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Sample records for pseudostaurosira fragilaria elliptica

  1. Chemical constituents of Salacia elliptica (Celastraceae

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    Lucienir Pains Duarte

    2010-01-01

    Full Text Available The chemical investigation of Salacia elliptica allowed to the isolation of 20 constituents: two polyols, one xanthone, a mixture of long chain hydrocarbons, one carboxylic acid, one polymer, two steroidal compounds, one aromatic ester and eleven pentacyclic triterpenes. These triterpenes include 3β-stearyloxy-oleanane, 3β-stearyloxy-ursane, one seco-friedelane, and eight compounds of the friedelane serie. The chemical structure and the relative configuration of a new triterpene 1,3-dioxo-16α-hydroxyfriedelane (15 were established through ¹H and 13C NMR including 2D experiments (HMBC, HMQC, COSY and NOESY and herein reported for the first time.

  2. Chemical constituents of Salacia elliptica (Celastraceae)

    Energy Technology Data Exchange (ETDEWEB)

    Duarte, Lucienir Pains; Figueiredo, Rute Cunha; Sousa, Grasiely Faria de; Soares, Debora Barbosa da Silva; Rodrigues, Salomao Bento Vasconcelos; Silva, Fernando Cesar; Silva, Gracia Divina de Fatima, E-mail: lucienir@ufmg.b [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Quimica; Vieira Filho, Sidney Augusto [Universidade Federal de Ouro Preto, MG (Brazil). Escola de Farmacia. Dept. de Farmacia

    2010-07-01

    The chemical investigation of Salacia elliptica allowed to the isolation of 20 constituents: two polyols, one xanthone, a mixture of long chain hydrocarbons, one carboxylic acid, one polymer, two steroidal compounds, one aromatic ester and eleven pentacyclic triterpenes. These triterpenes include 3{beta}-stearyloxy-oleanane, 3{beta}-stearyloxy-ursane, one seco-friedelane, and eight compounds of the friedelane series. The chemical structure and the relative configuration of a new triterpene 1,3-dioxo-16alpha-hydroxyfriedelane (15) were established through {sup 1}H and {sup 13}C NMR including 2D experiments (HMBC, HMQC, COSY and NOESY) and herein reported for the first time (author)

  3. Phytochemical constituents, antioxidant and antibacterial activities of methanolic extract of Ardisia elliptica

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    Nazeh M. Al-Abd

    2017-06-01

    Conclusions: The results provide evidence that fruit and leaf of A. elliptica extracts might indeed be used as a potential source of effective natural antimicrobial and antioxidant agents in pharmaceutical and food industries.

  4. Antioxidant and antimicrobial properties of Litsea elliptica Blume and Litsea resinosa Blume (Lauraceae

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    Mui-Hung Wong

    2014-05-01

    Conclusions: Overall, methanol extracts from root and stem of both species showed antioxidant activity comparable to standard butylated hydroxytoluene. Extracts from L. resinosa demonstrated stronger antimicrobial properties compared to that from L. elliptica.

  5. Chemical constituents and leishmanicidal activity of Gustavia elliptica (Lecythidaceae); Constituintes quimicos e atividade leishmanicida de Gustavia elliptica (Lecythidaceae)

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Maria de Fatima Oliveira; Melo, Ana Claudia Rodrigues de; Pinheiro, Maria Lucia Belem; Silva, Jefferson Rocha de Andrade; Souza, Afonso Duarte Leao de, E-mail: souzadq@ufam.edu.br [Universidade Federal do Amazonas (UFAM), Manaus, AM (Brazil). Dept. de Quimica; Barison, Andersson; Campos, Francinete Ramos [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept. de Quimica; Amaral, Ana Claudia Fernandes [Fundacao Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, RJ (Brazil). Instituto de Tecnologia de Farmacos. Farmanguinhos; Machado, Gerzia Maria de Carvalho; Leon, Leonor Laura Pinto [Fundacao Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, RJ (Brazil). Dept. de Imunologia

    2011-07-01

    The phyto chemical investigation of the stem bark and leaves of G. elliptica provided a mixture of the norisoprenoids blumenol B and 6-epi blumenol B along with the triterpenes friedelin, as the major constituent, friedelan ol, ursa-9(11),12-dien-3-ol, a-amyrin, b-amyrin, morentenol, epifriedelanol, as well as the sesquiterpenes trans-caryophyllene, a-humulene, ethyl hydnocarpate and other fatty acid esters. The identification of the compounds was performed on basis of spectrometric methods such as GC-MS, IR, MS and 1D and 2D NMR. Stem bark extracts showed significant leishmanicidal activity against promastigote forms of Leishmania braziliensis, with the best results for the chloroform extract. (author)

  6. Note on the rare terrestrial orchid Apostasia elliptica found in Borneo

    NARCIS (Netherlands)

    Poulsen, A.D.

    1993-01-01

    Apostasia elliptica J.J. Smith has only been collected twice before, in Sumatra and on the Malay Peninsula. The species has now been found in Borneo. The collection by Bünnemeijer (107) from Sumatra, Westcoast Reserve, Ophir District, N of Talu represents the type and is deposited in BO. The Malay

  7. Anti-Inflammatory and Antibothropic Properties of Jatropha Elliptica, a Plant from Brazilian Cerrado Biome

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    Sára Costa Ferreira-Rodrigues

    2016-12-01

    Full Text Available Purpose: The aim of this study was to evaluate the antibothropic and anti-inflammatory properties of J. elliptica. Methods: Phytochemical screening and thin-layer chromatography (TLC assays were performed on J. elliptica hydroalcoholic extract (TE in order to observe its main constituents. The antibothropic activity of TE was evaluated by the in vitro neuromuscular blockade caused by Bothrops jararacussu venom (Bjssu, in a mouse phrenic nerve-diaphragm model (PND. A quantitative histological study was carried out to observe a possible protection of TE against the venom myotoxicity. The anti-inflammatory activity was also evaluated in two models, Bjssu-induced paw edema, and carrageenan-induced neutrophils migration in the peritoneal cavity. Results: TLC analysis revealed several compounds in TE, such as saponins, alkaloids, and phenolic constituents. TE was able to neutralize the blockade and the myotoxicity induced by venom, when it was pre-incubated for 30 min with venom. In addition, it showed anti-inflammatory activity, inducing less neutrophils migration and reducing paw edema. Conclusion: J. elliptica showed both antibothropic and anti-inflammatory properties.

  8. Transcriptome-Wide Analysis of Botrytis elliptica Responsive microRNAs and Their Targets in Lilium Regale Wilson by High-Throughput Sequencing and Degradome Analysis

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    Xue Gao

    2017-05-01

    Full Text Available MicroRNAs, as master regulators of gene expression, have been widely identified and play crucial roles in plant-pathogen interactions. A fatal pathogen, Botrytis elliptica, causes the serious folia disease of lily, which reduces production because of the high susceptibility of most cultivated species. However, the miRNAs related to Botrytis infection of lily, and the miRNA-mediated gene regulatory networks providing resistance to B. elliptica in lily remain largely unexplored. To systematically dissect B. elliptica-responsive miRNAs and their target genes, three small RNA libraries were constructed from the leaves of Lilium regale, a promising Chinese wild Lilium species, which had been subjected to mock B. elliptica treatment or B. elliptica infection for 6 and 24 h. By high-throughput sequencing, 71 known miRNAs belonging to 47 conserved families and 24 novel miRNA were identified, of which 18 miRNAs were downreguleted and 13 were upregulated in response to B. elliptica. Moreover, based on the lily mRNA transcriptome, 22 targets for 9 known and 1 novel miRNAs were identified by the degradome sequencing approach. Most target genes for elliptica-responsive miRNAs were involved in metabolic processes, few encoding different transcription factors, including ELONGATION FACTOR 1 ALPHA (EF1a and TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTOR 2 (TCP2. Furthermore, the expression patterns of a set of elliptica-responsive miRNAs and their targets were validated by quantitative real-time PCR. This study represents the first transcriptome-based analysis of miRNAs responsive to B. elliptica and their targets in lily. The results reveal the possible regulatory roles of miRNAs and their targets in B. elliptica interaction, which will extend our understanding of the mechanisms of this disease in lily.

  9. A Dynamic Energy Budget (DEB model to describe Laternula elliptica (King, 1832 seasonal feeding and metabolism.

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    Antonio Agüera

    Full Text Available Antarctic marine organisms are adapted to an extreme environment, characterized by a very low but stable temperature and a strong seasonality in food availability arousing from variations in day length. Ocean organisms are particularly vulnerable to global climate change with some regions being impacted by temperature increase and changes in primary production. Climate change also affects the biotic components of marine ecosystems and has an impact on the distribution and seasonal physiology of Antarctic marine organisms. Knowledge on the impact of climate change in key species is highly important because their performance affects ecosystem functioning. To predict the effects of climate change on marine ecosystems, a holistic understanding of the life history and physiology of Antarctic key species is urgently needed. DEB (Dynamic Energy Budget theory captures the metabolic processes of an organism through its entire life cycle as a function of temperature and food availability. The DEB model is a tool that can be used to model lifetime feeding, growth, reproduction, and their responses to changes in biotic and abiotic conditions. In this study, we estimate the DEB model parameters for the bivalve Laternula elliptica using literature-extracted and field data. The DEB model we present here aims at better understanding the biology of L. elliptica and its levels of adaptation to its habitat with a special focus on food seasonality. The model parameters describe a metabolism specifically adapted to low temperatures, with a low maintenance cost and a high capacity to uptake and mobilise energy, providing this organism with a level of energetic performance matching that of related species from temperate regions. It was also found that L. elliptica has a large energy reserve that allows enduring long periods of starvation. Additionally, we applied DEB parameters to time-series data on biological traits (organism condition, gonad growth to describe the

  10. Two Cytotoxic Coumarin Glycosides from the Aerial Parts of Diceratella elliptica (DC. Jonsell Growing in Egypt

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    Mona M. Marzouk

    2012-03-01

    Full Text Available Two new coumarin glycosides, 6-methoxy-5,7-dihydroxy-3,4-dihydrocoumarin-8-C-glucopyranoside (1 and 5-vinyl-6,7-dimethoxy-3,4-dihydrocoumarin-8-C-glucopyranoside (2, along with four known flavonoid compounds, were isolated from the aerial parts of Diceratella elliptica (DC. Jonsell growing in Egypt. Their structures were established on the basis of detailed chromatographic and spectroscopic techniques (UV, 1D NMR, 2D NMR, and ESIMS. Compounds 1 and 2 were evaluated for their cytotoxic activity and showed relatively high activity against three human carcinoma cell lines; liver (HEPG2, cervix (HELA and colon (HCT116.

  11. A Dynamic Energy Budget (DEB) model to describe Laternula elliptica (King, 1832) seasonal feeding and metabolism.

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    Agüera, Antonio; Ahn, In-Young; Guillaumot, Charlène; Danis, Bruno

    2017-01-01

    Antarctic marine organisms are adapted to an extreme environment, characterized by a very low but stable temperature and a strong seasonality in food availability arousing from variations in day length. Ocean organisms are particularly vulnerable to global climate change with some regions being impacted by temperature increase and changes in primary production. Climate change also affects the biotic components of marine ecosystems and has an impact on the distribution and seasonal physiology of Antarctic marine organisms. Knowledge on the impact of climate change in key species is highly important because their performance affects ecosystem functioning. To predict the effects of climate change on marine ecosystems, a holistic understanding of the life history and physiology of Antarctic key species is urgently needed. DEB (Dynamic Energy Budget) theory captures the metabolic processes of an organism through its entire life cycle as a function of temperature and food availability. The DEB model is a tool that can be used to model lifetime feeding, growth, reproduction, and their responses to changes in biotic and abiotic conditions. In this study, we estimate the DEB model parameters for the bivalve Laternula elliptica using literature-extracted and field data. The DEB model we present here aims at better understanding the biology of L. elliptica and its levels of adaptation to its habitat with a special focus on food seasonality. The model parameters describe a metabolism specifically adapted to low temperatures, with a low maintenance cost and a high capacity to uptake and mobilise energy, providing this organism with a level of energetic performance matching that of related species from temperate regions. It was also found that L. elliptica has a large energy reserve that allows enduring long periods of starvation. Additionally, we applied DEB parameters to time-series data on biological traits (organism condition, gonad growth) to describe the effect of a

  12. Iceberg scour and shell damage in the Antarctic bivalve Laternula elliptica.

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    Harper, Elizabeth M; Clark, Melody S; Hoffman, Joseph I; Philipp, Eva E R; Peck, Lloyd S; Morley, Simon A

    2012-01-01

    We document differences in shell damage and shell thickness in a bivalve mollusc (Laternula elliptica) from seven sites around Antarctica with differing exposures to ice movement. These range from 60% of the sea bed impacted by ice per year (Hangar Cove, Antarctic Peninsula) to those protected by virtually permanent sea ice cover (McMurdo Sound). Patterns of shell damage consistent with blunt force trauma were observed in populations where ice scour frequently occurs; damage repair frequencies and the thickness of shells correlated positively with the frequency of iceberg scour at the different sites with the highest repair rates and thicker shells at Hangar Cove (74.2% of animals damaged) compared to the other less impacted sites (less than 10% at McMurdo Sound). Genetic analysis of population structure using Amplified Fragment Length Polymorphisms (AFLPs) revealed no genetic differences between the two sites showing the greatest difference in shell morphology and repair rates. Taken together, our results suggest that L. elliptica exhibits considerable phenotypic plasticity in response to geographic variation in physical disturbance.

  13. Extraction of rotenone from Derris elliptica and Derris malaccensis by pressurized liquid extraction compared with maceration.

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    Sae-Yun, Attawadee; Ovatlarnporn, Chitchamai; Itharat, Arunporn; Wiwattanapatapee, Ruedeekorn

    2006-09-01

    The extraction of active compounds from plants is one of the most critical steps in the commercial development of natural products for medicinal, herbicidal or pesticidal use. The focus of this study was to compare conventional maceration and pressurized liquid extraction (PLE) techniques for the efficient extraction of rotenone from the stem and root of Derris elliptica Benth and Derris malaccensis Prain. The effects of experimental variables, such as solvent, temperature and pressure, on PLE efficiency have been studied. Chloroform was determined to be a good extraction solvent (rotenone content 40.6%, w/w) compared to commonly used solvent, 95% ethanol (rotenone content 15.0%, w/w). The optimal conditions for PLE were 50 degrees C and 2000 psi. PLE showed higher extraction efficiency (rotenone content 46.1%, w/w) as compared with conventional maceration method (rotenone content 40.6%, w/w). The order of rotenone content found in crude extract obtained by optimized method from the highest to the lowest was root (46.1%, w/w) and stem (9.4%, w/w) of D. elliptica and stem of D. malaccensis (5.2%, w/w), respectively. Moreover, the results from this study indicated that PLE was considerably less time and solvent consuming (30 min, 3 ml/g of dried sample) than the conventional maceration techniques (72 h, 10 ml/g of dried sample).

  14. The influence of sedimentation on metal accumulation and cellular oxidative stress markers in the Antarctic bivalve Laternula elliptica

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    Husmann, G.; Abele, D.; Monien, D.; Monien, P.; Kriews, M.; Philipp, E. E. R.

    2012-10-01

    Recent rapid climate warming at the western Antarctic Peninsula (WAP) results in elevated glacial melting, enhanced sedimentary run-off, increased turbidity and impact of ice-scouring in shallow coastal areas. Discharge of mineral suspension from volcanic bedrock ablation and chronic physical disturbance is expected to influence sessile filter feeders such as the Antarctic soft shell clam Laternula elliptica (King and Broderip, 1832). We investigated effects of sedimentary run-off on the accumulation of trace metals, and together with physical disturbance, the cumulative effect on oxidative stress parameters in younger and older L. elliptica from two stations in Potter Cove (King George Island, Antarctica) which are distinctly impacted by turbidity and ice-scouring. Fe, Mn, Sr, V and Zn concentrations were slightly higher in sediments of the station receiving more sediment run-off, but not enriched in bivalves of this station. The only element that increased in bivalves experimentally exposed to sediment suspension for 28 days was Mn. Concentration of the waste accumulation biomarker lipofuscin in nervous tissue was higher in L. elliptica from the “exposed” compared to the “less exposed” site, whereas protein carbonyl levels in bivalve mantle tissue were higher at the less sediment impacted site. Tissue metal content and lipofuscin in nervous tissue were generally higher in older compared to younger individuals from both field stations. We conclude that elevated sediment ablation does not per se result in higher metal accumulation in L. elliptica. Instead of direct absorbance from sediment particles, metal accumulation in gills seems to indicate uptake of compounds dissolved in the water column, whereas metals in digestive gland appear to originate from enriched planktonic or detritic food. Accumulation of cellular waste products and potentially reactive metals over lifetime presumably alters L. elliptica physiological performance with age and may

  15. Ethnobotanical review and pharmacological properties of selected medicinal plants in Brunei Darussalam: Litsea elliptica, Dillenia suffruticosa, Dillenia excelsa, Aidia racemosa, Vitex pinnata and Senna alata

    National Research Council Canada - National Science Library

    Goh, May Poh Yik; Basri, Aida Maryam; Yasin, Hartini; Taha, Hussein; Ahmad, Norhayati

    2017-01-01

    The aim of the current study is to review the medicinal properties of the plants found in Brunei Darussalam namely Litsea elliptica, Dillenia suffruticosa, Dillenia excelsa, Aidia racemosa, Vitex pinnata and Senna alata...

  16. Constituintes químicos e atividade Leishmanicida de Gustavia elliptica (Lecythidaceae

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    Maria de Fátima Oliveira Almeida

    2011-01-01

    Full Text Available The phytochemical investigation of the stem bark and leaves of G. elliptica provided a mixture of the norisoprenoids blumenol B and 6-epiblumenol B along with the triterpenes friedelin, as the major constituent, friedelanol, ursa-9(11,12-dien-3-ol, a-amyrin, β-amyrin, morentenol, epifriedelanol, as well as the sesquiterpenes trans-caryophyllene, α-humulene, ethyl hydnocarpate and other fatty acid esters. The identification of the compounds was performed on basis of spectrometric methods such as GC-MS, IR, MS and 1D and 2D NMR. Stem bark extracts showed significant leishmanicidal activity against promastigote forms of Leishmania braziliensis, with the best results for the chloroform extract.

  17. Florivory Modulates the Seed Number-Seed Weight Relationship in Halenia elliptica (Gentianaceae

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    Linlin Wang

    2015-01-01

    Full Text Available Generally, plant reproductive success might be affected negatively by florivory, and the effects may vary depending on the timing and intensity of florivory. To clarify the impacts of florivory by the sawfly larvae (Tenthredinidae on seed production of Halenia elliptica D. Don, we simulated florivory by removing different proportion of flowers at three reproductive stages in this alpine herb and then examined the seed number per fruit, the seed weight, and the seed mass per fruit of the remaining flowers. Seed number per fruit reduced significantly when flowers were removed at flowering and fruiting stages or when 15% and 60% of flowers were removed. However, seed weight increased significantly after flowers were removed, independent of treatments of reproductive stage and proportion. There was a similar seed mass per fruit between the plants subjected to simulation of florivory and control. The results indicated that florivory modulated the seed number-seed weight relationship in this alpine species. Our study suggested that selective seed abortion and resource reallocation within fruits may ensure fewer but larger seeds, which were expected to be adaptive in the harsh environments.

  18. Population dynamics of freshwater oyster Etheria elliptica (Bivalvia: Etheriidae in the Pendjari River (Benin-Western Africa

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    Akélé G.D.

    2015-01-01

    Full Text Available Etheria elliptica (Bivalvia: Etheriidae is the only freshwater oyster occurring in Africa. The current study provides the first data on the population structure, growth, age, mortality and exploitation status of this species in the Pendjari River. E. elliptica length-frequency data were collected monthly from January to December 2009 and analyzed with FiSAT software. Population parameters including the asymptotic length (L∞ and growth coefficient (K were assessed to evaluate the stock status. The recruitment pattern was modeled with a FiSAT routine. The asymptotic length (L∞ was 14.75 cm, while the growth coefficient (K was 0.38 year-1. The growth performance index (ø′ reached 1.92. Specimens of Etheria elliptica reached a mean size of 4.66 cm and 6.41 cm at the end of one year and 1.5 years, respectively. We estimated total mortality (Z, natural mortality (M and fishing mortality (F to be 2.90 year-1, 1.16 year-1 and 1.74 year-1, respectively. The recruitment pattern was continuous over the year with one major peak event during the rainy season (July. The exploitation rate (E = 0.60 revealed that the freshwater oyster was probably facing overexploitation due to lack of a minimum limit size and also due to an increase in the harvesting effort. Therefore, efficient management methods were urgently required to conserve the species. The return of empty shells into the water to increase the recruitment surface, rotation planning among harvesting sites and the imposition of a minimum limit size were recommendations made in order to ensure the sustainable exploitation of wild stocks.

  19. Ethnobotanical review and pharmacological properties of selected medicinal plants in Brunei Darussalam: Litsea elliptica, Dillenia suffruticosa, Dillenia excelsa, Aidia racemosa, Vitex pinnata and Senna alata

    OpenAIRE

    May Poh Yik Goh; Aida Maryam Basri; Hartini Yasin; Hussein Taha; Norhayati Ahmad

    2017-01-01

    The aim of the current study is to review the medicinal properties of the plants found in Brunei Darussalam namely Litsea elliptica, Dillenia suffruticosa, Dillenia excelsa, Aidia racemosa, Vitex pinnata and Senna alata. The known phytochemical constituents of these plants and their ability to bring about a range of biological activities are included in this review. These plants have been used traditionally for a multitude of diseases and illnesses. There is a lot of untapped potential in the...

  20. Age-dependent expression of stress and antimicrobial genes in the hemocytes and siphon tissue of the Antarctic bivalve, Laternula elliptica, exposed to injury and starvation.

    Science.gov (United States)

    Husmann, G; Abele, D; Rosenstiel, P; Clark, M S; Kraemer, L; Philipp, E E R

    2014-01-01

    Increasing temperatures and glacier melting at the Western Antarctic Peninsula (WAP) are causing rapid changes in shallow coastal and shelf systems. Climate change-related rising water temperatures, enhanced ice scouring, as well as coastal sediment runoff, in combination with changing feeding conditions and microbial community composition, will affect all elements of the nearshore benthic ecosystem, a major component of which is the Antarctic soft-shelled clam Laternula elliptica. A 454-based RNA sequencing was carried out on tissues and hemocytes of L. elliptica, resulting in 42,525 contigs, of which 48 % was assigned putative functions. Changes in the expression of putative stress response genes were then investigated in hemocytes and siphon tissue of young and old animals subjected to starvation and injury experiments in order to investigate their response to sedimentation (food dilution and starvation) and iceberg scouring (injury). Analysis of antioxidant defense (Le-SOD and Le-catalase), wound repair (Le-TIMP and Le-chitinase), and stress and immune response (Le-HSP70, Le-actin, and Le-theromacin) genes revealed that most transcripts were more clearly affected by injury rather than starvation. The upregulation of these genes was particularly high in the hemocytes of young, fed individuals after acute injury. Only minor changes in expression were detected in young animals under the selected starvation conditions and in older individuals. The stress response of L. elliptica thus depends on the nature of the environmental cue and on age. This has consequences for future population predictions as the environmental changes at the WAP will differentially impact L. elliptica age classes and is bound to alter population structure.

  1. The efficacy of a topically applied combination of cyphenothrin and pyriproxyfen against the southern African yellow dog tick, Haemaphysalis elliptica, and the cat flea, Ctenocephalides felis, on dogs

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    J. J. Fourie

    2010-05-01

    Full Text Available The objective of this study was to determine the therapeutic and residual efficacy of a topically applied combination of cyphenothrin (40 % and pyriproxyfen (2 % against the tick Haemaphysalis elliptica and the flea Ctenocephalides felis on dogs. Twelve dogs were infested with 50 ticks 2 days before they were treated and with approximately 100 fleas 6 days before treatment and again 2 days before treatment and with 50 ticks and approximately 100 fleas at weekly intervals thereafter. They were ranked according to their flea counts and sex 5 days before treatment and randomly allocated to an untreated control group of 6 dogs and a treated group of 6 dogs. Ticks and fleas were collected from the dogs 48 h after treatment and 48 h after each infestation and live and dead ticks and live fleas were counted. The counts of ticks and fleas were transformed to geometric means, and efficacy was calculated by comparing these means. The product had a therapeutic efficacy of 83.1 % against H. elliptica and 97.5 % against C. felis 2 days after treatment. The residual period of protection during which efficacy was ≥ 90 % was 5 weeks for both H. elliptica and C. felis.

  2. Insights into shell deposition in the Antarctic bivalve Laternula elliptica: gene discovery in the mantle transcriptome using 454 pyrosequencing

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    Power Deborah M

    2010-06-01

    Full Text Available Abstract Background The Antarctic clam, Laternula elliptica, is an infaunal stenothermal bivalve mollusc with a circumpolar distribution. It plays a significant role in bentho-pelagic coupling and hence has been proposed as a sentinel species for climate change monitoring. Previous studies have shown that this mollusc displays a high level of plasticity with regard to shell deposition and damage repair against a background of genetic homogeneity. The Southern Ocean has amongst the lowest present-day CaCO3 saturation rate of any ocean region, and is predicted to be among the first to become undersaturated under current ocean acidification scenarios. Hence, this species presents as an ideal candidate for studies into the processes of calcium regulation and shell deposition in our changing ocean environments. Results 454 sequencing of L. elliptica mantle tissue generated 18,290 contigs with an average size of 535 bp (ranging between 142 bp-5.591 kb. BLAST sequence similarity searching assigned putative function to 17% of the data set, with a significant proportion of these transcripts being involved in binding and potentially of a secretory nature, as defined by GO molecular function and biological process classifications. These results indicated that the mantle is a transcriptionally active tissue which is actively proliferating. All transcripts were screened against an in-house database of genes shown to be involved in extracellular matrix formation and calcium homeostasis in metazoans. Putative identifications were made for a number of classical shell deposition genes, such as tyrosinase, carbonic anhydrase and metalloprotease 1, along with novel members of the family 2 G-Protein Coupled Receptors (GPCRs. A membrane transport protein (SEC61 was also characterised and this demonstrated the utility of the clam sequence data as a resource for examining cold adapted amino acid substitutions. The sequence data contained 46,235 microsatellites and 13

  3. High resolution microscopy reveals significant impacts of ocean acidification and warming on larval shell development in Laternula elliptica.

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    Christine H Bylenga

    Full Text Available Environmental stressors impact marine larval growth rates, quality and sizes. Larvae of the Antarctic bivalve, Laternula elliptica, were raised to the D-larvae stage under temperature and pH conditions representing ambient and end of century projections (-1.6°C to +0.4°C and pH 7.98 to 7.65. Previous observations using light microscopy suggested pH had no influence on larval abnormalities in this species. Detailed analysis of the shell using SEM showed that reduced pH is in fact a major stressor during development for this species, producing D-larvae with abnormal shapes, deformed shell edges and irregular hinges, cracked shell surfaces and even uncalcified larvae. Additionally, reduced pH increased pitting and cracking on shell surfaces. Thus, apparently normal larvae may be compromised at the ultrastructural level and these larvae would be in poor condition at settlement, reducing juvenile recruitment and overall survival. Elevated temperatures increased prodissoconch II sizes. However, the overall impacts on larval shell quality and integrity with concurrent ocean acidification would likely overshadow any beneficial results from warmer temperatures, limiting populations of this prevalent Antarctic species.

  4. High resolution microscopy reveals significant impacts of ocean acidification and warming on larval shell development in Laternula elliptica

    Science.gov (United States)

    Cummings, Vonda J.; Ryan, Ken G.

    2017-01-01

    Environmental stressors impact marine larval growth rates, quality and sizes. Larvae of the Antarctic bivalve, Laternula elliptica, were raised to the D-larvae stage under temperature and pH conditions representing ambient and end of century projections (-1.6°C to +0.4°C and pH 7.98 to 7.65). Previous observations using light microscopy suggested pH had no influence on larval abnormalities in this species. Detailed analysis of the shell using SEM showed that reduced pH is in fact a major stressor during development for this species, producing D-larvae with abnormal shapes, deformed shell edges and irregular hinges, cracked shell surfaces and even uncalcified larvae. Additionally, reduced pH increased pitting and cracking on shell surfaces. Thus, apparently normal larvae may be compromised at the ultrastructural level and these larvae would be in poor condition at settlement, reducing juvenile recruitment and overall survival. Elevated temperatures increased prodissoconch II sizes. However, the overall impacts on larval shell quality and integrity with concurrent ocean acidification would likely overshadow any beneficial results from warmer temperatures, limiting populations of this prevalent Antarctic species. PMID:28423059

  5. Ethnobotanical review and pharmacological properties of selected medicinal plants in Brunei Darussalam: Litsea elliptica, Dillenia suffruticosa, Dillenia excelsa, Aidia racemosa, Vitex pinnata and Senna alata

    Directory of Open Access Journals (Sweden)

    May Poh Yik Goh

    2017-02-01

    Full Text Available The aim of the current study is to review the medicinal properties of the plants found in Brunei Darussalam namely Litsea elliptica, Dillenia suffruticosa, Dillenia excelsa, Aidia racemosa, Vitex pinnata and Senna alata. The known phytochemical constituents of these plants and their ability to bring about a range of biological activities are included in this review. These plants have been used traditionally for a multitude of diseases and illnesses. There is a lot of untapped potential in these medicinal plants which could cure multiple diseases.

  6. Métodos de superação de dormência em sementes de croada (Mouriri elliptica Mart Dormancy breaking methods in croada (Mouriri elliptica Mart seeds

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    Jaqueline Martins Vasconcelos

    2010-10-01

    Full Text Available Sementes de croada (Mouriri elliptica Mart. Melastomataceae, espécie frutífera nativa do cerrado, foram submetidas aos seguintes tratamentos, visando a superação de dormência: pré-resfriamento a 5° C por 7 dias; pré-aquecimento em estufa com circulação de ar a 40º C por 7 dias; escarificação química em ácido sulfúrico concentrado por 5 e 15 minutos; imersão em água fervente por 5 e 15 minutos; imersão em ácido giberélico a 100 e 200 mg L-1 por 48 horas; imersão em água destilada por 24 e 48 horas; escarificação mecânica com lixa nº 80 na parte superior e oposta ao eixo embrionário e testemunha (sementes sem tratamento prévio. Quatro repetições de quinze sementes foram colocadas para germinar sobre papel umedecido com água destilada ou nitrato de potássio a 0,2%, em temperatura de 30º C em presença de luz. Foram realizadas contagens diárias do 2º dia após a implantação do experimento até a estabilização da porcentagem de germinação, que acorreu no 60º dia. A germinação foi mais rápida em sementes pré-embebidas em ácido giberélico (em substrato umedecido com água ou com solução de nitrato de potássio 0,2%, pré-embebidas em água por 24 horas, em substrato umedecido com água, e pré-embebidas em água por 48 horas ou escarificadas mecanicamente e colocadas para germinar em substrato umedecido com água. Taxas de germinação mais elevadas ocorreram em sementes pré-embebidas em ácido giberélico a 100 ou 200 mg L-1, em substrato umedecido com solução de nitrato de potássio 0,2%.Croada seeds (Mouriri elliptica Mart. Melastomataceae, a fruit-bearing species native of the cerrado (savannah-like vegetation, were submitted to the following dormancy breaking methods: pre-cooling at 5° C for 7 days; pre-heating in a oven air circualtion at 40º C for 7 days; chemical escarification in concentrated sulfuric acid for 5 and 15 min; soaking in boiling water for 5 and 15 min; soaking in gibbereli

  7. A importância do silício nas relações entre herbívoros e Davilla elliptica (Dilleniaceae) St. Hil no cerrado

    OpenAIRE

    Korndörfer, Ana Paula

    2006-01-01

    Foi analisado o efeito da concentração de silício no solo para as defesas físicas de Davilla elliptica St. Hil. Os resultados mostraram que as plantas com maior concentração de silício no solo, absorveram e acumularam mais silício em suas folhas. A maior concentração de silício nas folhas provocou uma maior dureza foliar e um aumento no número de tricomas. O incremento de ambas defesas físicas, tricomas e dureza foliar, nas plantas com silício interferiram na alimentação de ...

