitudinal gradient of a first-order rural stream

    Directory of Open Access Journals (Sweden)

    Jardel Nimet

    2015-12-01

    Full Text Available Abstract Aim: This study evaluated the trophic structure of the fish assemblage along the longitudinal gradient of a first-order rural stream. Methods Fish were sampled by electrofishing technique in December 2007, September 2008 and March 2009, at three stretch of the Itiz stream (headwater, middle and mouth. We sampled 1,255 individuals relating to 18 species. The categorization of trophic guilds was based on stomach content data of 1,096 individuals, analyzed according to the volumetric method, except for four species, which were classified according to the literature. To test the hypothesis of differences in the richness, abundance and biomass of trophic guilds along the headwater-mouth gradient, it was performed non-parametric statistical analysis of the dietary data. Was also calculated, the amplitude of trophic niche (Levins's index for each guild. To summarize the composition and abundance of the trophic guilds along the longitudinal gradient, we applied a non-metric multidimensional scaling (NMDS. Results We registered seven guilds: herbivorous, detritivorous, aquatic insectivorous, terrestrial insectivorous, invertivorous, omnivorous and piscivorous, the latter was exclusive to headwater and middle stretches. The omnivorous guild was not recorded in the headwater. Through PERMANOVA analysis it was found that the species richness of more specialized guilds (detritivorous and insectivorous terrestrial and of generalist invertivorous increased, while less specialized guilds like aquatic insectivorous and herbivorous, decrease significantly in headwater-mouth direction. Except by the non-expected increase of insectivorous terrestrial and decrease of herbivorous downstream, the non-metric multidimensional scaling (NMDS identified longitudinal variations in abundance and biomass of the guilds that agree with general patterns of fish guilds distribution along environmental gradients. Conclusion These results suggest that the influence of

  6. Trophic models: What do we learn about Celtic Sea and Bay of Biscay ecosystems?

    Science.gov (United States)

    Moullec, Fabien; Gascuel, Didier; Bentorcha, Karim; Guénette, Sylvie; Robert, Marianne

    2017-08-01

    Trophic models are key tools to go beyond the single-species approaches used in stock assessments to adopt a more holistic view and implement the Ecosystem Approach to Fisheries Management (EAFM). This study aims to: (i) analyse the trophic functioning of the Celtic Sea and the Bay of Biscay, (ii) investigate ecosystem changes over the 1980-2013 period and, (iii) explore the response to management measures at the food web scale. Ecopath models were built for each ecosystem for years 1980 and 2013, and Ecosim models were fitted to time series data of biomass and catches. EcoTroph diagnosis showed that in both ecosystems, fishing pressure focuses on high trophic levels (TLs) and, to a lesser extent, on intermediate TLs. However, the interplay between local environmental conditions, species composition and ecosystem functioning could explain the different responses to fisheries management observed between these two contiguous ecosystems. Indeed, over the study period, the ecosystem's exploitation status has improved in the Bay of Biscay but not in the Celtic Sea. This improvement does not seem to be sufficient to achieve the objectives of an EAFM, as high trophic levels were still overexploited in 2013 and simulations conducted with Ecosim in the Bay of Biscay indicate that at current fishing effort the biomass will not be rebuilt by 2030. The ecosystem's response to a reduction in fishing mortality depends on which trophic levels receive protection. Reducing fishing mortality on pelagic fish, instead of on demersal fish, appears more efficient at maximising catch and total biomass and at conserving both top-predator and intermediate TLs. Such advice-oriented trophic models should be used on a regular basis to monitor the health status of marine food webs and analyse the trade-offs between multiple objectives in an ecosystem-based fisheries management context.

  7. Distributions and natural levels of related metals in a trophic pathway

    International Nuclear Information System (INIS)

    Lemons, J.D.

    1976-06-01

    The first objective was to test the hypothesis that metal distributions and trends in organisms are, in part, a function of metal positions in the periodic table in unpolluted ecosystems. The data have shown that large soil crustal abundance differences of related elements (e.g. alkali metals) are proportionately approximated in higher organisms. Concentration factors for related nutritious and nonessential and toxic metals were determined along a trophic pathway. When the concentration factors were reported as the concentration of a particular metal by itself, all metal concentrations increased along the trophic pathway. The second objective of this study was to test the hypothesis that distributions and natural levels of chemically related nonessential and toxic metals can better be known when the metals are reported as a ratio, in ash, of the nonessential or toxic metal to its chemically related nutritious metal (e.g. strontium/calcium) as the metals are transferred through trophic pathways. The data have shown that when this method of reporting metal abundances in trophic levels is used, nonessential and toxic metals are discriminated against, relative to their chemically related nutritious metal, as the metals are transferred through the trophic pathway levels. The third objective was designed to test the hypothesis that surface deposition of toxic metals upon plants influences the trends of metal abundances through trophic pathways. This study indicates that metal pollution in the form of deposition upon plant surfaces bypasses the discrimination mechanisms in plants, and consequently elevates the total body burden in herbivores. It is likely that there is no herbivore defense for this type of metal exposure, because herbivores have probably come to rely, in part, upon the discriminatory mechanism of plants throughout the course of evolutionary history to keep toxic metal burdens low

  8. Trophic cascades from wolves to grizzly bears or changing abundance of bears and alternate foods?

    Science.gov (United States)

    Barber-Meyer, Shannon M

    2015-05-01

    This is a Forum article commenting on: Ripple, W. J., Beschta, R. L., Fortin, J. K., & Robbins, C. T. (2014) Trophic cascades from wolves to grizzly bears in Yellowstone. Journal of Animal Ecology, 83, 223-233. Comparisons Ripple et al. (2014) used to demonstrate increased fruit availability and consumption by grizzly bears post-wolf reintroduction are flawed and tenuous at best. Importantly, a more parsimonious (than trophic cascades) hypothesis, not sufficiently considered by Ripple et al., exists and is better supported by available data I review. Published 2015. This article is a U. S. Government work and is in the public domain in the USA.

  9. [Use of magnetic therapy combined with galvanization and tissue electrophoresis in the treatment of trophic ulcers].

    Science.gov (United States)

    Alekseenko, A V; Gusak, V V; Stoliar, V F; Iftodiĭ, A G; Tarabanchuk, V V; Shcherban, N G; Naumets, A A

    1993-01-01

    The results of treatment of 86 patients with the use of magnetotherapy in combination with galvanization and intratissue electrophoresis are presented. To create an electric field, the "Potok-1" apparatus with a density of current equal to 0.05-0.1 mA/cm2 was employed. Simultaneously, the "MAG-30" apparatus for low-frequency magnetotherapy with induction of 30 mT and area of exposure of 20 cm2 was applied to a trophic ulcer site. The use of magnetogalvanotherapy in the complex of treatment of trophic ulcers of the lower extremities is recommended.

  10. The dynamics the quantitative changes of mycoflora in two lakes differing in trophicity (Poland. I.

    Directory of Open Access Journals (Sweden)

    Teresa Korniłłowicz

    2014-08-01

    Full Text Available It was demonstrated that the number of saprophytic fungi in the population of plankton in mesotrophic lake changing to eutrophic (Lake Piaseczno was mountained a similiar level (average values as in the eutrophic one (Lake Głębokie. The seasonal and annual changes in the number of fungi in the waters of the lake with lower trophicity were markedly stronger than those in the lake with higher trophicity. In the mesotrophic lake this was connected with the intensity of phytoplankton development. The greatest accumulation of fungi occured in the waters of littoral zone in both lakes and in the pelagial metha- and hypolimniun of the Lake Piaseczno.

  11. Trophic polymorphism, habitat and diet segregation in Percichthys trucha (Pisces : Percichthyidae) in the Andes

    DEFF Research Database (Denmark)

    Ruzzante, D.E.; Walde, S.J.; Cussac, V.E.

    1998-01-01

    Divergent natural selection affecting specific trait combinations that lead to greater efficiency in resource exploitation is believed to be a major mechanism leading to trophic polymorphism and adaptive radiation. We present evidence of trophic polymorphism involving two benthic morphs within...... Percichthys trucha, a fish endemic to temperate South America. In a series of lakes located in the southern Andes, we found two morphs of P. trucha that could be distinguished on the basis of gill raker length and five other morphological measures, most of which are likely associated with the use of food...

  12. Trophic interactions in contrating production systems: MiSeq versus multiplex PCR

    Science.gov (United States)

    Maintaining biodiversity is an important aspect of long-term agricultural sustainability. Generalist predators such as spiders and insect predators often prey upon common pest species, making them a beneficial component of agroecosystems. Much research has been devoted to understanding the roles of ...

  13. Trophic interactions in contrasting production systems: MiSeq versus multiplex PCR

    Science.gov (United States)

    Maintaining biodiversity is an important aspect of long-term agricultural sustainability. Generalist predators such as spiders and insect predators oftern prey upon common species, making them a beneficial component of agroecosystems. Much research has been devoted to understanding the roles of ge...

