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Registros recuperados: 18 | |
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Migne, A; Davoult, D. |
Because of strong tidal currents, the bottom of the Dover Strait consists of coarse sediment which is colonized by a pebble community. A quantitative study, based on 0.1 m(2) quadrat samples taken by divers, was conducted on this community to establish the richness of benthic macrofauna (in terms of biomass and diversity) and to provide conclusive data on global community structure (spatial and temporal heterogeneity, trophic structure). Eight samples were taken between June 1992 and June 1993, eight replicates being taken on each sampling visit. One hundred and one species were identified, in 10 zoological groups, and a mean biomass of 281 g.m(-2) (ash free dry weight) was calculated. The Shannon diversity index was low (H' = 1.24) because of the strong... |
Tipo: Text |
Palavras-chave: Macrobenthos; Biomass; Trophic structure; Diversity; Spatial heterogeneity. |
Ano: 1997 |
URL: http://archimer.ifremer.fr/doc/00093/20409/18076.pdf |
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Bernal, A.; Zea, S.. |
Se estudiaron las variaciones en la estructura taxonómica y trófica de la comunidad de zooplancton en la provincia nerítica del área de Santa Marta, Mar Caribe Colombiano, asociadas a fertilizaciones alternantes entre descarga continental y afloramiento costero. Los muestreos se efectuaron en noviembre de 1991 durante la temporada mayor de lluvias, y en marzo de 1992 durante la temporada seca. Los organismos fueron identificados y contabilizados, determinándose la biomasa por nivel trófico. Se discriminaron 82 especies-taxa, la mayoría de ellas oceánico costeras y con predominancia de omnívoros. La composición de la comunidad varió temporal y espacialmente con las condiciones oceanográficas predominantes, evidenciando procesos sucesionales relacionados con... |
Tipo: Journal Contribution |
Palavras-chave: Zooplankton; Trophic structure; Coastal upwelling; Zooplankton; Http://aims.fao.org/aos/agrovoc/c_15490. |
Ano: 2000 |
URL: http://hdl.handle.net/1834/3303 |
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Beraja, A.R.. |
La comunidad circalitoral de Mytilus platensis presenta dos tipos de tramas tróficos; una que depende de la producción primaria fitoplanctónica y otraíde los detritos orgánicos en sedimentos. (Penchaszadeh,1971 a). Entre los organismos suspensívoros de la comunidad se destacan el propio mejillóm adulto y juvenil, otros Pelecipodos como Ostrea puelchana y Chlarnys tehuelcha , Gasterópodos (Crepidula un~uiformis) y otros organismos como Cirripedios y algunos pOliquetos. Si bien hasta el presente se ha tipificado la dieta de la mayoría de los organismos carnívoros de la comunidad (Penchaszadeh,inéd.1973) no se había analizado cuantitativamente la dieta de los suspensívoros filtradores fitoplanct6fagos. Los organismos filtradores son aquellos que se alimentan... |
Tipo: Theses and Dissertations |
Palavras-chave: Trophic structure; Stomach content. |
Ano: 1973 |
URL: http://hdl.handle.net/1834/3880 |
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Chabanet, P; Tessier, E; Durville, P; Mulochau, T; Rene, Francois. |
The ichtyofauna of Geyser and Zelee coral banks (north of Mozambique canal) was investigated in 1996, this work being the first quantitative study on this area. Quantitative data were collected on 11 stations (mean depth 18 m) by visual observations along 50 m transect, widened to 2 m for small sedentary species, and to 5 m for commercial species with a large action range. The main descriptors of the fish communities (species richness, abundance per species) and the trophic structure (omnivorous, herbivorous, carnivorous, browsers of sessile invertebrates) were described and analysed.A total of 294 fish species, belonging to 43 families were recorded. The species richness varied from 45 to 83 species / station, and the abundance, from 292 to 1322... |
Tipo: Text |
Palavras-chave: Ichtyofauna; Western Indian Ocean; Coral reefs; Geyser and Zelee; Trophic structure. |
Ano: 2002 |
URL: http://archimer.ifremer.fr/doc/00000/10132/7687.pdf |
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Hermi, M.; Aissa, P.. |
The answer of the free nematode populations to the physico - chemical state of “ lake ” south Tunis has been studied in autumn 96 from 10 sampling sites. Their very weak specific diversity (Hermi, 2001) and the non selective détritivorous proliferation (1B) bound to the strong contents in recorded organic matter (Hermi, 2001) revealed the sensitivity of nematodes to the eutrophication and nutritionnal pollution. According to several interrelationships calculations, the waters saturation in oxygen, their contents in abeyance matter and in nitrogen as well as the sediments granulometry and their contents in certain heavy metals, appeared the most lagoonar determining parameters. Otherwise, the answer of nematofaunistic communities living in South lake was... |