  8. Element ratios between digestive gland and gill tissues of the Antarctic bivalve Laternula elliptica as a proxy for element uptake from different environmental sources

    Science.gov (United States)

    Poigner, H.; Monien, D.; Monien, P.; Kriews, M.; Brumsack, H.-J.; Wilhelms-Dick, D.; Abele, D.

    2012-04-01

    Trace metals in bivalve carbonate shells are frequently used as environmental or paleoclimate proxies. Carbonate mineralogy and animals' physiology affect the incorporation of elements from different environmental sources into bivalve shells. Generally, metals from particulate matter are assimilated via the digestive tract; whereas dissolved metals are absorbed via gills. Therefore, measurements of element concentrations deposited in the shell matrix do not necessarily allow inference with respect to the assimilation pathways. In this study, we used element ratios between digestive gland (DG) and gills (cDG/cGill) of the Circum-Antarctic clam Laternula elliptica to identify predominating assimilation pathways and potential sources of bio-available metals. This normalization between tissues of each individual eliminates the effects of individual age and physiological condition (e.g. accumulation over lifetime, metabolic activity) on metal assimilation. These effects also minimize the reproducibility, when absolute element concentrations are compared between individuals from different locations. Therefore, an additional normalization is required. We favored "ellipsoid shell volume" over shell length or soft tissue weight as more conservative approximation for intra- and intersite comparisons. Metal concentrations in DG, gills, and hemolymph of the bivalve L. elliptica, collected at Potter Cove (King George Island, Antarctic Peninsula), were analyzed by means of inductively coupled plasma - optical emission spectroscopy and mass spectrometry after total acid digestion. The element ratios (cDG/cGill) indicate a predominant assimilation of Al, Ca, Fe, K, Mn, and Mg from the dissolved phase. These high Al and Fe concentrations in gill tissues and hemolymph are in contrast to the low solubility of Al and Fe in seawater. But high dissolved Fe concentrations in pore waters (up to 1400 μg L-1 due to suboxic sediment conditions) and glacial melt waters enriched in dissolved

  9. Seasonal proliferation rates and the capacity to express genes involved in cell cycling and maintenance in response to seasonal and experimental food shortage in Laternula elliptica from King George Island.

    Science.gov (United States)

    Husmann, G; Philipp, E E R; Abele, D

    2016-07-01

    Melting of coastal glaciers at the West Antarctic Peninsula (WAP) causes shorter winter sea ice duration, intensified ice scouring, sediment erosion and surface freshening in summer, which alters coastal productivity and feeding conditions for the benthos. The soft shell clam Laternula elliptica is a fast growing and abundant filter feeder in coastal Antarctica and a key element for bentho-pelagic carbon recycling. Our aim was to assess the cellular growth and maintenance capacity of small and large clams during natural winter food shortage (seasonal sampling) and in response to experimental starvation exposure. We measured tissue specific proliferation rates, the expression of cell cycling genes, and the iron binding protein Le-ferritin in freshly collected specimens in spring (Nov 2008) and at the end of summer (March 2009). For the experimental approach, we focused on 14 cell cycling and metabolic genes using the same animal size groups. Mantle tissue of young bivalves was the only tissue showing accelerated proliferation in summer (1.7% of cells dividing per day in March) compared to 0.4% dividing cells in animals collected in November. In mantle, siphon and adductor muscle proliferation rates were higher in younger compared to older individuals. At transcript level, Le-cyclin D was upregulated in digestive gland of older animals collected in spring (Nov) compared to March indicating initiation of cell proliferation. Likewise, during experimental starvation Le-cyclin D expression increased in large clam digestive gland, whereas Le-cyclin D and the autophagic factor beclin1 decreased in digestive gland of smaller starved clams. The paper corroborates earlier findings of size and age dependent differences in the metabolic response and gene expression patterns in L. elliptica under energetic deprivation. Age structure of shallow water populations can potentially change due to differences in cellular response between young and old animals as environmental stress

  10. Traditional exploitation of edible freshwater oyster Etheria elliptica ...

    African Journals Online (AJOL)

    Finally, oyster`s shell, a main substrate for larval settlement and bed restoration, were left on riverbanks after exploitation, reducing stocks reconstitution potential. Appropriate measures were suggested to Reserve staff for sustainable management. Keywords: Freshwater mollusk, harvesting activities, human pressure, ...

  11. Ecological effects of some heavy metals (Cd, Pb, Hg, Cr) pollution of ...

    African Journals Online (AJOL)

    ... Gomphospheria, Oscillatoria, Phormidium, Anabaena, Nostoc, Cystodinium, Dinobryon, Ankistrodesmus, Chlorella, Coelastrum, Oocystis, Pediastrum, Scenedesmus, Cosmarium, Oedogonium, Cyclotella, Achnanthes, Amphora, Anomoneis, Cocconeis, Cymbella, Diatoma, Diploneis, Fragilaria, Gomphonema, Navicula, ...

  12. (BURCHELL 1822) JUVENILES EXPOSED TO D

    African Journals Online (AJOL)

    concentrations than necessary, causing contamination of fresh water bodies and thereby affecting non target organisms. Toxicity studies of Derris elliptica root powder were carried out with juveniles of. Clarias gariepinus ..... gariepinus exposed to various acute concentrations of D. elliptica root powder and the LC50 at 96h ...

  13. Haematological characteristics of clarias gariepinus (Burchell 1822 ...

    African Journals Online (AJOL)

    In particular Derris elliptica, which contains rotenone which is toxic to fish when it is used in higher concentrations than necessary, causing contamination of fresh water bodies and thereby affecting non target organisms. Toxicity studies of Derris elliptica root powder were carried out with juveniles of Clarias gariepinus using ...

  14. The accumulation of heavy metals (Cd, Pb, Hg, Cr) and their state in ...

    African Journals Online (AJOL)

    While in Mogan Lake, Spirogyra sp., Zygnema sp., Euglena sp., Achnanthes sp., Cymbella sp., Fragilaria sp. Navicula sp., Scenedesmus sp., Oocystis sp., Synedra sp., Oscillatoria sp., Chlorella sp., Cosmarium sp. and Nitzshia sp. were determined. Zooplanktonic dominant organisms determined in Beysehir Lake were ...

  15. Spatial And Temporal Distribution Of Epiphytic Diatoms On ...

    African Journals Online (AJOL)

    The important components in the flora of the epiphytic diatoms were belonging to the genera: Achnanthes, Achnanthidium, Fragilaria, Gyrosigma, Licmophora, Navicula, Pleurosigma, Synedra and Tabellaria. The rest recorded epiphytic diatoms were considered rare and of no significance in defining the epiphytic flora on ...

  16. Occurrence of phytoplankton in the water and gut of the volta clam ...

    African Journals Online (AJOL)

    Members of the Bacillariophyta found at the surface and bottom layers belonged to six (6) genera (Asterionella, Diatoma, Fragilaria, Melosira, Navicula, and Synedra). Members of the Cyanophyta which were isolated from the gut only were Merismopedia elegans, Oscillatoria tenius and Planktothrix agardhii. Practical ...

  17. The accumulation of heavy metals (Cd, Pb, Hg, Cr) and their state in ...

    African Journals Online (AJOL)

    Beysehir and Mogan Lakes are two shallow Lakes that are under environmental protection status. Phytoplanktonic dominant algae determined in Beysehir Lake were Oscillatoria sp., Cladophora sp., Achnanthes sp., Gomphonema sp., Navicula sp., Cosmarium sp., Cymbella sp., Fragilaria sp., Oocystis sp., Spirogyra sp., ...

  18. Preliminary Studies on the Occurrence of Freshwater Epipelic Algae ...

    African Journals Online (AJOL)

    A total of 38 algal genera were identified over the period, with the Bacillariophyceae dominating with 19 genera followed by the Chlorophyta and the Cyanophyta with 13 and 6 genera, respectively. Fragilaria, Melosira and Rhizosolenia were the most abundant Bacillariophyta genera encountered. The Chlorophyta had ...

  19. OVIPOSITION PREFERENCE OF Aedes aegypti AGAINST VARIOUS LEAF EXTRACT AS AN ATRACTANT

    Directory of Open Access Journals (Sweden)

    Sara Gustia Wibowo

    2015-07-01

    Full Text Available Aedes aegypti merupakan vektor pembawa virus Dengue yang menyebabkan penyakit Demam Berdarah Dengue (DBD.Pengendalian secara alami menggunakan bahan nabati merupakan alternatif pengendalian yang ramah lingkungan. Salahsatu pengendalian secara alami adalah memodifikasi ovitrap dengan penambahan zat aktif nabati sebagai atraktan untukmenarik nyamuk bertelur dan dapat menjadi ovisida dan larvasida. Tujuan penelitian ini adalah mengetahui preferensibertelurnya nyamuk Ae. aegypti pada ovitrap dengan ekstrak daun mimba (Azadirachta indica, kecubung (Datura metel,zodia (Evodia suavolens dan jenu (Derris elliptica. Jenis penelitian eksperimen dengan rancangan acak lengkap. Keempatjenis ekstrak daun tersebut diisiikan pada ovitrap, dimasukan ke dalam kandang yang berisi 30 ekor Ae. aegypti dengankondisi kenyang darah. Pengamatan dilakukan setiap hari sampai hari ke-3. Hasil uji preferensi berbagai jenis ekstrak inimenunjukkan ovitrap yang berisi ekstrak daun jenu (D. elliptica lebih banyak ditemukan telur Ae. aegypti dibandingkandengan kontrol maupun ovitrap dengan ekstrak daun lainnya. Persentase telur pada kontainer dengan ekstrak jenu adalah44,2%, sedangkan yang terkecil ekstrak zodia (E. suaveolans 9,2%. Hasil uji Anova menunjukkan bahwa perlakuan antarkelompok berbeda nyata (p=0,000. Tanaman jenu (D. elliptica mempunyai potensi sebagai atraktan terhadap nyamuk Ae.aegypti dalam proses oviposisi.Kata kunci: atraktan, oviposisi, jenu (Derris elliptica, Aedes aegypti

  20. Selection for protection from insolation results in the visual isolation of Yellow-eyed Penguin Megadyptes antipodes nests

    CSIR Research Space (South Africa)

    Clark, RD

    2015-06-01

    Full Text Available with randomly sampled unused sites in flax Phormium tenax and Hebe elliptica coastal scrub at Boulder Beach, and in coastal forest at Hinahina Cove, New Zealand, 2006–2007. Results of univariate tests and the evaluation of logistic regression models suggested...

  1. A new species of Roupala (proteaceae) in Suriname

    NARCIS (Netherlands)

    Mennega, Alberta M.W.

    1967-01-01

    Arbor 8 m alta, altitudine pectoris 20 cm diam.; ramuli teretes, glabri. Folia coriacea, glabra, plana, late elliptica vel late obovata, apice obtusa, rotundata vel subacuminata, basi attenuata et in petiolum decurrentia, 9-12 cm longa, 5-7½ cm lata, statu sicco supra viridia, leviter nitida, infra

  2. NEW EUROPEAN RECORDS AND FIRST EVIDENCE OF EPIDERMAL STRUCTURES OF SLOANEA L. FROM THE ITALIAN OLIGOCENE – REVISED TYPE AND ORIGINAL MATERIAL OF PRINCIPI 1916

    Directory of Open Access Journals (Sweden)

    LILLA HABLY

    2007-11-01

    Full Text Available Leaves of Sloanea elliptica (Andreánszky Z. Kvaèek & Hably and S. peolai (Principi Hably, Tamás & Cioppi  with preserved organic structures were found during the study of Principi’s collection from the Oligocene flora of Santa Giustina. Fossil leaves of Sloanea elliptica have so far been recorded exclusively from the Palaeogene Basin of the Inner Carpathian Region, i.e. from the Lower Oligocene strata of Hungary and Slovenia, whereas S. peolai has been described from a single locality, Chiavon in Italy. Organic structure of S. peolai hitherto has not been recorded. The mass occurrence of Sloanea elliptica in the fossil assemblage of Santa Giustina indicates that its area was much more extensive than it was presumed. It was a characteristic element mainly of Oligocene floras, and even predominated them. This is the first record of the co-occurrence of two Sloanea species described on the basis of leaf remains. During the study 6 types and more than 30 illustrated specimens published in Principi's monograph were revised and identified as S. elliptica.    

  3. Eine neue Gnetum Art aus Sarawak

    NARCIS (Netherlands)

    Markgraf, F.

    1966-01-01

    Frutex alte scandens glaber. Ramuli teretes laeves, infra nodos crassiores lenticellosi. Folia opposita, elliptica, in petiolum 1 cm longum angustata, apice breviter acuminata, usque ad 15 cm longa et 7 cm lata, supra fibris parallelis sericeo-nitida. Nervi secundarii 6—8 in utroque latere, obliqui,

  4. Eine neue Gnetum-Art aus Borneo

    NARCIS (Netherlands)

    Markgraf, F.

    1966-01-01

    Frutex alte scandens. Rami sulcati et crebre lenticellosi. Ramuli teretes laeves. Folia (adumbrata?) opposita, petiolus 12 mm longus, lamina glabra, elliptica, acuminata, 11—17 cm longa, 6—7½cm lata, firme chartacea; nervi secundarii 9 paria, arcuata, ante marginem coniuncta, subtus conspicua.

  5. Florae Malesianae Precursores II. The Convolvulaceae of Malaysia IX

    NARCIS (Netherlands)

    Hoogland, R.D.

    1953-01-01

    Erycibe beccariana Hoogl. sp. nov. — Frutex scandens, ramulis junioribus sparsim stellato-hirsutis, adultioribus glabrescentibus cortice rimis longitudinalibus fisso. Folia elliptica ad elliptico-oblonga, 9—13 X 4— 71/2 cm, apice breviter acuminata, basi rotundata vel minute cordata, supra glabra,

  6. Control strategies with reduced fungicide input for Botrytis leaf blight in lily - a simulation analysis

    NARCIS (Netherlands)

    Kraker, de J.; Ende, van den J.E.; Rossing, W.A.H.

    2005-01-01

    Leaf blight, caused by the pathogen Botrytis elliptica (Berk.) Cooke, is the most important foliar disease in ornamental lily cultivation. The conventional control strategy of Dutch bulb growers is to apply protective fungicides at weekly intervals from crop emergence until harvest. We applied

  7. Mutagenic and antimutagenic potentials of fruit juices of five ...

    African Journals Online (AJOL)

    Mutagenic and antimutagenic activities of freeze dried fruit juices (FDFJ) of Morinda elliptica Ridl. (Rubiaceae), Morinda citrifolia L. (Rubiaceae), Averrhoa bilimbi L. (Oxalidaceae), Phyllantus acidus (L.) Skeels (Phyllantaceae) and Myristica fragrans Houtt. (Myristicaceae) in Allium cepa L was evaluated. Testing the ...

  8. Research Paper

    African Journals Online (AJOL)

    Prof. Adewunmi

    Phytochemical methods. 3rd ed., Chapman and Hall Ltd., London, pp. 135 – 203. 6. Khan, M. R., Omoloso, A. D. and Barewai, Y. (2006) Antimicrobial activity of the Derris elliptica, Derris indica and Derris trifoliate extractives. Fitoterapia. 77: 327 – 330. 7. Kochhar, S. L. (1981). Tropical crops: A textbook of economy botany.

  9. New amazonian species: Coussapoa prancei and Perebea mennegae (Moraceae)

    NARCIS (Netherlands)

    Berg, C.C.

    1978-01-01

    Planta ephytica; rami glabri. Folia elliptica, oblonga vel subobovata, 2-6 cm longa, 1-3.5 cm lata, apice indistincte breviterque acuminata, basi obtusa, undique glabra; venae laterales 2-4-jugae, venulae interpositae parallelae fere horizontaliter patentes approximatae; petiolus 0.5-2.5 cm longus;

  10. Los ostrácodos de la cuenca del Lido (Laguna de Venecia, NF Italia)

    OpenAIRE

    Ruiz Muñoz, Francisco; González-Regalado Montero, María Luz; Menegazzo, L.; Rampazzo, G.; Pistolato, M.; Molinaroli, E.

    1999-01-01

    The ostracofaune of the Lido basin (Venice lagoon) is dominated by Cyprideis torosa, with the presence of Loxoconcha elliptica in zones drained by industrial and agricultural waters and Xestoleberis if the energy is very low. No ostracods were found in stress conditions due to environmental polution

  11. A new Phrynium (Matantaceae) from Great Nicobar Island, India

    NARCIS (Netherlands)

    Balakrishnan, N.P.

    1978-01-01

    Herbae erectae caespitosae 1.5—2.0 m altae; rhizoma suberectum 1—2 cm diametro. Folia multa apice rhizomatis spiratim aggregata; petioli usque ad 1 m longi basi vaginantes, sparsim pubescentes; laminae ellipticae oblongo-lanceolatae glabrae 18—35 cm longae, 8—15 cm latae, basi acutae vel cuneatae,

  12. Novel sex cells and evidence for sex pheromones in diatoms.

    Science.gov (United States)

    Sato, Shinya; Beakes, Gordon; Idei, Masahiko; Nagumo, Tamotsu; Mann, David G

    2011-01-01

    Diatoms belong to the stramenopiles, one of the largest groups of eukaryotes, which are primarily characterized by a presence of an anterior flagellum with tubular mastigonemes and usually a second, smooth flagellum. Based on cell wall morphology, diatoms have historically been divided into centrics and pennates, of which only the former have flagella and only on the sperm. Molecular phylogenies show the pennates to have evolved from among the centrics. However, the timing of flagellum loss--whether before the evolution of the pennate lineage or after--is unknown, because sexual reproduction has been so little studied in the 'araphid' basal pennate lineages, to which Pseudostaurosira belongs. Sexual reproduction of an araphid pennate, Pseudostaurosira trainorii, was studied with light microscopy (including time lapse observations and immunofluorescence staining observed under confocal scanning laser microscopy) and SEM. We show that the species produces motile male gametes. Motility is mostly associated with the extrusion and retrieval of microtubule-based 'threads', which are structures hitherto unknown in stramenopiles, their number varying from one to three per cell. We also report experimental evidence for sex pheromones that reciprocally stimulate sexualization of compatible clones and orientate motility of the male gametes after an initial 'random walk'. The threads superficially resemble flagella, in that both are produced by male gametes and contain microtubules. However, one striking difference is that threads cannot beat or undulate and have no motility of their own, and they do not bear mastigonemes. Threads are sticky and catch and draw objects, including eggs. The motility conferred by the threads is probably crucial for sexual reproduction of P. trainorii, because this diatom is non-motile in its vegetative stage but obligately outbreeding. Our pheromone experiments are the first studies in which gametogenesis has been induced in diatoms by cell

  13. Novel sex cells and evidence for sex pheromones in diatoms.

    Directory of Open Access Journals (Sweden)

    Shinya Sato

    Full Text Available BACKGROUND: Diatoms belong to the stramenopiles, one of the largest groups of eukaryotes, which are primarily characterized by a presence of an anterior flagellum with tubular mastigonemes and usually a second, smooth flagellum. Based on cell wall morphology, diatoms have historically been divided into centrics and pennates, of which only the former have flagella and only on the sperm. Molecular phylogenies show the pennates to have evolved from among the centrics. However, the timing of flagellum loss--whether before the evolution of the pennate lineage or after--is unknown, because sexual reproduction has been so little studied in the 'araphid' basal pennate lineages, to which Pseudostaurosira belongs. METHODS/PRINCIPAL FINDING: Sexual reproduction of an araphid pennate, Pseudostaurosira trainorii, was studied with light microscopy (including time lapse observations and immunofluorescence staining observed under confocal scanning laser microscopy and SEM. We show that the species produces motile male gametes. Motility is mostly associated with the extrusion and retrieval of microtubule-based 'threads', which are structures hitherto unknown in stramenopiles, their number varying from one to three per cell. We also report experimental evidence for sex pheromones that reciprocally stimulate sexualization of compatible clones and orientate motility of the male gametes after an initial 'random walk'. CONCLUSIONS/SIGNIFICANCE: The threads superficially resemble flagella, in that both are produced by male gametes and contain microtubules. However, one striking difference is that threads cannot beat or undulate and have no motility of their own, and they do not bear mastigonemes. Threads are sticky and catch and draw objects, including eggs. The motility conferred by the threads is probably crucial for sexual reproduction of P. trainorii, because this diatom is non-motile in its vegetative stage but obligately outbreeding. Our pheromone experiments

  14. Screening of plants with antimicrobial activity against enterobacteria, Pseudomonas spp. and Staphylococcus spp.

    Science.gov (United States)

    Girondi, Camila Miorelli; de Oliveira, Analu Barros; Prado, Jackeline Alves; Koga-Ito, Cristiane Yumi; Borges, Aline Chiodi; Botazzo Delbem, Alberto Carlos; Alves Pereira, Daniel Freitas; Salvador, Marcos José; Brighenti, Fernanda Lourenção

    2017-06-01

    This study screened plants for antibacterial properties against bacteria of medical importance. 60 extracts were obtained from the leaves of ten plants (Jatropha weddelliana, Attalea phalerata, Buchenavia tomentosa, Croton doctoris, Mouriri elliptica, Mascagnia benthamiana, Senna aculeata, Unonopis guatterioides, Allagoptera leucocalyx and Bactris glaucescens) using different extraction methods: A) Ethanol 70°C/72 h; B) Water/5 min/100°C; C) Water/1 h/55°C; D) Water/72 h; E) Hexane/72 h and F) Ethanol 99°C/72 h. Enterobacteria/Pseudomonas and staphylococci reference strains and 201 clinical isolates were used. Primary screening was done using agar well-diffusion assay. MIC/minimum bactericidal concentration and chemical characterization were determined. Extracts 5F and 3A showed the best MIC/minimum bactericidal concentration against clinical isolates and showed the presence of phenols. The present study demonstrated that Mouriri elliptica and Buchenavia tomentosa were the most active plants against the studied bacteria.

  15. Diversity of Araliaceae in Sulasih Talang Nature Reserve, West Sumatra and its acclimatization

    Directory of Open Access Journals (Sweden)

    DWI MURTI PUSPITANINGTYAS

    2008-04-01

    Full Text Available Sulasih Talang Nature Reserve is a conservation area in West Sumatra Province, which contains high diversity of plants including Araliaceae. Araliaceae mostly consist of attractive plants which have potentiallity as ornamental plants. The aim of this research is to record the diversity of Araliaceae in Sulasih Talang Nature Reserve. The result of the study indicates that there are, species of Araliaceae found in Sulasih Talang Nature Reserve, which are : Arthrophyllum diversifolium, Brassaiopsis glomerulata, Brassaiopsis sumatrana var. variaefolia, Macropanax dispermus, Schefflera elliptica, S. farinosa, S. lucescens, S. scandens, Schefflera sp., and Trevesia beccarii, in which Bogor Botanic Garden collected 6 species of them, i.e.: Brassaiopsis glomerulata, Brassaiopsis sumatrana var. variaefolia, Macropanax dispermus, Schefflera elliptica, S. scandens, Schefflera sp. Most of the collections are successfully acclimated in the gardens.

  16. IDENTIFIKASI STRUKTUR ANATOMI STOMATA PENAMPANG MEMBUJUR DAUN PADA BEBERAPA JENIS POHON HUTAN KOTA UNHAS MAKASSAR

    OpenAIRE

    Elis, Tambaru

    2014-01-01

    Penelitian ini bertujuan untuk mengidentifikasi struktur anatomi stomata penampang membujur daun pada beberapa jenis pohon Hutan Kota UNHAS Makassar. Penelitian identifikasi ini digunakan metode olesan aceton untuk mengamati karakter anatomi stomata, analisis data stomata secara deskriptif. Hasil penelitian didapatkan, bahwa tipe stomata adalah: Tipe parasitik pada daun jati putih Gmelina elliptica J.E. Smith.; lobi-lobi Flacourtia inermis Roxb.; tengguli Cassia fistula L.; bitti Vitex co...

  17. IDENTIFIKASI STRUKTUR ANATOMI STOMATA PENAMPANG MEMBUJUR DAUN PADA BEBERAPA JENIS POHON HUTAN KOTA UNHAS MAKASSAR

    OpenAIRE

    Elis Tambaru; Latunra, Andi Ilham; Sri Suhadiyah

    2013-01-01

    Penelitian ini bertujuan untuk mengidentifikasi struktur anatomi stomata penampang membujur daun pada beberapa jenis pohon Hutan Kota UNHAS Makassar. Penelitian identifikasi ini digunakan metode olesan aceton untuk mengamati karakter anatomi stomata, analisis data stomata secara deskriptif. Hasil penelitian didapatkan, bahwa tipe stomata adalah: Tipe parasitik pada daun jati putih Gmelina elliptica J.E. Smith.; lobi-lobi Flacourtia inermis Roxb.; tengguli Cassia fistula L.; bitti Vitex copass...

  18. Anti-hemorrhagic activity of four Brazilian vegetable species against Bothrops jararaca venom.

    Science.gov (United States)

    Nishijima, Catarine Massucato Nishijima; Rodrigues, Clenilson Martins; Silva, Marcelo Aparecido; Lopes-Ferreira, Mônica; Vilegas, Wagner; Hiruma-Lima, Clélia Akiko

    2009-03-09

    Around 20,000 snakebites are reported annually in Brazil and 90% of them are inflicted by species of the genus Bothrops. Intravenous administration of antibothropic antivenom neutralizes the systemic actions, but it is of little effect on the reversal of local symptoms and often induces adverse reactions, a context that drives the search for complementary treatments for snakebite accidents. Vegetable extracts with a range of antiophidian activities constitute an excellent alternative. In this study, we investigated the anti-hemorrhagic effects of Mouriri pusa Gardn. (Melastomataceae), Byrsonima crassa Niedenzu (Malpighiaceae), Davilla elliptica St. Hill. (Dilleniaceae) and Strychnos pseudoquina St. Hil. (Loganiaceae) against Bothrops jararaca venom. The methanolic extracts from M. pusa (leaves), B. crassa (leaves) and D. elliptica (leaves) showed total neutralization capacity against local hemorrhages. The amenthoflavone and quercetin fractions from B. crassa and the flavonoids fractions (quercetin and myricetin) from M. pusa and D. elliptica also showed total neutralization capacity. We conclude that flavonoids derived from myricetin, quercetin and amenthoflavone play an important role in the anti-hemorrhagic potential of these Brazilian vegetables species against B. jararaca venom.

  19. Anti-hemorrhagic Activity of Four Brazilian Vegetable Species Against Bothrops jararaca Venom

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    2009-03-01

    Full Text Available Around 20,000 snakebites are reported annually in Brazil and 90% of them are inflicted by species of the genus Bothrops. Intravenous administration of antibothropic antivenom neutralizes the systemic actions, but it is of little effect on the reversal of local symptoms and often induces adverse reactions, a context that drives the search for complementary treatments for snakebite accidents. Vegetable extracts with a range of antiophidian activities constitute an excellent alternative. In this study, we investigated the anti-hemorrhagic effects of Mouriri pusa Gardn. (Melastomataceae, Byrsonima crassa Niedenzu (Malpighiaceae, Davilla elliptica St. Hill. (Dilleniaceae and Strychnos pseudoquina St. Hil. (Loganiaceae against Bothrops jararaca venom. The methanolic extracts from M. pusa (leaves, B. crassa (leaves and D. elliptica (leaves showed total neutralization capacity against local hemorrhages. The amenthoflavone and quercetin fractions from B. crassa and the flavonoids fractions (quercetin and myricetin from M. pusa and D. elliptica also showed total neutralization capacity. We conclude that flavonoids derived from myricetin, quercetin and amenthoflavone play an important role in the anti-hemorrhagic potential of these Brazilian vegetables species against B. jararaca venom.

  20. Pengaruh beberapa Jenis Ekstrak Tanaman sebagai Moluskisida Nabati terhadap Keong Mas (Pomacea canaliculata

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    Agus Kardinan

    1997-12-01

    Full Text Available Research has been carried out at the Pest and Disease Laboratory, Research Institute for Spices and Medicinal Crops, Bogar, in the 1997. Research consisted of three parts, those were; (I The toxicity of Dens elliptica, Blumea balsamifera, and methaldehyde, by determining the LC50 values, (2 Effect of the leaves of B.balsamifera, Euphorbia tirucalli and Tephrosia vogelii, (3 Effect of the most poisonous plant as ovicides. Result showed that D.elliptica was the most poisonous material to golden snail with its LC50 value was 400ppm, but it was still under the toxicity value of methaldehyde (11. 78 ppm. There was no significant difference among B.balsamifera, T.vogelii and E. canaliculata, but extract of B.balsarnifera tended to be better material among those plant extracts tested. The extract of D.elliptica did not affect egg hatching of golden snail.

  1. Thai plants with high antioxidant levels, free radical scavenging activity, anti-tyrosinase and anti-collagenase activity.

    Science.gov (United States)

    Chatatikun, Moragot; Chiabchalard, Anchalee

    2017-11-09

    Ultraviolet radiation from sunlight induces overproduction of reactive oxygen species (ROS) resulting in skin photoaging and hyperpigmentation disorders. Novel whitening and anti-wrinkle compounds from natural products have recently become of increasing interest. The purpose of this study was to find products that reduce ROS in 14 Thai plant extracts. To determine total phenolic and flavonoid content, antioxidant activity, anti-tyrosinase activity and anti-collagenase activity, we compared extracts of 14 Thai plants prepared using different solvents (petroleum ether, dichloromethane and ethanol). Antioxidant activities were determined by DPPH and ABTS assays. Total phenolic content of the 14 Thai plants extracts was found at the highest levels in ethanol followed by dichloromethane and petroleum ether extracts, respectively, while flavonoid content was normally found in the dichloromethane fraction. Scavenging activity ranged from 7 to 99% scavenging as assessed by DPPH and ABTS assays. The ethanol leaf extract of Ardisia elliptica Thunb. had the highest phenolic content, antioxidant activity and collagenase inhibition, while Cassia alata (L.) Roxb. extract had the richest flavonoid content. Interestingly, three plants extracts, which were the ethanolic fractions of Annona squamosa L., Ardisia elliptica Thunb. and Senna alata (L.) Roxb., had high antioxidant content and activity, and significantly inhibited both tyrosinase and collagenase. Our finding show that the ethanol fractions of Annona squamosa L., Ardisia elliptica Thunb. and Senna alata (L.) Roxb. show promise as potential ingredients for cosmetic products such as anti-wrinkle agents and skin whitening products.