  14. Ecological and Evolutionary Consequences of Plant Mediation of Multi-Trophic Interactions

    OpenAIRE

    Abdala, Luis Alejandro

    2014-01-01

    Consumers are strongly influenced by plant phenotypic variation. Such variation may have a genetic or environmental basis, and occurs when plant genotypes or species vary in traits or when patches of co-occurring plants vary in the number of genotypes or species. However, these sources of plant variation have usually been studied separately, their underlying mechanisms are poorly understood, and the evolutionary consequences are largely unknown. This dissertation aims to fill these gaps in re...

  15. Predator diversity and environmental change modifity the strengths of trophic and nontrophic interactions

    Czech Academy of Sciences Publication Activity Database

    Sentis, Arnaud; Gémard, C.; Jaugeon, B.; Boukal S., David

    2017-01-01

    Roč. 23, č. 7 (2017), s. 2629-2640 ISSN 1354-1013 R&D Projects: GA ČR(CZ) GA14-29857S Grant - others:European Social Fund(CZ) CZ.1.07/2.3.00/30.0049 Institutional support: RVO:60077344 Keywords : biodiversity-ecosystem functioning * facilitation * functional response Subject RIV: EH - Ecology, Behaviour OBOR OECD: Ecology Impact factor: 8.502, year: 2016 http://onlinelibrary.wiley.com/doi/10.1111/gcb.13560/pdf

  16. Thermal acclimation modulates the impacts of temperature and enrichment on trophic interaction strengths and population dynamics

    Czech Academy of Sciences Publication Activity Database

    Sentis, Arnaud; Morisson, J.; Boukal S., David

    2015-01-01

    Roč. 21, č. 9 (2015), s. 3290-3298 ISSN 1354-1013 R&D Projects: GA ČR GAP505/10/0096 Grant - others:European Social Fund(CZ) CZ1.07/2.3.00/30.0049 Institutional support: RVO:60077344 Keywords : biodiversity loss * climate change * consumer-resource Subject RIV: EH - Ecology, Behaviour Impact factor: 8.444, year: 2015 http://onlinelibrary.wiley.com/doi/10.1111/gcb.12931/abstract

  17. Trophic interactions and productivity of copepods as live feed from tropical Taiwanese outdoor aquaculture ponds

    DEFF Research Database (Denmark)

    Blanda, Elisa; Drillet, Guillaume; Huang, Cheng-Chien

    2015-01-01

    The present study describes three outdoor ponds for mass rearing of copepods in tropical southern Taiwan. The systems are designed for culturing and harvesting of copepods, which are used as live feed in the production of groupers in the region. However, the production of the most common copepod...... to enable a correct description of the copepods ecology and a preliminary evaluation of the status of the pond management; and (III) provide advices for improved management leading towards a higher and more stable output of P. annandalei. Copepods were experiencing prey ad libitum since the quantity...... during high season. This harvest, in terms of biomass, corresponded to 20–40% of the copepod standing stock, which indicates a sustainable management when compared to the secondary productivity of the copepods. To further increase the copepod production of the ponds, better water quality must be achieved...

  18. Trophic interactions among invertebrates in termitaria in the African savanna : a stable isotope approach

    NARCIS (Netherlands)

    De Visser, Sarah N.; Freymann, Bernd P.; Schnyder, Hans

    2008-01-01

    1. Termites (Isoptera) in tropical savannas are known as ecosystem engineers, affecting the spatial and temporal distribution of water, carbon, cations, and nutrients through their mound structures. Their mounds, however, also offer habitation to diverse taxa and feeding guilds of other

  19. Tri-trophic interactions affect density dependence of seed fate in a tropical forest palm

    NARCIS (Netherlands)

    Visser, Marco D.; Muller-Landau, Helene C.; Wright, S. Joseph; Rutten, Gemma; Jansen, Patrick A.

    2011-01-01

    Natural enemies, especially host-specific enemies, are hypothesised to facilitate the coexistence of plant species by disproportionately inflicting more damage at increasing host abundance. However, few studies have assessed such Janzen-Connell mechanisms on a scale relevant for coexistence and no

  20. Trophic Interactions during Primary Succession: Herbivores Slow a Plant Reinvasion at Mount St. Helens.

    Science.gov (United States)

    Fagan, William F; Bishop, John G

    2000-02-01

    Lupines (Lupinus lepidus var. lobbii), the earliest plant colonists of primary successional habitats at Mount St. Helens, were expected to strongly affect successional trajectories through facilitative effects. However, their effects remain localized because initially high rates of reinvasive spread were short lived, despite widespread habitat availability. We experimentally tested whether insect herbivores, by reducing plant growth and fecundity at the edge of the expanding lupine population, could curtail the rate of reinvasion and whether those herbivores had comparable impacts in the older, more successionally advanced core region. We found that removing insect herbivores increased both the areal growth of individual lupine plants and the production of new plants in the edge region, thereby accelerating the lupine's intrinsic rate of increase at the front of the lupine reinvasion. We found no such impacts of herbivory in the core region, where low plant quality or a complex of recently arrived natural enemies may hold herbivores in check. In the context of invasion theory, herbivore-mediated decreases in lupine population growth rate in the edge region translate into decreased rates of lupine spread, which we quantify here using diffusion models. In the Mount St. Helens system, decreased rate of lupine reinvasion will result in reductions in rates of soil formation, nitrogen input, and entrapment of seeds and detritus that are likely to postpone or alter trajectories of primary succession. If the type of spatial subtleties in herbivore effects we found here are common, with herbivory focused on the edge of an expanding plant population and suppressed or ineffective in the larger, denser central region (where the plants might be more readily noticed and studied), then insect herbivores may have stronger impacts on the dynamics of primary succession and plant invasions than previously recognized.

  1. Trophic Interactions in the Baltic Sea: Predation on cod eggs by clupeids

    DEFF Research Database (Denmark)

    Neumann, Viola

    datasets on stomach contents of sprat and herring, ambient hydrographic conditions, ichthyoplankton distribution and abundance as well as predator distribution and abundance from hydroacoustic data for the 1990s and 2004-2008. Changes in diet composition of sprat and herring were investigated, including....... As a next step, predation pressure was quantified separately for egg development stages, both for cod and sprat (Paper III). Furthermore, ichthyoplankton prey selection by clupeids was investigated, with specific focus of predation on different fish egg species and development stages, to improve our...

  2. Macrophage migration inhibitory factor (MIF) modulates trophic signaling through interaction with serine protease HTRA1

    DEFF Research Database (Denmark)

    Fex Svenningsen, Åsa; Loering, Svenja; Sørensen, Anna Lahn

    2017-01-01

    Macrophage migration inhibitory factor (MIF), a small conserved protein, is abundant in the immune- and central nervous system (CNS). MIF has several receptors and binding partners that can modulate its action on a cel-lular level. It is upregulated in neurodegenerative diseases and cancer although...

  3. Light, stress and herbivory : from photoprotection to trophic interactions using Arabidopsis thaliana as a model organism

    OpenAIRE

    Frenkel, Martin

    2008-01-01

    Photosynthesis is the most important process for nearly all life on earth. Photosynthetic organisms capture and transfer light energy from the sun into chemical energy which in turn provides a resource base for heterotrophic organisms. Natural light regimes are irregular and vary over magnitudes. At a certain light intensity, metabolic processes cannot keep up with the electron flow produced by the primary photoreactions, and thus reactive oxygen species (ROS) are produced. ROS are highly rea...

  4. Using Stable Isotopes of Carbon and Nitrogen to Evaluate Trophic Interactions in Aquatic Environments

    Science.gov (United States)

    Christensen, David R.; LaRoche, Andrew

    2012-01-01

    This paper describes a series of laboratory exercises for upper level biology courses, independent research and/or honors programs. Students sampled fish from a local water body with the assistance of a local fish and wildlife agency. Tissue samples from collected fish were utilized to obtain estimates of the stable isotopes delta[superscript 13]C…

  5. Interactions among species in a tri-trophic system: the influence of ...

    African Journals Online (AJOL)

    Metapopulation dynamics is now so widely used to describe the distribution and abundance of species living in fragmented landscapes that other ecological factors (e.g. habitat quality) can be overlooked. To determine the precise habitat requirements of an endangered and narrowly endemic lycaenid butterfly, I studied its ...

  6. Trophic interactions between rhizosphere bacteria and bacterial feeders influenced by phosphate and aphids in barley

    DEFF Research Database (Denmark)

    Strandmark, Lisa Bjørnlund; Mørk, Søren; Madsen, Mette Vestergård

    2006-01-01

    -Proteobacteria supported the growth of Cercomonas sp. well, whereas Actinobacteria did not. In contrast, C. elegans reproduced poorly on most a-proteobacteria but were able to reproduce well on some Actinobacteria. These results suggest that the different response of protozoa and nematodes to P addition could be mediated...

  7. The effects of trophic interactions and spatial competition on algal community composition on Hawaiian coral reefs

    NARCIS (Netherlands)

    Vermeij, M.J.A.; Dailer, M.L.; Walsh, S.M.; Donovan, M.K.; Smith, C.M.

