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Metabólitos secundários bioativos de invertebrados marinhos: isolamento, determinação estrutural e atividades biológicas; Bioactive secondary metabolites from marine invertebrates: isolation, structure determination and biological activities

Kossuga, Miriam Harumi
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 21/10/2008 PT
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Ao longo dos últimos 20 anos os organismos marinhos se tornaram uma das fontes mais interessantes para o isolamento de produtos naturais biologicamente ativos. Apesar disso, os organismos marinhos da costa brasileira foram muito pouco explorados como fonte de metabólitos secundários. A presente investigação se insere no âmbito de dois projetos temáticos, o primeiro desenvolvido entre 2002 e 2006 e o segundo em andamento, que têm por objetivo melhor conhecer as potencialidades de organismos marinhos da costa brasileira como fonte de metabólitos secundários biologicamente ativos. Assim, foram investigados extratos bioativos de cinco espécies de invertebrados marinhos: três ascídias, uma esponja e um octocoral, todos oriundos da costa brasileira. O fracionamento dos extratos destes animais resultou no isolamento de 15 compostos, dos quais sete inéditos na literatura. A partir do extrato bruto da ascídia Clavelina oblonga foram isolados dois compostos: a 5-[3,5-dibromo-4([2-oxo-5-oxazonidinil)]metoxifenil]2-oxazolidinona e o (2S,3R)- 2-amino-3-dodecanol. Este último apresentou uma potente atividade antifúngica contra Candida albicans. Do extrato da ascídia Didemnum ligulum foram obtidos dois compostos: a asterubina e a N...

Avaliação ecotoxicológica do fármaco Triclosan para invertebrados marinhos; Ecotoxicological assessment of the pharmaceutical Triclosan for marine invertebrates

Cortez, Fernando Sanzi
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 10/02/2011 PT
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Triclosan é um composto orgânico de baixa solubilidade que vem sendo utilizado em formulações de cremes dentais e faciais, xampu, sabonetes, embalagens de gêneros alimentícios e diversos tipos de materiais, tais como, adesivos, brinquedos, sapatos, selantes, tintas, colchão, roupas, pisos, toldos e rejuntes. O amplo uso deste composto deve-se à grande eficácia contra bactérias Gram negativas e Gram positivas. Por seu extenso uso, evidências da presença de Triclosan têm sido frequentemente relatadas em efluentes urbanos e industriais, águas superficiais e sedimentos de ambientes dulcícolas, estuarinos e marinhos, como também em organismos aquáticos como algas, peixes e mamíferos. Neste contexto, o presente estudo avaliou a toxicidade aguda e crônica de Triclosan para diferentes invertebrados marinhos de águas tropicais. Para tanto, ensaios de toxicidade aguda foram realizados com o copépodo Nitokra sp (mortalidade) e com o ouriço-do-mar Lytechinus variegatus (taxa de fertilização). Para a avaliação do efeito crônico, ensaios de toxicidade de curta duração (desenvolvimento embriolarval) foram realizados com o ouriço-do-mar L. variegatus e Perna perna. Além desses métodos, o ensaio do Tempo de Retenção do Corante Vermelho Neutro foi empregado com a finalidade de se avaliar os efeitos do Triclosan sobre a estabilidade da membrana lisossômica de hemócitos de P. perna. Na avaliação do efeito agudo...

Hemocitical responses to environmental stress in invertebrates: a review

Perez, Danielli Giuliano; Fontanetti, Carmem Silvia
Fonte: Springer Publicador: Springer
Tipo: Artigo de Revista Científica Formato: 437-447
ENG
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Although invertebrates are recognized by the great facility to accumulate pollutants present in their environment and many of them are used as sentinel species in biomonitoring studies, little is known about the impact of toxicants on the immune system of these animals. In this regard, hemocytes play a fundamental role: these cells circulate freely through the hemolymph of invertebrates and act on the recognition of foreign material to the organism, mediating and effecting the cellular defense, such as phagocytosis, nodulation, and encapsulation. Different morphological types can be recognized but still there is controversy among the researchers about the exact classification of the hemocytes due to the diversity of techniques for the preservation and observation of these cells. In the present study, a review on the main hemocyte responses to environmental stress in different invertebrate organisms is presented, emphasizing the contamination by heavy metals. It is discussed parameters such as: alteration in the number of cells involved in the defense reaction, phagocytic activity, lysosomal responses...