  2. The dynamics of questing ticks collected for 164 consecutive months off the vegetation of two landscape zones in the Kruger National Park (1988–2002. Part III. The less commonly collected species

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    Gordon J. Gallivan

    2011-02-01

    Full Text Available Despite many studies regarding tick ecology, limited information on long-term changes in tick populations exist. This study assessed the long-term population dynamics of the less frequently collected questing ixodid ticks in the Kruger National Park (KNP. From 1988 to 2002, monthly dragging of the vegetation was performed in three habitats (grassland, woodland and gully at two sites in the KNP (Nhlowa Road, Landscape Zone 17, and Skukuza, Landscape Zone 4. Amblyomma marmoreum and Rhipicephalus evertsi evertsi were collected as larvae most commonly. Most A. marmoreum larvae were collected at Skukuza and numbers peaked from March to July. More R. evertsi evertsi larvae were collected at Nhlowa Road and numbers peaked in summer and in winter, while at Skukuza there was a single peak in spring. Haemaphysalis elliptica, Rhipicephalus simus and Rhipicephalus turanicus were collected as adults most commonly. More Ha. elliptica and R. turanicus were collected at Nhlowa Road than at Skukuza, while R. simus numbers from the two sites were approximately equal. Ha. elliptica were collected most often between February and June, and R. simus and R. turanicus during February and March. All three species were collected more frequently in gullies than in grassland or woodland. Their numbers increased in 1994/1995 following an eruption of rodents, the preferred hosts of the immature stages. The different host-seeking strategies of ticks largely determine the development stage at which they are likely to be collected during vegetation dragging and reflect a complex interaction between ticks, their hosts and the environment.

  3. Ecological guilds of epiphytic diatoms (Bacillariophyta on Acrostichum danaeifolium Längst. & Fisch in a subtropical wetland in southern Brazil

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    Vanessa Corrêa da Rosa

    2015-09-01

    Full Text Available Abstract Aim: Seasonal patterns diatom community on Acrostichum danaeifolium were examined in a wetland in southern Brazil. Methods The adhered diatoms were removed from the plant, species identification and growth forms were performed, and determined physical-chemical parameters of water. Results In total, 96 taxa belonging to 46 genera were identified. Nitzschia frustulum, Pseudostaurosira brevistriata and Plagiogramma tenuissimum were abundant species. Distinct growth forms that formed low-and high-profile ecological guilds and a mobile guild were observed. Navicula and Nitzschia were the genera with the greatest number of species, and these diatoms formed mucilage tubes. The water temperature varied from 10-26 °C, the depth from 0.35-0.80 m, the transparency from 0.20-0.23 m, the flow from 9.4-42.12 m3 s–1, the pH from 7.08-8.89, the electrical conductivity from 0.65-15.83 mS cm–1, the total organic phosphorus from 0.03-0.11 mg L–1, and the total organic nitrogen from 0.29-0.49 mg L–1. In summer, marine species such as Thalassiosira eccentrica and Rhaphoneis castracanii were also present. Conclusions The high-profile guild prevailed in all seasons of the year, with higher number of growth forms in the guild in winter. The richness found on A. danaeifolium shows that this plant provide a favorable habitat for epiphytic diatoms in wetlands such as Lagoa Pequena.

  4. A taxonomic study of the beetle cockroaches (Diploptera Saussure) from China, with notes on the genus and species worldwide (Blattodea: Blaberidae: Diplopterinae).

    Science.gov (United States)

    Li, Xinran; Wang, Zongqing

    2015-09-14

    Four taxa of beetle cockroaches (Diploptera Saussure, 1864) from South China are described and illustrated, viz., two new species D. elliptica sp. n. and D. naevus sp. n., one new subspecies D. nigrescens guani subsp. n. and one widespread known species D. punctata (Eschscholtz, 1822). The genus and known species from around the world are discussed based on types and other specimens. D. pulchra Anisyutkin, 2007 is now regarded as a junior synonym of D. bicolor Hanitsch, 1925. Whether the populations of D. punctata represent or not different species needs to be studied in the future. A key, a distribution map, and photos of species are provided.

  5. Análisis cariológico de ocho especies de encinos (Quercus, Fagaceae) en México

    OpenAIRE

    Flores-Maya, Saúl; Flores-Moreno, Ivonne; Romero-Rangel, Silvia; Rojas-Zenteno, Carlos; Rubio-Licona, Liliana Elizabeth

    2006-01-01

    Karyotype analyses of eight species of the Quercus genus were performed and are reported here. Five species (Q. candicans, Q. crassifolia, Q. elliptica, Q. hintonii and Q. urbanii) belong to the Lobatae section and three (Q. frutex, Q. obtusata and Q. rugosa) to the Quercus section. This is the first report of the chromosome numbers of all of them except Q. rugosa, and demonstrate that they are diploid (2n = 2x = 24) and the karyotypes are moderately asymmetrical.Se han realizado los estudios...

  6. SOIL ALGOLOGICAL SINUSIAE OF URBANIZED ECOSYSTEMS OF DONETSK PRIAZOVYE (THE CASE OF MARIUPOL

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    Shekhovtseva O.G.

    2012-12-01

    Full Text Available During research of urboekosystem of Donetsk Priazovye 105 types and intraspecific algosoil taxons are revealed: Chlorophyta – 42, Cyanoprocaryota – 34, Xanthophyta – 19,Bacillariophyta – 8, Eustigmatophyta – 2. It is often met: Phormidium autumnale, Chlamydomonas elliptica, Chlamydomonas gloeogama, Palmellopsis gelatinosa, Chlorella minutissima, Сhlorella vulgaris, Stichococcus minor, Stichococcus bacillaris, Bracteacoccus minor, Botrydiopsis arhiza, Pleurochloris magna, Navicula mutica, Navicula pelliculosa, Hantzschia amphioxys. Ecological structure of algogroupping: Ch31 P27 X16 C11 H7 B7 СF3 M2 amph1 (105.

  7. Antibacterial constituents of the diatom Navicula delognei.

    Science.gov (United States)

    Findlay, J A; Patil, A D

    1984-01-01

    The novel ester (E)-phytol (5Z,8Z,11Z,14Z,17Z)-eicosapentaenoate++ + (1); (6Z,9Z,12Z,15Z)-hexadecatetraenoic acid; (6Z,9Z,12Z,15Z)-octadecatetraenoic acid; and (6Z,9Z,12Z)-hexadecatrienoic acid isolated from the diatom Navicula delognei f. elliptica, show significant antibacterial activity against Staphylococcus aureus, Staphylococcus epidermidis, Salmonella typhimurium, and Proteus vulgaris. beta-Carotene, alpha-cryptoxanthin, fucoxanthin, lutein, trans-phytol, and plastoquinone-9 were also isolated from this diatom.

  8. Crustacea Isopoda collected during the Oc/S "Almirante Saldanha" cruises in southern South America, II: additions to the species of Serolis (Flabellifera, Serolidae

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    Plínio Soares Moreira

    1977-12-01

    Full Text Available This paper reports on part of the species of Serolis Leach, 1818 (Crustacea, Flabellifera, Serolidae collected from benthic stations performed during cruises of the Brazilian Navy Oc/S "Almirante Saldanha" along southern South America. The species studied are Serolis schythei Lütken, 1858, Serolis polaris Richardson, 1911, Serolis foresti Bastida & Torti, 1970, Serolis uaperta Moreira, 1971, Serolis exigua Nordenstam, 1933 and Serolis elliptica Sheppard, 1933. New localities of occurrence are reported, as well as it is given a com plete synonymy for each species treated, and for Serolis schythei and Serolis exigua also its main distinctive characteristics.O presente trabalho versa sobre as especies de isópodes do gênero Serolis Leach, 1818 (Crustacea, Flabellifera, Serolidae coletadas em estações bênticas realizadas ao largo da América do Sul pelo N/Oc "Almirante Saldanha". São estudadas as espécies S. schythei Lütken, 1858, S. polaris Richardson, 1911, S. foresti Bastida & Torti, 1970, S. uaperta Moreira, 1971, S. exigua Nordenstam, 1933 and S. elliptica Sheppard, 1933. Novas localidades de ocorrência são assinaladas, e para algumas espécies as distribuições geográfica e/ou batimétrica são ampliadas. Completa sinonímia e dada para todas as especies, e para S. schythei e S. exigua suas principais características distintivas.

  9. Análisis cariológico de ocho especies de encinos (Quercus, Fagaceae en México

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    Flores-Maya, Saúl

    2006-12-01

    Full Text Available Karyotype analyses of eight species of the Quercus genus were performed and are reported here. Five species (Q. candicans, Q. crassifolia, Q. elliptica, Q. hintonii and Q. urbanii belong to the Lobatae section and three (Q. frutex, Q. obtusata and Q. rugosa to the Quercus section. This is the first report of the chromosome numbers of all of them except Q. rugosa, and demonstrate that they are diploid (2n = 2x = 24 and the karyotypes are moderately asymmetrical.Se han realizado los estudios cariológicos de ocho especies del género Quercus, de las cuales cinco (Q. candicans, Q. crassifolia, Q. elliptica, Q. hintonii y Q. urbanii pertenecen a la sección Lobatae y tres (Q. frutex, Q. obtusata y Q. rugosa a la sección Quercus. Se indica por primera vez el número cromosómico de todas ellas excepto Q. rugosa. En todos los casos se trata de diploides (2n = 2x = 24 con cariotipos moderadamente asimétricos.

  10. Distribution of non-marine diatoms in surface sediments of streams in Socotra Island, Yemen

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    Abdelfattah A. Zalat

    2011-11-01

    Full Text Available Abundance and species composition of non-marine benthic diatom assemblages were studied from surface sediments samples of 11 streams distributed in Socotra Island, located in the northwest Indian Ocean. A total of 145 diatom species, representing 44 genera, were identified. The overall diatom communities appear to be the first recorded off the island. Pennales and non-planktonic taxa were most dominant over centrales and planktonic forms, both in diversity of genera and species. The majority of recognized diatoms are of cosmopolitan distribution. The predominant diatom flora in the surface sediment samples follow: Synedra ulna, Synedra longissima, Encyonema caespitosum, Encyonema silesiacum, Encyonemopsis microcephala, Mastogloia braunii, Mastogloia dansei, Mastogloia elliptica, Navicula cryptocephala, Navicula cryptotenella, Navicula rhynchocephala, Navicula cincta, Nitzschia amphibian, Nitzschia frustulum, Nitzschia perminuta, Cocconeis placentula, Pleurosira laevis and Staurosirella pinnata. These are found in addition to the common occurrence of Amphora coffeaeformis, Amphora Montana, Anomoeoneis sphaerophora, Cyclotella meneghiniana, Cymbella affinis, Diploneis elliptica, Encyonema mesianum, Diploneis smithii, Gomphonema gracile, Gomphonema parvulum, Kobayasia subtilissima, Mastogloia smithii, Navicula minuscule, Navicula notha, Navicula tenelloides, Nitzschia obtuse, Nitzschia palea, Nitzschia scalaris, Synedra nana, Tryblionella acuminate, Tryblionella granulate and Tryblionella punctata. Multivariate statistical techniques including detrended correspondence and cluster analyses were used to summarize changes in the diatom assemblages present in the examined streams. The results indicated six major diatom assemblages with a variation in dominant species. Each assemblage reflects distinctive environmental conditions based on salinity preference of the recognized and dominant.

  11. Late Cenozoic lacustrine and climatic environments at Tule Lake, northern Great Basin, USA

    Science.gov (United States)

    Platt, Bradbury J.

    1992-01-01

    Cores of lake sediment to a depth of 334 m in the town of Tulelake, Siskiyou County, northern California, document the late Cenozoic paleolimnologic and paleoclimatic history of the northwestern edge of the Great Basin. The cores have been dated by radiometric, tephrochronologic and paleomagnetic analyses. Lacustrine diatoms are abundant throughout the record and document a nearly continuous paleolimnologic history of the Tule Lake basin for the last 3 Myr. During most of this time, this basin (Tule Lake) was a relatively deep, extensive lake. Except for a drier (and cooler?) interval recorded by Fragilaria species about 2.4 Ma, the Pliocene is characterized by a dominance of planktonic Aulacoseira solida implying a warm monomictic lake under a climatic regime of low seasonality. Much of the Pleistocene is dominated by Stephanodiscus and Fragilaria species suggesting a cooler, often drier, and highly variable climate. Benthic diatoms typical of alkaline-enriched saline waters commonly appear after 1.0 Ma, and tephrochronology indicates slow deposition and possible hiatuses between about 0.6 and 0.2 Ma. The chronology of even-numbered oxygen isotope stages approximately matches fluctuations in the abundance of Fragilaria since 800 ka indicating that glacial periods were expressed as drier environments at Tule Lake. Glacial and interglacial environments since 150 ka were distinct from, and more variable than, those occurring earlier. The last full glacial period was very dry, but shortly thereafter Tule Lake became a deep, cool lacustrine system indicating a substantial increase in precipitation. Aulacoseira ambigua characterized the latest glacial and Holocene record of Tule Lake. Its distribution indicates that warmer and wetter climates began about 15 ka in this part of the Great Basin. Diatom concentration fluctuates at 41 000 year intervals between 3.0 and 2.5 Ma and at approximately 100 000 year intervals after 1.0 Ma. In the late Pliocene and early Pleistocene

  12. Diatoms as an indicator for tile drainage flow in a German lowland catchment

    Science.gov (United States)

    Wu, Naicheng; Faber, Claas; Ulrich, Uta; Schmalz, Britta; Fohrer, Nicola

    2014-05-01

    The separation of flow components within a model simulation is of great importance for a successful implementation of management measures. Tracers are commonly used to identify and assess runoff-generating processes and to detect sources of stream flow components within a target catchment. Diatoms could be an ideal tracer due to their diverse preferences to different aquatic habitats (van Dam et al. 1994, Pfister et al. 2009). As a part of a DFG (Deutsche Forschungsgemeinschaft) project, we collected diatom samples of 9 sites (4 tile drainage, and 5 river sites) weekly or biweekly from March to July 2013 in a German lowland catchment (the Kielstau catchment). First results showed that diatom species Achnanthes lanceolata, Fragilaria biceps and Navicula ingapirca dominated in tile drainage flow with relative abundances of 22.2%, 21.5% and 10.9%, respectively. For river sites, the most abundant species was Navicula cryptocephala (20.5%), followed by Fragilaria biceps (12.9%), Cyclotella meneghiniana (9.5%) and Achnanthes lanceolata (9.3%). Compared with river sites, tile drainage flow had lower diatom density, biomass, species richness and percentage of Aquatic/Riparian diatoms (AqRi%). However, the proportion of Riparian diatoms (RiZo%) increased at tile drainage flow. Indicator value method (IndVal) revealed that the two water types were characterized by different indicator species. Fifteen taxa (e.g. Cocconeis placentula, Cyclotella meneghiniana, Navicula cryptocephala and Fragilaria biceps) were significant indicators for river sites. Achnanthes lanceolata, Achnanthes minutissima and Navicula ingapirca were significant indicators for tile drainage flow. These results highlight the suitability of diatoms as an indicator for tile drainage flow. Spatial and temporal variations of diatom community should be considered in future surveys. Keywords: Diatoms, Flow components, Indicator value method, Tracer References: Pfister, L., J. J. McDonnell, S. Wrede, D. Hl

  13. THE EFFECT OF ANTHROPOGENIC CHANGE IN THE STRUCTURE OF DIATOMS AND WATER QUALITY OF THE ŻOŁYNIANKA AND JAGIELNIA STREAMS

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    Łukasz Peszek

    2015-02-01

    Full Text Available The studies on bentic diatoms were conducted in 2009–2011 at eight samplings sites over the Żołynianka stream and its tributary, the Jagielnia. 427 diatom taxa were recorded in total. Achnanthidium minutissimum var. minutissimum, Aulacoseira ambigua, Fragilaria capucina var. capucina, Gomphonema parvlum, Navicula gregaria, Nitzschia palea and Planothidium lanceolatum were dominant taxa in both watercourses. Chemical analysis of water showed high chemical status of water at most of sampling sites. The results of diatomaceous analysis conducted with OMNIDIA software revealed moderate and poor condition of water. The best water quality was recorded in the Jagielnia stream (good or moderate status. The values of the analyzed indices showed the worst water quality on the Żołynianka at site four, showing bad ecological status. TDI index deviated the most from the other two indices (IPS and GDI, always indicating poorer water quality.

  14. Interaction between local hydrodynamics and algal community in epilithic biofilm.

    Science.gov (United States)

    Graba, Myriam; Sauvage, Sabine; Moulin, Frédéric Y; Urrea, Gemma; Sabater, Sergi; Sanchez-Pérez, José Miguel

    2013-05-01

    Interactions between epilithic biofilm and local hydrodynamics were investigated in an experimental flume. Epilithic biofilm from a natural river was grown over a 41-day period in three sections with different flow velocities (0.10, 0.25 and 0.40 m s(-1) noted LV, IV and HV respectively). Friction velocities u* and boundary layer parameters were inferred from PIV measurement in the three sections and related to the biofilm structure. The results show that there were no significant differences in Dry Mass and Ash-Free Dry Mass (g m(-2)) at the end of experiment, but velocity is a selective factor in algal composition and the biofilms' morphology differed according to differences in water velocity. A hierarchical agglomerative cluster analysis (Bray-Curtis distances) and an Indicator Species Analysis (IndVal) showed that the indicator taxa were Fragilaria capucina var. mesolepta in the low-velocity (u*. = 0.010-0.012 m s(-1)), Navicula atomus, Navicula capitatoradiata and Nitzschia frustulum in the intermediate-velocity (u*. = 0.023-0.030 m s(-1)) and Amphora pediculus, Cymbella proxima, Fragilaria capucina var. vaucheriae and Surirella angusta in the high-velocity (u*. = 0.033-0.050 m s(-1)) sections. A sloughing test was performed on 40-day-old biofilms in order to study the resistance of epilithic biofilms to higher hydrodynamic regimes. The results showed an inverse relationship between the proportion of detached biomass and the average value of friction velocity during growth. Therefore, water velocity during epilithic biofilm growth conditioned the structure and algal composition of biofilm, as well as its response (ability to resist) to higher shear stresses. This result should be considered in modelling epilithic biofilm dynamics in streams subject to a variable hydrodynamics regime. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Anti-bacterial activity of some Brazilian medicinal plants.

    Science.gov (United States)

    de Lima, Maria Raquel Ferreira; de Souza Luna, Josiane; dos Santos, Aldenir Feitosa; de Andrade, Maria Cristina Caño; Sant'Ana, Antônio Euzébio Goulart; Genet, Jean-Pierre; Marquez, Béatrice; Neuville, Luc; Moreau, Nicole

    2006-04-21

    Extracts from various organs of 25 plants of Brazilian traditional medicine were assayed with respect to their anti-bacterial activities against Escherichia coli, a susceptible strain of Staphylococcus aureus and two resistant strains of Staphylococcus aureus harbouring the efflux pumps NorA and MsrA. Amongst the 49 extracts studied, 14 presented anti-bacterial activity against Staphylococcus aureus, including the ethanolic extracts from the rhizome of Jatropha elliptica, from the stem barks of Schinus terebinthifolius and Erythrina mulungu, from the stems and leaves of Caesalpinia pyramidalis and Serjania lethalis, and from the stem bark and leaves of Lafoensia pacari. The classes of compounds present in the active extracts were determined as a preliminary step towards their bioactivity-guided separation. No extracts were active against Escherichia coli.

  16. The tiger beetles (Coleoptera: Carabidae, Cicindelinae) of Angola: a descriptive catalogue and designation of neotypes.

    Science.gov (United States)

    Serrano, Artur R M; Capela, Rúben A

    2013-11-01

    An annotated catalogue of the species and subspecies of tiger beetles (Coleoptera: Carabidae, Cicindelinae) hitherto known from Angola is given. A total of 89 forms (74 species and 15 subspecies) is recorded from this southwestern country of Africa. Within this assemblage there are 31 endemic forms (33.3%). Some species are represented by only the holotype specimen (some without locality) or the type series. Others were recorded based on a single specimen. Records for six species previously unknow from Angola are given: Foveodromica sp. n. 1, Foveodromica sp. n. 2, Ophryodera rufomarginata bradshawi Péringuey, 1888, Elliptica muata parallelestriata (W. Horn, 1923), Lophyra differens (W. Horn, 1892) and Myriochila jucunda (Péringuey, 1892). A historical review, as well as some considerations on the distribution and conservation status of these beetles in Angola are also presented.

  17. First records of Zygnematales (Zygnematophyceae, Streptophyta for the state of Bahia, Brazil

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    Ivania Batista de Oliveira

    2013-12-01

    Full Text Available This study presents the first taxonomic inventory of the order Zygnematales in the Litoral Norte Environmentally Protected Area, in the state of Bahia, Brazil. Fifty samples of planktonic and periphytic material were collected, from lotic and lentic environments, during the summer (January-March and winter (June-August of 2009. We identified 18 taxa distributed among five genera (Cylindrocystis, Mougeotia, Netrium, Spirogyra, and Spirotaenia. Of those 18 taxa, eight were new additions to the Brazilian desmid flora: Mougeotia calcarea; Mougeotia elegantula; Spirogyra gracilis; Cylindrocystis crassa var. elliptica; Cylindrocystis brebissonii var. minor; Cylindrocystis brebissonii var. turgida; Netrium digitus var. parvum; and Netrium oblongum var. oblongum. The geographical distributions of ten taxa were extended to include northeastern Brazil.

  18. An Antarctic molluscan biomineralisation tool-kit

    Science.gov (United States)

    Sleight, Victoria A.; Marie, Benjamin; Jackson, Daniel J.; Dyrynda, Elisabeth A.; Marie, Arul; Clark, Melody S.

    2016-11-01

    The Antarctic clam Laternula elliptica lives almost permanently below 0 °C and therefore is a valuable and tractable model to study the mechanisms of biomineralisation in cold water. The present study employed a multidisciplinary approach using histology, immunohistochemistry, electron microscopy, proteomics and gene expression to investigate this process. Thirty seven proteins were identified via proteomic extraction of the nacreous shell layer, including two not previously found in nacre; a novel T-rich Mucin-like protein and a Zinc-dependent metalloprotease. In situ hybridisation of seven candidate biomineralisation genes revealed discrete spatial expression patterns within the mantle tissue, hinting at modular organisation, which is also observed in the mantle tissues of other molluscs. All seven of these biomineralisation candidates displayed evidence of multifunctionality and strong association with vesicles, which are potentially involved in shell secretion in this species.

  19. Parasites of domestic and wild animals in South Africa. XLVIII . Ticks (Acari: Ixodidae infesting domestic cats and wild felids in southern Africa

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    Ivan G. Horak

    2010-08-01

    Full Text Available Ticks collected from domestic cats (Felis catus, cheetahs (Acinonyx jubatus,caracals (Caracal caracal, African wild cats (Felis lybica, black-footed cats (Felis nigripes, a serval (Leptailurus serval, lions(Panthera leo, and leopards (Panthera pardus were identified and counted. Thirteen species of ixodid ticks and one argasid tick were identified from domestic cats and 17 species of ixodid ticks from wild felids. The domestic cats and wild felids harboured 11 ixodid species in common. The adults of Haemaphysalis elliptica, the most abundant tick species infesting cats and wild felids, were most numerous on a domestic cat in late winter and in mid-summer, during 2 consecutive years. The recorded geographic distribution of the recently described Haemaphysalis colesbergensis, a parasite of cats and caracals, was extended by 2 new locality records in the Northern Cape Province,South Africa.

  20. Chemical markers in Veronica sect. Hebe

    DEFF Research Database (Denmark)

    Johansen, Maria; Larsen, Tania Surrow; Mattebjerg, Maria Ahlm

    2007-01-01

    The content of iridoid glucosides and other water soluble compounds of Veronica sect. Hebe, three species and two hybrids were investigated. V. (Hebe) elliptica and V. (Hebe) brachysiphon, both from sect. Apertae were chemically different since the former contained two esters of 6-O......-rhamnopyranosylcatalpol while the latter had a 6-O-catalpol ester, compounds characteristic for most Veronica species. V. (Hebe) odora, from sect. Buxifoliatae as well as two hybrids presumably between this and two different "whipcord" species were also investigated. The parent species contained two 6-O-catalpol esters, one...... and hebridoside as well as 1-O-benzoyl b-rutinose had not previously been described from nature. The results confirm previous studies in that esters of 6-O-rhamnopyranosylcatalpol could be useful chemical markers in Veronica sect. Hebe....

  1. Experimental growth pattern calibration of Antarctic bivalves shells to provide a biogenic archive of long-term high-resolution records of environmental and climatic change.

    Science.gov (United States)

    Lartaud, F.; Toulot, A.; Paulet, Y. M.

    2009-04-01

    Mollusc shells are used as an archive of climate variability in polar areas. The geochemistry (isotope and trace element) of the mineralized tissues is sensitive to the seawater physico-chemical changes (temperature, salinity, primary production …) and the accretionary growth of the shells provide intra-annual to centennial information. However, a serious age and growth profile calibration is necessary to establish a chronological time scale in the micro-sampling strategy. This kind of investigation on biogenic carbonates from Polar Regions suffers to the difficulties of a precise field-based standardization and validation. That's why ecology and shell growth history of many molluscs from those areas still remain unknown. In Boreal seas, bivalve metabolic activity is usually more reduced than in tropical or temperate domains, and the life span increase. For example, growth bands counting in the shells of the ocean Quahog (Arctica islandica) reveals that some of these shells are up to 250 years old (Wanamaker et al., 2008). Nevertheless in those environments, few species have highly defined growth increments calibration. The shell growth of the Antarctic scallop Adamussium colbecki is presently not well defined. Some authors attribute a growth rate close to the temperate equivalent species (Heilmayer et al., 2003) whereas others show a lower performance (Berkman et al., 2004). During the MACARBI program, to investigate the shell growth rate and determine a sclerochronologic profile, Adamussium colbecki and Laternula elliptica shells from Terre Adélie (Antarctic) were marked in situ with calcein during 6 hours and recapture a month later, in the austral summer 2007-2008. At the same time, a control of environmental conditions (temperature, salinity and chlorophyll) was carried out. All shells marked provide a distinct green fluorescent line, corresponding to the date of the marking. Calcein marking did not affect survivorship or growth of A. colbecki and L

  2. Stereochemistry of 16a-Hydroxyfriedelin and 3-Oxo-16-methylfriedel-16-ene Established by 2D NMR Spectroscopy

    Directory of Open Access Journals (Sweden)

    Vagner Fernandes Knupp

    2009-02-01

    Full Text Available Friedelin (1, 3b-friedelinol (2, 28-hydroxyfriedelin (3, 16a-hydroxyfriedelin (4, 30-hydroxyfriedelin (5 and 16a,28-dihydroxyfriedelin (6 were isolated through fractionation of the hexane extract obtained from branches of Salacia elliptica. After a week in CDCl3 solution, 16a-hydroxyfriedelin (4 reacted turning into 3-oxo-16-methylfriedel-16-ene (7. This is the first report of a dehydration followed by a Nametkin rearrangement of a pentacyclic triterpene in CDCl3 solution occurring in the NMR tube. These seven pentacyclic triterpenes was identified through NMR spectroscopy and the stereochemistry of compound 4 and 7 was established by 2D NMR (NOESY spectroscopy and mass spectrometry (GC-MS. It is also the first time that all the 13C-NMR and 2D NMR spectral data are reported for compounds 4 and 7.

  3. Assessment of fuel resource diversity and utilization patterns in Askot Wildlife Sanctuary in Kumaun Himalaya, India, for conservation and management

    Energy Technology Data Exchange (ETDEWEB)

    Samant, Sher S.; Dhar, Uppeandra; Rawal, Ranbeer S. [G.B. Pant Inst. of Himalayan Environment and Development, Uttar Pradesh (India)

    2000-07-01

    A general decrease in abundance of wood plant species used as sources of fuel suggests that more detailed information is urgently needed on species-level trends and their conservation. Such studies have not been carried out so far in India and elsewhere; we therefore quantified the species-wise extraction of fuel from a site (Gori Ganga Valley) in Askot Wildlife Sanctuary in the Kumaun Himalaya. In all, 31 species (26 trees and 5 shrubs) were used as fuel, of which 14 were native to the Himalaya. Utilisation patterns, distributions, probabilities of use (PU), resources use indices (RUI), preferences and availabilities in forest communities of these species were determined. Use pattern did not vary much amongst low altitude villages (Similarity: 52-74%), whereas along the vertical (elevational) gradient it varied considerably (Similarity: 15-31%). Woodfordia fruticosa (L.) Kurz, Pinus roxburghii Sarg., Quercus leucotrichophora A. Camus, Macaranga pustulata King ex Hk. F., Quercus lanuginosa Don, Engelhardtia spicata Bl. and Mallotus philippensis (Lamk.) Muell. contributed most to collections, while Pyracantha crenulata (Don) Roem., Syzygium cuminii (L.) Skeels, Alnus nepalensis Don and Bauhinia vahlii Wt. and Arn. were in lesser demand. W. fruticosa, P. roxburghii, M. pustulata, Casearia elliptica Willd., E. spicata, M. philippensis, Q. leucotrichophora and Phoebe lanceolata (Nees) Nees showed high values of PU and RUI, indicating high pressure. Higher density of P. roxburghii, Rhododendron arboreum Sm., Q. lanuginosa, Q. leucotrichophora, Lyonia ovalifolia (Wall.) Drude, C. elliptica and M. pustulata amongst trees and Maesa indica A.DC., P. crenulata and W. fruticosa amongst shrubs exhibited high density but the remaining species showed low density indicating the possible depletion. Intensive management of natural habitats of species highly-referred for fuel, diversification of choice of species from natives to non-natives, large scale propagation of highly

  4. Ecological patterns of phytoplankton assemblages in Lake Garda: seasonal, spatial and historical features

    Directory of Open Access Journals (Sweden)

    Nico SALMASO

    2002-02-01

    Full Text Available The development of phytoplankton assemblages in the two main basins of the deep (Zmax=350 m and large (49 km3 subalpine Lake Garda (Northern Italy was investigated through monthly samplings from 1998 to 2000. The algal development was strongly typified by the alternation, from spring to autumn, of Fragilaria crotonensis and Mougeotia sp. and by the increasing importance of filaments of the complex Planktothrix rubescens/agardhii in summer and autumn. These three “master species” are characterised by higher biovolumes and/or more regular and wide annual development in comparison to the other dominant taxa. The simultaneous application of ordination (NMDS-Non metric Multi Dimensional Scaling and cluster analysis techniques revealed an ordered and coherent temporal succession of phytoplankton assemblages in the two main basins of the lake. These temporal and spatial regularities arise from the high inertia and resilience against perturbations that characterise the deep and large lakes, and contrast sharply with the less ordered or chaotic and unpredictable seasonal assemblages that may be found in small and shallow lakes. It is stressed that, owing to the use of different methodologies, the modifications of the phytoplankton assemblages in the last fifty years must be interpreted with particular caution. The only demonstrable differences seem to indicate that, with the speeding up of eutrophication processes in the 1960s and 1970s, detectable populations of Planktothrix and irregular increases of Conjugatophyceae (Mougeotia sp., Closterium aciculare were established. During and after the 1980s, the increase of phosphorus concentrations in the lake and the progression towards more mesotrophic conditions was accompanied by the appearance of further substantial populations of cyanobacteria (Planktolyngbya limnetica, Anabaena lemmermannii. In contrast with these signs of alteration, Fragilaria crotonensis, Asterionella formosa, Ceratium

  5. Ash, Asterionella, and Anglers: A Paleolimnological Approach to Understanding Anthropogenic and Volcanogenic Disturbances in a Small Sub-Alpine Watershed

    Science.gov (United States)

    Howard, K. L.; Noble, P. J.