    2010-01-01

    Much of coral reef ecology has focused on how human impacts change coral reefs to macroalgal reefs. However, macroalgae may not always be a good indicator of reef decline, especially on reefs with significant sea urchin populations, as found in Kenya and Hawaii. This study tests the effects of

  8. Effects of dietary nicotine on the development of an insect herbivore, its parasitoid and secondary hyperparasitoid over four trophic levels

    NARCIS (Netherlands)

    Harvey, J.A.; Dam, van N.M.; Witjes, L.M.A.; Soler, R.; Gols, R.

    2007-01-01

    1. Allelochemicals in herbivore diet are known to affect the development of higher trophic levels, such as parasitoids and predators. 2. This study examines how differing levels of nicotine affects the development of a herbivore, its parasitoid and secondary hyperparasitoid over four trophic levels.

  9. Meta-analysis review of fish trophic level at marine protected areas based on stable isotopes data

    Directory of Open Access Journals (Sweden)

    J. J. de LOPE ARIAS

    2016-04-01

    Full Text Available Stable isotopes (δ15N are used to determine trophic level in marine food webs. We assessed if Marine Protected Areas (MPAs affect trophic level of fishes based on stable isotopes on the Western Mediterranean. A total of 22 studies including 600 observations were found and the final dataset consisted of 11 fish species and 146 observations comparing trophic level inside and outside MPAs. The database was analysed by meta-analysis and the covariate selected was the level of protection (inside vs. outside MPAs. The results indicate significant difference between trophic levels inside and outside MPAs. However, results differ from expectations since the trophic level inside was lower than outside MPAs. Three habitats were analysed (coastal lagoons, demersal and littoral and significant differences were found among them. Trophic level was higher in demersal habitats than in coastal lagoons and littoral areas. No significant differences were found in species classified by trophic functional groups. We consider several hypotheses explaining the obtained results linked to protection level of the MPAs, time since protection and MPAs size. We debate the suitability of using the stable isotope (δ15N as direct indicator of trophic level in evaluating MPAs effects on food webs.

  10. PCBs and DDE, but not PBDEs, increase with trophic level and marine input in nestling bald eagles

    International Nuclear Information System (INIS)

    Hamish Elliott, Kyle; Cesh, Lillian S.; Dooley, Jessica A.; Letcher, Robert J.; Elliott, John E.

    2009-01-01

    Concentrations of persistent contaminants often vary widely among individuals within a population. We hypothesized that such variation was caused mainly by differences in diet (biomagnification) and in coastal systems by the tendency of marine systems to act as contaminant sinks. We examined the relationship between contaminant concentrations and stable isotope ratios in nestling plasma from an apex predator with a particularly broad diet. Our study included freshwater, estuarine, inshore and pelagic breeding sites. Bald eagles (Haliaeetus leucocephalus) at the pelagic marine sites showed high trophic level and marine input, eagles at the freshwater sites showed low trophic level and marine input, and eagles at the estuarine and inshore marine sites had intermediate values. The relationship between trophic level and marine input may reflect longer food chains in pelagic compared to terrestrial ecosystems. ΣPCBs and DDE concentrations generally increased with trophic level and marine input, with the exception of the freshwater sites, while ΣPBDEs, hydroxylated-PBDEs and hydroxylated-PCBs increased with marine input, but were independent of trophic level. The relationships for ΣPCBs and DDE were often slightly stronger with marine input than trophic level, suggesting that oceanographic processes may be more important than trophic level. At freshwater locations, spatial variation may be more important than trophic level due to the heterogeneity of contaminant profiles between feeding locations (lakes, rivers, agricultural fields). Adults had similar isotopic composition to their chicks but higher contamination. Based on nests where prey composition was determined independently, isotopic enrichment values for nestling plasma were 1.6 ± 0.1 (δ 15 N) and - 0.4 ±0.2 (δ 13 C). We conclude that trophic level and marine influence are significant factors influencing PCB and DDE concentrations in eagles. However, trophic level in particular did not influence PBDEs

  11. Trophic modeling of the Northern Humboldt Current Ecosystem, Part I: Comparing trophic linkages under La Niña and El Niño conditions

    Science.gov (United States)

    Tam, Jorge; Taylor, Marc H.; Blaskovic, Verónica; Espinoza, Pepe; Michael Ballón, R.; Díaz, Erich; Wosnitza-Mendo, Claudia; Argüelles, Juan; Purca, Sara; Ayón, Patricia; Quipuzcoa, Luis; Gutiérrez, Dimitri; Goya, Elisa; Ochoa, Noemí; Wolff, Matthias

    2008-10-01

    The El Niño of 1997-98 was one of the strongest warming events of the past century; among many other effects, it impacted phytoplankton along the Peruvian coast by changing species composition and reducing biomass. While responses of the main fish resources to this natural perturbation are relatively well known, understanding the ecosystem response as a whole requires an ecotrophic multispecies approach. In this work, we construct trophic models of the Northern Humboldt Current Ecosystem (NHCE) and compare the La Niña (LN) years in 1995-96 with the El Niño (EN) years in 1997-98. The model area extends from 4°S-16°S and to 60 nm from the coast. The model consists of 32 functional groups of organisms and differs from previous trophic models of the Peruvian system through: (i) division of plankton into size classes to account for EN-associated changes and feeding preferences of small pelagic fish, (ii) increased division of demersal groups and separation of life history stages of hake, (iii) inclusion of mesopelagic fish, and (iv) incorporation of the jumbo squid ( Dosidicus gigas), which became abundant following EN. Results show that EN reduced the size and organization of energy flows of the NHCE, but the overall functioning (proportion of energy flows used for respiration, consumption by predators, detritus and export) of the ecosystem was maintained. The reduction of diatom biomass during EN forced omnivorous planktivorous fish to switch to a more zooplankton-dominated diet, raising their trophic level. Consequently, in the EN model the trophic level increased for several predatory groups (mackerel, other large pelagics, sea birds, pinnipeds) and for fishery catch. A high modeled biomass of macrozooplankton was needed to balance the consumption by planktivores, especially during EN condition when observed diatoms biomass diminished dramatically. Despite overall lower planktivorous fish catches, the higher primary production required-to-catch ratio implied a

  12. Recovery of African wild dogs suppresses prey but does not trigger a trophic cascade

    Science.gov (United States)

    Large carnivores can powerfully shape ecosystems by directly suppressing herbivores, thereby indirectly benefitting plants in a process known as a trophic cascade. In 2002, after a 20-year absence, African wild dogs (Lycaon pictus) recolonized the Laikipia Plateau in central Kenya. We hypothesized t...

  13. Trophic ecology and food consumption of fishes in a hypersaline tropical lagoon.

    Science.gov (United States)

    Almeida-Silva, P H; Tubino, R A; Zambrano, L C; Hunder, D A; Garritano, S R; Monteiro-Neto, C

    2015-06-01

    This study evaluated the trophic ecology (diet composition, trophic strategy, similarities and overlap between species, feeding period and food consumption) of six benthivorous fish species in Araruama Lagoon, the largest hypersaline tropical lagoon on the east coast of South America, with an area of 210 km(2) and an average salinity of 52. The burrfish Chilomycterus spinosus fed on Anomalocardia flexuosa shell deposits, ingesting associated fauna. The caitipa mojarra Diapterus rhombeus differed from all other species, having not only the highest proportions of algae and Nematoda, but also feeding on polychaete tentacles. The two mojarras Eucinostomus spp. showed similar trophic strategies, feeding mostly on Polychaeta. The corocoro grunt Orthopristis ruber also fed mainly on Polychaeta, but differed from Eucinostomus spp. in secondary items. The whitemouth croacker Micropogonias furnieri fed mainly on small Crustacea at night, showing a high number of secondary prey items with low frequencies and high prey-specific abundance. The daily food consumption (g food g(-1) fish mass) for Eucinostomus argenteus was 0·012 and was 0·031 and 0·027 for M. furnieri in two different sampling events. The diet similarities between Araruama Lagoon and other brackish and marine environments indicate that hypersalinity is not a predominant factor shaping the trophic ecology of fishes in this lagoon. The stability of hypersaline conditions, without a pronounced gradient, may explain the presence of several euryhaline fishes and invertebrates well adapted to this condition, resulting in a complex food web. © 2015 The Fisheries Society of the British Isles.

  14. Trophic habits of mesostigmatid mites associated with bark beetles in Mexico

    Science.gov (United States)

    M. Patricia Chaires-Grijalva; Edith G. Estrada-Venegas; Armando Equihua-Martinez; John C. Moser; Stacy R. Blomquist

    2016-01-01

    Samples of bark and logs damaged by bark beetles were collected from 16 states of Mexico from 2007 to 2012. Fifteen bark beetle species were found within the bark and log samples and were examined for phoretic mites and arthropod associates. Thirty-three species of mesostigmatid mites were discovered within the samples. They were identified in several trophic guilds...

  15. Ecological impact of transhumance on the trophic state of alpine lakes in Gran Paradiso National Park

    Directory of Open Access Journals (Sweden)

    Tiberti R.