The role of invertebrates and aquatic fungi on the decomposition of eucalyptus leaves in streams

Mesquita, Ana; Pascoal, Cláudia; Cássio, Fernanda
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Conferência ou Objeto de Conferência
Publicado em /07/2004 ENG
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Resumo da comunicação apresentada no XII Congresso da Association Española de Limnología - IV Congresso Ibérico de Limnologia. CIMAR, Universidade do Porto, 5-9 Julho 2004.; Leaves entering in streams are subject to physical abrasion, invertebrate fragmentation and microbial degradation. Fungi, particularly aquatic hyphomycetes, dominate microbial leaf decomposition and condition the leaves, increasing their palatability for invertebrate shredders. The aim of this work was to study the relative role of invertebrates and aquatic fungi on leaf decomposition of Eucalyptus globulus Labill. in two rivers of Northwest Portugal with different water chemistry. For that purpose, leaf decomposition was followed in coarse-mesh and fine-mesh bags. Physical, chemical and microbial analyses of the stream water, as well as, biotic indices and diversity measures applied to the invertebrates associated with leaves showed that the Guisande River had better water quality than the Este River. Decomposition rates of eucalyptus leaves were significantly higher in the Guisande River (k = 0.019 to 0.029 dˉ¹) than in the Este River (k = 0.009 to 0.011 dˉ¹). Significantly higher fungal biomass (up to 790 μg ergosterol gˉ¹ AFDM) and sporulation rates (up to 370 conidia mgˉ¹ AFDM dˉ¹) occurred in the Guisande River in comparison with the Este River (fungal biomass up to 280 μg ergosterol gˉ¹ AFDM; sporulation rates up to 90 conidia mgˉ¹ AFDM dˉ¹). Correspondence analyses applied to aquatic hyphomycete and invertebrate assemblages discriminated the two rivers and higher richness in taxa was found in the Guisande River. In this river...

Use of ATLANTIS TIERRA 2.0 in mapping the biodiversity (invertebrates and bryophytes) of caves in the Azorean archipelago

Borges, Paulo A. V.; Gabriel, Rosalina; Pereira, Fernando E. A. P.; Mendonça, Enésima; Sousa, Eva
Fonte: Ramón Espinasa-Pereña and John Pint (eds.) Publicador: Ramón Espinasa-Pereña and John Pint (eds.)
Tipo: Conferência ou Objeto de Conferência
Publicado em //2008 ENG
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XII International Symposium on vulcanospeleology. Tepoztlan, Morelos, Mexico, July 2-7, 2006.; In this contribution the software ATLANTIS Tierra 2.0 is described as a promising tool to be used in the conservation management of the animal and plant biodiversity of caves in Macaronesia. In the Azores, the importance of cave entrances to bryophytes is twofold: i) since these are particularly humid, sheltered habitats, they support a diverse assemblage of bryophyte species and circa 25% of the Azorean brioflora is referred to this habitat and ii) species, either endemic or referred in the European red list due to their vulnerability (19 species) or rarity (13) find refuge there. Cave adapted arthropods are also diverse in the Azores and 21 endemic obligate cave species were recorded. Generally these species have restricted distributions and some are known from only one cave. ATLANTIS Tierra 2.0 allows the mapping of the distribution of all species in a 500 x 500 m grid in a GIS interface. This allows an easy detection of species rich caves (hotspots) and facilitates the interpretation of spatial patterns of species distribution. For instance, predictive models of species distribution could be constructed using the distribution of lava flows or other environmental variables. Using this new tool we will be better equipped to answer the following questions: a) Where are the current “hotspot caves” of biodiversity in the Azores?; b) How many new caves need to be selected as specially protected areas in order to conserve the rarest endemic taxa?; c) Is there congruence between the patterns of richness and distribution of invertebrates and bryophytes?; d) Are environmental variables good surrogates of species distributions?

Seven invertebrates new for the marine fauna of Madeira Archipelago

Wirtz, Peter
Fonte: Universidade dos Açores Publicador: Universidade dos Açores
Tipo: Artigo de Revista Científica
Publicado em //2014 ENG
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Ocaña and den Hartog (2002) recorded 18 species of sea anemones from Madeira archipelago. During SCUBA dives along the coasts of Madeira and Porto Santo, the present author encountered a further three sea anemone species and several other marine invertebrates not yet recorded for the marine fauna of Madeira Island. Similar to previous publications (e.g. Wirtz 1998, Wirtz 2007, Ocaña & Wirtz 2009), these findings are reported here.