Tipo: Journal Contribution |
Palavras-chave: Species diversity; Trophic structure; Anthropogenic factors; Species diversity; Http://aims.fao.org/aos/agrovoc/c_33954. |
Ano: 2002 |
URL: http://hdl.handle.net/1834/245 |
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Aissa, P.; Soltani, A.; Mahmoudi, E.; Louati, H.; Beyrem, H.. |
Une étude microcosmique a été effectuée pour examiner l’influence d’un lubrifiant minéral avant et après son utilisation dans un moteur de véhicule sur la structure trophique de la communauté de nématodes libres originaire de la lagune de Ghar El Melh. Une concentration de 1mg kg-1 de sédiment a été testée pour évaluer l’effet du polluant après 40 jours d’exposition. Les résultats de l’étude ont révélé que les consommateurs non sélectifs (1B), les plus abondants dans le microcosme témoin, ont été très affectés et leur dominance a diminué significativement sous l’effet de la contamination par le lubrifiant minéral avant ou après usage. Les détritivores sélectifs (1A) dont la dominance augmente significativement au iveau des microcosmes traités avec le... |
Tipo: Journal Contribution |
Palavras-chave: Microcosms; Oil pollution; Petroleum; Pollution effects; Sediments; Trophic structure. |
Ano: 2008 |
URL: http://hdl.handle.net/1834/4255 |
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Wolff,Luciano Lazzarini; Carniatto,Natália; Hahn,Norma Segatti. |
This study described the use of food resources and the distribution of fish trophic guilds along the longitudinal gradient of a coastal Atlantic stream, southern Brazil. Allochthonous resources (terrestrial insects) predominated in the headwaters, whereas autochthonous food items (algae, fish) and detritus predominated in the mouth section. Detritivorous, aquaticinvertivorous, and terrestrial- and aquatic-insectivorous species occurred throughout the gradient, while omnivorous and piscivorous in the headwaters and middle stretches, respectively, and herbivorous in the middle and mouth. Detritivores and aquatic-insectivores were significantly more specialized than the other guilds, however, there was no evidence of a longitudinal increase in trophic... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Atlantic Rainforest; Food availability; Freshwater fish; River Continuum Concept; Trophic structure. |
Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252013000200375 |
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Davoult, D; Dewarumez, Jm; Migne, A. |
The long-term variations of two coastal benthic communities (Eastern English Channel, France) were studied between 1979 and 1994 by means of factor correspondence analysis (FCA), trophic structure and rank-frequency diagrams (RFD). FCA identified periods of relative homogeneity and periods of strong variation in the structure of the two communities. The first community, established on heterogeneous sand, showed a multi-annual cycle Linked to grain-size variations in the sediment. As passive supplies of organic matter were not important and suspension feeders could hardly live in these conditions, the community remained poor and stable and was dominated by deposit-feeders and carnivores. The other one, a rich and diverse mussel (Mytilus edulis) bed, showed... |
Tipo: Text |
Palavras-chave: Série à long terme; Benthos; Analyse factorielle; Diagrammes rang-fréquence; Structure trophique; Long-term series; Benthos; Factor analysis; Rank-frequency diagrams; Trophic structure. |
Ano: 1998 |
URL: http://archimer.ifremer.fr/doc/00325/43663/43207.pdf |
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Marinoni,Renato C.. |
The beetles are a useful group for studies on trophic structure of communities, mainly in forested areas. These kind of studies are based on food habits of species groups. The different terms applied to nomminated these groups (trophic category, ecologic group, trophic group, guild, trophic guild) are discussed. The term trophic group, a natural unity, is proposed to form a group of species with the same food habits, not considering the trophic level. The guild, an artificial unity, is recognized as an important tool to group organisms group that use the same resources as defined by the investigator (Hawkins & MacMaiion, 1989; Simberloff & Dayan 1991; Wilson 1999). The known alimentary habits of Coleoptera are classified in five trophic... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Coleoptera; Trophic groups; Guilds; Communities; Trophic structure. |