    2014-01-01

    Full Text Available Transhumance – the summer transfer of livestock to highland pastures – is a traditional practice in the European Alps and is considered an integral part of the mountain ecosystem. Mountain lakes are generally oligotrophic systems and are particularly sensitive to the nutrient input caused by livestock. The aim of the present study was to quantify the impact of livestock grazing on the trophic state of high-altitude lakes in an area where transhumance is a traditional practice (Gran Paradiso National Park, Western Italian Alps, taking into account its dual value of ecosystem component and potential threat to lakes’ trophic status. The impact of flocks and herds grazing was estimated on sensitive parameters related to the trophic state of alpine lakes: water transparency, nutrient content, bacterial load and chlorophyll-a concentration. Transhumance produced a significant increase in the trophic state of lakes with high grazing pressure, but little or no effect was found at soft-impacted lakes. Even though heavy-impacted lakes represent a minority of the studied lakes (three out of twenty, we indicated conservation measures such as fencing, wastewater treatment and livestock exclosure to be tested in Gran Paradiso National Park.

  16. Mapping of trophic states based on nutrients concentration and phytoplankton abundance in Jatibarang Reservoir

    Science.gov (United States)

    Rudiyanti, Siti; Anggoro, Sutrisno; Rahman, Arif

    2018-02-01

    Jatibarang Reservoir is one of the Indonesian Reservoirs, which used for human activities such as tourism and agriculture. These activities will provide input of organic matter and nutrients into the water. These materials will impact water quality and eutrophication process. Eutrophication is the water enrichment by nutrients, especially nitrogen and phosphorus which can promote the growth of phytoplankton. Some indicators of eutrophication are increasing nutrients, trophic states, and change of phytoplankton composition. The relationship between water quality and phytoplankton community can be used as an indicator of trophic states in Jatibarang Reservoir. The aim of this study was to analyze the effect of nutrients concentration and phytoplankton abundance to the trophic states and mapping trophic states based on nutrients concentration and phytoplankton in Jatibarang Reservoir. This study was conducted in June and July 2017 at 9 stations around Jatibarang Reservoir. The results showed that average concentration of nitrate, phosphate, and chlorophyll-a in Jatibarang Reservoir was 0.69 mg/L, 0.27 mg/L, and 1.66 mg/m3, respectively. The phytoplankton abundance ranged 16-62,200 cells/L, consists of 21 genera of four classes, i.e. Chlorophyceae, Cyanophyceae, Bacillariophyceae, and Dinophyceae. Cyanophyceae was a dominant phytoplankton group based on the composition of abundance (>80%). High nutrient concentrations and phytoplankton dominated by Anabaena (Cyanophyceae) which indicated that the waters in Jatibarang Reservoir were eutrophic.

  17. Temporal changes in periphytic meiofauna in lakes of different trophic states

    Directory of Open Access Journals (Sweden)

    Kurt Pettersson

    2012-01-01

    Full Text Available Meiofaunal organisms in the periphyton of stony hard-substrates (epilithon were studied in three Swedish lakes with different trophic states (oligo-, meso- and eutrophic with respect to seasonal successions in abundance, biomass, and production. Over a period of 2 years, the meiofaunal population of all three lakes fluctuated greatly, with densities varying up to nine-fold within a season. In the oligotrophic lake, a significant decrease in meiofauna in winter was striking, whereas in the other two lakes, richer in nutrients, there was a pronounced peak in early summer. Although the lakes, on average, did not differ in epilithic organic and inorganic material, the differences in meiofaunal abundance, biomass, and production were significant. Correlation analysis revealed that altogether the meiofaunal biomass was positively related to the lakes’ trophic state (total phosphorus, while the meiofaunal abundance and production along the trophic spectrum displayed a humped-shape distribution, with maximum values measured in the mesotrophic Lake Erken (1324 ind cm-2 and 2249 mg DW cm-2 y-1. Nematodes were the dominant meiofaunal group in the epilithon of all three lakes, accounting for up to 58% in abundance, 33% in biomass and 55% in production of the whole meiofaunal community. However, their relative importance tended to decrease with increasing trophic state. Beside nematodes, rotifers, oligochaetes, copepods and tardigrades were also found in large numbers in the epilithon. Overall, the results demonstrated that, due to their high abundance, biomass, and production, meiofaunal organisms play an important role in epilithic communities.

  18. Trophic ecology of Lepidoptera larvae associated with woody vegetation in a savanna ecosystem

    CSIR Research Space (South Africa)

    Scholtz, CH

    1982-06-01

    Full Text Available This study represents a quantitative survey of a Lepidoptera community and deals with the trophic ecology of the 27 species of foliage-feeding Lepidoptera on the eight dominant woody plants in the Burkea africana-Eragrostis pallens savanna...

  19. Trophic Structure Over the Northern Mid-Atlantic Ridge: The Bathypelagic Zone Really Matters

    Science.gov (United States)

    We present preliminary results and ongoing efforts to characterize the trophic structure and energy flow of the pelagic ecosystems of the northern Mid-Atlantic Ridge (MAR), from Iceland to the Azores. This study is one component of the international CoML field project MAR-ECO (ww...

  20. Effects of sexual dimorphism and landscape composition on the trophic behavior of Greater Prairie-Chicken.

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    Beatriz Blanco-Fontao

    Full Text Available Partitioning of ecological niche is expected in lekking species that show marked sexual size dimorphism as a consequence of sex-specific ecological constraints. However, niche partitioning is uncertain in species with moderate sexual dimorphism. In addition, the ecological niche of a species may also be affected by landscape composition; particularly, agricultural fragmentation may greatly influence the trophic behavior of herbivores. We studied trophic niche variation in Greater Prairie-Chickens (Tympanuchus cupido, a grouse species that shows moderate sex-dimorphism. Greater Prairie-Chickens are native to tallgrass prairies of North America, although populations persist in less natural mosaics of cropland and native habitats. We used stable isotope analysis of carbon and nitrogen in blood, claws and feathers to assess seasonal differences in trophic niche breadth and individual specialization between male and female Greater Prairie-Chickens, and between birds living in continuous and fragmented landscapes. We found that females showed broader niches and higher individual specialization than males, especially in winter and autumn. However, differences between females and males were smaller in spring when birds converge at leks, suggesting that females and males may exhibit similar feeding behaviors during the lekking period. In addition, we found that birds living in native prairies showed greater annual trophic variability than conspecifics in agricultural mosaic landscapes. Native habitats may provide greater dietary diversity, resulting in greater diversity of feeding strategies.

  1. Ecosystem differences in the trophic enrichment of 13C in aquatic food webs

    International Nuclear Information System (INIS)

    France, R.L.; Peters, R.H.

    1997-01-01

    Data from 35 published studies were collated to examine patterns in the trophic enrichment of 13 C of consumers. Because both δ 13 C and δ 14 N vary systematically across ecosystems, it was necessary to standardize for such differences before combining data from numerous sources. Relationships of these measures of ecosystem-standardized δ 13 C to ecosystem-standardized trophic position (Δδ 15 N) for freshwater, estuarine, coastal, and open-ocean and for all aquatic ecosystems yielded regression equations of low predictive capability (average of 20% explained variance in δ 13 C). However, differences were observed in the slopes between δ 13 C and standardized trophic position when data were examined study-specifically: the average trophic fractionation of 13 C was found to increase from +0.2micron for freshwater to +0.5micron for estuarine to +0.8micron for coastal, and to +1.1micron for open-ocean food webs. This ecosystem-specific gradient in 13 C enrichment for consumers supports previous findings of a similar continuum existing for zooplankton - particulate organic matter differences in δ 13 C. Possible mechanisms to explain these ecosystem-specific patterns in 13 C enrichment may be related to the relative importance of detritus, heterotrophic respiration, partial reliance on alternative food sources, and lipid influences in the different ecosystems. (author)

  2. Long-chain omega-3 from low-trophic-level fish provides value to farmed seafood.

    Science.gov (United States)

    Bibus, Douglas M

    2015-03-01

    Low-trophic-level fish are a crucial source of long-chain (LC) omega-3 fatty acids for farmed fish and humans. Many farm-raised fish species have a clear need for these nutrients. Farmed fish deposit the LC omega-3s in their flesh and transfer them up the food chain. However, the content of LC omega-3s in farm-raised seafood continues to decline, while the content of shorter-chain plant-sourced omega-3s, and pro-inflammtory omega-6s continue to increase. This reduces its nutritional worth. The value of low-trophic-level fish is often viewed merely as its price at the dock. Some reports and metrics steer public attention towards the mass balance between quantities of low-trophic-level fish and farmed seafood. However, the the nutritional value of seafood is more important than its mere quantities. The role of low-trophic-level fish in human nutrition, health, and wellbeing is a fundamental component of its economic value to society.

  3. Combined Influence of Landscape Composition and Nutrient Inputs on Lake Trophic Structure

    Science.gov (United States)

    The concentration of chlorophyll a is a measure of the biological productivity of a lake and is largely (but not exclusively) determined by available nutrients. As nutrient inputs increase, productivity increases and lakes transition from low trophic state (e.g. oligotrophic) to...

  4. Exploring the Use of Multimedia Fate and Bioaccumulation Models to Calculate Trophic Magnification Factors (TMFs)

    Science.gov (United States)

    The trophic magnification factor (TMF) is considered to be a key metric for assessing the bioaccumulation potential of organic chemicals in food webs. Fugacity is an equilibrium criterion and thus reflects the relative thermodynamic status of a chemical in the environment and in ...