    2014-12-01

    This poster summarizes geochemical, biological, hydrological, and watershed data that characterize Manzanita Lake, a small sub-alpine catchment in Lassen Volcanic National Park, CA. The future objective is to use characteristics of this system to interpret variations in diatom and sediment composition dating back to the 1914 Mt. Lassen eruption from a recently recovered lake core. Manzanita Lake is a small (0.18 km2) lake with a ~30 km2 watershed area situated on the northwest flank of Mt. Lassen, one of the most active Cascade volcanoes, and is a valuable recreational spot for anglers and visitors. Hydraulic residence time is short; roughly 119 days, and is derived from lake volume (1.0 X 106m3) and estimates of stream inflow (~6 ft3/sec) and outflow (~3 ft3/sec) that were made from May 2014 sampling data. Limnological sampling in 2012-2014 suggests that Manzanita Lake exhibits stable thermal stratification in the summer months, which is unusual given the shallow depth (~10m), but possibly supported by the morphometry of the lake basin and inputs of cold snowmelt from the flank of Lassen Peak. The lake is a moderately conductive (100-114 μS), mesotrophic system with secchi depths ranging from 8m to the bottom (~10m). Total phosphorus (TP) ranges from 15-25 ppb and dissolved inorganic nitrogen (DIN) from 2-15 ppb, with ammonium in the epilimnion being the largest contributor. A high concentration of silica (Si) in surface water inputs (34 mg/L) to Manzanita Lake likely reflects the rhyodacitic bedrock geology and large drainage ratio (164) of the watershed. Variations in Si concentration in the lake seem to be coupled with diatom production. During the sampling period Manzanita Lake is has been dominated by diatom blooms throughout the summer and fall months. There is a seasonal succession in the diatom species present, with abundant Asterionella formosa in the spring, transitioning to abundant Fragilaria crotonensis in the summer months, to a mixed dominance of

  6. Diatomáceas indicadoras de paleoambientes do Quaternário de Dois Irmãos, Recife, PE, Brasil Diatoms as indicators of paleoenvironments during the Quaternary at Dois Irmãos, Recife, Pernambuco State, Brazil

    Directory of Open Access Journals (Sweden)

    Giane Soares de Souza

    2007-09-01

    Full Text Available O trabalho apresenta o levantamento da diatomoflórula identificada em sedimentos do Quaternário da Lagoa das Diatomáceas (Dois Irmãos, Recife, baseado em um testemunho de sondagem com 4,5 m, tendo sido analisadas amostras com intervalos de 10 em 10 cm. Foram identificados 46 táxons, distribuídos em 19 gêneros, 40 espécies e seis variedades. A coluna estratigráfica esteve composta por gêneros epífitos (Actinella, Amphora, Cocconeis Eunotia, Fragilaria, Frustulia, Gomphonema e Rhopalodia, bentônicos (Navicula, Neidium, Nitzschia e Surirella e planctônicos (Aulacoseira, Cyclotella e Skeletonema. A maioria das espécies é oligoalóbia e litoral, destacando-se em termos de freqüência e abundância: Actinella brasiliensis, Anomoeoneis serians, Eunotia pectinalis, Frustulia rhomboides, sugerindo uma deposição de sedimentos em ambiente limnético. O predomínio de espécies epífitas em determinadas profundidades confirma a presença de macrófitas durante uma parte do período de deposição. Das espécies identificadas sete são consideradas de ambiente marinho: Cocconeis heteroidea, Cocconeis scutellum, Diploneis decipiens, Nitzschia scalaris, Nitzschia sigma, Skeletonema costatum e Surirella heideni as quais ocorreram de forma esporádica.A study of fossil diatoms from Lagoa das Diatomáceas (Dois Irmãos, Recife was carried out based on a 4.5-meter-long core sample. Samples were analyzed at 10 cm intervals. A total of 46 taxa were identified in 19 genera, 40 species and six varieties. The stratigraphic column was composed of epiphytic (Actinella, Amphora, Cocconeis Eunotia, Fragilaria, Frustulia, Gomphonema and Rhopalodia, benthic (Navicula, Neidium, Nitzschia, Surirella, and planktonic (Aulacoseira, Cyclotella and Skeletonema genera. Actinella brasiliensis, Anomoeoneis serians, Eunotia pectinalis and Frustulia rhomboides are oligohalobe, littoral species with high frequency and abundance, which suggests sediment deposition in a

  7. VARIASI SPESIES DIATOM PADA TIPE PERAIRAN BERBEDA UNTUK KEPENTINGAN FORENSIK SEBAGAI PETUNJUK KEMATIAN AKIBAT TENGGELAM

    Directory of Open Access Journals (Sweden)

    Adelina Arifiani Purnomo

    2015-05-01

    Full Text Available The purpose of this research was to determine diatom species in Unda River, BadungRiver, Lake Beratan, estuarine and marine waters of Padang Galak, that can be used to indicatedeath scene caused by drowning. Waters collected to 50 liters by using plankton net and carriedin a 25 ml glass bottle. The results of the research found that there were 60 species diatom from26 genera, 23 families, 2 orders, and 1 class. Among the 60 species in this research, can beindicate as 12 species are typical species of Unda River, 5 species are typical species of BadungRiver, 1 species is typical of Lake Beratan, 9 species are typical of Padang Galak Estuary, and 19species are typical to Padang Galak Sea. Among the typical species in every research site, thereare one species that has higher number: Fragilaria sp. 1 in Unda River, Gomphonema sp. 3 inBadung River. Cymbella sp. 3 in Lake Beratan, Cyclotella sp., in Padang Galak Estuarine, andCocconeis sp. 2 in Padang Galak Sea.Keywords: forensic, diatom, river, lake, sea

  8. Effects of Climate Change on Lake Thermal Structure and Biotic Response in Northern Wilderness Lakes

    Directory of Open Access Journals (Sweden)

    Mark B. Edlund

    2017-09-01

    Full Text Available Climate disrupts aquatic ecosystems directly through changes in temperature, wind, and precipitation, and indirectly through watershed effects. Climate-induced changes in northern lakes include longer ice-free season, stronger stratification, browning, shifts in algae, and more cyanobacterial blooms. We compared retrospective temperature-depth relationships modeled using MINLAKE2012 with biogeochemical changes recorded in sediment cores. Four lakes in Voyageurs National Park (VOYA and four lakes in Isle Royale National Park (ISRO were studied. Meteorological data from International Falls and Duluth, Minnesota, were used for VOYA and ISRO, respectively. Model output was processed to analyze epilimnetic and hypolimnetic water temperatures and thermal gradients between two periods (1962–1986, 1987–2011. Common trends were increased summer epilimnion temperatures and, for deep lakes, increased frequency and duration of thermoclines. Changes in diatom communities differed between shallow and deep lakes and the parks. Based on changes in benthic and tychoplanktonic communities, shallow lake diatoms respond to temperature, mixing events, pH, and habitat. Changes in deep lakes are evident in the deep chlorophyll layer community of Cyclotella and Discostella species, mirroring modeled changes in thermocline depth and stability, and in Asterionella and Fragilaria species, reflecting the indirect effects of in-lake and watershed nutrient cycling and spring mixing.

  9. Factors affecting diatom dynamics in the alpine lakes of Colbricon (Northern Italy: a 10-year survey

    Directory of Open Access Journals (Sweden)

    Andrea SQUARTINI

    2010-08-01

    Full Text Available Planktonic diatom fluctuations, their diversity and relationships with environmental variables were analyzed for ten consecutive years in Colbricon Superiore and Inferiore, two small high-mountain lakes located in the Paneveggio-Pale di S. Martino Natural Park (Trento, Italy offering the rare opportunity to study two lakes differing only by area and volume and being in this respect in a ratio of 2:1 and 3:1 respectively. The lakes were monitored and sampled monthly, during ten ice-free periods, from 1998 to 2007, to correlate water chemical and physical characteristics with the recorded diversity and abundance of planktonic diatoms. 55 taxa of Bacillariophyceae were found, among which Cyclotella spp., Tabellaria flocculosa and Fragilaria spp. were dominant. Both chemical data and diatom community composition are consistent with well buffered mesotrophic lakes. We found statistical evidence that the development of diatoms was strongly related to the variation of water temperature. Furthermore, several different signatures of the diatom-enviroment relationships arose between the two lakes as e.g., a negative correlation between diatom development and water transparency was occurring in the larger lake only. As a result, the average diatom density recorded over the 10 years period were 1.17 fold higher than in the lower lake which corresponds to a 1.65 fold higher biomass. A size-dependent tighter response of the phytoplankton to chemical parameters appears to operate in the smaller waterbody compared to the larger one.

  10. Extremophile Diatoms: Implications to the Drake Equation

    Science.gov (United States)

    Sterrenburg, Frithjof A. S.; Hoover, Richard B.

    2011-01-01

    Diatoms are unicellular Eukaryotes that (as a group and phylogenetically) are not strictly regarded as extremophiles , since the vast majority of diatoms are mesophilic photoautotrophs. However, among the terrestrial Eukaryotes, diatoms are by far the single group of organisms with the ability to inhabit the greatest range of hostile environments on Earth. They are the dominant eukaryotes in the polar regions; in fumaroles, hot springs and geysers; and in hypersaline and hyperalkaline lakes and pools. Cryophilic species such as Fragilaria sublinearis and Chaetoceras fragilis are able to carry out respiration at extremely low rates at low temperatures in darkness. The Drake Equation refers to the likelihood of there being intelligent life at the technological level of electromagnetic communication. However, consideration of the range of conditions suitable for the habitability of eukaryotic diatoms and prokaryotic extremophiles, the likelihood that life exists elsewhere in the cosmos becomes many orders of magnitude greater than that predicted by the classical Drake Equation. In this paper we review the characteristics of diatoms as eukaryotic extremophiles and consider the implications to adjustments needed to the Drake Equation to assess the possibility that life exists elsewhere in the Universe.

  11. A comparison of the character of algal extracellular versus cellular organic matter produced by cyanobacterium, diatom and green alga.

    Science.gov (United States)

    Pivokonsky, Martin; Safarikova, Jana; Baresova, Magdalena; Pivokonska, Lenka; Kopecka, Ivana

    2014-03-15

    This study investigated characteristics of algal organic matter (AOM) derived from three species (cyanobacterium Microcystis aeruginosa, diatom Fragilaria crotonensis and green alga Chlamydomonas geitleri) which dominate phytoplanktonic populations in reservoirs supplying drinking water treatment plants. Algal growth was monitored by cell counting, optical density and dissolved organic carbon concentration measurements. Extracellular organic matter (EOM) released at exponential and stationary growth phases and cellular organic matter (COM) were characterised in terms of specific UV absorbance (SUVA), peptide/protein and non-peptide content, hydrophobicity and molecular weight (MW). It was found that both EOM and COM were predominantly hydrophilic with low SUVA. COM was richer in peptides/proteins, more hydrophilic (with about 89% of hydrophilic fraction for all three species) and had lower SUVA than EOM. MW fractionation showed that both EOM and COM of all three species contain large portions of low-MW (100 kDa) polysaccharides. Peptides/proteins exhibited narrower MW distribution than non-peptide fraction and it widened as the cultures grew. The highest amount of peptides/proteins with a significant portion of high-MW ones (22%) was observed in COM of M. aeruginosa. The results imply that the knowledge of AOM composition and characteristics predetermine which processes would be effective in the treatment of AOM laden water. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. An ecological and floristic study of the diatoms in Babolrud river

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    Naser Jafari

    2014-03-01

    Full Text Available Epilithic diatoms are a division of Bacillariophyceae which live on stone and hard surfaces. This study was aimed to investigate the population dynamics of diatoms in Babolrud river. Samples were collected from 5 stations from May 2012 through September 2012 in a monthly interval. Temperature, pH, NO3-, PO4- and (EC were measured for each sampling. Samples were prepared using Patrick and Reimer procedure. 72 taxa were identified, among which 33 taxa (46% were cosmopolitan or widely distributed. The genera with the highest species were Navicula (12, Nitzschia (9, Achnanthes (9, Cymbella (8 and Gomphonema (6. The decrease in diatoms diversity from upstream toward downstream can be regarded as an indicator of increasing water pollution. Trends in distribution of diatom species in the sampling sites were explained by variations in environmental parameters such as conductivity, pH, temperature, nitrate and phosphate. In highly contaminated sites of the Babolrud River, species such as Gomphonema olivaceum, Navicula pupula, Nitzschia flexa and Pinnularia major were observed, while individuals of Achnanthes clevei, Achnanthes deflexa, Cymbella affinis and Fragilaria virescens were found in sampling sites with relatively less environmental perturbation. We concluded that diatoms can be used as quantitative indicators of environmental conditions in lotic systems.

  13. Effects of 2,4-dichlorophenoxyacetic acid on Kentucky algae: simultaneous laboratory and field toxicity testings.

    Science.gov (United States)

    Kobraei, M E; White, D S

    1996-11-01

    2,4-D was applied to a cove in Kentucky Lake which was highly infested with Myriophllum spicatum (Eurasian watermilfoil). Effects of 2,4-D on nontarget algal communities were monitored concurrently in the field and in laboratory microcosms for eight days. Results indicated that indirect effects of water temperature and increased nutrient concentrations due to lysis in milfoil plants may be more important in the field community dominated by Chlorophyta, Pyrrhophyta, and Bacillariophyta. 2,4-D applied at the label-recommended rate of 2 mg/L or less stimulated total community growth in both laboratory and field indicating a possible hormonal effect of 2,4-D on algae. Reduced community growth and metabolism at high laboratory concentrations of 100 mg/L and 1000 mg/L may indicate an inhibitory effect on photosynthesis and/or respiration in algae. 2,4-D altered the laboratory community structure and function in all concentrations tested. Heterotrophic taxa such as Nitzschia, Euglena, Chlamydomonas, Mallomonas, Anabaena, and Oscillatoria appeared to be least affected by 2,4-D at high concentrations. Scenedesmus, Pediastrum, Characiosiphon, Navicula, Melosira, and Fragilaria appeared to be more sensitive, even in the lowest concentrations.

  14. [Phytoplankton community structure and eutrophication risk assessment of Beijiang River].

    Science.gov (United States)

    Gou, Ting; Ma, Qian-Li; Xu, Zhen-Cheng; Wang, Li; Li, Jie; Zhao, Xue-Min

    2015-03-01

    To study the distribution of phytoplankton and water quality of Beijiang River, the community structure of phytoplankton was investigated and analyzed in wet and dry seasons. The results showed that a total of 74 species belonging to six phyla, 29 family and 48 genera of phytoplankton were identified, including 58 species of five phyla, 23 family and 41 genera in wet season and 59 species of six phyla, 26 family and 40 genera in dry season. Phytoplankton community structure in Beijiang River was represented by Bacillariophyta, Chlorophyta and Cyanophyta. Bacillariophyta dominanted the phytoplankton, and the dominant species were Aulacoseira granulate, Fragilaria virescens, Surirella biseriata, Nitzschia amphibia, Navicula simplex, Cyclotella meneghiniana, Synedra ulna, Gomphonema angustatum and Cymbella tumida. There was little difference in phytoplankton density between both seasons with the mean values being 3.54 x 10(5) and 4.87 x 10(5) cells L(-1) in dry and wet seasons, respectively. Based on the RDA results, DO, permanganate index, nitrogen and phosphorus were the important environmental factors affecting the distribution of phytoplankton in Beijiang River. The water quality of Beijiang River was classified as oligo-mesotrophic level even if this river was subjected to nitrogen and phosphorus pollution mainly from agricultural non-point source.

  15. Variation of phytoplankton functional groups modulated by hydraulic controls in Hongze Lake, China.

    Science.gov (United States)

    Tian, Chang; Pei, Haiyan; Hu, Wenrong; Hao, Daping; Doblin, Martina A; Ren, Ying; Wei, Jielin; Feng, Yawei

    2015-11-01

    Hongze Lake is a large, shallow, polymictic, eutrophic lake in the eastern China. Phytoplankton functional groups in this lake were investigated from March 2011 to February 2013, and a comparison was made between the eastern, western, and northern regions. The lake shows strong fluctuations in water level caused by monsoon rains and regular hydraulic controls. By application of the phytoplankton functional group approach, this study aims to investigate the spatial and temporal dynamics and analyze their influencing factors. Altogether, 18 functional groups of phytoplankton were identified, encompassing 187 species. In order to seek the best variable describing the phytoplankton functional group distribution, 14 of the groups were analyzed in detail using redundancy analysis. Due to the turbid condition of the lake, the dominant functional groups were those tolerant of low light. The predominant functional groups in the annual succession were D (Cyclotella spp. and Synedra acus), T (Planctonema lauterbornii), P (Fragilaria crotonensis), X1 (Chlorella vulgaris and Chlorella pyrenoidosa), C (Cyclotella meneghiniana and Cyclotella ocellata), and Y (Cryptomonas erosa). An opposite relationship between water level and the biomass of predominant groups was observed in the present study. Water level fluctuations, caused by monsoonal climate and artificial drawdown, were significant factors influencing phytoplankton succession in Hongze Lake, since they alter the hydrological conditions and influence light and nutrient availability. The clearly demonstrated factors, which significantly influence phytoplankton dynamics in Hongze Lake, will help government manage the large shallow lakes with frequent water level fluctuations.

  16. Freshwater diatoms as a source of lipids for biofuels.

    Science.gov (United States)

    Graham, James M; Graham, Linda E; Zulkifly, Shahrizim B; Pfleger, Brian F; Hoover, Spencer W; Yoshitani, Jun

    2012-03-01

    Until recently, biodiesel production has been derived from terrestrial plants such as soybean and canola, leading to competition between biodiesel production and agricultural production for source materials. Microalgae have the potential to synthesize 30 times more oil per hectare than terrestrial plants without competing for agricultural land. We examined four genera (Cyclotella, Aulacoseira, Fragilaria, Synedra) of common freshwater diatoms (Bacillariophyceae) for growth and lipid content in defined medium (sD11) that replicates hypereutrophic conditions in lakes and wastewater treatment plant effluents and optimized the medium for silicon content. Cyclotella and Aulacoseira produced the highest levels of total lipids, 60 and 43 μg total lipids/ml, respectively. Both diatoms are rich in fatty acids C14, C16, C16:1, C16:2,7,10, and C22:5n3. Of the diatoms examined, Cyclotella reached the highest population density (>2.5 × 10(6) cells/ml) in stationary phase when many of the cells appeared to be filled entirely with oil. Silicon enrichment studies indicated that for optimal utilization of phosphorus and nitrogen by diatoms growing in wastewater effluent, the amount of silicon present or added to the effluent should be 17.5 times the mass of phosphorus in the effluent. With high growth rates, high lipid contents, and rapid settling rates, Cyclotella and Aulacoseira are candidates for biodiesel production.

  17. Recent dynamics (1995-1999 of the phytoplankton assemblages in Lago Maggiore as a basic tool for defining association patterns in the Italian deep lakes

    Directory of Open Access Journals (Sweden)

    Pierisa PANZANI

    2002-02-01

    Full Text Available The main goal of the study presented here is to identify a repeatable pattern in the seasonal succession of phytoplankton assemblages in Lago Maggiore. In order to fulfil this objective we analysed the phytoplaktonic succession during a five years period (1995-1999, through the calculation of the Bray-Curtis similarity index applied to biovolume data. A cluster analysis has been then applied to the distance matrix, allowing the identification of sample clusters possessing a similar species composition. The comparison, through the whole period considered, of the phytoplankton assemblages characterising each cluster allowed to recognise six seasonal periods (Winter, Early Spring, Late Spring, Early Summer, Late Summer, Autumn, each of them characterised by a peculiar and repeatable species assemblage. Among the most interesting findings we would mention the existence of a Late Spring/Early Summer association, dominated by Planktothrix rubescens and Fragilaria crotonensis, probably peculiar of the deep subalpine lakes, where these species can better take advantage of the physical and chemical environment of the metalimnetic niche. The identification of a pool of dominant and sub-dominant species common to other southern subalpine lakes and the existence of a similar time periodicity in the development and decline of most of them across this lake district seem to be promising in order to give our results a wider application.

  18. Long-term survey of heavy-metal pollution, biofilm contamination and diatom community structure in the Riou Mort watershed, South-West France

    Energy Technology Data Exchange (ETDEWEB)

    Morin, S. [Unite de Recherche Reseaux, Epuration et Qualite des Eaux REQE, Cemagref, 50 avenue de Verdun, F-33612 Cestas Cedex (France)]|[Equipe Geochimie et Ecotoxicologie des Metaux dans les systemes Aquatiques GEMA, UMR 5805 EPOC, Univ. Bordeaux 1, Place du Docteur Bertrand Peyneau, F-33120 Arcachon (France)], E-mail: soizic.morin@bordeaux.cemagref.fr; Duong, T.T. [Unite de Recherche Reseaux, Epuration et Qualite des Eaux REQE, Cemagref, 50 avenue de Verdun, F-33612 Cestas Cedex (France)]|[Equipe Geochimie et Ecotoxicologie des Metaux dans les systemes Aquatiques GEMA, UMR 5805 EPOC, Univ. Bordeaux 1, Place du Docteur Bertrand Peyneau, F-33120 Arcachon (France); Dabrin, A.; Coynel, A. [Equipe Geochimie et Ecotoxicologie des Metaux dans les systemes Aquatiques GEMA, UMR 5805 EPOC, Universite Bordeaux 1, Avenue des Facultes, F-33405 Talence (France); Herlory, O.; Baudrimont, M. [Equipe Geochimie et Ecotoxicologie des Metaux dans les systemes Aquatiques GEMA, UMR 5805 EPOC, Univ. Bordeaux 1, Place du Docteur Bertrand Peyneau, F-33120 Arcachon (France); Delmas, F. [Unite de Recherche Reseaux, Epuration et Qualite des Eaux REQE, Cemagref, 50 avenue de Verdun, F-33612 Cestas Cedex (France); Durrieu, G. [Equipe Geochimie et Ecotoxicologie des Metaux dans les systemes Aquatiques GEMA, UMR 5805 EPOC, Univ. Bordeaux 1, Place du Docteur Bertrand Peyneau, F-33120 Arcachon (France); Schaefer, J. [Equipe Geochimie et Ecotoxicologie des Metaux dans les systemes Aquatiques GEMA, UMR 5805 EPOC, Univ. Bordeaux 1, Avenue des Facultes, F-33405 Talence (France); Winterton, P. [Univ. Paul Sabatier-Toulouse III, 118 route de Narbonne, F-31062 Toulouse Cedex 4 (France); Blanc, G. [Equipe Geochimie et Ecotoxicologie des Metaux dans les systemes Aquatiques GEMA, UMR 5805 EPOC, Univ. Bordeaux 1, Avenue des Facultes, F-33405 Talence (France); Coste, M. [Unite de Recherche Reseaux, Epuration et Qualite des Eaux REQE, Cemagref, 50 avenue de Verdun, F-33612 Cestas Cedex (France)

    2008-02-15

    In a metal-polluted stream in the Riou Mort watershed in SW France, periphytic biofilm was analyzed for diatom cell densities and taxonomic composition, dry weight and metal bio-accumulation (cadmium and zinc). Periphytic diatom communities were affected by the metal but displayed induced tolerance, seen through structural impact (dominance of small, adnate species) as well as morphological abnormalities particularly in the genera Ulnaria and Fragilaria. Species assemblages were characterized by taxa known to occur in metal-polluted environments, and shifts in the community structure expressed seasonal patterns: high numbers of Eolimna minima, Nitzschia palea and Pinnularia parvulissima were recorded in Summer and Autumn, whereas the species Surirella brebissonii, Achnanthidium minutissimum, Navicula lanceolata and Surirella angusta were dominant in Winter and Spring. Commonly used indices such as the Shannon diversity index and Specific Pollution Sensitivity Index reflected the level of pollution and suggest seasonal periodicity, the lowest diversities being observed in Summer. - Periphytic biofilm diatom communities are suitable indicators for the bioassay of elevated levels of metals in contaminated river water.

  19. Effects of the hydrological cycle on the phycoperiphyton assemblage in an Andean foothill stream in Colombia

    Directory of Open Access Journals (Sweden)

    María I. Ríos-Pulgarín

    2016-03-01

    Full Text Available The Guarinó River is a torrential system that is located in the foothills of the Colombian central Andean mountains that naturally experiences severe hydrological disturbances, which were higher during the Niño-Niña/Southern Oscillation (ENSO between 2007 and 2010. The seasonal and interannual variabilities in the taxonomic composition, richness and density of phycoperiphyton assemblages (ecological descriptors from the Guarinó River were examined in relation to the physical and chemical environmental changes associated with the hydrological cycle between 2007 and 2010. The values of the ecological descriptors and environmental variables were analysed via ANOVA, ANCOVA and Canonical Discriminant Analysis to establish temporal patterns and relationships between the variables. Eighty-seven taxa belonging to Cyanobacteria, Chlorophyta, Charophyta, Ochrophyta, Cryptophyta, Euglenozoa and Dinophyta were identified. Flow, water temperature and dissolved oxygen corresponded with the hydroclimatic variation and allowed for the differentiation of the El Niño and La Niña periods. Phycoperiphyton density differences matched the environmental variation pattern with a significant annual increase in the number of individuals during El Niño, whereas annual differences related to richness were not evident. The replacement of genera according to their drag or desiccation tolerance and the persistence of genera tolerant to high hydrological disturbances, such as Fragilaria, Nitzschia, Gomphonema, Navicula and especially Lyngbya, was observed.

  20. Biofouling Growth in Cold Estuarine Waters and Evaluation of Some Chitosan and Copper Anti-Fouling Paints

    Science.gov (United States)

    Pelletier, Émilien; Bonnet, Claudie; Lemarchand, Karine

    2009-01-01

    Ecological concerns about antifouling paints containing non-green tin and copper compounds have highlighted the need for environmentally friendly alternatives. We report here a field test conducted in estuarine waters over two months designed to evaluate the efficiency of a number of active natural and man-made chemical ingredients added into a silicon-polyurethane marine paint. Early steps of biofouling in cold seawater of the St. Lawrence Estuary (Canada) were observed. Analyses, including dry biomass, flow cytometry and spectrofluorimetry, demonstrated a short-term antibacterial action of chitosan-based paints although no significant anti-algal action was observed. Cuprous oxide paints were efficient against bacteria and algae invasion in the first two weeks, especially those with added organic biocides such as isothiazolone and copper pyrithione. However, the overall dry biomass and chlorophyll a content were similar for all chitosan-and copper-based paints after 63 days. Microscopic observations revealed variation in the highly diverse benthic diatom population including species Navicula, Melosira, Cocconeis, Nitshzcia, Fragilaria and Amphora. Results suggest no real long-term efficiency for tested antifouling paints and highlight a particular need for green antifouling ingredients that are active under northern estuarine conditions. PMID:19742133

  1. Biofouling Growth in Cold Estuarine Waters and Evaluation of Some Chitosan and Copper Anti-Fouling Paints

    Directory of Open Access Journals (Sweden)

    Karine Lemarchand

    2009-07-01

    Full Text Available Ecological concerns about antifouling paints containing non-green tin and copper compounds have highlighted the need for environmentally friendly alternatives. We report here a field test conducted in estuarine waters over two months designed to evaluate the efficiency of a number of active natural and man-made chemical ingredients added into a silicon-polyurethane marine paint. Early steps of biofouling in cold seawater of the St. Lawrence Estuary (Canada were observed. Analyses, including dry biomass, flow cytometry and spectrofluorimetry, demonstrated a short-term antibacterial action of chitosan-based paints although no significant anti-algal action was observed. Cuprous oxide paints were efficient against bacteria and algae invasion in the first two weeks, especially those with added organic biocides such as isothiazolone and copper pyrithione. However, the overall dry biomass and chlorophyll a content were similar for all chitosan- and copper-based paints after 63 days. Microscopic observations revealed variation in the highly diverse benthic diatom population including species Navicula, Melosira, Cocconeis, Nitshzcia, Fragilaria and Amphora. Results suggest no real long-term efficiency for tested antifouling paints and highlight a particular need for green antifouling ingredients that are active under northern estuarine conditions.

  2. Effect of addition of Navicula sp. on plankton composition and postlarvae growth of Litopenaeus vannamei reared in culture tanks with zero water exchange

    Directory of Open Access Journals (Sweden)

    Yllana Ferreira-Marinho

    2014-07-01

    Full Text Available The aim of this study was to evaluate the effect of the addition of Navicula sp. on plankton composition and postlarvae growth of Litopenaeus vannamei reared in culture tanks with zero water exchange systems. Four treatments were considered: zero water exchange (ZWE; ZWE with the addition of feed (ZWE-F; ZWE with the addition of Navicula sp. (ZWE-N and ZWE with the addition of feed and Navicula sp. (ZWE-FN, all in triplicate. Shrimp of 17.7 ± 0.02 mg were stocked at a density of 2500 shrimp m-3 and microalgae added on the 1st, 5th and 15th day at a density of 5x10(4 cell mL-1. The shrimp were fed a commercial feed composed by 42% crude protein four times a day except in the ZWE treatment. For data analysis we used Cochran, Shapiro-Wilk, ANOVA, Tukey and Student-t tests (P < 0.05. The most frequent genera were: Anabaena, Arcella, Asplanchma, Bosmina, Brachionus, Cylindrotheca, Daphnia, Fragilaria, Hemiaulus, Keratella, Orthoseira, Oscillatoria, Phymatodocis, Rhabdonema, Skeletonema, Sckizothrix and Ulothrix. Significant differences between treatments were observed for TAN, NO2-N, alkalinity, final weight, weight gain, final biomass, biomass gain, feed conversion ratio, specific growth rate and survival. The ZWE-FN treatment showed better production parameters, indicating the benefits of the addition of Navicula sp. as a natural food source for L. vannamei postlarvae in zero water exchange systems.

  3. Seasonal variation and occurrence of algal turf community in Lake Ladik, Turkey.

    Science.gov (United States)

    Maraşlioğlu, Faruk; Soylu, Elif Neyran; Gönülol, Arif

    2013-01-01

    The composition and seasonal variation of the algal turf of Lake Ladik were studied using samples collected from one station between June 2000 and May 2001. 50 taxa of diatoms were identified in the epiphyton. Navicula veneta, N. halophila, Nitzschia fonticola and Aulacoseira distans were particularly important on turf community. During the October month several Novicula species become progressively more important. Gomphonema lateripunctatum was particularly notable. Other diatoms were occasionally abundant, including Cymbella affinis, C. silesiaca, Navicula cryptocephala, Gomphonema olivaceum and Cyclotella ocellata. Also Navicula lanceolata and Anomoeoneis brachysira were conspicuous, owing to their large size, but were never numerically abundant. Fragilaria ulna and Nitzschia palea were found in low numbers in study area and this pointed out there has not been a remarkable abundance of algal pollution in Lake Ladik. The associations between July and August with bonds to June, January and February with bonds to April were most significant in the study period obtained by cluster analysis. Shannon diversity and evenness presented small variations during the study period. Lake Ladik presented low values of species richness particularly during summer period and highest values were recorded in April. According to canonical correspondence analysis, there was association between some Navicula and Nitzschia species with PO4-, NH3-N. Also the multivariate analysis showed, temperature as the most important factor in the distribution and abundance of diatoms on turf biomass.