Thesis abstract. Applying species distribution modeling for the conservation of Iberian protected invertebrates

Chefaoui, Rosa
Fonte: International Biogeography Society Publicador: International Biogeography Society
Tipo: Artigo de Revista Científica
Publicado em //2011 POR
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This article outlines the approaches to modeling the distribution of threatened invertebrates using data from atlases, museums and databases. Species Distribution Models (SDMs) are useful for estimating species’ ranges, identifying suitable habitats, and identifying the primary factors affecting species’ distributions. The study tackles the strategies used to obtain SDMs without reliable absence data while exploring their applications for conservation. I examine the conservation status of Copris species and Graellsia isabelae by delimiting their populations and exploring the effectiveness of protected areas. I show that the method of pseudo‐absence selection strongly determines the model obtained, generating different model predictions along the gradient between potential and realized distributions. After assessing the effects of species’ traits and data characteristics on accuracy, I found that species are modeled more accurately when sample sizes are larger, no matter the technique used.

Heparan sulfates and heparins: similar compounds performing the same functions in vertebrates and invertebrates?

Nader,H.B.; Chavante,S.F.; dos-Santos,E.A.; Oliveira,F.W.; de-Paiva,J.F.; Jerônimo,S.M.B.; Medeiros,G.F.; de-Abreu,L.R.D.; Leite,E.L.; de-Sousa-Filho,J.F.; Castro,R.A.B.; Toma,L.; Tersariol,I.L.S.; Porcionatto,M.A.; Dietrich,C.P.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/05/1999 EN
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The distribution and structure of heparan sulfate and heparin are briefly reviewed. Heparan sulfate is a ubiquitous compound of animal cells whose structure has been maintained throughout evolution, showing an enormous variability regarding the relative amounts of its disaccharide units. Heparin, on the other hand, is present only in a few tissues and species of the animal kingdom and in the form of granules inside organelles in the cytoplasm of special cells. Thus, the distribution as well as the main structural features of the molecule, including its main disaccharide unit, have been maintained through evolution. These and other studies led to the proposal that heparan sulfate may be involved in the cell-cell recognition phenomena and control of cell growth, whereas heparin may be involved in defense mechanisms against bacteria and other foreign materials. All indications obtained thus far suggest that these molecules perform the same functions in vertebrates and invertebrates.

Field experimental evaluation of secondary metabolites from marine invertebrates as antifoulants

PEREIRA,R. C; CARVALHO,A. G. V.; GAMA,B. A. P.; COUTINHO,R.
Fonte: Instituto Internacional de Ecologia Publicador: Instituto Internacional de Ecologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/05/2002 EN
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The crude organic extracts of the endemic gorgonian Phyllogorgia dilatata and two sponge species Aplysina fulva and Mycale microsigmatosa were evaluated for anti-fouling properties through field experiments. To investigate this property in ecologically meaningful conditions, crude extracts from these invertebrates were incorporated at concentrations naturally found in these marine organisms into a stable gel used as a substratum for fouling settlement. Crude extract from A. fulva showed no significant anti-fouling property at the natural concentrations used in the field experiments. In fact, fouling organisms settled significantly more on gels treated with A. fulva extract than on the control gel. On the other hand, both M. microsigmatosa and P. dilatata yielded crude extracts that exhibited a selective action inhibiting only the settlement of barnacles. The evidences obtained here by means of field experiments can provide a basis for future development of one kind of natural antifoulant technology to prevent marine biofouling.

Mechanism of acute silver toxicity in marine invertebrates

Bianchini, Adalto; Playle, Ricardo; Wood, Chris; Walsh, Patrick
Fonte: Universidade Federal do Rio Grande Publicador: Universidade Federal do Rio Grande
Tipo: Artigo de Revista Científica
ENG
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In freshwater crustaceans and in both freshwater and marine fish, the key mechanism of acute silver toxicity involves ionoregulatory impairment. An inhibition of the Na+,K+-ATPase located at the basolateral membrane of the gill epithelium seems to be the key site for silver toxicity. However, studies to determine if the same mechanism of toxicity is occurring in marine invertebrates, which also are ionoregulators, had not been done. Thus, the present study was carried out to determine acute silver effects on hemolymph osmo- and ionoregulation in three marine invertebrates: the shrimp Penaeus duorarum, the sea hare Aplysia californica, and the sea urchin Diadema antillarum. Animals were exposed to silver (1 or 10 _g/L), as silver nitrate, in seawater for 48 h. Results show that acute silver exposure did not affect hemolymph osmolality or ion concentration (Na+, Cl−, K+, Ca2+ and Mg2+) in the three species studied. However, silver induced significant changes in the water content in shrimp gill and sea hare gill and hepatopancreas. Silver also caused significant changes in Na+,K+ ATPase activity and in both total and intracellular ion (Cl−, Na+, K+,Mg2+, and Ca2+) concentrations in different tissues of the three species studied. Overall...