  5. Trophic transfer of differently functionalized zinc oxide nanoparticles from crustaceans (Daphnia magna) to zebrafish (Danio rerio)

    DEFF Research Database (Denmark)

    Skjolding, Lars Michael; Winther-Nielsen, M.; Baun, Anders

    2014-01-01

    ) higher than toxic levels reported for zinc in D. magna. Consequently, the zinc recovered in the animals was not solely due to soluble zinc, but agglomerates/aggregates of ZnO NP or ZnO-octyl NP contributed to the body burdens. The trophic transfer study showed uptake of both ZnO NP and ZnO-octyl NP...

  6. Adaptive behaviour, tri-trophic food-web stability and damping of chaos

    DEFF Research Database (Denmark)

    Visser, Andre; Mariani, Patrizio; Pigolotti, Simone

    2012-01-01

    We examine the effect of adaptive foraging behaviour within a tri-trophic food web with intra-guild predation. The intra-guild prey is allowed to adjust its foraging effort so as to achieve an optimal per capita growth rate in the face of realized feeding, predation risk and foraging cost. Adapti...

  7. Review of Lepidoptera with trophic relationships to Picea abies (L. in the conditions of Czechia

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    Modlinger Roman

    2016-12-01

    Full Text Available Trophic relationships of Lepidoptera (Insecta occurring in the territory of Czechia to the Norway spruce (Picea abies L. was evaluated on the basis of the excerption and critical evaluation of literature. Each species was classified into the following categories – spruce as the host plant, regular development on spruce, narrow trophic relationship, indirect relationship and episodical occurrence. The particular taxa were also characterized according to their distribution and the form of larval life was specified. The development on spruce was documented in 96 species of Lepidoptera, which represented less than 3% of taxa belonging to this group and being reported from Czechia. Of that, spruce was a common host plant for 67 species, 23 species were polyphagous and might develop on spruce, and 6 species belonged to soil species damaging spruce roots, mainly in forest nurseries. Among the species of Lepidoptera, which regularly develop on spruce in the Czech conditions, 55 species were classified. As narrow specialists with special trophic relationship to spruce, 33 taxa could be considered. There were 15 spruce species with forestry importance, which were able to outbreak their populations regularly or irregularly. Among spruce species it was possible to classify 16 taxa as rare. The provided information on Lepidoptera with trophic relationship to spruce is applicable also for other Central European areas. Besides the species with importance for forest pest management, also rare taxa, which can become endangered by climate change or by forest management, were indicated.

  8. Diet compositions and trophic guild structure of the eastern Chukchi Sea demersal fish community

    Science.gov (United States)

    Whitehouse, George A.; Buckley, Troy W.; Danielson, Seth L.

    2017-01-01

    Fishes are an important link in Arctic marine food webs, connecting production of lower trophic levels to apex predators. We analyzed 1773 stomach samples from 39 fish species collected during a bottom trawl survey of the eastern Chukchi Sea in the summer of 2012. We used hierarchical cluster analysis of diet dissimilarities on 21 of the most well sampled species to identify four distinct trophic guilds: gammarid amphipod consumers, benthic invertebrate generalists, fish and shrimp consumers, and zooplankton consumers. The trophic guilds reflect dominant prey types in predator diets. We used constrained analysis of principal coordinates (CAP) to determine if variation within the composite guild diets could be explained by a suite of non-diet variables. All CAP models explained a significant proportion of the variance in the diet matrices, ranging from 7% to 25% of the total variation. Explanatory variables tested included latitude, longitude, predator length, depth, and water mass. These results indicate a trophic guild structure is present amongst the demersal fish community during summer in the eastern Chukchi Sea. Regular monitoring of the food habits of the demersal fish community will be required to improve our understanding of the spatial, temporal, and interannual variation in diet composition, and to improve our ability to identify and predict the impacts of climate change and commercial development on the structure and functioning of the Chukchi Sea ecosystem.

  9. An In Vivo Characterization of Trophic Factor Production Following Neural Precursor Cell or Bone Marrow Stromal Cell Transplantation for Spinal Cord Injury

    Science.gov (United States)

    Hawryluk, Gregory W.J.; Mothe, Andrea; Wang, Jian; Wang, Shelly; Tator, Charles

    2012-01-01

    Cellular transplantation strategies for repairing the injured spinal cord have shown consistent benefit in preclinical models, and human clinical trials have begun. Interactions between transplanted cells and host tissue remain poorly understood. Trophic factor secretion is postulated a primary or supplementary mechanism of action for many transplanted cells, however, there is little direct evidence to support trophin production by transplanted cells in situ. In the present study, trophic factor expression was characterized in uninjured, injured-untreated, injured-treated with transplanted cells, and corresponding control tissue from the adult rat spinal cord. Candidate trophic factors were identified in a literature search, and primers were designed for these genes. We examined in vivo trophin expression in 3 paradigms involving transplantation of either brain or spinal cord-derived neural precursor cells (NPCs) or bone marrow stromal cells (BMSCs). Injury without further treatment led to a significant elevation of nerve growth factor (NGF), leukemia inhibitory factor (LIF), insulin-like growth factor-1 (IGF-1), and transforming growth factor-β1 (TGF-β1), and lower expression of vascular endothelial growth factor isoform A (VEGF-A) and platelet-derived growth factor-A (PDGF-A). Transplantation of NPCs led to modest changes in trophin expression, and the co-administration of intrathecal trophins resulted in significant elevation of the neurotrophins, glial-derived neurotrophic factor (GDNF), LIF, and basic fibroblast growth factor (bFGF). BMSCs transplantation upregulated NGF, LIF, and IGF-1. NPCs isolated after transplantation into the injured spinal cord expressed the neurotrophins, ciliary neurotrophic factor (CNTF), epidermal growth factor (EGF), and bFGF at higher levels than host cord. These data show that trophin expression in the spinal cord is influenced by injury and cell transplantation, particularly when combined with intrathecal trophin infusion

  10. Extensive geographic and ontogenetic variation characterizes the trophic ecology of a temperate reef fish on southern California (USA) rocky reefs

    Science.gov (United States)

    Hamilton, Scott L.; Caselle, Jennifer E.; Lantz, Coulson A.; Egloff, Tiana L.; Kondo, Emi; Newsome, Seth D.; Loke-Smith, Kerri; Pondella, Daniel J.; Young, Kelly A.; Lowe, Christopher G.

    2015-01-01

    Interactions between predator and prey act to shape the structure of ecological communities, and these interactions can differ across space. California sheephead Semicossyphus pulcher are common predators of benthic invertebrates in kelp beds and rocky reefs in southern California, USA. Through gut content and stable isotope (δ13C and †15N) analyses, we investigated geographic and ontogenetic variation in trophic ecology across 9 populations located at island and mainland sites throughout southern California. We found extensive geographic variation in California sheephead diet composition over small spatial scales. Populations differed in the proportion of sessile filter/suspension feeders or mobile invertebrates in the diet. Spatial variation in diet was highly correlated with other life history and demographic traits (e.g. growth, survivorship, reproductive condition, and energy storage), in addition to proxies of prey availability from community surveys. Multivariate descriptions of the diet from gut contents roughly agreed with the spatial groupings of sites based on stable isotope analysis of both California sheephead and their prey. Ontogenetic changes in diet occurred consistently across populations, despite spatial differences in size structure. As California sheephead increase in size, diets shift from small filter feeders, like bivalves, to larger mobile invertebrates, such as sea urchins. Our results indicate that locations with large California sheephead present, such as many marine reserves, may experience increased predation pressure on sea urchins, which could ultimately affect kelp persistence. PMID:26246648

  11. Assessment of trophic ecomorphology in non-alligatoroid crocodylians and its adaptive and taxonomic implications.

    Science.gov (United States)

    Iijima, Masaya

    2017-08-01

    Although the establishment of trophic ecomorphology in living crocodylians can contribute to estimating feeding habits of extinct large aquatic reptiles, assessment of ecomorphological traits other than the snout shape has scarcely been conducted in crocodylians. Here, I tested the validity of the proposed trophic ecomorphological traits in crocodylians by examining the correlation between those traits and the snout shape (an established trophic ecomorphology), using 10 non-alligatoroid crocodylian species with a wide range of snout shape. I then compared the ontogenetic scaling of trophic ecomorphology to discuss its adaptive and taxonomic significance. The results demonstrated that degree of heterodonty, tooth spacing, size of supratemporal fenestra (STF), ventral extension of pterygoid flange and length of lower jaw symphysis are significantly correlated with snout shape by both non-phylogenetic and phylogenetic regression analyses. Gavialis gangeticus falls outside of 95% prediction intervals for the relationships of some traits and the snout shape, suggesting that piscivorous specialization involves the deviation from the typical transformation axis of skull characters. The comparative snout shape ontogeny revealed a universal trend of snout widening through growth in the sampled crocodylians, implying the existence of a shared size-dependent biomechanical constraint in non-alligatoroid crocodylians. Growth patterns of other traits indicated that G. gangeticus shows atypical trends for degree of heterodonty, size of STF, and symphysis length, whereas the same trends are shared for tooth spacing and ventral extension of pterygoid flange among non-alligatoroid crocodylians. These suggest that some characters are ontogenetically labile in response to prey preference shifts through growth, but other characters are in keeping with the conserved biomechanics among non-alligatoroid crocodylians. Some important taxonomic characters such as the occlusal pattern are

  12. Trophic Cascades Induced by Lobster Fishing Are Not Ubiquitous in Southern California Kelp Forests

    Science.gov (United States)

    Guenther, Carla M.; Lenihan, Hunter S.; Grant, Laura E.; Lopez-Carr, David; Reed, Daniel C.