  4. Multiproxies (benthic foraminifera, ostracods and biopolymers approach applied to identify the environmental partitioning of the Guadiana River Estuary (Iberian Peninsula

    Directory of Open Access Journals (Sweden)

    Lazaro Luiz Mattos Laut

    2016-04-01

    Full Text Available The Guadiana River is the fourth longest river in Europe and is a natural frontier between southern Portugal and Spain. This river was historically used to transport minerals exploited in the region since the Roman Empire and therefore suffered human interventions that have been intensified after the industrial revolution. The Guadiana River has in its limits the Guadiana Valley Natural Park, which is of great value for the Conservation of Geobiodiversity. This study mainly aims to identify zones with the environmental characteristics in the estuarine area of the Guadiana River based on the distribution and ecology of microorganisms (ostracods and foraminifera associated with physicochemical parameters and sedimentological and geochemical (carbohydrate, lipid, protein, total organic carbon and total sulfur data. Fifty-five foraminifera taxa were identified along the estuary with dominance of Ammonia tepida and Miliammina fusca and 13 ostracods taxa with dominance Leptocythere lacertosa and Loxoconcha elliptica. Detrended correspondence analysis (DCA performed using biotic and abiotic variables indicated that pH, grain size, total organic carbon (TOC and lipids were the most influent factors in the distribution of these organisms. Four zones were identified in the Guadiana River estuary: i Low estuary - region with the largest marine influence with sandy sediment, higher salinity and total sulfur and mainly represented by the dominance of estuarine species of foraminifera (Ammonia tepida and Cribroelphidium vadescens and by the ostracods (Darwinula stevensoni, Semicytherura sulcata and Urocythereis oblonga; ii Intermediate estuary - region characterized by neutral pH and sandy sediment enriched in carbohydrates; this region is characterized by the presence of the ostracods species Cytherois fischeri and Neocytherideis subulata and by calcareous and agglutinated species in foraminiferal assemblages; iii Upper estuary - silt, high TOC, proteins and

  5. [Genetic Differentiation of the Three Species of Genus Astragalus L. of Section Cenantrum Bunge (Fabaceae)].

    Science.gov (United States)

    Dymshakova, O S; Krivenko, D A; Belyaev, A Yu; Verkhozina, A V

    2015-08-01

    Genetic differentiation based on allozyme data was detected between species of the genus Astragalus L., section Cenantrum Bunge (Fabaceae): A.frigidus (L.) A. Gray s.l., A. mongholicus Bunge s. l, and A. sericeocanus Gontsch, which is endemic to the Northeast coast of Lake Baikal. The results of allozyme analysis confirm the natural division of the section into subsections based on morphological features. Differences between A. frigidus (subsection Elliptica Gontsch.) and A. mongholicus and A. sericeocanus (subsection Semilunaria Gontsch.) were observed. These differences were caused by the presence of species-specific alleles and the allele frequencies of the primary alleles, DN = 1.24. The genetic distance obtained for A. mongholicus and A. sericeocanus (0.10) corresponds to the status of closely related species of one subsection. Between populations of A. frigidus and between populations of A. mongholicus from the central part of areal, DN = 0.02 and 0.03 respectively. This genetic distance corresponds to the interpopulation level and was determined by the allele frequencies. The peripheral population of A. mongholicus is separated (DN = 0.36), which is probably due to the long isolation and the "founder effect."

  6. Inhibitory effect of Jeju endemic seaweeds on the production of pro-inflammatory mediators in mouse macrophage cell line RAW 264.7*

    Science.gov (United States)

    Yang, Eun-Jin; Moon, Ji-Young; Kim, Min-Jin; Kim, Dong Sam; Kim, Chan-Shick; Lee, Wook Jae; Lee, Nam Ho; Hyun, Chang-Gu

    2010-01-01

    Seaweed has been used in traditional cosmetics and as a herbal medicine in treatments for cough, boils, goiters, stomach ailments, and urinary diseases, and for reducing the incidence of tumors, ulcers, and headaches. Despite the fact that seaweeds are frequently used in the practice of human health, little is known about the role of seaweed in the context of inflammation. This study aimed to investigate the influence of Jeju endemic seaweed on a mouse macrophage cell line (RAW 264.7) under the stimulation of lipopolysaccharide (LPS). Ethyl acetate extracts obtained from 14 different kinds of Jeju seaweeds were screened for inhibitory effects on pro-inflammatory mediators. Our results revealed that extracts from five seaweeds, Laurencia okamurae, Grateloupia elliptica, Sargassum thunbergii, Gloiopeltis furcata, and Hizikia fusiformis, were potent inhibitors of the production of pro-inflammatory mediators such as nitric oxide (NO), prostaglandin E2 (PGE2), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α). Based on these results, the anti-inflammatory effects and low cell toxicity of these seaweed extracts suggest potential therapeutic applications in the regulation of the inflammatory response. PMID:20443209

  7. {delta}{sup 13}C and {delta}{sup 15}N shifts in benthic invertebrates exposed to sewage from McMurdo Station, Antarctica

    Energy Technology Data Exchange (ETDEWEB)

    Conlan, Kathleen E. [Canadian Musem of Nature, P.O. Box 3443 Station D, Ottawa, Ont., K1P 6P4 (Canada)]. E-mail kconlan@mus-nature.ca; Rau, Greg H. [Institute of Marine Sciences, University of California, Santa Cruz, CA 95064 (United States); Kvitek, Rikk G. [Earth Systems Science and Policy, California State University Monterey Bay, 100 Campus Center, Seaside, CA 93955 (United States)

    2006-12-15

    In an effort to identify biomonitors for contamination of Antarctic marine benthos by sewage, this study determines whether the US Antarctic Program's McMurdo Station produces a benthic sewage footprint and whether resident megafauna are assimilating sewage-derived material. We identified strong C and N isotopic gradients in benthic sediment as a function of downstream distance from McMurdo Station's point-source sewage addition. Sediment C and N isotope ratios approached marine background levels at the sampling end-point 612 m downcurrent. Based on isotope abundances in their tissues, at least some sewage C and N were assimilated by the sedentary, suspension feeding soft coral Alcyonium antarcticum, ascidian Cnemidocarpa verrucosa and bivalve Laternula elliptica. However, as inferred by tissue-sediment differences in downstream isotope trends, such assimilation was not in proportion to sewage exposure and input, therefore implying non-generalist feeding behavior by these species. In contrast, the motile, generalist feeding sea urchin Sterechinus neumayeri, sea star Odontaster validus and ribbon worm Parborlasia corrugatus showed isotopic evidence of sewage C and N assimilation roughly in proportion to sewage input. We recommend these generalist feeders for further use as biomonitors at this site now that sewage treatment has been implemented. As these species are circumpolar in distribution, they may also prove useful elsewhere in the Antarctic.

  8. Species richness of the genera Trachelomonas and Strombomonas (pigmented Euglenophyceae in a subtropical urban lake in the Porto Alegre Botanical Garden, RS, Brazil

    Directory of Open Access Journals (Sweden)

    Sandra Maria Alves-da-Silva

    2013-09-01

    Full Text Available The objective of this study was to evaluate the taxonomic composition and richness of the genera Trachelomonas and Strombomonas (pigmented Euglenophyceae in a subtropical urban lake (30º03'05"S; 51º10'34"W within the Botanical Garden, in the city of Porto Alegre, located in the state of Rio Grande do Sul, Brazil, in order to contribute to the floristic knowledge of Euglenophyta in artificial urban lakes. From July 2007 to June 2008, we collected samples monthly from two sampling stations, using a 25-µm mesh plankton net. The samples were preserved in 4% formaldehyde. We evaluated the following environmental variables related to the water in the lake: ammonia content, silica content, organic matter content, dissolved oxygen concentration, temperature, pH, depth, transparency, electrical conductivity and rainfall. To study the species composition in relation to environmental factors, we used cluster analysis, principal components analysis, canonical correspondence analysis and indicator species analysis. At the specific and infraspecific level, 22 taxa were identified, Trachelomonas elliptica (Playf. Defl. and T. gracillima Bal. & Dast. representing new records for the state of Rio Grande do Sul. The cluster analysis indicated seasonal variation, species richness being highest in the spring of 2007. Seven indicator species were characterized as acid-tolerant.

  9. Ellipticine induces apoptosis through p53-dependent pathway in human hepatocellular carcinoma HepG2 cells.

    Science.gov (United States)

    Kuo, Yu-Chun; Kuo, Po-Lin; Hsu, Ya-Ling; Cho, Chien-Yu; Lin, Chun-Ching

    2006-04-25

    Ellipticine (5,11-dimethyl-6H-pyrido[4,3-b]carbazole), one of the simplest naturally occurring alkaloids, was isolated from the leaves of the evergreen tree Ochrosia elliptica Labill (Apocynaceae). Here, we reported that ellipticine inhibited the cell growth of human hepatocellular carcinoma cell line HepG2 and provided molecular understanding of this effect. The XTT assay results showed that ellipticine decreased the cell viability of HepG2 cells in a dose- and time-dependent manner, and the IC50 value was 4.1 microM. Furthermore, apoptosis induction by ellipticine in HepG2 cells was verified by the appearance of DNA fragmentation and annexin V-FITC/propidium iodide (PI) staining assay. Ellipticine treatment was found to result in the upregulation of p53, Fas/APO-1 receptor and Fas ligand. Besides, ellipticine also initiated mitochondrial apoptotic pathway through regulation of Bcl-2 family proteins expression, alteration of mitochondrial membrane potential (DeltaPsim), and activation of caspase-9 and caspase-3. Taken together, ellipticine decreased the cell growth and induced apoptosis in HepG2 cell.

  10. Probiotic Potential of Lactobacillus Strains with Antifungal Activity Isolated from Animal Manure.

    Science.gov (United States)

    Ilavenil, Soundharrajan; Park, Hyung Soo; Vijayakumar, Mayakrishnan; Arasu, Mariadhas Valan; Kim, Da Hye; Ravikumar, Sivanesan; Choi, Ki Choon

    2015-01-01

    The aim of the study was to isolate and characterize the lactic acid bacteria (LAB) from animal manure. Among the thirty LAB strains, four strains, namely, KCC-25, KCC-26, KCC-27, and KCC-28, showed good cell growth and antifungal activity and were selected for further characterization. Biochemical and physiology properties of strains confirmed that the strains are related to the Lactobacillus sp.; further, the 16S rRNA sequencing confirmed 99.99% sequence similarity towards Lactobacillus plantarum. The strains exhibited susceptibility against commonly used antibiotics with negative hemolytic property. Strains KCC-25, KCC-26, KCC-27, and KCC-28 showed strong antifungal activity against Aspergillus fumigatus, Penicillium chrysogenum, Penicillium roqueforti, Botrytis elliptica, and Fusarium oxysporum, respectively. Fermentation studies noted that the strains were able to produce significant amount of lactic, acetic, and succinic acids. Further, the production of extracellular proteolytic and glycolytic enzymes, survival under low pH, bile salts, and gastric juice together with positive bile salt hydrolase (Bsh) activity, cholesterol lowering, cell surface hydrophobicity, and aggregation properties were the strains advantages. Thus, KCC-25, KCC-26, KCC-27, and KCC-28 could have the survival ability in the harsh condition of the digestive system in the gastrointestinal tract. In conclusion, novel L. plantarum KCC-25, KCC-26, KCC-27, and KCC-28 could be considered as potential antimicrobial probiotic strains.

  11. Direct versus indirect climate controls on Holocene diatom assemblages in a sub-tropical deep, alpine lake (Lugu Hu, Yunnan, SW China)

    Science.gov (United States)

    Wang, Qian; Yang, Xiangdong; Anderson, Nicholas John; Dong, Xuhui

    2016-07-01

    The reconstruction of Holocene environmental changes in lakes on the plateau region of southwest China provides an understanding of how these ecosystems may respond to climate change. Fossil diatom assemblages were investigated from an 11,000-year lake sediment core from a deep, alpine lake (Lugu Hu) in southwest China, an area strongly influenced by the southwest (or the Indian) summer monsoon. Changes in diatom assemblage composition, notably the abundance of the two dominant planktonic species, Cyclotella rhomboideo-elliptica and Cyclostephanos dubius, reflect the effects of climate variability on nutrient dynamics, mediated via thermal stratification (internal nutrient cycling) and catchment-vegetation processes. Statistical analyses of the climate-diatom interactions highlight the strong effect of changing orbitally-induced solar radiation during the Holocene, presumably via its effect on the lake's thermal budget. In a partial redundancy analysis, climate (solar insolation) and proxies reflecting catchment process (pollen percentages, C/N ratio) were the most important drivers of diatom ecological change, showing the strong effects of climate-catchment-vegetation interactions on lake functioning. This diatom record reflects long-term ontogeny of the lake-catchment ecosystem and suggests that climatic changes (both temperature and precipitation) impact lake ecology indirectly through shifts in thermal stratification and catchment nutrient exports.

  12. A study of the dry forest communities in the Dominican Republic

    Directory of Open Access Journals (Sweden)

    Antonio García-Fuentes

    2015-03-01

    Full Text Available This paper is a floristic and phytosociological study of the dry forest communities of the Dominican Republic. A total of 69 relevés in dry forest biotopes were carried out. The samples were subsequently subjected to Detrended Correspondence Analysis for the determination and study of possible groupings. The study does not cover tree formations growing on serpentines, nor the so-called semideciduous forests, peculiar to areas with higher rainfall. A total of nine phytocoenoses were identified. The most significant results led to the description of six new phytosociological associations: Simaroubetum berteroani(thorny dry forest on coastal dunes, Phyllostylo rhamnoidis-Prosopidetum juliflorae (southern Dominican disturbed dry forest, Consoleo moniliformis-Camerarietum linearifoliae(dry forest on hard limestones, Lemaireocereo hystricis-Prosopidetum juliflorae(northern Dominican disturbed dry forest, Lycio americani-Prosopidetum juliflorae (disturbed dry forest on saline soils and Guettardo ellipticae-Guapiretum discoloris (dry forest on flat-topped hillocks in Montecristi. This is an important step forward in the phytosociological and floristic studies of the Caribbean territories.

  13. Migrated Hopene Synthases from Colysis pothifolia and Identification of a Migration Switch Controlling the Number of 1,2-Hydride and Methyl Shifts.

    Science.gov (United States)

    Shinozaki, Junichi; Hiruta, Masayoshi; Okada, Takayuki; Masuda, Kazuo

    2016-01-01

    Ferns are known to produce triterpenes, derived from squalene, that are synthesized by squalene cyclases (SCs). Among these, Colysis species produce onoceroids, the bis-cyclic skeleton of which can be cyclized from both termini of squalene. To gain insight into the molecular basis of triterpene structural diversity, cDNA cloning of SCs from C. elliptica and C. pothifolia was performed; this leads to the isolation of five SC cDNAs. Functional analysis of these clones revealed their enzymatic products to be hop-22(29)-ene, α-polypodatetraene, and hop-17(21)-ene. One of these clones (CPF) is a transcribed pseudogene with a 22-nucleotide deletion causing a nonsense mutation. To predict the inherent function of CPF, we constructed an insertion mutant of CPF that successfully converted inert CPF to the active SC, the product of which is fern-9(11)-ene. Subsequent mutations identified active-site residues that control the number of 1,2-hydride and methyl shifts. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Probiotic Potential of Lactobacillus Strains with Antifungal Activity Isolated from Animal Manure

    Directory of Open Access Journals (Sweden)

    Soundharrajan Ilavenil

    2015-01-01

    Full Text Available The aim of the study was to isolate and characterize the lactic acid bacteria (LAB from animal manure. Among the thirty LAB strains, four strains, namely, KCC-25, KCC-26, KCC-27, and KCC-28, showed good cell growth and antifungal activity and were selected for further characterization. Biochemical and physiology properties of strains confirmed that the strains are related to the Lactobacillus sp.; further, the 16S rRNA sequencing confirmed 99.99% sequence similarity towards Lactobacillus plantarum. The strains exhibited susceptibility against commonly used antibiotics with negative hemolytic property. Strains KCC-25, KCC-26, KCC-27, and KCC-28 showed strong antifungal activity against Aspergillus fumigatus, Penicillium chrysogenum, Penicillium roqueforti, Botrytis elliptica, and Fusarium oxysporum, respectively. Fermentation studies noted that the strains were able to produce significant amount of lactic, acetic, and succinic acids. Further, the production of extracellular proteolytic and glycolytic enzymes, survival under low pH, bile salts, and gastric juice together with positive bile salt hydrolase (Bsh activity, cholesterol lowering, cell surface hydrophobicity, and aggregation properties were the strains advantages. Thus, KCC-25, KCC-26, KCC-27, and KCC-28 could have the survival ability in the harsh condition of the digestive system in the gastrointestinal tract. In conclusion, novel L. plantarum KCC-25, KCC-26, KCC-27, and KCC-28 could be considered as potential antimicrobial probiotic strains.

  15. Diatoms as paleoecological indicators of environmental change in the Lake Czechowskie catchments ecosystem (Northern Tuchola Pinewoods, Poland)

    Science.gov (United States)

    Rzodkiewicz, Monika; Zawiska, Izabela; Noryśkiewicz, Agnieszka Maria; Obremska, Milena; Ott, Florian; Kramkowski, Mateusz; Słowiński, Michał; Błaszkiewicz, Mirosław; Brauer, Achim

    2016-04-01

    In this study we investigated four cores of biogenic sediments from the lakes located in close vicinity. Three cores are situated along a transect in the Lake Czechowskie basin from its deepest point towards a former lake bay. The fourth sediment core was retrieved from the nearby Trzechowskie paleolake. Lake Czechowskie is located in the northern part of the Tuchola Pinewoods District (Northern Poland) in a young glacial landscape. At present, the majority of the area is forested or used for agriculture. The main focus was of the study was Late Glacial and early Holocene period. We performed diatom, Cladocera and pollen analyses, the chronology was established by varve counting, confirmed by AMS 14C dating and Laacher See Tephra (Wulf et. all 2013). In this study we focused on the results of diatom analyses. Diatom assemblages are integrated indicators of environmental change because their distributions are closely linked to water quality parameters including such as nutrient availability. At the beginning of Allerød there are more eutrophic diatom taxa such as Staurosira construens, Pseudostaurosira brevistriata, Staurosira pinnata. These species are widely distributed in the littoral mainly freshwater, many of which are species of epiphytic, preferring water rich in nutrients. At the end of the Allerød we observe significant changes within diatom assemblages. The increase of planktonic Cyclotella comensis together with the decrease of benthic Stauroseria construens indicate the shortening of time with ice cove on the lake and longer time with summer stratification. In the Younger Dryas cooling we can see the increase of the abundance of diatom Staurosira construens which indicate cold spring and late ice-out (Bradbury et al., 2002). At the early Holocene planktonic diatoms increase in particular Cyclotella comensis, Punciculata radiosa and Cyclotella praetermissa. Some of Aulacoseira species at the end of Younger Dryas. The Holocene sediments showed no

  16. The Effect of Local Lacustrine Conditions on the Expression of Regional Holocene Climate in the Ruby Mountains, Nevada, USA

    Science.gov (United States)

    Starratt, S.; Kusler, J. E.; Addison, J. A.; Wahl, D.

    2013-12-01

    Climate of the north-central Great Basin currently exhibits a bimodal precipitation pattern, dominated by winter (NDJF) precipitation from the eastern Pacific Ocean, augmented by late spring (MJ) convectional precipitation. Reconstruction of past moisture variability has proven difficult due to limited paleoclimate records in this region and the effect of lake-specific and local watershed characteristics. In order to better understand the Holocene climate record a series of cores were collected in Favre Lake (2902 masl, 8 ha, 12 m deep) using a modified Livingstone piston corer. The presence of the Mazama ash in the basal sediment (~4 m below the sediment/water interface) indicates the record extends to ~7700 cal yr B.P. The pollen record is dominated by Pinus and Artemisia, followed by subordinate levels of Poaceae, Asteraceae, Amaranthaceae, and Sarcobatus. Small fragilarioid diatoms (Pseudostaurosira, Staurosira, and Staurosirella) comprise as much as 80% of the assemblage. The remainder of the assemblage is dominated by benthic taxa. Planktonic species account for about 10% of the assemblage. Biogenic silica values vary between 20 and 30 wt %. These proxies suggest that the lake was small between 7,700 and 5,500 cal yr BP; for most of the remainder of the record, the lake covered a shallow (~1 m deep) shelf, resulting in the dominance of small fragilarioid diatoms. Planktonic species increase in abundance in the last 200 years, indicating the establishment of modern conditions. In order to evaluate the role of local conditions on the climate record, surface sediments were collected from tarns in the northern Ruby Mountains (Lamoille Lake, 2976 masl, 6 ha; Upper Dollar Lake, 2942 masl, ~1 ha, 2 m deep; Lower Dollar Lake, 2937 masl, ~1 ha, 2 m deep; Liberty Lake, 3064 masl, 9 ha, 33 m deep; Castle Lake, 2980 masl, 6 ha, 4.6 m deep; Favre Lake), and East Humboldt Range (Angel Lake, 2553 masl, 5 ha, 9 m deep). Slope aspects above the lakes are north (Lamoille

  17. Nitrogen deposition effects on diatom communities in lakes from three National Parks in Washington State

    Science.gov (United States)

    Sheibley, Richard W.; Enache, Mihaela; Swarzenski, Peter W.; Moran, Patrick W.; Foreman, James R.

    2014-01-01

    The goal of this study was to document if lakes in National Parks in Washington have exceeded critical levels of nitrogen (N) deposition, as observed in other Western States. We measured atmospheric N deposition, lake water quality, and sediment diatoms at our study lakes. Water chemistry showed that our study lakes were ultra-oligotrophic with ammonia and nitrate concentrations often at or below detection limits with low specific conductance (−1 year−1 and were variable both within and across the parks. Diatom assemblages in a single sediment core from Hoh Lake (Olympic National Park) displayed a shift to increased relative abundances of Asterionella formosa and Fragilaria tenera beginning in the 1969–1975 timeframe, whereas these species were not found at the remaining (nine) sites. These diatom species are known to be indicative of N enrichment and were used to determine an empirical critical load of N deposition, or threshold level, where changes in diatom communities were observed at Hoh Lake. However, N deposition at the remaining nine lakes does not seem to exceed a critical load at this time. At Milk Lake, also in Olympic National Park, there was some evidence that climate change might be altering diatom communities, but more research is needed to confirm this. We used modeled precipitation for Hoh Lake and annual inorganic N concentrations from a nearby National Atmospheric Deposition Program station, to calculate elevation-corrected N deposition for 1980–2009 at Hoh Lake. An exponential fit to this data was hindcasted to the 1969–1975 time period, and we estimate a critical load of 1.0 to 1.2 kg N ha−1 year−1 for wet deposition for this lake.

  18. Temperature and nutrients are significant drivers of seasonal shift in phytoplankton community from a drinking water reservoir, subtropical China.

    Science.gov (United States)

    Lv, Hong; Yang, Jun; Liu, Lemian; Yu, Xiaoqing; Yu, Zheng; Chiang, Penchi

    2014-05-01

    Reservoirs are an important source of water supply in many densely populated areas in southeast China. Phytoplankton plays an important role in maintaining the structure and function of these reservoir ecosystems. Understanding of seasonal succession in phytoplankton communities and its driving factors is essential for effective water quality management in drinking-water reservoirs. In this study, water samples were collected monthly at the surface layers of riverine, transitional, and lacustrine zones from May 2010 to April 2011 in Tingxi Reservoir, southeast China. The phytoplankton showed distinct seasonal shifts in community structure at both taxonomic and functional levels. Cyanophyta was the dominant group in summer, especially species of Raphidiopsis in May and Aphanizomenon in June, and cyanobacterial dominance was promoted by both warmer conditions and excessive nutrients loading. Cyanophyta was gradually replaced by Cryptophyta (e.g., Chroomonas caudata) in abundance and by Bacillariophyta (Fragilaria sp. or Synedra sp. and Melosira sp.) in biomass with decreasing temperature. It appeared that seasonal shifts in phytoplankton composition were closely related to climate, nutrient status, and hydrology in this reservoir. Our partial RDA results clearly showed that water temperature and nutrients (TN and TP) were the most critical factors driving phytoplankton community shift in the abundance and biomass data, respectively. Further, with the global warming, cyanobacterial blooms may increase in distribution, duration, and intensity. In our study, the abundance and biomass of cyanobacteria had significant and positive correlations with temperature and phosphorus. Therefore, a stricter limit on nutrient input should be a priority in watershed management to protect drinking water from the effects of cyanobacterial blooms, especially in high-temperature period.

  19. Ecological Study of Periphytic Algal Community of Doodh Ganga and Khansha-Mansha Streams of Yusmarg Forests: A Health Resort of Kashmir Valley, India

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    Rafia Rashid

    2013-06-01

    Full Text Available The present study on Doodh Ganga and Khansha-Mansha streams of Yusmarg forests deals with the general ecological studies on periphytic algal community in terms of species composition and density. During the present investigation the periphytic algal community of Doodh Ganga and Khansha-Mansha streams were represented by 30 taxa which belonged to 4 major classes namely Bacillariophyceae (14, Chlorophyceae (11, Cyanophyceae (4 and Euglenophyceae (1. The most common periphytic species encountered across all the sites included Closterium sp., Zygnema sp., Amphora sp., Cymbella sp., Epithemia sp., Fragilaria sp., Navicula sp., Synedra sp., Tabellaria sp., Lyngbya sp. and Phormidium sp. Among the two streams, Doodh Ganga showed large number of taxa (45 and Khansha-Mansha was having 37 taxa of periphyton. Bacillariophyceae was the dominant group both in diversity and density and included 14 taxa contributing 57% of total periphytic algal population. Cyanophyceae forming the second dominant class was represented by 4 genera comprising 22% of the total periphytic algae .Chlorophyceae ranked third in its dominance pattern with 11 genera forming 20% of all the periphytic algae. Euglenophyceae was represented by only one species of Euglena sp. forming 1% of all the periphytic algae and found only at site 2 (Doodh Ganga downstream.Amongst the study sites the highest (5.69 value of Shannon Weiner Index was found at Doodh Ganga upstream while as lowest (4.38 at Khansha-Mansha downstream. The primary conclusion is that the streams, having crystal clear water, and are free from pollution as Chlorophyceae are better represented in both the streams. Further, as a result of less anthropogenic pressures the quality of water is fairly good.

  20. Effects of copper on species composition of periphyton in a Sierra Nevada, California, stream

    Energy Technology Data Exchange (ETDEWEB)

    Leland, H.V.; Carter, J.L.

    1984-06-01

    Changes in species composition of the periphyton of an oliotrophic, Sierra Nevada stream continuously dosed for 1 year at three concentrations of copper (2.5, 5 and 10..mu..g 1/sup -1/ Cu/sub T/; approximately 12, 25 and 50 ng 1/sup -1/ Cu/sup 2 +/) were determined. The numerically most abundant taxa were Bacillariophyceae (Achnanthes minutissima, Cocconeis placentula, Cymbella microcephala, C. sinuata, Fragilaria construens, F. crotonensis, Navicula spp., Synedra acus and S. rumpens), and the Cyanophyta Lynbya spp., a co-dominant during spring and summer. Population densities of Lyngbya spp. were markedly reduced at all test concentrations of copper. Population densities of the principal Chlorophyta (Spirogyra spp. and Cladophora spp.) and the diatom Amphipleura pellucida were reduced at 5 ..mu..g 1/sup -1/ Cu/sub T/. Of the twenty-two most abundant taxa, sixteen were reduced in abundance by continuous exposure to 10 ..mu..g 1/sup -1/ Cu/sub T/. There was no commensurate reduction in standing crop (total number of individuals of all taxa). Achnanthes minutissima, a co-dominant in the control, was the primary replacement species. Other taxa that were more abundant at 5 ..mu..g 1/sup -1/ Cu/sub T/ than in the control were Ceratoneis arcus, Cocconeis placentula, Navicula spp. and Synedra rumpens. Only A. minutissima and Calothrix spp. were more abundant at l10 ..mu..g 1/sup -1/ than in the control. Three resemblance measures (Canberra metric, Bray-Curtis and Dice) and diversity (Brillouin's) were evaluated for detecting differences in species composition among experimental stream sections. The Canberra metric, an index sensitive to proportional rather than absolute differences, was the most informative of these indices.

  1. Responses of aquatic organisms to metal pollution in a lowland river in Flanders: A comparison of diatoms and macroinvertebrates

    Energy Technology Data Exchange (ETDEWEB)

    Jonge, Maarten de [Department of Biology, Ecophysiology, Biochemistry and Toxicology Group, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium)], E-mail: maarten.dejonge@ua.ac.be; Vijver, Bart van de [Department of Bryophytes and Thallophytes, National Botanic Garden of Belgium, Domein van Bouchout, 1860 Meise (Belgium); Blust, Ronny; Bervoets, Lieven [Department of Biology, Ecophysiology, Biochemistry and Toxicology Group, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium)

    2008-12-15

    The role of macroinvertebrates and diatoms as indicator for metal pollution was investigated by assessing both biota along a metal gradient in the Belgian river the Dommel. Macroinvertebrates and diatoms were sampled in summer and winter and physical-chemical characteristics of the water were measured at four different sample periods and related to sediment characteristics. Although metal concentrations, except cadmium, in the water nowhere exceeded water quality standards, high metal concentrations were measured in the sediment, indicating historical contamination of the Dommel. At the sites that were situated downstream of the pollution source, high levels of conductivity and chloride were measured in the water. Redundancy Analysis (RDA) indicated pH, phosphate and zinc as the significant environmental variables explaining each respectively 7.7%, 11.6% and 22.6% of the macroinvertebrate community composition. Two clusters could be separated, with Gammarus pulex, Leptocerus interruptus, Baetis rhodani and Cloeon dipterum associated with low zinc concentrations and Tubificidae, Asellus aquaticus, Erpobdella sp. and Chironomus thummi-plumosus associated with higher zinc concentrations. Ammonium (10.6%), conductivity (16.5%), chloride (11.4%) and zinc (5.9%) turned out to be significant variables explaining the diatom community structure. Based on physical-chemical differences and species composition, three different groups could be separated. With this Tabellaria flocculosa and Fragilaria capucina var. rumpens were associated with low metal concentrations, Gomphonema parvulum and Nitzschia palea with elevated concentrations and Eolimna minima and Sellaphora seminulum with high zinc concentrations. In conclusion, the diatom community best reflected the metal gradient. With regard to water quality indices, those based on macroinvertebrates best followed the metal pollution gradient and were most strongly correlated with physical-chemical variables of water and

  2. Decline of Pseudodiaptomus hessei (Copepoda, Calanoida) in two water bodies located in the Senegal River hydrosystem (West Africa): Hypotheses and perspectives

    Science.gov (United States)

    Mendoza-Vera, Juana Mireya; Kâ, Samba; Cuoc, Corinne; Bouvy, Marc; Pagano, Marc

    2008-09-01

    Pseudodiaptomus hessei is a key species in many water bodies in the Senegal River hydrosystem but it became rare or completely disappeared from two ecosystems (Lake Guiers and Dakar Bango Reservoir; Senegal, West Africa) after major hydrological changes caused by human action, mainly impoundments on the river in 1985, and the opening of a new estuary mouth in 2003. Kâ et al. [Kâ, S., Pagano, M., Ba, N., Bouvy, M., Leboulanger, C., Arfi, R., Thiaw, O.T., Ndour, E.H.M., Corbin, D., Defaye, D., Cuoc, C., Kouassi, E., 2006. Zooplankton distribution related to environmental factors and phytoplankton in a shallow tropical lake (Lake Guiers, Senegal, West Africa). International Review of Hydrobiology 91(5), 389-405] put forward several hypotheses to explain the reasons for this decline: salinity and chemical changes in the water, predation by a cyclopid predator Mesocyclops ogunnus and/or the inhibiting effects of cyanobacteria and/or diatoms (allelopathy). This study assessed these hypotheses by studying the distribution of P. hessei in 13 stations (including the Dakar Bango reservoir and Lake Guiers) in relation to physical, chemical and biological (phyto- and zooplanktons) factors at each station. We produced a distribution pattern for this species in the Senegal River hydrosystem. Rank correlations and principal component analysis showed that P. hessei was not correlated with conductivity but was positively correlated with pH and alkalinity, suggesting chemical effects. The clear association with two filamentous cyanobacteria ( Cylindrospermopsis raciborskii and Anabaena sp.) did not appear to support the hypothesis of cyanobacteria inhibition but blooming conditions were never encountered during the study. Negative correlation with diatoms (especially with Fragilaria sp.) suggested that aldehyde producing diatoms had a negative effect. Negative correlations with cyclopids such as Mesocyclops supported the hypothesis of cyclopid predation to explain the decline of P

  3. Use of diatom assemblages as biomonitor of the impact of treated uranium mining effluent discharge on a stream: case study of the Ritord watershed (Center-West France).