Ano: 2001 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-81752001000100024 |
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Carvalho,Lucélia Nobre; Fidelis,Luana; Arruda,Rafael; Galuch,André; Zuanon,Jansen. |
Floating litter banks are an ephemeral habitat consisting of branches, twigs, flowers, seeds, and fruits that are trapped on the stream water surface by a variety of retention mechanisms. These heterogeneous materials form a deep layer of dead plant matter that is colonized by a variety of organisms, including fish that forage on the aquatic macroinvertebrates found in this unique habitat. In this study, we aimed to characterize which fish species occupy the floating litter banks and their trophic characteristics, as well as determine if fish assemblage composition and species richness can be predicted by the size of the floating litter banks. Fish sampling was conducted in five rivers located in the Amazon basin. Of the 31 floating litter banks sampled... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Ephemeral habitats; Fish assemblages; Insectivores; Lotic systems; Trophic structure. |
Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252013000100085 |
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Callier, Myriam; Lefebvre, Sebastien; Dunagan, Mary K.; Bataille, Marie-paule; Coughlan, Jennifer; Crowe, Tasman P.. |
The extent of the influence of salmon farming on the environment and on the uptake of particulate and dissolved effluents by benthic organisms was assessed using community structure and stable isotope analyses. Sediment cores were collected in 2 directions: perpendicular and parallel to the main residual current, 0, 25 and 200 m from 2 salmon farms (Millstone and Cranford) located in Mulroy Bay, Ireland. In addition, artificial substrates were placed for 2 mo at 1 m depth 0, 25 and 200 m from one farm to trace the uptake of farm-related nutrients by fouling organisms. The extent of measurable change in benthic communities (abundance, diversity, structure, trophic composition) depended on residual current direction. Intraspecific variation in isotopic... |
Tipo: Text |
Palavras-chave: Aquaculture; Organic matter; Stable isotope; Community structure; Diet shift; Trophic structure. |
Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00144/25481/23634.pdf |
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Mahmoudi, E.; Essid, N.; Beyrem, H.; Hedfi, A.; Boufahja, F.; Aissa, P.; Vitiello, P.. |
Une étude en microcosme a été entreprise pour examiner l’influence d’un métal lourd (le cadmium) et/ou du diesel sur la structure trophique d’une communauté de nématodes libres provenant de la lagune de Ghar El Melh (Tunisie). Trois doses en cadmium [faible : 0,54 mg Cd kg-1 (poids sec, ps), moyenne : 0,90 mg Cd kg-1 (ps) et forte : 1,40 mg Cd kg-1(ps)], une dose de diesel de 0,25 mg kg-1 (ps) et un mélange de cadmium et de diesel [1,40 mg Cd kg-1(ps) + 0,25 mg kg-1 de diesel (ps)] ont été testées pour évaluer les effets de ces polluants après 90 jours d’exposition. Les résultats des analyses statistiques univariées n’ont montré aucune différence significative pour la plupart des indices des communautés traitées par rapport à l’assemblage témoin. Ainsi,... |
Tipo: Journal Contribution |
Palavras-chave: Nematoda; Cadmium; Chemical pollution; Heavy metals; Microcosms; Pollution effects; Trophic structure; Heavy metals; Cadmium; Http://aims.fao.org/aos/agrovoc/c_2223; Http://aims.fao.org/aos/agrovoc/c_1178. |
Ano: 2005 |
URL: http://hdl.handle.net/1834/3740 |
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Alfaro-lucas, Joan Manel; Shimabukuro, Mauricio; Ogata, Isabella, V; Fujiwara, Yoshihiro; Sumida, Paulo Y. G.. |
The trophic structure and role of chemosynthesis remain unexplored in deep-sea whale-fall communities in areas other than the California margin. This gap limits the understanding of these communities and their ecological relationships with other chemosynthetic ecosystems, such as vents and seeps. Here, we studied 3 different whale skeleton microhabitats with hypothesized high, intermediate and low reducing conditions as well as the sediments surrounding an abyssal whale fall (4204 m depth, SW Atlantic Ocean). We analyzed trophic structures (δ13C and δ15N) and the contribution of chemosynthetically derived carbon to heterotrophic species. The high and intermediate reducing microhabitats harbored food webs dominated by consumers of chemosynthetic production,... |
Tipo: Text |
Palavras-chave: Deep sea; Whale fall; Trophic structure; Chemosynthesis; Osedax. |
Ano: 2018 |
URL: http://archimer.ifremer.fr/doc/00442/55342/56853.pdf |
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Registros recuperados: 18 | |
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