    2012-01-01

    Fishing can trigger trophic cascades that alter community structure and dynamics and thus modify ecosystem attributes. We combined ecological data of sea urchin and macroalgal abundance with fishery data of spiny lobster (Panulirus interruptus) landings to evaluate whether: (1) patterns in the abundance and biomass among lobster (predator), sea urchins (grazer), and macroalgae (primary producer) in giant kelp forest communities indicated the presence of top-down control on urchins and macroalgae, and (2) lobster fishing triggers a trophic cascade leading to increased sea urchin densities and decreased macroalgal biomass. Eight years of data from eight rocky subtidal reefs known to support giant kelp forests near Santa Barbara, CA, USA, were analyzed in three-tiered least-squares regression models to evaluate the relationships between: (1) lobster abundance and sea urchin density, and (2) sea urchin density and macroalgal biomass. The models included reef physical structure and water depth. Results revealed a trend towards decreasing urchin density with increasing lobster abundance but little evidence that urchins control the biomass of macroalgae. Urchin density was highly correlated with habitat structure, although not water depth. To evaluate whether fishing triggered a trophic cascade we pooled data across all treatments to examine the extent to which sea urchin density and macroalgal biomass were related to the intensity of lobster fishing (as indicated by the density of traps pulled). We found that, with one exception, sea urchins remained more abundant at heavily fished sites, supporting the idea that fishing for lobsters releases top-down control on urchin grazers. Macroalgal biomass, however, was positively correlated with lobster fishing intensity, which contradicts the trophic cascade model. Collectively, our results suggest that factors other than urchin grazing play a major role in controlling macroalgal biomass in southern California kelp forests, and

  13. Limited trophic partitioning among sympatric delphinids off a tropical oceanic atoll.

    Directory of Open Access Journals (Sweden)

    Hillary Young

    Full Text Available Understanding trophic relationships among marine predators in remote environments is challenging, but it is critical to understand community structure and dynamics. In this study, we used stable isotope analysis of skin biopsies to compare the isotopic, and thus, trophic niches of three sympatric delphinids in the waters surrounding Palmyra Atoll, in the Central Tropical Pacific: the melon-headed whale (Peponocephala electra, Gray's spinner dolphin (Stenella longirostris longirostris, and the common bottlenose dolphin (Tursiops truncatus. δ15N values suggested that T. truncatus occupied a significantly higher trophic position than the other two species. δ13C values did not significantly differ between the three delphinds, potentially indicating no spatial partitioning in depth or distance from shore in foraging among species. The dietary niche area-determined by isotopic variance among individuals-of T. truncatus was also over 30% smaller than those of the other species taken at the same place, indicating higher population specialization or lower interindividual variation. For P. electra only, there was some support for intraspecific variation in foraging ecology across years, highlighting the need for temporal information in studying dietary niche. Cumulatively, isotopic evidence revealed surprisingly little evidence for trophic niche partitioning in the delphinid community of Palmyra Atoll compared to other studies. However, resource partitioning may happen via other behavioral mechanisms, or prey abundance or availability may be adequate to allow these three species to coexist without any such partitioning. It is also possible that isotopic signatures are inadequate to detect trophic partitioning in this environment, possibly because isotopes of prey are highly variable or insufficiently resolved to allow for differentiation.

  14. Trophic structure of the fouling community in Odessa Bay (Black Sea

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    A. Y. Varigin

    2016-06-01

    Full Text Available The trophic structure of the coastal fouling community of Odessa Bay (Black Sea, which was composed of 10 species of macrophytes, 57 invertebrate species and 4 species of fish, was determined. The basic trophic relationship between organisms composing the community is shown. A minimization of interspecific trophic competition within the community is noted. The main sources of food material entering the fouling community were determined. We show that a significant proportion of food in the form of detritus, dissolved organic matter and small planktonic organisms enters the community from the water column. Filtration and pumping activity of sestonophage-organisms, particularly mussels, helps to attract food material to the community. Primary producers of the community are macrophytes and microphytes, which develop on account of their photosynthetic activity and ensure the provision of food to herbivores. The trophic group of detritophages consumes different fractions of the detritus which accumulates in the byssus threads of bivalve molluscs. In this context, mussel druses act as sediment traps, collecting detritus. Numerous polyphages, which are essentially omnivores and do not usually lack food material, were noted in the community. A small group of carnivorous invertebrates, whose representatives actively attack small animals, was identified. The abundance of these species in the community was about 1%, and their biomass less than 0.6%. Fish living in macrophyte weeds are the consumers in the community. We determined that the highest relative abundance (over 36% in the fouling community was reached by sestonophages and polyphages. We found that the undisputed leader in the relative biomass (over 97% in the fouling community ofOdessaBaywas the sestonophages (mainly composed of mussels. We determined that the trophic structure index of the community was 0.94, which confirms the significant dominance in biomass of bivalves over other species in

  15. Nutrients distribution and trophic status assessment in the northern Beibu Gulf, China

    Science.gov (United States)

    Lai, Junxiang; Jiang, Fajun; Ke, Ke; Xu, Mingben; Lei, Fu; Chen, Bo

    2014-09-01

    Using historical and 2010 field data, the distribution of nutrients in the northern Beibu Gulf of China is described. There was a decreasing trend in the concentration of nutrients from the north coast to offshore waters of the northern Beibu Gulf, reflecting the influence of inputs from land-based sources. High concentrations of dissolved inorganic nitrogen (DIN) and phosphate (PO4-P) occurred mainly at Fangchenggang Bay, Qinzhou Bay, and Lianzhou Bay. Four different methods were used to assess eutrophication. The trophic status of the Beibu Gulf was characterized using the single factor, Eutrophication index (EI), Trophic index (TRIX) and Assessment of Estuarine Trophic Status (ASSETS) methods. Based on nutrient concentrations, 73.9% of DIN and 26.7% of PO4-P samples exceeded the fourth grade Seawater Quality Standard of China. Eutrophication index values varied widely, but higher levels of eutrophication were generally found in bays and estuaries. TRIX values ranged from 2.61 to 7.27, with an average of 4.98, indicating a mesotrophic and moderately productive system. A positive correlation between TRIX and harmful algal species richness and abundance was observed. The ASSETS model evaluates eutrophication status based on a Pressure-State-Response approach, including three main indices: influencing factors, overall eutrophic condition, and future outlook. The Beibu Gulf was graded as moderate using ASSETS. The single factor and Chinese nutrient index methods were considered inadequate for the assessment of trophic status. TRIX can be used as an indicator of trophic state and ASSETS showed good potential to assess eutrophication. The results of TRIX and ASSETS depend on threshold values. To establish these values, further research is required within the northern Beibu Gulf.

  16. Trophic Niche Differentiation in Rodents and Marsupials Revealed by Stable Isotopes.

    Directory of Open Access Journals (Sweden)

    Mauro Galetti

    Full Text Available Tropical rainforests support the greatest diversity of small mammals in the world, yet we have little understanding about the mechanisms that promote the coexistence of species. Diet partitioning can favor coexistence by lessening competition, and interspecific differences in body size and habitat use are usually proposed to be associated with trophic divergence. However, the use of classic dietary methods (e.g. stomach contents is challenging in small mammals, particularly in community-level studies, thus we used stable isotopes (δ13C and δ15N to infer about trophic niche. We investigated i how trophic niche is partitioned among rodent and marsupial species in three Atlantic forest sites and ii if interspecific body size and locomotor habit inequalities can constitute mechanisms underlying the isotopic niche partitioning. We found that rodents occupied a broad isotopic niche space with species distributed in different trophic levels and relying on diverse basal carbon sources (C3 and C4 plants. Surprisingly, on the other hand, marsupials showed a narrow isotopic niche, both in δ13C and δ15N dimensions, which is partially overlapped with rodents, contradicting their description as omnivores and generalists proposed classic dietary studies. Although body mass differences did not explained the divergence in isotopic values among species, groups of species with different locomotor habit presented clear differences in the position of the isotopic niche space, indicating that the use of different forest strata can favor trophic niche partitioning in small mammals communities. We suggest that anthropogenic impacts, such as habitat modification (logging, harvesting, can simplify the vertical structure of ecosystems and collapse the diversity of basal resources, which might affect negatively small mammals communities in Atlantic forests.