    Science.gov (United States)

    Herlory, Olivier; Bonzom, Jean-Marc; Gilbin, Rodolphe; Frelon, Sandrine; Fayolle, Stéphanie; Delmas, François; Coste, Michel

    2013-10-01

    The rehabilitation of French former uranium mining sites has not prevented the contamination of the surrounding aquatic ecosystems with metal elements. This study assesses the impact of the discharge of treated uranium mining effluents on periphytic diatom communities to evaluate their potential of bioindication. A 7-month survey was conducted on the Ritord watercourse to measure the environmental conditions of microalgae, the non-taxonomic attributes of periphyton (photosynthesis and biomass) and to determine the specific composition of diatom assemblages grown on artificial substrates. The environmental conditions were altered by the mine waters, that contaminate the watercourse with uranium and with chemicals used in the pit-water treatment plants (BaCl2 and Al2(SO4)3). The biomass and photosynthetic activity of periphyton seemed not to respond to the stress induced by the treated mining effluents whereas the altered environmental conditions clearly impacted the composition of diatom communities. Downstream the discharges, the communities tended to be characterized by indicator species belonging to the genera Fragilaria, Eunotia and Brachysira and were highly similar to assemblages at acid mine drainage sites. The species Eunotia pectinalis var. undulata, Psammothidium rechtensis, Gomphonema lagenula and Pinnularia major were found to be sensitive to uranium effluents whereas Neidium alpinum and several species of Gomphonema tolerated this contamination. The relevance of diatoms as ecological indicator was illustrated through the changes in structure of communities induced by the discharge of uranium mining effluents and creates prospects for development of a bioindicator tool for this kind of impairment of water quality.

  4. Ecological value of macrophyte cover in creating habitat for microalgae (diatoms and zooplankton (rotifers and crustaceans in small field and forest water bodies.

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    Sofia Celewicz-Gołdyn

    Full Text Available Due to their small area and shallow depth ponds are usually treated as a single sampling unit, while various microhabitats offer different environmental conditions. Thus, we tested the effect of different habitat types typically found within small ponds on the microalgae and zooplankton communities. We found that submerged macrophytes have the strongest impact on microalgae and zooplankton communities out of all the analysed habitats. Some epontic diatoms (e.g. Fragilaria dilatata, Cymbella affinis and littoral-associated zooplankton species (e.g. Simocephalus vetulus, Lecane bulla were significantly related to elodeids. However, pelagic species (e.g. bosminids preferred less complex helophytes, which suggests that the most heterogeneous elodeid habitats were not an anti-predator shelter for cladocerans. Selection of different macrophyte types by taxonomically various organisms suggests that it is not only macrophyte cover that is desired for healthy aquatic environment but that a level of habitat mosaic is required to ensure the well-being of aquatic food webs. Species-specific preferences for different types of macrophytes indicate the high ecological value of macrophyte cover in ponds and a potential direction for the management of small water bodies towards maintaining a great variation of aquatic plants. Moreover, the type of surrounding landscape, reflecting human-induced disturbance (28 field ponds and natural catchment (26 forest ponds, significantly influenced only zooplankton, while diatoms were affected indirectly through the level of conductivity. Nutrient overload (higher content of TRP and increased conductivity in the field landscape contributed to a rise in microalgae (e.g. Amphora pediculus, Gomphonema parvulum and zooplankton (e.g. Thermocyclops oithonoides, Eubosmina coregoni abundance. An awareness of the responses of both components of plankton communities to environmental factors is necessary for maintaining the good state

  5. Ecological value of macrophyte cover in creating habitat for microalgae (diatoms) and zooplankton (rotifers and crustaceans) in small field and forest water bodies.

    Science.gov (United States)

    Celewicz-Gołdyn, Sofia; Kuczyńska-Kippen, Natalia

    2017-01-01

    Due to their small area and shallow depth ponds are usually treated as a single sampling unit, while various microhabitats offer different environmental conditions. Thus, we tested the effect of different habitat types typically found within small ponds on the microalgae and zooplankton communities. We found that submerged macrophytes have the strongest impact on microalgae and zooplankton communities out of all the analysed habitats. Some epontic diatoms (e.g. Fragilaria dilatata, Cymbella affinis) and littoral-associated zooplankton species (e.g. Simocephalus vetulus, Lecane bulla) were significantly related to elodeids. However, pelagic species (e.g. bosminids) preferred less complex helophytes, which suggests that the most heterogeneous elodeid habitats were not an anti-predator shelter for cladocerans. Selection of different macrophyte types by taxonomically various organisms suggests that it is not only macrophyte cover that is desired for healthy aquatic environment but that a level of habitat mosaic is required to ensure the well-being of aquatic food webs. Species-specific preferences for different types of macrophytes indicate the high ecological value of macrophyte cover in ponds and a potential direction for the management of small water bodies towards maintaining a great variation of aquatic plants. Moreover, the type of surrounding landscape, reflecting human-induced disturbance (28 field ponds) and natural catchment (26 forest ponds), significantly influenced only zooplankton, while diatoms were affected indirectly through the level of conductivity. Nutrient overload (higher content of TRP) and increased conductivity in the field landscape contributed to a rise in microalgae (e.g. Amphora pediculus, Gomphonema parvulum) and zooplankton (e.g. Thermocyclops oithonoides, Eubosmina coregoni) abundance. An awareness of the responses of both components of plankton communities to environmental factors is necessary for maintaining the good state of small

  6. Paleolimnological assessment of nutrient enrichment on diatom assemblages in a priori defined nitrogen- and phosphorus-limited lakes downwind of the Athabasca Oil Sands, Canada

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    Kathleen R. Laird

    2017-04-01

    Full Text Available As the industrial footprint of the Athabasca Oil Sands Region (AOSR continues to expand, concern about the potential impacts of pollutants on the surrounding terrestrial and aquatic ecosystems need to be assessed. An emerging issue is whether recent increases in lake production downwind of the development can be linked to AOSR activities, and/or whether changing climatic conditions are influencing lake nutrient status. To decipher the importance of pollutants, particularly atmospheric deposition of reactive nitrogen (Nr, and the effects of climate change as potential sources of increasing lake production, lakes from both within and outside of the nitrogen deposition zone were analyzed for historical changes in diatom assemblages. Lake sediment cores were collected from a priori defined nitrogen (N - and phosphorus (P - limited lakes within and outside the N plume associated with the AOSR. Diatom assemblages were quantified at sub-decadal resolution since ca. 1890 to compare conditions prior to oil sands expansion and regional climate warming, to the more recent conditions in each group of lakes (Reference and Impacted, N- and P-limited lakes. Analyses of changes in assemblage similarity and species turnover indicates that changes in diatom assemblages were minimal both within and across all lake groups.  Small changes in percent composition of planktonic taxa, particularly small centric taxa (Discostella and Cyclotella species and pennate taxa, such as Asterionella formosa and Fragilaria crotonensis, occurred in some of the lakes. While these changes were consistent with potential climate effects on algal growth, water column stability and other factors; the timing and direction of biotic changes were variable among sites suggesting that any apparent response to climate was lake dependent. The absence of a consistent pattern of diatom changes associated with receipt of reactive nitrogen or intrinsic nutrient-limitation status of the lake

  7. Comparison of phytoplankton succession in two lakes of different mixing regimes

    Science.gov (United States)

    Agbeti, M.D.; Kingston, J.C.; Smol, J.P.; Watters, C.

    1997-01-01

    The influence of frequent water-column mixing on phytoplankton succession and species composition was studied by comparing plankton dynamics in two lakes (Lake Opinicon and Upper Rock Lake) which have similar water chemistry, but differ widely in their basin morphometries: Opinicon is shallow and frequently-mixed during the ice-free season, whereas nearby Upper Rock is deep and dimictic. The species composition and the seasonal succession of phytoplankton were broadly similar in both lakes over the three years of study. The spring phytoplankton in both lakes consisted of diatoms that were replaced in the summer and fall by cyanobacteria. Diatom peaks in Opinicon preceded similar peaks in Upper Rock. Loss of diatoms from the phytoplankton in Upper Rock appeared to be related to sedimentation; in contrast, zooplankton herbivory may have resulted, partly, in loss of diatoms in Opinicon. Lightly-silicified and spindle-shaped diatoms (Rhizosolenia and single-celled Fragilaria) were more abundant in the dimictic lake, whereas heavily-silicified diatoms (Aulacoseira) were more abundant in the frequently-mixed lake. Zooplankton taxa and their seasonal patterns were similar in both lakes, but populations were considerably denser in the frequently-mixed lake. The results of canonical correspondence analysis and detrended correspondence analysis (multivariate ordination techniques) indicated that, although phytoplankton growth was influenced by similar physical and chemical variables in both lakes, the influence of chemical variables was stronger in Upper Rock. A frequently-mixed system, such as Lake Opinicon, appeared to provide a similar environment for plankton development to a well-mixed epilimnion of a typical dimictic lake, such as Upper Rock Lake.

  8. Processes of seasonal layer formation in varved Lake Czechowskie (N Poland): Linking monitoring and sediment core data

    Science.gov (United States)

    Ott, Florian; Brykała, Dariusz; Gierszewski, Piotr; Schwab, Markus; Brademann, Brian; Dräger, Nadine; Kienel, Ulrike; Pinkerneil, Sylvia; Plessen, Birgit; Słowiński, Michał; Błaszkiewicz, Mirosław; Brauer, Achim

    2017-04-01

    The interpretation of environmental and climate records, such as lake sediments, rely on the profound understanding of the proxy sensitivity towards past changes. Monitoring of lake sedimentation, limnological, hydrological and climate parameters are natural experiments combining measurements and observations. In this study, we present monitoring data from Lake Czechowskie (N Poland) for the period 2013-2016. Lake Czechowskie has a surface area of 73 ha and a maximum water depth of 32 m. Sediment has been trapped in a 4-cylinder and an automatic sequential trap installed at 12 and 30 m water depths close to the deepest part of the lake, respectively. Sampling intervals range from 15 (sequential) to 30 days (4 cylinder) days. The sediment has been analyzed for total sediment flux, calcium carbonate and organic matter contents. Continuous water temperature measurements (30 min. intervals) are based on 17 data loggers covering the entire water column (1 m steps from 0-12 m; 5 m steps from 12-32 m). Limnological measurements (e.g. electrical conductivity, dissolved oxygen and pH) have been carried out manually on a monthly routine. Air temperature, precipitation, wind speed and direction are available for the same period from a meteorological station installed at the shore of Lake Czechowskie. Our dataset exhibit seasonal deposition starting with diatom blooms and calcite precipitation in spring after lake stratification. A second deposition peak occurs at the onset of lake mixing in late autumn and winter. This is caused by an initial deposition of planktonic diatoms (mainly Fragilaria spp.) indicating lake productivity, followed by an increase in larger calcite patches (>30 µm) and periphyitic diatoms (mainly Navicula spp.) representing resuspension of littoral sediments. We paired sediment trap data with micro-facies analyses from a sediment core obtained in autumn 2016 covering the same time interval. This study is a contribution to the Virtual Institute of

  9. Tortum Gölü'nün (Erzurum Bentik Alg Florasının Mevsimsel Değişimi.

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    Ersin Kıvrak

    2015-12-01

    Full Text Available Mart 2002-Şubat 2003 tarihleri arasında Tortum Gölü’nün bentik alglerinin kompozisyonu, yoğunluğu ve mevsimsel değişimleri incelenmiştir. Elde edilen veriler 21 yıl önce yapılan araştırmanın sonuçlarıyla karşılaştırılmıştır. Bu araştırmada Navicula capitata var. hungarica (Grunow Ross, Navicula cryptocephala Kütz., Cymbella affinis Kütz., Amphora ovalis (Kütz. Kütz., Cocconeis placentula var. euglypta (Ehrenb. Grunow, Nitzschia sublinearis Hust, Cyclotella krammeri Håk., Merismopedia elegans A. Braun epipelik alg florasında dominant taksonlar olmuştur. Yaz başında ve sonbaharda epipelik florada artış gözlenmiştir. Cymbella affinis, Cymbella lanceolata (Ehrenb. Kirchner, Fragilaria capucina var. rumpens (Kütz. Lange-Bert., Cocconeis placentula var. euglypta, Cyclotella krammeri epilitik alg florasında bol ve yaygın bulunan taksonlardır. Spirogyra aequinoctialis G. S. West ise sadece yaz aylarında epilitik florada çok bol olarak bulunmuştur. Bentik alg florasının, gölün organik maddelerle kirlenmesinden etkilendiği sonucuna varılmıştır

  10. Changes in epilithic diatom assemblages in a Mediterranean high mountain lake (Laguna de La Caldera, Sierra Nevada, Spain after a period of drought

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    D. FERNÁNDEZ-MORENO

    2008-02-01

    Full Text Available The epilithic diatom assemblages studied in the high mountain lake “La Caldera” (Granada, Spain from 1996 to 1998 went through two clearly different stages. The initial one, in 1996, corresponded to the reflooding of the basin after a severe drought and was composed mainly of the colonising species Fragilaria rumpens, together with a lesser presence of Nitzschia sublinearis and Hantzschia amphioxys. The predominant presence of F. rumpens at the end of the summer of 2006 coincided with low species diversity (values of Shannon and Wiener Index: 0.3-0.6. During the following two years another assemblage established itself, dominated by Achnanthidium minutissimum, which is considered to be more stable and widespread among the lakes of the Sierra Nevada. The most notable subdominant species (less than 20% of relative abundance in this assemblage were: Encyonema minutum, Encyonopsis microcephala and Navicula cryptocephala. The diversity values during this second period were much higher than in the first: 1.0-2.2. Nutrient concentrations were measured separately in the limnetic (epilimnetic and benthic (epilithic environments. These abiotic parameters show that the dynamics of ammonia and silica were much the same in both, showing a gradual decrease from the beginning to the end of the study period. Epilimnetic phosphorus followed a similar pattern to ammonia and silica. In the epilithon, nitrates and phosphates increased during the first year, only to descend notably during the second. The effect of other environmental parameters such as temperature and the preceding drought on the dynamics of the diatom assemblage are discussed. Ratio DIN:SRP let us test the different degrees of phosphorus limitation in epilithon and epilimnion environments; our results suggest that phosphorus limitation of primary production in high mountain lakes is much more severe in the limnetic environment that it is in the epilithon.

  11. SUCESIÓN DE MICROALGAS PERIFÍTICAS EN TRIBUTARIOS DEL RÍO GAIRA, SIERRA NEVADA DE SANTA MARTA, COLOMBIA

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    Farid Jesús OSORIO ÁVILA

    2015-01-01

    Full Text Available Las microalgas poseen atributos para la bioindicación, el estudio de algas perifíticas en ecosistemas fluviales tropicales, es de vital importancia ya que permite interpretar la dinámica de estos ecosistemas con importancia ecológica y con vocación para ofrecer servicios de abastecimiento. Para este estudio se seleccionaron tributarios de la cuenca media del río Gaira (SNSM, se evaluó el proceso sucesional de microalgas perifíticas, siguiendo el avance de la comunidad desde enero hasta abril de 2012, mediante la metodología de sustratos artificiales. El propósito fue analizar la variación en la estructura de la comunidad, durante el proceso de sucesión y evaluar los factores ambientales que determinan esta variación en un rio tropical. Los resultados destacan caudal, luz y oxígeno disuelto los cuales presentaron los valores más altos para el tributario C (Jabalí; el pH fue ligeramente básico para todos los sitios, la temperatura y conductividad presentaron valores más altos en el tributario A (Honduras. Durante las primeras semanas de exposición del sustrato Melosira varians y Lyngbya sp. fueron dominantes para los tributarios A y B (La Picúa, mientras que para el tributario C lo fueron Fragilaria sp., Nitzschia sp. y Melosira varians. Después de la cuarta semana de colecta se registraron los mayores valores de diversidad y riqueza de especies. Fueron más notorios los cambios en densidad que en composición de especies, a pesar de esto el proceso de sucesión fue completo y se evidenció la presencia de especies pioneras (Lyngbya sp., Nitzschia sp., intermedias (Melosira varians, Cocconeis placentula y tardías (Surirella sp..

  12. Studies on the phytoplankton of the deep subalpine Lake Iseo

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    Rosario MOSELLO

    2003-08-01

    Full Text Available This paper reports the results of investigations carried out on the chemical characteristics and phytoplankton community of Lake Iseo. Samplings were performed on a monthly basis from 1998 to 2000. At least three main algal groups dominated the community throughout the study period. The large Bacillariophyceae were dominant mainly during late winter and early spring (Aulacoseira spp., Melosira varians, Asterionella formosa, with few species able to maintain occasional positive growth also during mid summer and/or autumn (Fragilaria crotonensis and Diatoma elongatum. The thermal stability of the water column and silica depletion were the main factors responsible for the decline of the large spring diatoms. The subsequent growth of Mougeotia sp. (Conjugatophyceae was favoured by its lower sinking rate and resistance to increasing grazing pressure by the dominant copepods (Copidodiaptomus steueri and cladocerans (Daphnia hyalina × galeata. Among the cyanobacteria, the greater development of Planktothrix rubescens in the autumn months, with conditions of vertical homogenisation and decreasing Zeu/Zmix ratios, was favoured by its ability to survive at low light irradiances. The temporal replacement of these three groups constitutes the main sequence of the annual phytoplankton succession in Lake Iseo. A large development of other algal groups was recorded only in one or two of the three study years (e.g. Dinophyceae and Chlorococcales. The changes observed in the annual phytoplankton development are discussed in the light of differences in the spring fertilisation of the waters, caused by differences in the depth of the layer involved in the late winter and spring vertical mixing.

  13. Macromicetos del Parque Educativo Laguna Bélgica, municipio de Ocozocoautla de Espinosa, Chiapas, México Macrofungi from Parque Educativo Laguna Bélgica, Municipality of Ocozocoautla de Espinosa, Chiapas, Mexico

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    Freddy Chanona-Gómez

    2007-12-01

    Full Text Available El presente estudio tuvo como objetivos contribuir al conocimiento de los macromicetos que crecen en el Parque Educativo Laguna Bélgica (PELB, en Ocozocoautla de Espinosa, Chiapas y determinar el índice de diversidad de Simpson y similitud de Sorensen de la micobiota existente en los diferentes tipos de vegetación. Se realizaron 24 exploraciones micológicas durante un año, encontrándose 144 especies (24 Ascomycota y 120 Basidiomycota. El índice de diversidad, mostró que la vegetación con la micobiota más diversa fue la del bosque de Quercus elliptica (D= 0.9678 la cual presentó mayor similitud con el bosque de Liquidambar stracyflua (Is= 83 %. El sustrato más frecuente fue la madera en descomposición (57.63 %. Se determinaron las especies de macromicetos potencialmente utilizables para el consumo humano (22 especies, lo que determinó el valor micológico del área de estudio en 15.27 %. Del total de especies determinadas 22 son nuevos registros para el estado de Chiapas; 4 Ascomicetos Scutellinia scutellata, Xylaria amphitele, X. persicaria, Chlorociboria aeruginosa, y 18 Basidiomicetos Amanita pantherina, Geastrum striatum, Hydnum repandum, Hygrocybe miniata, Scleroderma verrucosum, Cotylidia diaphana, Lactarius indigo, Phlogiotis helvelloides, Hydnochaete olivaceae, Phellinus ferruginosus, P. contiguus, P.rufitinctus, Thelephora terrestris, T. cervicornis, Perenniporia ohiensis, Diplomitoporus lenis, Schizopora paradoxa y Tremella fuciformis.The objectives of this study were to contribute to the knowledge of macro fungi growing in the "Parque Educativo Laguna Belgica" (PELB, in Chiapas, Mexico and to determine the diversity and similarity indexes for its mycobiota in each type of vegetation. Twenty four mycological explorations were made during a year, resulting in the identification of 144 species (24 Ascomycota and 120 Basidiomycota. The diversity of fungal species was determined through the index of Simpson and the similarity

  14. Water-use dynamics of a peat swamp forest and a dune forest in Maputaland, South Africa

    Science.gov (United States)

    Clulow, A. D.; Everson, C. S.; Price, J. S.; Jewitt, G. P. W.; Scott-Shaw, B. C.

    2013-05-01

    Peat swamp forests are the second rarest forest type found in South Africa while dune forests have been under severe threat through mining and agriculture. Both forest types exist in the conservation area, and World Heritage site, known as the iSimangaliso Wetland Park on the East coast of South Africa. The area is prone to severe droughts (Taylor et al., 2006) and recent attempts to understand the local water balance revealed that there was insufficient information on the water use of the indigenous forests of the area. The peat swamp forest and dune forest sites studied in this research were located within close proximity to each other, yet, are characterised by different landscape positions in terms of water availability. The coastal dune forest soil profile was generally dry and sandy and the tree roots did not have access to the water table. In contrast the peat swamp forest is located in an interdunal wetland where the trees have permanent access to water. The climate at both sites is subtropical with a mean annual precipitation of 1200 mm yr-1. However, over 20 months of measurement, the first summer (October 2009 to March 2010) was drier (424 versus 735 mm) than the second summer (October 2010 to March 2011) emphasising the variability of the rainfall in the area and providing a wide range of conditions measured. The sap flow of an evergreen, overstory Syzygium cordatum and a semi-deciduous, understory Shirakiopsis elliptica were measured in the peat swamp forest using the heat ratio method. The Syzygium cordatum water use was not highly seasonal and the daily maximum water use ranged from approximately 30 L d-1 in winter to 45 L d-1 in summer whereas the Shirakiopsis elliptica water use was more seasonal at 2 L d-1 in winter and 12 L d-1 in summer. The water use of the Syzygium cordatum was not influenced by seasonal rainfall variations and was actually higher in the drier summer (October 2009 to March 2010). Three trees of different heights were monitored

  15. Water-use dynamics of a peat swamp forest and a dune forest in Maputaland, South Africa

    Directory of Open Access Journals (Sweden)

    A. D. Clulow

    2013-05-01

    Full Text Available Peat swamp forests are the second rarest forest type found in South Africa while dune forests have been under severe threat through mining and agriculture. Both forest types exist in the conservation area, and World Heritage site, known as the iSimangaliso Wetland Park on the East coast of South Africa. The area is prone to severe droughts (Taylor et al., 2006 and recent attempts to understand the local water balance revealed that there was insufficient information on the water use of the indigenous forests of the area. The peat swamp forest and dune forest sites studied in this research were located within close proximity to each other, yet, are characterised by different landscape positions in terms of water availability. The coastal dune forest soil profile was generally dry and sandy and the tree roots did not have access to the water table. In contrast the peat swamp forest is located in an interdunal wetland where the trees have permanent access to water. The climate at both sites is subtropical with a mean annual precipitation of 1200 mm yr−1. However, over 20 months of measurement, the first summer (October 2009 to March 2010 was drier (424 versus 735 mm than the second summer (October 2010 to March 2011 emphasising the variability of the rainfall in the area and providing a wide range of conditions measured. The sap flow of an evergreen, overstory Syzygium cordatum and a semi-deciduous, understory Shirakiopsis elliptica were measured in the peat swamp forest using the heat ratio method. The Syzygium cordatum water use was not highly seasonal and the daily maximum water use ranged from approximately 30 L d−1 in winter to 45 L d−1 in summer whereas the extit{Shirakiopsis elliptica} water use was more seasonal at 2 L d−1 in winter and 12 L d−1 in summer. The water use of the Syzygium cordatum was not influenced by seasonal rainfall variations and was actually higher in the drier summer (October 2009 to March 2010. Three trees of

  16. Ecología de ostracodos en medios estuarinos: el Subsistema Carreras (río Guadiana, SO de España

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    Morales, J. A.

    1997-12-01

    Full Text Available Analyses from 69 samples collected in the Carreras subsystem delimited ten grain size distributions (five in the channel, four in the channel border and one in the salt marsh. The geochemical analysis of some samples shows low pollution in this zone. Four ostracod assemblages were delimitated: a indigenous estuarine assemblage (Loxoconcha elliptica, Cyprideis torosa, Cytherois fischeri, Elofmnia pusilla and Leptocythere sp., dominant in all samples, both in biocoenosis and tanathocoenosis; b coastal assemblage (Urocythereis oblonga, Pontocythere elongata, Aurila convexa and Cytheretta adriatica, with high species well represented in the main channels with marine connection; c open sea assemblage (Carinocythereis whitei, Palmoconcha guttata and Palmoconcha turbida, with small species very abundant in deeper marine environments (> 10 m deep of the Huelva littoral; and d fresh water assemblage (Candona sp., Cyprinotus salinus and Limnocythere inopinata, very minoritary in the silty-muddy tidal flats. The estuarine biocoenosis is composed by euryhaline species, with numerous live individuals in waters with low hydrodynamics and important vegetation. The coastal and, to a lesser extent, the open sea association were introduced during the tidal flux; in addition, these assemblages may be collected in some secondary channels, owing to the erosion of fossil spits.El análisis de 69 muestras del Subsistema Carreras ha permitido diferenciar 10 distribuciones granulométricas (cinco de canal, cuatro de borde de canal y uno de marisma salada. El análisis geoquímico efectuado en algunas muestras revela un bajo grado de contaminación en los sedimentos superficiales. El estudio de la fauna permite diferenciar cuatro asociaciones de ostrácodos: a asociación estuarina sensu strictu (Loxoconcha elliptica, Cyprideis torosa, Cytherois fischeri, Elofmnia pusilla y Leptocythere sp., dominante en la biocenosis y tanatocenosis de todo el Subsistema; b asociaci

  17. Estructura y composición florística de la vegetación del Parque Educativo Laguna Bélgica, Chiapas, México Structure and floristic composition of vegetation on Parque Educativo Laguna Bélgica, Chiapas, Mexico

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    Ma. Consuelo Escobar-Ocampo

    2007-12-01

    Full Text Available El estudio se realizó en el Parque Educativo Laguna Bélgica (PELB. El objetivo fue el de caracterizar las asociaciones vegetales para sentar las bases para su manejo y conservación. El mapa de vegetación se realizó con la interpretación de ortofotos, verificaciones de campo y un Sistema de Información geográfica. La caracterización de la vegetación y los inventarios de flora leñosa se elaboraron según el método de Mueller-Dombois y Ellenberg. Se censaron todas las leñosas con altura > 1 m y diámetro a la altura del pecho > 3 cm. La cobertura se evaluó cualitativamente. Se reconocieron 5 asociaciones vegetales: encinar de Quercus oleoides, encinar de Q. elliptica, acahual arbóreo, pastizal y asociación secundaria de herbáceas. En la zona de estudio se colectaron 159 especies, las cuales se complementaron mediante revisión bibliográfica obteniéndose un total de 254 especies, comprendidas en 157 géneros y 64 familias. Se aportan 68 nuevos registros para el PELB. La flora de Laguna Bélgica presenta una mayor afinidad florística con los bosques húmedos de la vertiente del golfo que con los de la depresión central. Se resalta la alta diversidad florística y la importancia por conservar y manejar este relicto de vegetación.The study was conducted in the Parque Educativo Laguna Bélgica (PELB. The objective was to characterize the vegetal associations to establish basis for management. The vegetation map was elaborated on interpretation of ortophotos, supported with field verification and processed using a GIS. The characterization of the vegetation used the method of Mueller-Dombois and Ellenberg. For forest inventories we registered woody species > 1 m height and > 3 cm diameter breast height. The coverage was evaluated in qualitative form based on Braun-Blanquet method. Five types of vegetal associations were recognized: oak forest of Quercus oleoides, oak forest of Q. elliptica, tree-secondary vegetation, grasslands, and

  18. Two new species of African Haemaphysalis ticks (Acari: Ixodidae), carnivore parasites of the H. (Rhipistoma) leachi group.

    Science.gov (United States)

    Apanaskevich, Dmitry A; Horak, Ivan G

    2008-06-01

    Two new tick species belonging to the African Haemaphysalis (Rhipistoma) leachi subgroup, namely H. (R.) colesbergensis n. sp. and H. (R.) oliveri n. sp., are described. Haemaphysalis (R.) colesbergensis adults are easily differentiated from the other species of the H. (R.) leachi subgroup, including H. (R.) oliveri, by the spur on coxa IV, which is considerably longer than that on coxa III. The adults of the 2 new species are equal in size, but the dental formula of the hypostome of H. (R.) colesbergensis is 4/4 compared to 5/5 for H. (R.) oliveri. The dental formula of H. (R.) oliveri also distinguishes it from other ticks in the subgroup, namely H. (R.) leachi, H. (R.) elliptica, H. (R.) moreli, and H. (R.) punctaleachi (4/4 in these species), but not from H. (R.) paraleachi, which has a 5/5 dental arrangement. However, the average total length and width of H. (R.) oliveri males (2.47 x 1.20 mm) are considerably shorter and narrower than those of H. (R.) paraleachi males (3.81 x 1.79 mm). Similar differences in size apply to the females. Nymphs and larvae of H. (R.) colesbergensis and H. (R.) oliveri can be distinguished from those of other members of the H. (R.) leachi subgroup, as well as from each other, by a combination of the following characters: size and measurement ratios, length of posterodorsal and posteroventral spurs on palpal segment II, and number of denticles per file on the hypostome. Haemaphysalis (R.) colesbergensis is known only from South Africa, where it has been collected from domestic cats and dogs and medium-sized wild felids. Haemaphysalis (R.) oliveri is recorded only from Sudan, where it has been collected from small- to medium-sized wild felids and canids and an antelope. The hosts of the immature stages of H. (R.) colesbergensis are unknown, while nymphs of H. (R.) oliveri have been collected from rodents.