Short-term silver accumulation in tissues of three marine invertebrates: Shrimp Penaeus duorarum, sea hare Aplysia californica, and sea urchin Diadema antillarum

Bianchini, Adalto; Playle, Richard; Wood, Chris; Walsh, Patrick
Fonte: Universidade Federal do Rio Grande Publicador: Universidade Federal do Rio Grande
Tipo: Artigo de Revista Científica
ENG
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36.87%
The present study was carried out to examine possible differential silver distribution among several tissues of three marine invertebrate species: the shrimp Penaeus duorarum, the sea hare Aplysia californica, and the sea urchin Diadema antillarum. Animals were exposed to sub-lethal concentrations of silver (1 or 10 _g/L) in seawater for 48 h. In gill-breathing species (shrimp and sea hare), higher silver accumulation in gills were associated with higher hemolymph silver levels. Furthermore, sea urchin showed lower hemolymph silver concentrations than shrimp and sea hare. These findings suggest that gills are an important route for silver uptake in marine invertebrates. In both sea hare and shrimp, hepatopancreas silver accumulation was concentration-dependent and this organ accumulated the most silver after 48 h of exposure, suggesting a possible involvement of the hepatopancreas in both silver accumulation and detoxification in marine invertebrates. In shrimp and sea hare, substantial silver accumulation in nervous tissues was detected, suggesting the need for further studies on possible behavioral effects of silver in these invertebrate species. In sea urchin, egg mass accumulated more silver than other tissues analyzed, indicating the need for future studies on possible reproductive effects of silver in sea urchin. In all three species...

Occurrence of aquatic invertebrates of the wheatbelt region of Western Australia in relation to salinity

Pinder, A.; Halse, S.; McRae, J.; Shiel, R.
Fonte: Kluwer Academic Publ Publicador: Kluwer Academic Publ
Tipo: Artigo de Revista Científica
Publicado em //2005 EN
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The wheatbelt region of Western Australia has been extensively cleared of indigenous vegetation for agriculture and is now severely affected by dryland salinity. Wetlands that were once freshwater are now saline and others are under threat, as are the animals and plants that inhabit them. Rising groundwater is also affecting the many naturally saline playas. To provide a framework for setting conservation priorities in this region a biological survey was undertaken, including sampling of aquatic invertebrates at 230 wetlands. In this paper, we have used data from the survey to summarise occurrence of species in relation to salinity. Total species richness at a wetland showed no response to salinity below 4.1 g l)1 and then declined dramatically as salinity increased. When halophilic species were excluded from consideration, species richness was found to decline from 2.6 g l)1. These patterns are compared to previous studies of richnesssalinity relationships. There is some evidence that the freshwater invertebrate fauna of the wheatbelt may be comparatively salt tolerant, with 46% of freshwater species collected at salinities above 3 g l)1 and 17% above 10 g l)1, though these proportions differed between various invertebrate groups. While this tolerance will provide a buffer against the effects of mild salinisation...

Historical configuration of habitat influences the effects of disturbance on mobile invertebrates

Goodsell, P.; Connell, S.
Fonte: Inter-research Publicador: Inter-research
Tipo: Artigo de Revista Científica
Publicado em //2005 EN
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Mobile animals can be affected by disturbance because of changes to the structure of their habitat. Few studies, however, recognise the potential for the historical configuration of habitat (e.g. density prior to disturbance) to affect the way animals respond to the disturbance. Furthermore, there is a tendency for ecologists to study or manipulate only the most severe disturbances, but such events are less likely to be common. We tested the hypothesis that the density of Ecklonia radiata before disturbance affects the response of assemblages of mobile invertebrates to different severities of disturbance. Differences in the severity of disturbance caused changes in the structure of assemblages, but this response varied depending on the historical configuration of habitat. The magnitude by which assemblage structure differed between undisturbed and disturbed habitats was greater where habitats were historically sparse rather than dense. We emphasise the importance of assessing a range of severities of disturbance and demonstrate the importance of habitat configuration prior to the disturbance, particularly for animals with close association to their habitat.; Paris J. Goodsell and Sean D. Connell; Copyright © 2005 Inter-Research.