  17. Laboratory and field assessment of uranium trophic transfer efficiency in the crayfish Orconectes limosus fed the bivalve C. fluminea

    International Nuclear Information System (INIS)

    Simon, Olivier; Garnier-Laplace, Jacqueline

    2005-01-01

    At present, ecotoxicological information regarding the impact of natural uranium (U) on freshwater ecosystems via the trophic contamination route is scarce. We generated an experimental trophic food chain involving the prey species, Corbicula fluminea, and a predator, Orconectes limosus, for a 10-day and a 30-day feeding periods (food ration: one whole soft body/day/crayfish). We studied the efficiency of U trophic transfer and the distribution of U in the predator. During the test, we varied the quantity of dietary U (from beforehand contaminated bivalves at concentrations ranging from 0.9 ± 0.1 to 20.2 ± 9 μg/g fw provided to each crayfish over the 10 days) applying a daily feeding rate equal to 3.9 ± 0.8% fw. The efficiency of U trophic transfer from clams to crayfish varied between 1 and 13% depending on the prey exposure modalities. Accumulation of U was observed in the digestive gland but also in gills, in the muscle, and in the molt of the crayfish after trophic exposure treatments. Under high-level exposure conditions, the digestive gland was the main target-organ, however a significant accumulation was also observed in the stomach. With regard to low levels of trophic exposure, accumulation of U in gills, in the stomach, and in the digestive gland was of the same order of magnitude. Longer exposure period which incorporated a crayfish molt, resulted in a decrease of trophic transfer ratio and a modified U tissue distribution

  18. Trophic Ecology of Benthic Marine Invertebrates with Bi-Phasic Life Cycles: What Are We Still Missing?

    Science.gov (United States)

    Calado, Ricardo; Leal, Miguel Costa

    2015-01-01

    The study of trophic ecology of benthic marine invertebrates with bi-phasic life cycles is critical to understand the mechanisms shaping population dynamics. Moreover, global climate change is impacting the marine environment at an unprecedented level, which promotes trophic mismatches that affect the phenology of these species and, ultimately, act as drivers of ecological and evolutionary change. Assessing the trophic ecology of marine invertebrates is critical to understanding maternal investment, larval survival to metamorphosis, post-metamorphic performance, resource partitioning and trophic cascades. Tools already available to assess the trophic ecology of marine invertebrates, including visual observation, gut content analysis, food concentration, trophic markers, stable isotopes and molecular genetics, are reviewed and their main advantages and disadvantages for qualitative and quantitative approaches are discussed. The challenges to perform the partitioning of ingestion, digestion and assimilation are discussed together with different approaches to address each of these processes for short- and long-term fingerprinting. Future directions for research on the trophic ecology of benthic marine invertebrates with bi-phasic life cycles are discussed with emphasis on five guidelines that will allow for systematic study and comparative meta-analysis to address important unresolved questions. © 2015 Elsevier Ltd. All rights reserved.

  19. Short Communication: Growth of seaweed Eucheuma cottonii in multi trophic sea farming systems at Gerupuk Bay, Central Lombok, Indonesia

    Directory of Open Access Journals (Sweden)

    SUKIMAN

    2014-05-01

    Full Text Available Sukiman, Faturrahman, Rohyani IS, Ahyadi H. 2014. Growth of seaweed Eucheuma cottonii in multi trophic sea farming systems at Gerupuk Bay, Central Lombok, Indonesia. Nusantara Bioscience 6: 82-85. Eucheuma cottonii is a seaweed commodity that has a high economic value because it contains compounds used as raw materials for industries. Various methods of seaweed farming have been developed, one of which is a system of cultivation Multi Trophic Sea Farming. This study aimed to analyze the growth of E. cottonii by observing the production of biomass in four trophic combinations in the system Multi Trophic Sea Farming. The study was conducted in the area of the marine aquaculture Gerupuk bay, Central Lombok, Indonesia. Experiments were performed on four plots cages with trophic combination treatment as follows: K1 (E. cottonii-lobster-abalone, K2 (E. cottonii-abalone-red carp, K3 (E. cottonii-abalone-grouper, and K4 (E. cottonii-abalone-pomfret fish. Seedling of E. cottonii weighing 50 g was tied to a rope and placed at a depth of 5 cm, 50 cm, 100 cm and 150 cm. Measurement of biomass production was done every ten days until the thirtieth day. The highest biomass production of E. cottonii was obtained in K3 trophic combination (E. cottonii-abalone-grouper fish with a depth of seedlings of 5 cm. The combination of K3 trophic is recommended for cultivation of seaweed in the MTSF system.

  20. Theodoro Peckolt: a produção científica de um pioneiro da fitoquímica no Brasil Theodoro Peckolt: the scientific work of a pioneer in phytochemistry in Brazil

    Directory of Open Access Journals (Sweden)

    Nadja Paraense dos Santos

    2005-08-01

    Full Text Available Este trabalho descreve, analisa e avalia a produção científica de Theodoro Peckolt, naturalista e farmacêutico alemão, e sua contribuição decisiva para o desenvolvimento da fitoquímica no Brasil. Suas realizações são discutidas tendo como pano de fundo o meio cultural e científico do século XIX, compondo o seu legado e influência nas ciências brasileiras.The article describes, analyzes, and evaluates the scientific production of Theodoro Peckolt, a German naturalist and pharmacist who made a decisive contribution to the development of phytochemistry in Brazil. His achievements are discussed against the backdrop of the nineteenth-century cultural and scientific milieu, revealing his legacy and influence in the Brazilian sciences.

  1. Ocean Acidification-Induced Food Quality Deterioration Constrains Trophic Transfer

    OpenAIRE

    Rossoll, Dennis; Bermúdez, Rafael; Hauss, Helena; Schulz, Kai G.; Riebesell, Ulf; Sommer, Ulrich; Winder, Monika

    2012-01-01

    Our present understanding of ocean acidification (OA) impacts on marine organisms caused by rapidly rising atmospheric carbon dioxide (CO(2)) concentration is almost entirely limited to single species responses. OA consequences for food web interactions are, however, still unknown. Indirect OA effects can be expected for consumers by changing the nutritional quality of their prey. We used a laboratory experiment to test potential OA effects on algal fatty acid (FA) composition and resulting c...

  2. Infusing considerations of trophic dependencies into species distribution modelling.

    Science.gov (United States)

    Trainor, Anne M; Schmitz, Oswald J

    2014-12-01

    Community ecology involves studying the interdependence of species with each other and their environment to predict their geographical distribution and abundance. Modern species distribution analyses characterise species-environment dependency well, but offer only crude approximations of species interdependency. Typically, the dependency between focal species and other species is characterised using other species' point occurrences as spatial covariates to constrain the focal species' predicted range. This implicitly assumes that the strength of interdependency is homogeneous across space, which is not generally supported by analyses of species interactions. This discrepancy has an important bearing on the accuracy of inferences about habitat suitability for species. We introduce a framework that integrates principles from consumer-resource analyses, resource selection theory and species distribution modelling to enhance quantitative prediction of species geographical distributions. We show how to apply the framework using a case study of lynx and snowshoe hare interactions with each other and their environment. The analysis shows how the framework offers a spatially refined understanding of species distribution that is sensitive to nuances in biophysical attributes of the environment that determine the location and strength of species interactions. © 2014 John Wiley & Sons Ltd/CNRS.

  3. Exploring crowded trophic niche space in a novel reservoir fish assemblage: how many predators is too many?

    Science.gov (United States)

    Winters, Lisa K.; Budy, Phaedra

    2015-01-01

    In highly managed reservoir systems, species interactions within novel fish assemblages can be difficult to predict. In high-elevation Scofield Reservoir in Utah the unintentional introduction of Utah Chub Gila atraria and subsequent population expansion prompted a shift from stocking exclusively Rainbow Trout Oncorhynchus mykiss to include tiger trout (female Brown Trout Salmo trutta × male Brook Trout Salvelinus fontinalis) and Bonneville Cutthroat Trout O. clarkii utah, which composed a novel suite of top predators and potential competitors. We examined the interspecific interactions among Scofield Reservoir piscivores using a multifaceted approach including gut analyses, stable isotopes, and gape limitation. Large Cutthroat Trout consumed 50–100% Utah Chub and tiger trout consumed 45–80%. In contrast, small and large Rainbow Trout consumed primarily invertebrate prey and exhibited significant overlap with small tiger trout, Cutthroat Trout, and Utah Chub. Large Cutthroat Trout and tiger trout occupy a top piscivore trophic niche and are more littoral, while Rainbow Trout occupy an omnivore niche space and are more pelagic. Both Cutthroat and tiger trout varied in niche space with respect to size-class, demonstrating an ontogenetic shift to piscivory at approximately 350 mm TL. Cutthroat Trout and tiger trout are capable of consuming prey up to 50% of their own size, which is larger than predicted based on their theoretical gape limit. Because it appears food resources (Utah Chub) are not limited, and performance metrics are high, competition is unlikely between Cutthroat Trout and tiger trout. In contrast, apparent survival of Rainbow Trout has recently declined significantly, potentially due to shared food resources with Utah Chub or negative behavioral interactions with other members of the community. Collectively, this research aids in understanding biotic interactions within a top-heavy and novel fish community and assists towards developing

  4. The Wide Potential Trophic Niche of the Asiatic Fruit Fly Drosophila suzukii: The Key of Its Invasion Success in Temperate Europe?