  19. Biodiversity in marine invertebrate responses to acute warming revealed by a comparative multi-omics approach.

    Science.gov (United States)

    Clark, Melody S; Sommer, Ulf; Sihra, Jaspreet K; Thorne, Michael A S; Morley, Simon A; King, Michelle; Viant, Mark R; Peck, Lloyd S

    2017-01-01

    Understanding species' responses to environmental change underpins our abilities to make predictions on future biodiversity under any range of scenarios. In spite of the huge biodiversity in most ecosystems, a model species approach is often taken in environmental studies. To date, we still do not know how many species we need to study to input into models and inform on ecosystem-level responses to change. In this study, we tested current paradigms on factors setting thermal limits by investigating the acute warming response of six Antarctic marine invertebrates: a crustacean Paraceradocus miersi, a brachiopod Liothyrella uva, two bivalve molluscs, Laternula elliptica, Aequiyoldia eightsii, a gastropod mollusc Marseniopsis mollis and an echinoderm Cucumaria georgiana. Each species was warmed at the rate of 1 °C h(-1) and taken to the same physiological end point (just prior to heat coma). Their molecular responses were evaluated using complementary metabolomics and transcriptomics approaches with the aim of discovering the underlying mechanisms of their resilience or sensitivity to warming. The responses were species-specific; only two showed accumulation of anaerobic end products and three exhibited the classical heat shock response with expression of HSP70 transcripts. These diverse cellular measures did not directly correlate with resilience to heat stress and suggested that each species may have a different critical point of failure. Thus, one unifying molecular mechanism underpinning response to warming could not be assigned, and no overarching paradigm was supported. This biodiversity in response makes future ecosystems predictions extremely challenging, as we clearly need to develop a macrophysiology-type approach to cellular evaluations of the environmental stress response, studying a range of well-rationalized members from different community levels and of different phylogenetic origins rather than extrapolating from one or two arbitrary model species

  20. Alcohol based-deep eutectic solvent (DES) as an alternative green additive to increase rotenone yield

    Energy Technology Data Exchange (ETDEWEB)

    Othman, Zetty Shafiqa; Hassan, Nur Hasyareeda; Zubairi, Saiful Irwan [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor (Malaysia)

    2015-09-25

    Deep eutectic solvents (DESs) are basically molten salts that interact by forming hydrogen bonds between two added components at a ratio where eutectic point reaches a melting point lower than that of each individual component. Their remarkable physicochemical properties (similar to ionic liquids) with remarkable green properties, low cost and easy handling make them a growing interest in many fields of research. Therefore, the objective of pursuing this study is to analyze the potential of alcohol-based DES as an extraction medium for rotenone extraction from Derris elliptica roots. DES was prepared by a combination of choline chloride, ChCl and 1, 4-butanediol at a ratio of 1/5. The structure of elucidation of DES was analyzed using FTIR, {sup 1}H-NMR and {sup 13}C-NMR. Normal soaking extraction (NSE) method was carried out for 14 hours using seven different types of solvent systems of (1) acetone; (2) methanol; (3) acetonitrile; (4) DES; (5) DES + methanol; (6) DES + acetonitrile; and (7) [BMIM] OTf + acetone. Next, the yield of rotenone, % (w/w), and its concentration (mg/ml) in dried roots were quantitatively determined by means of RP-HPLC. The results showed that a binary solvent system of [BMIM] OTf + acetone and DES + acetonitrile was the best solvent system combination as compared to other solvent systems. It contributed to the highest rotenone content of 0.84 ± 0.05% (w/w) (1.09 ± 0.06 mg/ml) and 0.84 ± 0.02% (w/w) (1.03 ± 0.01 mg/ml) after 14 hours of exhaustive extraction time. In conclusion, a combination of the DES with a selective organic solvent has been proven to have a similar potential and efficiency as of ILs in extracting bioactive constituents in the phytochemical extraction process.

  1. The response of benthic foraminifer, ostracod and mollusc assemblages to environmental conditions: a case study from the Camalti Saltpan (Izmir-Western Turkey

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    E. MERIC

    2010-03-01

    Full Text Available The subject of this report is benthic foraminifer populations preserved in the saltpan of Camalti in the Province of Izmir. High salinity in certain habitats of Ammonia tepida Cushman may be the primary cause of the high rate of twins and triplets as well as other morphological abnormalities recorded within this species (50 % as compared to an anomaly rate of 1 % in normal marine waters. Thicker cyst membrane developing in extremely saline environments may encourage twins and other morphological deformities by denying free movement of the offspring. Ecological factors such as heavy metal contamination of ambient waters as well as contamination by other wastes are also not ruled out as leading to such developmental anomalies. Of the 27 collected samples, Number 5 (that is closest to the sea includes the typical marine foraminifers. Nonion depressulum (Walker & Jacob, Ammonia tepida Cushman and Porosononion subgronosum(Egger are the dominant species in other samples. A total of 63 abnormal individuals (8 triplets, 24 twins, and 31 morphological anomalies was found within seven of the 27 samples collected. Ten samples contained freshwater ostracods: Darwinula stevensoni(Brady and Robertson, Leptocythere lacertosa Hirschmann, Cyprideis torasa (Jones, Cyprideis (C. anatolica Bassiouni, and Loxochoncha elliptica Brady. Among these samples (some of which contained only a few species of ostracods - and those limited in number of offspring, one had an unusually high ratio of healthy foraminifers vs those with anomalies. Worthy of note in another sample was a high abundance of molluscs. Among pelecypods, were found Ostrea edulis Linné, Lucinella divaricata (Linné, Pseudocama gryphina Lamarck,Cerastoderma edule (Linné, and Scrobicularia plana da Costa; and among gastropods were identified Hydrobi (Hydrobia acuta(Draparnaud, Rissoa labiosa (Montagu, R. parva (da Costa, R. violacea Desmarest, Pirenella conica (Blainville, Bittium desayesi(Cerulli and

  2. Response Surface Optimization of Rotenone Using Natural Alcohol-Based Deep Eutectic Solvent as Additive in the Extraction Medium Cocktail

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    Zetty Shafiqa Othman

    2017-01-01

    Full Text Available Rotenone is a biopesticide with an amazing effect on aquatic life and insect pests. In Asia, it can be isolated from Derris species roots (Derris elliptica and Derris malaccensis. The previous study revealed the comparable efficiency of alcohol-based deep eutectic solvent (DES in extracting a high yield of rotenone (isoflavonoid to binary ionic liquid solvent system ([BMIM]OTf and organic solvent (acetone. Therefore, this study intends to analyze the optimum parameters (solvent ratio, extraction time, and agitation rate in extracting the highest yield of rotenone extract at a much lower cost and in a more environmental friendly method by using response surface methodology (RSM based on central composite rotatable design (CCRD. By using RSM, linear polynomial equations were obtained for predicting the concentration and yield of rotenone extracted. The verification experiment confirmed the validity of both of the predicted models. The results revealed that the optimum conditions for solvent ratio, extraction time, and agitation rate were 2 : 8 (DES : acetonitrile, 19.34 hours, and 199.32 rpm, respectively. At the optimum condition of the rotenone extraction process using DES binary solvent system, this resulted in a 3.5-fold increase in a rotenone concentration of 0.49 ± 0.07 mg/ml and yield of 0.35 ± 0.06 (%, w/w as compared to the control extract (acetonitrile only. In fact, the rotenone concentration and yield were significantly influenced by binary solvent ratio and extraction time (P<0.05 but not by means of agitation rate. For that reason, the optimal extraction condition using alcohol-based deep eutectic solvent (DES as a green additive in the extraction medium cocktail has increased the potential of enhancing the rotenone concentration and yield extracted.

  3. Three cryptic new species of Aristea (Iridaceae from southern Africa

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    P. Goldblatt

    2005-12-01

    Full Text Available Field work in southern Africa over the past several years has resulted in the discovery of three new species of the sub- Saharan African and Madagascan genus Aristea Aiton, which now comprises some 53 species. Aristea has a pronounced centre in southern Africa and a centre of diversity in the winter rainfall zone of the subcontinent, where all three new species occur, one extending eastward into the adjacent southern edge of the summer rainfall zone. All three novelties have been collected in the past but were confused with related species. A elliptica (subgenus Eucapsulares, confused in the past with A. pusilla (Thunb. Ker Gawl., has a more robust habit, usually with 4 or 5 flower clusters per flowering stem, pale blue flowers, smooth ellipsoid seeds with flattened surface cells, and pollen shed as monads, whereas A. pusilla usually has 1-3 flower clusters per flowering stem, dark blue flowers, pollen shed as tetrads, and globose seeds with faint foveate sculpturing and colliculate surface cells. A. nana (also subgenus  Eucapsulares, known from few collections, and also confused with A. pusilla or A. anceps Eckl. ex Klatt. has the unbranched and leafless flowering stem of the latter but has large green floral spathes, flowers borne on long pedicels, and lacks a leaf subtending the single terminal flower cluster in contrast to nearly sessile flowers in A. pusilla and A. anceps, and in the latter, dry, rusty spathes. A. cistiflora (subgenus Pseudaristea closely resembles A. teretifoha Goldblatt & J.C.Manning but has linear to narrowly sword-shaped leaves and ± secund flowers with the outer tepals only slightly smaller than the inner and with small, dark brown markings at the bases of all the tepals. In contrast, A. teretifolia has narrower, sometimes terete leaves and flowers held upright with the outer tepals notice-ably smaller than the inner and bearing dark markings covering the lower half, whereas the inner tepals are unmarked.

  4. Fungal Planet description sheets: 320-370.

    Science.gov (United States)

    Crous, P W; Wingfield, M J; Guarro, J; Hernández-Restrepo, M; Sutton, D A; Acharya, K; Barber, P A; Boekhout, T; Dimitrov, R A; Dueñas, M; Dutta, A K; Gené, J; Gouliamova, D E; Groenewald, M; Lombard, L; Morozova, O V; Sarkar, J; Smith, M Th; Stchigel, A M; Wiederhold, N P; Alexandrova, A V; Antelmi, I; Armengol, J; Barnes, I; Cano-Lira, J F; Castañeda Ruiz, R F; Contu, M; Courtecuisse, Pr R; da Silveira, A L; Decock, C A; de Goes, A; Edathodu, J; Ercole, E; Firmino, A C; Fourie, A; Fournier, J; Furtado, E L; Geering, A D W; Gershenzon, J; Giraldo, A; Gramaje, D; Hammerbacher, A; He, X-L; Haryadi, D; Khemmuk, W; Kovalenko, A E; Krawczynski, R; Laich, F; Lechat, C; Lopes, U P; Madrid, H; Malysheva, E F; Marín-Felix, Y; Martín, M P; Mostert, L; Nigro, F; Pereira, O L; Picillo, B; Pinho, D B; Popov, E S; Rodas Peláez, C A; Rooney-Latham, S; Sandoval-Denis, M; Shivas, R G; Silva, V; Stoilova-Disheva, M M; Telleria, M T; Ullah, C; Unsicker, S B; van der Merwe, N A; Vizzini, A; Wagner, H-G; Wong, P T W; Wood, A R; Groenewald, J Z

    2015-06-01

    Novel species of fungi described in the present study include the following from Malaysia: Castanediella eucalypti from Eucalyptus pellita, Codinaea acacia from Acacia mangium, Emarcea eucalyptigena from Eucalyptus brassiana, Myrtapenidiella eucalyptorum from Eucalyptus pellita, Pilidiella eucalyptigena from Eucalyptus brassiana and Strelitziana malaysiana from Acacia mangium. Furthermore, Stachybotrys sansevieriicola is described from Sansevieria ehrenbergii (Tanzania), Phacidium grevilleae from Grevillea robusta (Uganda), Graphium jumulu from Adansonia gregorii and Ophiostoma eucalyptigena from Eucalyptus marginata (Australia), Pleurophoma ossicola from bone and Plectosphaerella populi from Populus nigra (Germany), Colletotrichum neosansevieriae from Sansevieria trifasciata, Elsinoë othonnae from Othonna quinquedentata and Zeloasperisporium cliviae (Zeloasperisporiaceae fam. nov.) from Clivia sp. (South Africa), Neodevriesia pakbiae, Phaeophleospora hymenocallidis and Phaeophleospora hymenocallidicola on leaves of a fern (Thailand), Melanconium elaeidicola from Elaeis guineensis (Indonesia), Hormonema viticola from Vitis vinifera (Canary Islands), Chlorophyllum pseudoglobossum from a grassland (India), Triadelphia disseminata from an immunocompromised patient (Saudi Arabia), Colletotrichum abscissum from Citrus (Brazil), Polyschema sclerotigenum and Phialemonium limoniforme from human patients (USA), Cadophora vitícola from Vitis vinifera (Spain), Entoloma flavovelutinum and Bolbitius aurantiorugosus from soil (Vietnam), Rhizopogon granuloflavus from soil (Cape Verde Islands), Tulasnella eremophila from Euphorbia officinarum subsp. echinus (Morocco), Verrucostoma martinicensis from Danaea elliptica (French West Indies), Metschnikowia colchici from Colchicum autumnale (Bulgaria), Thelebolus microcarpus from soil (Argentina) and Ceratocystis adelpha from Theobroma cacao (Ecuador). Myrmecridium iridis (Myrmecridiales ord. nov., Myrmecridiaceae fam. nov.) is also

  5. Trophic structure of coastal Antarctic food webs associated with changes in sea ice and food supply.

    Science.gov (United States)

    Norkko, A; Thrush, S F; Cummings, V J; Gibbs, M M; Andrew, N L; Norkko, J; Schwarz, A M

    2007-11-01

    Predicting the dynamics of ecosystems requires an understanding of how trophic interactions respond to environmental change. In Antarctic marine ecosystems, food web dynamics are inextricably linked to sea ice conditions that affect the nature and magnitude of primary food sources available to higher trophic levels. Recent attention on the changing sea ice conditions in polar seas highlights the need to better understand how marine food webs respond to changes in such broad-scale environmental drivers. This study investigated the importance of sea ice and advected primary food sources to the structure of benthic food webs in coastal Antarctica. We compared the isotopic composition of several seafloor taxa (including primary producers and invertebrates with a variety of feeding modes) that are widely distributed in the Antarctic. We assessed shifts in the trophic role of numerically dominant benthic omnivores at five coastal Ross Sea locations. These locations vary in primary productivity and food availability, due to their different levels of sea ice cover, and proximity to polynyas and advected primary production. The delta15N signatures and isotope mixing model results for the bivalves Laternula elliptica and Adamussium colbecki and the urchin Sterechinus neumeyeri indicate a shift from consumption of a higher proportion of detritus at locations with more permanent sea ice in the south to more freshly produced algal material associated with proximity to ice-free water in the north and east. The detrital pathways utilized by many benthic species may act to dampen the impacts of large seasonal fluctuations in the availability of primary production. The limiting relationship between sea ice distribution and in situ primary productivity emphasizes the role of connectivity and spatial subsidies of organic matter in fueling the food web. Our results begin to provide a basis for predicting how benthic ecosystems will respond to changes in sea ice persistence and extent

  6. Seasonality in autotrophic mesoplankton in a coastal upwelling-mud bank environment along the southwest coast of India and its ecological implications

    Science.gov (United States)

    Karnan, C.; Jyothibabu, R.; Manoj Kumar, T. M.; Balachandran, K. K.; Arunpandi, N.; Jagadeesan, L.

    2017-08-01

    Mesoplankton refers to both autotrophic and heterotrophic plankton with a body size between 200 - 20,000 μm. Here, we applied a FlowCAM to identify the autotrophs present in the mesoplankton size class in a coastal environment along the southwest coast of India (off Alappuzha, Kerala), which is characterized by intense coastal upwelling and mud bank formation during the Southwest Monsoon. 18 time series sampling (weekly/biweekly) sessions were carried out spanning over the Pre-Southwest Monsoon (April) to the Late-Southwest Monsoon (September) period in 2014. The study showed that during the Pre-Southwest Monsoon when nitrate level was relatively low in the study area, the mesoplankton community was entirely contributed by zooplankton, mostly consisting of copepods. During this time, the only autotrophic mesoplankton found in the water column, that too inconsistently, was Trichodesmium erythraeum. However, the entire scenario changed with the onset of the Southwest Monsoon due to hydrographical transformation and nutrient enrichment caused by the coastal upwelling. Especially during the Peak (July) and Late-Southwest Monsoon (August), the mesoplankton composition changed with a significant dominance of larger diatoms such as Fragilaria and Coscinodiscus. The autotrophic mesoplankton abundance was noticeably low during the Pre-Southwest Monsoon (av. 3145 ± 2396 individual m-3 and av. 2045 ± 1907 individual m-3 in M1 and M2, respectively), as compared to the Southwest Monsoon (av. 30436 ± 5983 individual m-3 and av. 32346 ± 11664 individual m-3 in M1 and M2, respectively). Similar was the seasonal trend in the autotrophic mesoplankton biomass, which increased from a low Pre-Southwest Monsoon value (av. 8.45 ± 7.1 mgC m-3and av. 4 ± 3.7 mgC m-3 in M1 and M2, respectively) to a significantly high value during the Southwest Monsoon (av. 117.04 ± 40.2mgC m-3 and av. 136.9 ± 68.1 mgC m-3 in M1 and M2, respectively). The FlowCAM analysis results also showed that

  7. Spatial paradigms of lotic diatom distribution: A landscape ecology perspective

    Science.gov (United States)

    Passy, S.I.

    2001-01-01

    Spatial distributional patterns of benthic diatoms and their relation to current velocity were investigated in an unshaded cobble-bottom reach of White Creek (Washington County, NY). On 27 August 1999, diatoms were sampled and current velocity and depth were measured on a regular square sampling grid with a grain size of 0.01 m2, interval of 0.5 m, and extent of 16 m2. The relative abundance of the 18 common diatom species enumerated in the 81 samples was subjected to detrended correspondence analysis (DCA). The first axis (DCA1) explained 51% of the variance in diatom data and separated the samples according to current regimes. The spatial autocorrelation of DCA1 sample scores in deposition and erosion regions of White Creek was determined by Moran's I statistic to indicate patch size. In White Creek the patch length of all diatom communities was more than 3.1 m, whereas the patch width was 1 m in the deposition region and 0.5 m in the erosion region. There were 5 dominant diatom taxa, Achnanthes minutissima Ku??tz. et vars, Fragilaria capucina Dezmazie??res et vars, F. crotonensis Kitt., Diatoma vulgaris Bory, and Synedra ulna (Nitz.) Ehr. et vars. The patch length of the dominant species varied from 1 to more than 4.1 m, whereas the patch width, if defined, was 0.5 m. Achnanthes minutissima and F. capucina, the two diatom species with the highest relative abundance, displayed spatially structured patches of low abundance and comparatively random patches of high abundance, suggesting broad scale abiotic control of species performance in low abundance regions and finer scale biotic control of high abundance areas. Another objective of this study was to test the hypothesis that higher current velocities, which generally impede immigration, would increase randomness and complexity (i.e. homogeneity of diatom distributional patterns). The spatial complexity in low versus high velocity transects was determined by calculating the respective fractal dimension (D) of DCA

  8. Toxicity and sorption kinetics of dissolved cadmium and chromium III on tropical freshwater phytoperiphyton in laboratory mesocosm experiments

    Energy Technology Data Exchange (ETDEWEB)

    Bere, Taurai, E-mail: taubere@yahoo.com [Instituto Internacional de Ecologia, Rua Bento Carlos, 750, Centro, Sao Carlos, Sao Paulo (Brazil); Univeridade Federal De Sao Carlos, Programa de Pos-Graduacao em Ecologia e Recursos Naturais, Rodovia Washington Luis, km 235, SP-310, Sao Carlos, Sao Paulo (Brazil); Tundisi, Jose Galizia [Instituto Internacional de Ecologia, Rua Bento Carlos, 750, Centro, Sao Carlos, Sao Paulo (Brazil)

    2011-10-15

    The objective of this study was to assess the interactive effects of Cd and Cr III on tropical phytoperiphyton community growth, metal sorption kinetics, as well as Cd and Cr mixtures toxicity to diatom assemblages in laboratory mesocosm experiments. A natural phytoperiphyton community sampled from the Monjolinho River (South of Brazil) was inoculated into seven experimental systems containing clean glass substrates for phytoperiphyton colonization. The communities were exposed to mixtures of dissolved Cd and Cr concentrations of 0.01 and 0.1 mg.L{sup -1} Cd and 0.05 and 0.2 mg.L{sup -1} Cr. Phytoperiphyton chlorophyll a, ash-free dry mass, growth rate, diatom cell density and diatom community composition were analyzed on samples collected after 1, 2 and 3 weeks of colonization. High Cd concentration (0.1 mg.L{sup -1}) affects phytoperiphyton growth while high concentration of Cr (0.2 mg.L{sup -1}) decreased the toxic effects of Cd on phytoperiphyton growth demonstrating the importance of studying metal mixtures in field studies. Shifts in species composition (development of more resistant species like Achnanthidium minutissimum (Kuetzing) Czarnecki, and Nitzschia palea (Kuetzing) Smith and reduction of sensitive ones like Fragilaria capucina Desmazieres, Navicula cryptocephala (Grunow) Cleve, Encyonema silesiacum (Bleisch) Mann, Eunotia bilunaris (Ehrenberg) Mills and Gomphonema parvulum (Kuetzing) Kuetzing), of phytoperiphyton communities with increasing Cd and Cr concentrations and exposure duration have been demonstrated in this study making phytoperiphyton communities appropriate monitors of metal mixtures in aquatic systems. Good Cd and Cr accumulation capacity by phytoperiphyton was demonstrated with total and intracellular metal content in phytoperiphyton reflecting the effects of dissolved concentrations of metal in the culture media and exposure duration. Increase in both Cd and Cr reduced sequestration of each other, with generally more Cd being

  9. Plankton and Macrobiota Composition and Diversity of Three Tropical Freshwaters Rivers in Ogun and Ondo States, Southwest Nigeria

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    Taofikat Abosede ADESALU

    2016-06-01

    Full Text Available Three different rivers in Ogun and Ondo states were investigated for both micro and macro-biota of the water bodies. Several physical and chemical properties of these rivers were determined. The pH value of the studied water bodies was essentially neutral with salinity values between 0.02 - 4.0‰. Microalgae communities were represented by three divisions: Cyanophyta, Bacillariophyta and Chlorophyta at Oluwa and Ifara Rivers (Ondo state, while at Ibefun River (Ogun state, five divisions: Cyanophyta, Bacillariophyta, Chlorophyta, Euglenophyta and Pyrrhophyta were identified. Diatoms dominated these water bodies, with Navicula radiosa Kutz. at Ifara River, Fragilaria sp. in Oluwa River, while out of 90 algal taxa identified in Ibefun river, 64 were diatoms species belonging to 26 genera, with Melosira sp. and Synedra sp. recording the highest numbers of cell count. Dinoflagellates recorded only Peridinium sp. while Phacus orbicularis Hubner and Trachelomonas sp. dominated the euglenoids. For the zooplankton composition at Ibefun, rotifers (75.95% were represented by Brachionus sp., which recorded 62.03%, and Gastropus sp. with 13.92% of the total zooplankton, thus dominated the spectrum, while the copepod recorded 22.78% of the total organisms, with Copilia sp. and Euchirella sp. having 8.86% each. The macrobenthic invertebrates were represented by 3 taxa, belonging to 3 groups, with the dominant group Insecta accounted for 57% of the total individuals (7 individuals/m2, while Oligochaeta and Hirudinea accounted for 29% and 14% respectively of the total individuals at Oluwa and Ifara Rivers. At Ibefun River, the macrobenthic invertebrates were represented by 5 taxa, belonging to 3 groups, Bivalves, Oligochaeta and Insecta, with bivalves being the dominant group (51.7% of the total individuals, as 64 individuals/m2, while Oligochaeta and Insecta accounted for 26.6% and 21.9% respectively of the total individuals. The dominant taxon, Macoma cumana

  10. Holocene Paleoenvironment of the North-central Great Basin: Preliminary Results from Favre Lake, Northern Ruby Mountains, Nevada

    Science.gov (United States)

    Starratt, S.; Wahl, D.; Wan, E.; Anderson, L.; Wanket, J.; Olson, H.; Lloyd-Davies, T.; Kusler, J.

    2009-12-01

    Little is known about Holocene climate variability in north-central Nevada. This study aims to assess changes in watershed vegetation, fire history, lake levels and limnological conditions in order to understand secular to millennial-scale changes in regional climate. Favre Lake (2,899 m a.s.l.; 12 m deep; 7.7 hectares) is a flow-through lake in the northern Ruby Mountains. The primary sources of influent, both of which appear to be intermittent, are Castle Lake (2,989 m a.s.l.) and Liberty Lake (3,077 m a.s.l.). The bedrock of the three lake basins is early Paleozoic marble and Mesozoic granite and metamorphic rocks. Bathymetric maps and temperature, pH, salinity, and conductivity profiles have been generated for Favre Lake. Surface samples and a series of cores were also collected using a modified Livingstone piston corer. The presence of the Mazama ash in the basal sediment (~4 m below the sediment/water interface) indicates the record extends to ~7,700 cal yr B.P. Magnetic susceptibility (MS) and loss-on-ignition data indicate that the sediments in the lowest part of the core contain primary and reworked Mazama ash. About 2,000 years ago CaCO3 increased from 2 to 3% of the inorganic sediment. The upper 25 cm of the core are marked by an increase in MS which may indicate increased erosion due to grazing. Between about 7,700 and 6,000 cal yr B.P. the diatom flora is dominated by a diverse assemblage of benthic species. The remainder of the core is dominated by Fragilaria, suggesting that lake level rose and flooded the shelf that surrounds the depocenter of the lake. This is supported by changes in the abundance of the aquatic fern Isoetes. Pinus and Artemisia dominate the pollen record, followed by subordinate levels of Poaceae, Asteraceae, Amaranthaceae, and Sarcobatus. The late early Holocene (7,700-6,000 cal yr B.P.) is dominated by Pinus which is present in reduced amounts during the middle Holocene (6,000-3,000 cal yr B.P.) and then returns to dominance in

  11. Periphyton changes over 20 years of chemical recovery of Lake Orta, Italy: differential response to perturbation of littoral and pelagic communities

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    Giuseppe MORABITO

    2011-08-01

    Full Text Available Lake Orta, a large Italian subalpine lake, has a long history of industrial pollution by acid, ammonia, and metals. A whole-lake liming treatment in 1989-1990 led to a gradual increase in pH (from 4.4 to 7 and a concomitant decline in ammonia (from 2.5 to 0.05 mg L-1 and metal concentrations (e.g., copper: from 35 to 3 μg L-1. In this study, we examine the response of the littoral zone, in terms of chemistry and periphyton assemblages, to contamination and recovery of Lake Orta. We compare these findings with a long-term data set of chemistry and phytoplankton collected in the pelagic zone. We sampled periphyton at two sites from the liming period (1989 through 2010 when the lake approached chemical equilibrium. Chemical variables collected in the littoral zone near the periphyton samples followed the same temporal trends observed in the pelagic zone. Chlorophytes, the dominant algae in the preliming period, progressively waned after the calcium carbonate addition. Diatom importance gradually increased to reach up to 80% of the total biovolume in the most recent years. There was a clear shift in the diatom taxonomic composition over the study period. Acidophilous Pinnularia subcapitata var. hilseana and metal-tolerant Achnanthes minutissima were dominant before liming. With the progressive increase in pH and decline in metal concentrations, there was successively the dominance of Fragilaria nanoides (formerly identified as Synedra tenera and Cymbella microcephala in the transition period and of circumneutral Navicula cryptocephala, N. radiosa, and Synedra ulna in the most recent period. Pelagic diatoms were more affected than benthic diatoms by the industrial pollution and their recovery after the liming intervention was slower. Whereas present periphyton diatom assemblages are similar to those observed in nearby unpolluted Lake Mergozzo, pelagic assemblages are still in transition from severe disturbance towards characteristics reported before

  12. Multiproxy approach revealing climate and cultural changes during the last 26kyrs in south-central Chile

    Science.gov (United States)

    Abarzua, Ana M.; Jarpa, Leonora; Martel, Alejandra; Vega, Rodrigo; Pino, Mario

    2010-05-01

    Multiproxy approach from Purén Lumaco Valley (38°S) describes the paleonvironmental history during the Last Maximum Glacial (LGM) in south-central Chile. Three sediment cores and severals AMS 14C dates were used to perform a complete pollen, diatoms, chironomids, and sedimentological records demonstrating the existence of a large and non profundal paleolake, between 25 and 20kyr BP. Some of these evidence are laminated silty-clay sediments (lacustrine rhythmites), associated with the presence of siderite mineral (FeCO3), besides biological proxies like Fragilaria construens and Stauroforma inermes (planctonic diatoms), and Dicrotendipes sp. and Tanytarsini tribe (littoral chironomids). The pollen ensemble reveals the first glacial refuge of Araucaria araucana forests in the low lands during the LGM. The lake was drained abruptly into a swamp/bog at 12kyr BP and colonized by Myrtaceae wet forest. This evidence suggest the dry/warm climate period of early Holocene in south-central Chile. Later, the sediments indicate variable lacustrine levels, and increase of charcoal particles, associated to current climatic conditions. The pollen spectrum dominated by Myrtaceae and Nothofagus contrasts with a strongly disturb current landscape. Actually, Purén-Lumaco valley constitutes a complex peat-bog system dominated by exotic grasses and forest species (Tritricum aestivum, Pinus radiata and Eucalyptus spp.). Some archaeological antecedents in the area document the human development at ca. 7yrs BP. The greatest archaeological characteristic present in the valley is the kuel, a Mapuche earth accumulation. The presence and extension of almost 300 kuel in the valley reflect the social/economic development, and partly explains why the region was the major resistance area for Spanish colonizer during XVI-XVII centuries. Also the archaeological findings reveal the presence of maize pollen (Zea mays) within their food consumption. The influence of climate and human impact in

  13. Tödürge Gölünün (Sivas Epilitik Diatom Florasının Mevsimsel Değişimi.

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    E. Rıdvan Sıvacı

    2015-12-01

    Full Text Available Kasım-2000 ve Kasım-2001 tarihleri arasında Tödürge göllünde seçilen sekiz istasyonda epilitik diyatome florasının kompozisyonu ve yoğunluğunun mevsimsel değişimi incelenmiş ve karşılaştırılmıştır. Ayrıca göl suyunun bazı fiziksel ve kimyasal parametreleri ölçülmüştür. Kalsiyum ve Sülfat bölgede temel kimyasal maddeler olmuştur. Tödürge göllünde florayı öncelikle Cymbella, Amphora, Cocconeis, Gomphonema, Achnanthes ve Fragilaria genusuna ait türler oluşturmakla beraber Navicula, Nitzschia, Epithemia, Gyrosigma, Pinnularia ve Stauroneis genuslarına ait türler daha az sayılarda bulunmuştur. Çalışma sürecinde Cymbella affinis Kütz., Cocconeis placentula var. euglypta Ehr., Achnanthidium minutissimum Kütz. Czar., Amphora commutata Grunow, Gomphonema olivaceum (Hornemann Bréb., Mastogloia braunii Grunow Tödürge gölünde tüm istasyonlarda dominant türler olmuştur. Epithemia argus Kütz., Caloneis clevei (Lagerst. Cleve, Stauroneis anceps Ehr., Surirella minuta Bréb. dışındaki diğer diyatome türlerine sıkça ve fazla sayılarda rastlanmıştır. Genellikle istasyonların tümünde toplam organizma bahar sonu ve yaz başında artmış yaz ve kış sonlarında ise azalmıştır. Çeşitlilik ve zenginlik indeksi T6 istasyonunda en yüksek, T7 ve T2 istasyonunda ise en düşük olarak belirlenmiştir

  14. Water age – a major factor controlling phytoplankton community structure in a reconnected dynamic floodplain (Danube, Regelsbrunn, Austria

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    Stefan PREINER

    2009-08-01

    Full Text Available The study was carried out during four years that span a gradient in hydrological connectivity between the Danube and its sidearm system at Regelsbrunn (Austria. We evaluated the influences of distinct periods of hydrological connectivity on the phytoplankton community structure itself, but also interferences with biotic processes (including community succession, competition and zooplankton grazing that may take place within the constraints set by the hydrological disturbance regime. Algal biomass was highly related to the hydrological regime: lowest amounts were detected either during flood events or at long-lasting periods of isolation; on the other hand intermediate connection led to maximum concentrations. During floods and throughout the cold season, Bacillariophyceae were dominating the algal community. Summer and elongated periods of isolation favoured Chlorophyta. Cryptophyta occurred in early autumn after two months disconnection from the main channel, Dinophyta and Cyanoprokaryota were only of minor importance. Multivariate statistical analyses showed that water age was the primary determinant of phytoplankton community structure in the side-arm system. Cluster analyses revealed 7 groups that were characterized by 169 indicator taxa. Groups were dominated by Bacillariophyceae (Nitzschia, Navicula, Cymbella, Fragilaria and Diatoma, while species belonging to the Chloro-, Eugleno- and Dinophyta were less abundant. Non-metric Multidimensional Scaling was used for a comparison of community similarity between the main channel and the side-arm system. During high connectivity temporal trends of phytoplankton similarity in the side-arm tracked closely the community patterns of the Danube which indicated a major influence of the main channel on phytoplankton community structure. During low connectivity the temporal trends of the communities from both sampling stations were less coupled. A Canonical Correspondence Analysis explained 89.7% of the

  15. SUCESIÓN DE MICROALGAS PERIFÍTICAS EN TRIBUTARIOS DEL RÍO GAIRA SIERRA NEVADA DE SANTA MARTA-COLOMBIA

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    Farid Jesús Osorio Ávila

    2014-10-01

    Full Text Available En ecosistemas acuáticos tropicales con altos niveles de intervención antrópica como algunos ríos de la Sierra Nevada de Santa Marta (SNSM es de vital importancia la determinación del tipo de variables que permiten ponderar el buen estado o por el contrario, el nivel de impacto sufrido en estos ambientes con importancia ecológica y con vocación para ofrecer servicios de abastecimiento. Para este estudio se seleccionaron tributarios de la cuenca media del río Gaira (SNSM, se evaluó el proceso sucesional de microalgas perifíticas, desde enero hasta abril de 2012, mediante el análisis de la comunidad asociada a sustratos artificiales. El propósito del estudio fue analizar la variación en la estructura de la comunidad de microalgas perifíticas durante el proceso de sucesión y evaluar los factores ambientales que determinan esta variación en un rio tropical. Los resultados destacan el caudal, la luz y el oxígeno disuelto los cuales presentaron los valores más altos para el tributario C (Jabalí; el pH fue ligeramente básico para todos los sitios, la temperatura y conductividad presentaron valores más altos en el tributario A (Honduras. El análisis biológico mostró que durante las primeras semanas de exposición del sustrato Melosira varians y Lyngbya sp. fueron dominantes para los tributarios A y B (La Picúa, mientras que para el tributario C se registró una dominancia de Fragilaria sp, Nitzschia sp y Melosira varians. Semanalmente se evaluó la diversidad y riqueza de especies, los mayores valores se registraron después de la cuarta semana de colecta. En el estudio fueron más notorios los cambios en la densidad que en la composición de especies, a pesar de esto el proceso de sucesión fue completo y se evidenció la presencia de especies pioneras (Lyngbya sp, Nitzschia sp, intermedias (Melosira varians, Cocconeis placentula y tardías (Surirella sp; al igual que la desaparición de especies como Lyngbya sp., proceso

  16. Dichotomy of some satellites of the outer Solar system

    Science.gov (United States)

    Kochemasov, G. G.