Effekte von Xenohormonen auf die limnischen Invertebraten Gammarus fossarum (Crustacea, Amphipoda) und Marisa cornuarietis (Mollusca, Prosobranchia); Effects of xenohormones on the aquatic invertebrates Gammarus fossarum (Crustacea, Amphipoda) und Marisa cornuarietis (Mollusca, Prosobranchia)

Schirling, Martin
Fonte: Universidade de Tubinga Publicador: Universidade de Tubinga
Tipo: Dissertação
DE_DE
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In dieser Arbeit werden Effekte von Xenohormonen auf Gammarus fossarum und Marisa cornuarietis anhand verschiedener Parameter, auf unterschiedlichen biologischen Ebenen dargestellt. In einem Laborexperiment mit G. fossarum, das Grundlage für weitere Untersuchungen im Rahmen dieser Arbeit war, konnte gezeigt werden, dass sich die Stressproteine hsp90 und hsp70 im Laufe der Oocytenreifung gegenläufig verhalten. Sowohl in einem Freilandversuch, bei dem der Einfluss von Kläranlageneinleitern untersucht wurde, als auch durch Exposition von Gammariden gegenüber Bisphenol A in Fließrinnen, wurde eine Beschleunigung der Oocytenreifung anhand von histologischen und biochemischen Parametern festgestellt. Eine mögliche mechanistische Erklärung konnte durch den Nachweis eines Estrogenrezeptor alpha-ähnlichen Proteins, das ausschließlich bei adulten weiblichen Gammariden vorhanden ist, erbracht werden. Darüber hinaus konnte gezeigt werden, dass dieses Protein durch EE2 Exposition bei adoleszenten Weibchen verstärkt expremiert wurde. Um die Wirkung von Xenohormonen auf Invertebraten durch ein standartisierten Test nachzuweisen, wurde ein Embryotest mit M. cornuarietis erarbeitet. Hierbei zeigten sich die Parameter Schlupf, Herzschlagrate und Gewicht nach dem Schlupf als am aussagekräftigsten.; The focus of this work is on the effects of xenohormones on Gammarus fossarum and Marisa cornuarietis. To assess these effects...

PREVENTING THE INTRODUCTION AND THE SPREAD OF FRESHWATER INVASIVE INVERTEBRATES IN ONTARIO: ASSESSMENT OF THE PROPOSED INVASIVE SPECIES ACT (BILL 37)

Aleaga Aguilera, Liudmila
Fonte: Quens University Publicador: Quens University
Tipo: Project
EN
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Freshwater invasive species, especially invertebrates are an important environmental stressor associated with significant ecological and economic impacts particularly in the Great Lakes, one of the freshwater ecosystems with a significant number of invasive invertebrates compared to other taxa. Because of the importance that policy development and implantation play in managing invasive species for their effective prevention and spread, a policy analysis of the proposed Ontario’s Bill 37 (“An Act respecting Invasive Species”) was conducted based on an extensive literature review, the interview responses with provincial government officials, and the results from the constructed non-native species checklist. A total of 46 species were identified as having a high impact on the environment, according to the literature, among 409 species identified as recorded as non-native anywhere including native species to North America. Research attention seems to have been concentrated on high impact species despite they only represent 11.2% of the total species as well as on their main associated pathways, such as the ballast water and sediment of transoceanic and domestic ships in the Great Lakes. Particularly, research efforts are concentrated on only 16 invasive species...

Behavioural responses of indigenous benthic invertebrates (Echinogammarus meridionalis, Hydropsyche pellucidula and Choroterpes picteti) to a pulse of Acid Mine Drainage: A laboratorial study