    Science.gov (United States)

    Poyet, Mathilde; Le Roux, Vincent; Gibert, Patricia; Meirland, Antoine; Prévost, Geneviève; Eslin, Patrice; Chabrerie, Olivier

    2015-01-01

    The Asiatic fruit fly Drosophila suzukii has recently invaded Europe and North and South America, causing severe damage to fruit production systems. Although agronomic host plants of that fly are now well documented, little is known about the suitability of wild and ornamental hosts in its exotic area. In order to study the potential trophic niche of D. suzukii with relation to fruit characteristics, fleshy fruits from 67 plant species were sampled in natural and anthropic ecosystems (forests, hedgerows, grasslands, coastal areas, gardens and urban areas) of the north of France and submitted to experimental infestations. A set of fruit traits (structure, colour, shape, skin texture, diameter and weight, phenology) potentially interacting with oviposition choices and development success of D. suzukii was measured. Almost half of the tested plant species belonging to 17 plant families allowed the full development of D. suzukii. This suggests that the extreme polyphagy of the fly and the very large reservoir of hosts producing fruits all year round ensure temporal continuity in resource availability and contribute to the persistence and the exceptional invasion success of D. suzukii in natural habitats and neighbouring cultivated systems. Nevertheless, this very plastic trophic niche is not systematically beneficial to the fly. Some of the tested plants attractive to D. suzukii gravid females stimulate oviposition but do not allow full larval development. Planted near sensitive crops, these “trap plants” may attract and lure D. suzukii, therefore contributing to the control of the invasive fly. PMID:26581101

  5. Trait and density mediated indirect interactions in simple food webs

    Czech Academy of Sciences Publication Activity Database

    Křivan, Vlastimil; Schmith, O. J.

    2004-01-01

    Roč. 107, č. 2 (2004), s. 239-250 ISSN 0030-1299 R&D Projects: GA ČR GA201/03/0091 Institutional research plan: CEZ:AV0Z5007907 Keywords : Predator-prey dynamics * trophic interactions * antipredator behavior Subject RIV: EH - Ecology, Behaviour Impact factor: 2.901, year: 2004

  6. Plant interactions with multiple insect herbivores: from community to genes

    NARCIS (Netherlands)

    Stam, J.M.; Kroes, A.; Li, Y.; Gols, R.; Loon, van J.J.A.; Poelman, E.H.; Dicke, M.

    2014-01-01

    Every plant is a member of a complex insect community that consists of tens to hundreds of species that belong to different trophic levels. The dynamics of this community are critically influenced by the plant, which mediates interactions between community members that can occur on the plant

  7. Trophic structure in a pilot system for the integrated multi-trophic aquaculture off the east coast of Korean peninsula as determined by stable isotopes

    International Nuclear Information System (INIS)

    Park, Hyun Je; Han, Eunah; Lee, Won Chan; Kwak, Jung Hyun; Kim, Hyung Chul; Park, Mi Seon; Kang, Chang-Keun

    2015-01-01

    Highlights: • A pilot system for the integrated multi-trophic aquaculture was installed. • The black rockfish, sea cucumber, oyster, and macroalgae were co-cultured. • Co-cultured sea cucumber at the IMTA site assimilated aquaculture wastes. • Fish cage-waste contribution to food web in/around the IMTA system was minor. • The sea cucumber was identified as an extractive species of fish cage wastes. - Abstract: To assess the potential for nutritional exploitation of caged-fish-derived waste through the use of extractive co-cultured species in a pilot system for an integrated multi-trophic aquaculture (IMTA), we compared their C and N stable isotope ratios with those of uncultured macroinvertebrates in and around the system. Black rockfish were co-cultured with sea cucumber, oyster, and two macroalgae as extractive species. Isotope signatures of the co-cultured sea cucumber at the IMTA site differed from those at the control site, indicating their assimilation of aquaculture wastes. In contrast, δ 13 C and δ 15 N of individual taxa of the cultured oyster and uncultured invertebrates were consistent between sites, suggesting a minor contribution of the aquaculture waste to benthic and pelagic food chains in and around the IMTA system. These results provide evidence of the suitability of using sea cucumber as an extractive species to reduce the impact of a monoculture system on the ambient environment

  8. Spatial and Temporal Variations of Water Quality and Trophic Status in Sembrong Reservoir, Johor

    Science.gov (United States)

    Intan Najla Syed Hashim, Syarifah; Hidayah Abu Talib, Siti; Salleh Abustan, Muhammad

    2018-03-01

    A study of spatial and temporal variations on water quality and trophic status was conducted to determine the temporal (average reading by month) and spatial variations of water quality in Sembrong reservoir and to evaluate the trophic status of the reservoir. Water samples were collected once a month from November 2016 to June 2017 in seventeen (17) sampling stations at Sembrong Reservoir. Results obtained on the concentration of dissolved oxygen (DO), water temperature, pH and secchi depth had no significant differences compared to Total Phosphorus (TP) and chlorophyll-a. The water level has significantly decreased the value of the water temperature, pH and TP. The water quality of Sembrong reservoir is classified in Class II which is suitable for recreational uses and required conventional treatment while TSI indicates that sembrong reservoir was in lower boundary of classical eutrophic (TSI > 50).

  9. Trophic ecology of Mustelus schmitti (Springer, 1939) in a nursery area of northern Patagonia

    Science.gov (United States)

    Molina, Juan Manuel; Cazorla, Andrea López

    2011-05-01

    Mustelus schmitti is an endangered endemic shark of the southwest Atlantic, and an important economical resource in Argentina, Brazil and Uruguay. The objective of this study was to describe the trophic ecology of M. schmitti in Anegada Bay, its feeding strategy and diet composition, along with the possible dietary shifts, due to season, sex, ontogeny and the different geographical features of the bay. Our results show that M. schmitti is a carnivorous opportunistic predator, feeding on a variety of benthic invertebrates. The diet presented seasonal and ontogenetic variations, while no differences in diet composition were observed between sexes or the different sampling sites. This species behave as a generalize feeder, with a wide trophic spectrum and a diverse diet.

  10. Platforms of the Nicaraguan Rise: Examples of the sensitivity of carbonate sedimentation to excess trophic resources

    Science.gov (United States)

    Hallock, Pamela; Hine, Albert C.; Vargo, Gabriel A.; Elrod, Jane A.; Jaap, Walter C.

    1988-12-01

    The Nicaraguan Rise is an active tectonic structure in the western Caribbean. Carbonate accumulation on its platforms has not kept pace with relative Holocene sea-level rise, despite a tropical location remote from terrigenous sedimentation. Trophic resources apparently exceed levels favoring coral-reef development because sponge-algal communities dominate the drowning western platforms, in contrast to mixed coral-algal benthos on Pedro Bank and well- developed coral reefs along the north coast of Jamaica. Concentrations of biotic pigments in sea-surface waters show a corresponding west-east gradient; oceanic waters flowing over the western banks carry nearly twice as much biotic pigment as oceanic waters north of Jamaica. Sources enriching the western Caribbean are terrestrial runoff, upwelling off northern South America, and topographic upwelling over the Nicaraguan Rise. That relatively modest levels of trophic resources can suppress coral-reef development holds important implications for understanding carbonate platform drownings in the geologic record.

  11. Use of satellite imagery to assess the trophic state of Miyun Reservoir, Beijing, China

    International Nuclear Information System (INIS)

    Wang Zhengjun; Hong Jianming; Du Guisen

    2008-01-01

    The objective of this research is to explore an appropriate way of monitoring and assessing water quality by satellite remote sensing techniques in the Miyun reservoir of Beijing, China. Two scene Thematic Mapper images in May and October of 2003 were acquired and simultaneous in situ measurements, sampling and analysis were conducted. Statistical analysis indicates that satellite-based normalized ratio vegetation index (NRVI) and in situ measured water chlorophyll a (Chl-a) concentration have very high correlation. Two linear regression models with high determination coefficients were constructed for NRVI and Chl-a of sample points. According to the modified trophic state index map, water quality in the western section of Miyun reservoir was consistently higher than in the eastern section during the two months tested. The trophic grade of the eastern reservoir remained mesotrophic with a tendency for eutrophication. - Remote sensing techniques can effectively monitor the change of water quality with time and space

  12. The functional biology and trophic role of krill (Thysanoessa raschii) in a Greenlandic fjord

    DEFF Research Database (Denmark)

    Agersted, Mette Dalgaard; Nielsen, Torkel Gissel; Munk, Peter

    2011-01-01

    Despite being a key zooplankton group, knowledge on krill biology from the Arctic is inadequate. The present study examine the functional biology and evaluate the trophic role of krill in the GodthAyenbsfjord (64 degrees N, 51 degrees W) SW Greenland, through a combination of fieldwork...... and laboratory experiments. Krill biomass was highest in the middle fjord and inner fjord, whereas no krill was found offshore. The dominating species Thysanoessa raschii revealed a type III functional response when fed with the diatom Thalassiosira weissflogii. At food saturation, T. raschii exhibited a daily...... ration of 1% body C d(-1). Furthermore, T. raschii was capable of exploiting plankton cells from 5 to 400 mu m, covering several trophic levels of the pelagic food web. The calculated grazing impact by T. raschii on the fjord plankton community was negligible. However, the schooling and migratory...