    2011-10-01

    Recently acquired by the Cas as ini' CIR a temperature map (11 -16 microns radiation) of small satellite Mimas caused a perplexity among the Cassini scientists (an interpretation of PIA12867). They expected to have a regular temperature map characteristic of a homogeneous spherical body heated by Sun. Instead, the bizarre map with two sharply divided temperature fields was produced (Fig. 1). The temperature difference between two fields is about 15 Kelvin that is rather remarkable. The warm part has typical temperature near 92 Kelvin, the cold part -about 77 Kelvin. Obviously there are two icy substances with different conductivity of heat composing two planetary segments (hemispheres). But in this result there is nothing new for explorers insisting for many years that all celestial bodies are tectonically dichotomous [1, 2, 3]. However, this new beautiful confirmat ion of the wave planetology theorem 1 (" Celes tial bodies are dichotomous ") is not s uperfluous , as many s cientis ts , es pecially in the USA, are not acquainted with the wave p lanetology. The fundamental wave 1 long 2πR warping any body aris es in them becaus e they move in elliptica l keple rian orbits with periodically changing acceleration. Having in rotating bodies (but all bodies rotate!) a stationary character and four interfering directions (ortho- and diagonal) these waves inevitably produce uplifting (+), subsiding (-), and neutral (0) tectonic blocks (Fig. 7). The uplifts and subsidences are in an opposition (the best examples are the terrestrial Eastern (+) and Western ( -) segments-hemispheres and mart ian Northern (-) and Southern (+) ones) [3]. The small icy Mimas (396 km in diameter) is no exclusion (Fig. 1). Its dichotomy is well pronounced in two temperature fields obviously reflect ing slightly different in composition icy materials composing two segments. Presence of two kinds of surface materials is also revealed by spectrometry under combination of the UV, green and IR

  17. Historical data reveal 30-year persistence of benthic fauna associations in heavily modified waterbody

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    Ruth Callaway

    2016-08-01

    Full Text Available Baseline surveys form the cornerstone of coastal impact studies where altered conditions, for example through new infrastructure development, are assessed against a temporal reference state. They are snapshots taken before construction. Due to scarcity of relevant data prior to baseline surveys long-term trends can often not be taken into account. Particularly in heavily modified waterbodies this would however be desirable to control for changes in anthropogenic use over time as well as natural ecological variation. Here, the benthic environment of an industrialized embayment was investigated (Swansea Bay, Wales, UK where it is proposed to build a tidal lagoon that would generate marine renewable energy from the tidal range. Since robust long-term baseline data was not available, the value of unpublished historical benthos information from 1984 by a regional water company was assessed with the aim to improve certainty about the persistence of current benthic community patterns. A survey of 101 positions in 2014 identified spatially discrete benthic communities with areas of high and low diversity. Habitat characteristics including sediment properties and the proximity to a sewage outfall explained 17-35% of the variation in the community structure. Comparing the historical information from 1984 with 2014 revealed striking similarity in the benthic communities between those years, not just in their spatial distribution but also to a large extent in the species composition. The 30-year-old information confirmed spatial boundaries of discrete species associations and pinpointed a similar diversity hotspot. A group of five common species was found to be particularly persistent over time (Nucula nitidosa, Spisula elliptica, Spiophanes bombyx, Nephtys hombergii, Diastylis rathkei. According to the Infauna Quality Index (IQI linked to the EU Water Framework Directive (WFD the average ecological status for 2014 was ‘moderate’, but eleven samples

  18. The ant nest of Crematogaster rogenhoferi (Mayr, 1879 (Hymenoptera: Formicidae at Tarutao National Park, Satun Province, Southern Thailand

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    Suparoek Watanasit

    2006-07-01

    Full Text Available Nests of the ant Crematogaster rogenhoferi (Mayr, 1879 were investigated at Tarutao National Park, Satun Province. Fifteen ant nests were selected at random along Phante Malacca Bay between the 2-7 March 2004. They built their nests from leaf and stick debris on branches of trees, at between 248-469 cm above the ground level. The vegetation on which nests were built was composed of 5 species: Vitex pinnata L., Oleasalicifolia Wall, Syzygium gratum (Wight, Ardisia elliptica Thum and one unknown species. The physical features of each nest were recorded. The average dimensions of the nest width and length were 10.65±2.57 cm and 22.10±1.22 cm, respectively.Each nest was cut into small pieces for counting the numbers of each caste and developing stages. The results showed that the average number of queens, winged females, males and workers in each nest were 1.53±0.38, 1,753.33±506.55, 4,970.67±2,227.00, 15,577.93±2,637.84 respectively, while the developing stages of pupae, larvae, eggs were 1,589.93±480.37, 4,113.20±1,469.49 and 1,942.80±741.67 respectively. Thus the total number of ants in the population in each nest was 29,949.40±5,358.31.The relationships between the number of castes, developing stages and physical features of the nests were explored. The Spearman Rank Correlation indicated that the width of nest positively correlated with the number of queens (rs = 0.862, p = . 000, winged females (rs = 0.691, p = 0.004 and workers (rs = 0.667, p = 0.007. A comparison of the effects of vegetation types on the number of castes and development stages, showed that vegetation type did have an influence but only on the number of the worker caste (F = 7.712, P = 0.011, one-way ANOVA. Most workers were associated with nests from Vitex pinnata. No nests were found on the dominant tree species of the area probably due to its ability to produce an insect repellant oil.

  19. Age and origin of the Gezira alluvial fan between the Blue and White Nile rivers

    Science.gov (United States)

    Williams, martin

    2014-05-01

    The Gezira is a low-angle alluvial fan bounded by the Blue Nile to the east and the White Nile to the west. It is the main agricultural region of Sudan and produces high quality long-staple cotton for export. Dark cracking clays (vertisols) cover much of the Gezira and range in age from 50 kyr to Holocene. The Gezira is traversed by a series of defunct sandy channels that originate between Sennar and Wad Medani on the present-day Blue Nile. With a radius of 300 km and an area of 40,000 km2 the Gezira is a mega-fan. The younger channels range in age from early Holocene to 100 kyr, while near surface channels filled with rolled quartz and carbonate gravels have ages back to >250 kyr. Boreholes in the Gezira reveal coarse alluvial sands and gravels in now buried channels overlain by alluvial clays, forming a repetitive sequence of fining-upwards alluvial units. that probably extend back to Pliocene times. The fan is up to 180 m thick with a volume of ~1,800 km3. The sandy or gravelly bed-load channels coincide with colder drier climates and sparse vegetation in the Ethiopian headwaters of the Blue Nile and the alluvial clays denote widespread flooding during times of stronger summer monsoon. The early stages of such flood events were often accompanied by mass burial of Nile oyster (Etheria elliptica) beds, such as the 45-50 kyr floods that deposited up to 5 m of clay in the northern Gezira. A unique feature of the eastern Gezira is a former Blue Nile channel at least 80 km long running parallel to the present river and entirely filled with volcanic ash. The channel was only 3-4 m deep and 20-30 m wide. Very fine laminations and cross-beds, together with locally abundant phytoliths and sponge spicules, suggest slow-moving water, with flow dispersed across many distributary channels. The ash geochemistry is similar to that in the lower part of the Kibish Formation in the lower Omo valley of southern Ethiopia and points to a minimum age of 100 kyr and a maximum age of

  20. Ecological status of high altitude medicinal plants and their sustainability: Lingshi, Bhutan.

    Science.gov (United States)

    Lakey; Dorji, Kinley

    2016-10-11

    Human beings use plants for a multitude of purposes of which a prominent one across the globe is for their medicinal values. Medicinal plants serve as one of the major sources of income for high altitude inhabitants in the Himalaya, particularly in countries like Nepal, and Bhutan. People here harvest huge volumes of medicinal plants indiscriminately, risking their sustainability. This paper attempts to identify some of the priority medicinal plant species harvested in the wild and assess their ecological status for their judicious utilization, and to help provide policy guidance for possible domestication and support strategic conservation frameworks. Out of the 16 priority species identified by the expert group, collectors' perception on ecological status of the priority species differed from survey findings. Chrysosplenium nudicaule (clumps) ranked as most threatened species followed by Corydalis dubia, and Meconopsis simplicifolia. Onosma hookeri, Corydalis crispa and Delphinium glaciale were some of the species ranked as threatened species followed by Halenia elliptica (not in priority list). Percent relative abundance showed irregular pattern of species distribution. High species evenness was recorded among Nardostachys grandiflora, Chrysosplenium nudicaule, Saussurea gossypiphora and Aconitum orochryseum with average species density of 8 plant m-2. Rhodiola crenulata, and Dactylorhiza hatagirea followed by Meconopsis horridula and Meconopsis simplicifolia were ranked as most threatened species with average species density of 0.4, 0.4, 5.6 and 6.0 plant m-2, respectively. The most abundant (common) species was Onosma hookeri (plant m-2). Species composition and density also differed with vegetation, altitude, slope and its aspects. Priority species identified by expert group were found vulnerable and patchy in distribution. Survey results and collectors' perceptions tally to an extent. Some of the species (Dactylorhiza hatagirea, Rhodiola crenulata

  1. ESTUDIO TAXONOMICO DEL GENERO BYTTNERIA LOEFLING (STERCULIACEAE

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    Carmen L. Cristóbal

    2010-11-01

    su tratamiento de este grupo, el autor propone un nuevo nombre: El B. Mastersii, por B.elliptica Masters 1874 (no B.elliptica Pohl 1830, y por razones de prioridad el nombre B.grandifolia DC se utiliza en vez del B.aspera Colebr. ex Wall. Las áreas de las seis secciones, y la distribución de la especie americana se demuestran en mapas. El autor considera que Byttneria se originó en América, allí todas las secciones, a excepción de Gerontogaea, y encuentran a la mayoría de la especie. La existencia de tres centros de concentración de la especie se demuestra: uno en el Hylaea amazónico, uno en Madagascar, y el tercero en Asia suroriental. Las 19 especies cuyos números de cromosoma se han establecido son mencionadas. Las cuentas demuestran que hay dos series de polyploids: x = 13, 2n =26, ~2, 78· y x = 14 2n = 28, 56. Las relaciones de 12 de los géneros de Byttnerieae, como sugerencia de una compilación de información disponible, se demuestran por medio de un diagrama. Al parecer, los géneros Rulingia, Comtnersonia, Clossostemon, y Leptonychia son los más primitivos. Megatritheca, Ayenia y Byttneria, que presentan las estructuras florales más complicadas, parecerían haberse desarrollado en direcciones de opuestas. Guazuma parece intermedio entre estos y Scaphopetalum, Abroma, Theobroma, y Herranía, son los géneros donde la mayor parte de las características de la especialización se encuentran. Las relaciones de las secciones han sido similarmente consideradas, y las conclusiones demostradas en dos tablas. La sección Crassipetala debe ser la más primitiva, y las secciones Byttnería y Vahihara han seguido tendencias de oposición de la evolución.

  2. Changes in the trophic level of an Alpine lake, Jezero v Ledvici (NW Slovenia, induced by earthquakes and climate change

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    Darko OGRIN

    2000-09-01

    Full Text Available Despite relatively high nutrient levels, the Slovenian Alpine lake Jezero v Ledvici (1824 m a.s.l.; max. depth 15 m is oligotrophic, with high transparency and low chlorophyll concentrations (<1 μg l-1. Daily mean air temperatures at the lake are estimated to vary between –15.4 °C and +18.8 °C. Low air temperatures combined with the blocking of incident solar radiation by the local topography result in the lake being ice-covered for over six months of the year, suggesting that the effects of climate on the ecology of the lake may be mediated by the timing of the ice cover. Sediment cores taken in 1996 were dated by 210Pb and 137Cs and analysed for DW, LOI, cladoceran and diatom remains, pigments, C, N and S. A total of 50 diatom taxa and 4 cladoceran taxa were found. The base of the unsupported 210Pb record at 17.4 cm was dated to 1825 AD ± 25 y. An abrupt change in DW and LOI was observed at a depth of 17 cm, coinciding with a change in the cladoceran community and in C and N concentrations. From a depth of 12 cm (83 ± 4 y BP upward, a sharp change in S and plant pigment concentrations were recorded, followed by an increase in diatom abundance at a depth of about 10 cm (63 ± 4 y BP. The timing of quantitative changes in the physical and chemical properties of the sediment, and in the community structure of diatoms and Cladocera, coincides with the occurrence of three earthquakes in the 19th century. Changes in the diatom and cladoceran record were compared with a tree-ring width index based on Larix decidua from the shore of the lake over the last 136 years, and with reconstructed air temperatures from 1781 – 1996. With a 4-y lag, a weak positive correlation exists between the tree-ring width index and the air temperatures. Although diatom abundance generally shows no correlation with the tree-ring width index, a negative correlation was found in the case of Fragilaria pinnata and Amphora lybica, interrupted only between 1942 and 1955

  3. Arrow Lakes Reservoir Fertilization Experiment; Years 4 and 5, Technical Report 2002-2003.

    Energy Technology Data Exchange (ETDEWEB)

    Schindler, E.

    2007-02-01

    . Dissolved inorganic nitrogen concentrations have decreased in 2002 and 2003 compared to previous years. These results indicate that the surface waters in Arrow Lakes Reservoir were approaching nitrogen limitation. Results from the 2003 discrete profile series indicate nitrate concentrations decreased significantly below 25 {micro}g/L (which is the concentration where nitrate is considered limiting to phytoplankton) between June and July at stations in Upper Arrow and Lower Arrow. Nitrogen to phosphorus ratios (weight:weight) were also low during these months indicating that the surface waters were nitrogen deficient. These results indicated that the nitrogen to phosphorus blends of fertilizer added to the reservoir need to be fine tuned and closely monitored on a weekly basis in future years of nutrient addition. Phytoplankton results shifted during 2002 and 2003 compared to previous years. During 2002, there was a co-dominance of potentially 'inedible' diatoms (Fragilaria spp. and Diatoma) and 'greens' (Ulothrix). Large diatom populations occurred in 2003 and these results indicate it may be necessary to alter the frequency and amounts of weekly loads of nitrogen and phosphorus in future years to prevent the growth of inedible diatoms. Zooplankton density in 2002 and 2003, as in previous years, indicated higher densities in Lower Arrow than in Upper Arrow. Copepods and other Cladocera (mainly tiny specimens such as Bosmina sp.) had distinct peaks, higher than in previous years, while Daphnia was not present in higher numbers particularly in Upper Arrow. This density shift in favor to smaller cladocerans was mirrored in a weak biomass increase. In Upper Arrow, total zooplankton biomass decreased from 1999 to 2002, and in 2003 increased slightly, while in Lower Arrow the biomass decreased from 2000-2002. In Lower Arrow the majority of biomass was comprised of Daphnia throughout the study period except in 2002, while in Upper Arrow the total biomass was

  4. Establishing the Ecological Status of Mining-Impacted Freshwaters from Abrud River Catchment Area Using Benthic Diatom Communities (Ros, ia MontanÄă, Romania)

    Science.gov (United States)

    Olenici, Adriana; Baciu, Calin; Momeu, Laura; Cozma, Alexandra; Brahaita, Dorian; Pop, Cristian; Lazar, Laura; Popita, Gabriela; Teodosiu, Gabriela

    2015-04-01

    Keywords: diatom communities, indicator species, mine waters, water quality, Romania. Diatoms are a very distinct group of algae, identifiable under the light microscope by their yellow - brown coloration and by the presence of a thick silica cell wall. The potential for freshwater organisms to reflect changes in environmental conditions was first noted by Kolenati (1848) and Cohn (1853), who observed that biota in polluted waters were different from those in non-polluted situations. Diatoms are widely used to monitor river pollution because they are sensitive to water chemistry, especially to ionic content, pH, dissolved organic matter and nutrients. Wide geographic distribution and well-studied ecology of most diatom species are mentioned as major advantages of using diatoms as indicator organisms. At the same time water quality has begun to deteriorate increasingly, mainly as a result of the physical, chemical and bacteriological alterations, and the aquatic ecosystems are evermore affected by various types of pollution, the anthropic one being almost always included. A good example is Abrud River and its main tributaries (Roșia Montană and surrounding areas, Romania), which has suffered along the years because of the mining waters discharge. In this context, this study presents data on benthic diatom communities from the Abrud River catchment area. Sixteen sites have been sampled seasonal and the best represented diatom genera were Navicula, Nitzschia, Cymbella, Gomphonema, Achnantes, Surirella and Fragilaria. Qualitatively, the number of diatom species exhibited significant variation among sampling sites, also suggesting seasonal dynamics. For instance, in some sampling sites, algal assemblages were absent, as diatom communities were strongly affected by acid mine waters, released from old mining works and waste rocks depots. Some dominant taxa have been observed as well, suggesting critical saprobic levels of the Abrud River and some of its tributaries. The

  5. Using biodiversity of diatoms to identify hydrological connectivity in the hillslope-riparian zone-stream system

    Science.gov (United States)

    Wetzel, C. E.; Martínez-Carreras, N.; Ector, L.; Hlubikova, D.; Frentress, J.; McDonnell, J. J.; Hoffmann, L.; Pfister, L.

    2012-04-01

    very intense rainfall events cause a single-tailed rather small rise of the hydrograph in the Weierbach. Mixing diagrams suggest a very brief and intense switch from groundwater to soil water contribution. Almost simultaneously to incoming precipitation, terrestrial diatom abundance increases to 20-30% inside the stream. Species composition was also seasonally structured. During winter season (November 2010 and January 2011 events) the diatom drift was characterized and dominated by colony forming species (e.g. Fragilaria nevadensis Linares-Cuesta & Sánchez-Castillo and Fragilariforma virescens (Ralfs) Williams & Round), while summer events were characterized by a large number of small aerophytic species (i.e. Chamaepinnularia evanida (Hustedt) Lange-Bertalot, Eolimna tantula (Hustedt) Lange-Bertalot, Navicula obsoleta Hustedt, Navicula parsura Hustedt and Stauroneis thermicola (Petersen) Lund). Chemical tracers suggest a substantial role of soil water contributions to storm hydrographs in the Weierbach, regardless of the season, with overland flow playing no prominent role at all. Meanwhile, terrestrial diatom abundance in drift samples strongly increases during precipitation events, suggesting a rapid onset of connectivity between the soil surface and the stream. We assume the terrestrial diatoms to be mobilized during precipitation and eventually flushed to the stream through a subsurface network of macropores in the shallow soils and cracks in the fractured and weathered schistose bedrock.

  6. Development of anoxia during the last 90 years in Lake Tiefer See, NE Germany

    Science.gov (United States)

    Groß-Schmölders, Miriam; Dräger, Nadine; Kienel, Ulrike; Brauer, Achim

    2015-04-01

    medius in all water depths detectable; Asterionella, Fragilaria, Navicula, Stephanodiscus parvus, Synedra, Tabellaria in larger abundances only in the deeper parts; Aulacoseira mainly in the shallow areas. (4) Missing single varves have been only traced in the eastern part of the basin. Possible reasons for the observed differences including wind and wave activity near the shore-line and in shallow water, water circulation and lake bathymetry are discussed in this paper. The varves of Lake Tiefer See are part of an integrated multi-proxy study including high-resolution sediment analyses and monitoring of modern deposition processes within the Virtual Institute of Integrated Climate and Landscape Evolution Analysis -ICLEA- of the Helmholtz Association, grant number VH-VI-415. Reference KIENEL, U.; DULSKI, P.; OTT, F.; LORENZ, S.; BRAUER, A. (2013): Recently induced anoxia leading to the preservation of seasonal laminae in two NE-Germany lakes. Journal of Paleolimnology 50:535 - 544

  7. Do diatoms run downhill? Using biodiversity of terrestrial and aquatic diatoms to identify hydrological connectivity between aquatic zones in Luxembourg

    Science.gov (United States)

    Pfister, L.; Wetzel, C. E.; Martinez-Carreras, N.; Frentress, J.; Ector, L.; Hoffmann, L.; McDonnell, J. J.

    2011-12-01

    Diatoms are siliceous unicellular algae, and range in size between a few and more than 500 micrometers. Diatoms are spread worldwide, live in many aquatic habitats, have many life forms and their short generation time make them respond rapidly to environmental changes. Their taxonomic diversity represents a valuable tool to assess water quality as each taxon has specific responses to environmental factors. Recently, diatoms have been used as tracers to detect the onset/cessation of surface runoff through binary classification of terrestrial and aquatic species in the Attert basin in Luxembourg. In order to continue the validation of these first results, we have collected samples during rain events at different seasons of the year using automatic stream water samplers, grab samples of diatoms from various terrestrial and subaerial substrates (bryophytes, litter and leaves), as well as from aquatic habitats (epilithon, epipelon and drift samples). This new type of information will be used to constrain assumptions of the conventional tracer-based hydrograph separation technique (i.e. using geochemistry and stable isotopes). The first results concerning the diatom flora, based on 39 samples, revealed 152 species belonging to 38 genera. The most species-rich genera were Pinnularia (15.8% - 24 taxa), Eunotia (13.2% - 20 taxa), Gomphonema (8.6% - 13 taxa), Navicula (7.2% - 11 taxa) and Stauroneis (5.3% - 8 taxa). The flora are mainly composed of oligotrophic and/or acidophilic taxa (32.0%), ubiquitous (14.0%) or poorly known ecologically species (43.0%). The most important taxa found in drift samples were Fragilariforma virescens, Fragilaria capucina sensu lato, Planothidium lanceolatum, Eunotia minor, Achnanthidium kranzii, Karayevia oblongella and Eunotia incisa. In the riparian zone (n = 10), 102 species were observed, with Eunotia exigua var. tenella, Eunotia botuliformis and Pinnularia perirrorata being among the most frequent. Epilithic samples from the main channel

  8. Composite biostratigraphy and microfacies analysis of the Upper Jurassic - Lower Cretaceous carbonate platform to slope successions in Sivrihisar (Eskişehir) region (NW Turkey, Pontides): Remarks on the palaeogeographic evolution of the Western Sakarya Zo

    Science.gov (United States)

    Atasoy, Serdar G.; Altıner, Demir; Okay, Aral I.

    2017-04-01

    Two stratigraphical sections were measured along the Upper Jurassic - Lower Cretaceous carbonate successions exposed in a tectonic klippe of the Sakarya Zone (Pontides), north of Sivrihisar. According to the biozonation and microfacies types, two coeval but dissimiliar rock successions, separated by a thrust fault, have been detected. These successions belong to different depositional belts of the Edremit-Bursa-Bilecik Carbonate Platform (EBBCP), western Sakarya Zone. The lower succession displays a slope to basin facies and consists of the Kimmeridgian - Berriasian Yosunlukbayırı Formation and the overlying Valanginian Soǧukçam Limestone. Within these deposits the following biozones were defined: Globuligerina oxfordiana - Mohlerina basiliensis Zone (Kimmeridgian), Saccocoma Zone (Lower Tithonian), Protopeneroplis ultragranulata Zone (Upper Tithonian), Crassicollaria (massutiana subzone) Zone (uppermost Tithonian), Calpionella (alpina, Remaniella, elliptica subzones) Zone (Lower Berriasian), Calpionellopsis (simplex, oblonga subzones) Zone (Upper Berriasian) and Calpionellites (darderi subzone) Zone (Lower Valanginian). This succession is overthrusted from north to south by another distinct succession characterized by the shallow marine carbonate facies of the Kimmeridgian Günören Formation. Within this unit Labyrinthina mirabilis - Protopeneroplis striata (Kimmeridgian) Zone is recognized. A facies model is proposed for the Sivrihisar transect of the EBBCP for Kimmeridgian - Valanginian interval, based on the distribution of microfacies types. The toe-of-slope facies are characterized by peloidal-bioclastic packstone, mudstone-wackestone and calpionellid/ radiolarian wackestone-packstone comprising pelagic taxa (calpionellids, radiolaria, Globochaete sp., Pithonella sp., Saccocoma sp., calcareous dinocysts, aptychi, very rare planktonic foraminifera and nannoconids) and rare fossil groups transported from the carbonate platform (benthic foraminifera

  9. The Pliocene record around the Prydz Bay margin: review and questions (Invited)

    Science.gov (United States)

    Quilty, P. G.

    2010-12-01

    Cibicides from Larsemann Hills are currently being analysed as is Cibicides from Heidemann Valley. Fragments of the bivalve Cyclocardia and pectenids from Marine Plain, and of hiatellid and pectenids from Larsemann Hills have been sent for analysis in an attempt to get further refinement. It may be possible to get fragments of bivalves (hiatellid, pectenid and possible Laternula elliptica) from Heidemann Valley. Peculiar features are the presence of oolites in the Heidemann Valley section and abundant leiospheres of unknown affinities at Marine Plain. Issues to be addressed include the evolution of the Southern Hemisphere biota during the Pliocene, including the origin of the current seal fauna, dramatic changes to the cetacean fauna in the mid-Pliocene, changes in krill and the microbiota - in short, the ecosystem. How resilient or otherwise were elements of the ecosystem during change and how do we determine this?

  10. Bosques andinos del sur de Ecuador, clasificación, regeneración y uso

    Directory of Open Access Journals (Sweden)

    Rainer W. Bussmann

    2013-05-01

    Full Text Available Existen muy pocos inventarios y descripciones sintaxonómicas de la vegetación de bosques montanos tropicales. Este trabajo presenta datos sobre los bosques del sur de Ecuador localizados en la Reserva Biológica San Francisco, límite norte del Parque Nacional Podocarpus. Se propone la siguiente clasificación junto con notas sobre los factores edáficos que contribuyen a su establecimiento. El «Bosque Montano Bajo» (1800-2150 m, formando el orden Alzateetalia verticillatae, muestra 2-3 estratos arbóreos muy diversos, con árboles de 20-35 m de altura, y es una clímax mosaico típico. Creciendo sobre Terric Haplosaprists y Aquic Dystrupepts, originado del material de derrumbes viejos, este tipo de bosque se extiende hasta los 2300 m sobre el nivel del mar en quebradas protegidas de viento. A altitudes de 2100-2650 m (menos de 2750 m la estructura del bosque y la composición florística cambia totalmente. Esta vegetación, el «Bosque Montano Alto» forma el orden de Purdiaeaetalia nutantis y crece sobre Histic Petraquepts. Representando una vegetación monotípica con un solo estrato arbóreo de 5-10 m (–15 m de altura, completamente dominado por Purdiaea nutans (Cyrillaceae. El bosque ubicado a mayor altitud en el área, densamente enlazado con el páramo es el «Bosque Nublado Subalpino». Descritos como Clusio ellipticae-Weinmannietum cochensis aparecen más como una vegetación arbustiva casi impenetrable, y crecen sobre Humaquic Epiaquents. El límite del bosque es causado principalmente por los vientos fuertes de la región. Derrumbes e incendios naturales representan el «motor» de regeneración de los bosques. Se encontró carbón en la base de los niveles A de muchos perfiles de suelo. El análisis 14C precisó una edad de 710-980 ±50 años antes del presente. Esto indica que fuegos en la vegetación han contribuido a la dinámica de esta vegetación en el pasado y no es un fenómeno reciente. El diámetro basal de los

  11. Modern state of the pelagic ecosystem of the Large Aral Sea

    Science.gov (United States)

    Arashkevich, E. G.; Nikishina, A. B.; Soloviev, K. A.; Zhitina, L. S.; Sergeeva, V. M.

    2009-04-01

    During the last five decades, zooplankton of the Aral Sea has been undergoing dramatic changes. Mineralization in the western Large Aral increased from 10 ppt in 1960 to 116 ppt and 211 ppt in the western and eastern basins, correspondingly, in 2008. Concurrently the crucial changes have been occurring in zooplankton community manifesting in the disappearance of most native species and significant decline of biodiversity of the pelagic community. During this period, the number of phytoplankton species dropped more than in order of magnitude. In June 2008, only 29 species were identified in the western basin of Aral Sea, Bacillariophyta - 17 species, Chlorophyta - 5 species, Cryptophyta, Dinophyta, and Cyanophyta - 2 species of each division, and one species of Flagellatae. The average concentration of phytoplankton in terms of number was 2.3*106 cells l-1, in terms of biomass 231 µg C l-1. In the eastern basin, 14 species of Bacillariophyta were found; the dominant species were Amphora coffeaeformis, Fragilaria brevistriata, and Navicula spp. Chlorophyta was presented by only unidentified species. The total number of phytoplankton was 0.9*106 cells l-1, biomass was 93 µg C l-1. Composition of phytoplankton community changed depending on the site and depth. In the eastern basin, where mineralization reached 211 ppt, the community was dominated by diatoms and green algae while in the western basin, with mineralization of 119 ppt, all divisions of algae were presented. The vertical distribution of phytoplankton reflected the light and temperature preferences of the different groups. Bacillariophyta, Chlorophyta, and Cryptophyta peaked at the 20 m depth with the temperature of about of 2°C and low irradiation. Warm-water and light-requiring Cyanophyta inhabited mainly the upper 5-m layer. The number of zooplankton species decreased from 42 species in 1971 to 1 species, the brine shrimp Artemia parthenogenetica, in 2008. Artemia, a typical resident of hypersaline