Macedo-Sousa, Joaquim A.; Gerhardt, Almut; Brett, Christopher M.A.; Nogueira, António J.A.; Soares, Amadeu M.V.M.
Fonte: Universidade de Coimbra Publicador: Universidade de Coimbra
Tipo: Artigo de Revista Científica Formato: aplication/PDF
ENG
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The drainage of abandoned mines leads to several ecological problems, particularly the acidification of surface freshwater systems and heavy metal contamination. In order to study the possibility of using the behavioural early warning responses of Portuguese indigenous benthic invertebrates to detect an acute short-term pulse of Acid Mine Drainage (AMD), experiments with the Multispecies Freshwater Biomonitor MFB(TM) were performed and locomotion and ventilation were measured as endpoints. AMD was collected from the "São Domingos" mine (Southeast Portugal) and the following species were selected: Echinogammarus meridionalis (Pinkster, 1973), Hydropsyche pellucidula (Curtis, 1834) and Choroterpes picteti (Eaton, 1870). For simulating the pulsed exposure, AMD was added to river water where invertebrates were collected and pH was lowered until reaching 3.5. The effects of H+ and heavy metals were discriminated using HCl positive controls. In addition to behaviour, mortality was registered. E. meridionalis was the most sensitive species in terms of mortality and behavioural endpoints, followed by C. picteti and H. pellucidula. E. meridionalis early warning responses consisted of increased locomotion with subsequent increase in ventilation...

Behavioural responses of indigenous benthic invertebrates (Echinogammarus meridionalis, Hydropsyche pellucidula and Choroterpes picteti) to a pulse of Acid Mine Drainage: A laboratorial study

Macedo-Sousa, Joaquim A.; Gerhardt, Almut; Brett, Christopher M. A.; Nogueira, António J. A.; Soares, Amadeu M. V. M.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.87%
The drainage of abandoned mines leads to several ecological problems, particularly the acidification of surface freshwater systems and heavy metal contamination. In order to study the possibility of using the behavioural early warning responses of Portuguese indigenous benthic invertebrates to detect an acute short-term pulse of Acid Mine Drainage (AMD), experiments with the Multispecies Freshwater Biomonitor MFB (TM) were performed and locomotion and ventilation were measured as endpoints. AMD was collected from the "Sao Domingos" mine (Southeast Portugal) and the following species were selected: Echinogammarus meridionalis (Pinkster, 1973). Hydropsyche pellucidula (Curtis, 1834) and Choroterpes picteti (Eaton, 1870). For simulating the pulsed exposure, AMD was added to river water where invertebrates were collected and pH was lowered until reaching 3.5. The effects of H(+) and heavy metals were discriminated using HCl positive controls. In addition to behaviour, mortality was registered. E. meridionalis was the most sensitive species in terms of mortality and behavioural endpoints, followed by C. picteti and H. pellucidula. E. meridionalis early warning responses consisted of increased locomotion with subsequent increase in ventilation...

Evolutionary Trends in the Individuation and Polymorphism of Colonial Marine Invertebrates

Venit, Edward Peter
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Dissertação Formato: 1658524 bytes; application/pdf
EN_US
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All life is organized hierarchically. Lower levels, such as cells and zooids, are nested within higher levels, such as multicellular organisms and colonial animals. The process by which a higher-level unit forms from the coalescence of lower-level units is known as “individuation”. Individuation is defined by the strength of functional interdependencies among constituent lower-level units. Interdependency results from division of labor, which is evidenced in colonial metazoans as zooid polymorphism. As lower-level units specialize for certain tasks, they become increasing dependant on the rest of the collective to perform other tasks. In this way, the evolution of division of labor drives the process of individuation. This study explores several ways in which polymorphism evolves in colonial marine invertebrates such as cnidarians, bryozoans, and urochordates. A previous study on the effect of environmental stability on polymorphism is revisted and reinterpreted. A method for quantifying colonial-level individuation by measuring the spatial arrangement of polymorphic zooids is proposed and demonstrated. Most significantly, a comparison across all colonial marine invertebrate taxa reveals that polymorphism only appears in those colonial taxa with moderately to strongly compartmentalized zooids. Weakly compartmentalized and fully compartmentalized taxa are universally monomorphic. This pattern is seen across all colonial marine invertebrate taxa and is interpreted as a “rule” governing the evolution of higher-level individuation in the major taxa of colonial marine invertebrates. The existence of one rule suggests that there may be others...

Characterization of deepwater invertebrates at Isla del Coco National Park and Las Gemelas Seamount, Costa Rica

Starr,Richard M.; Cortés,Jorge; Barnes,Cheryl L.; Green,Kristen; Breedy,Odalisca
Fonte: Revista de Biología Tropical Publicador: Revista de Biología Tropical
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/11/2012 EN
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36.96%
The deepwater faunas of oceanic islands and seamounts of the Eastern Tropical Pacific are poorly known. From 11-22 September 2009, we conducted an exploration of the deepwater areas around Isla del Coco National Park and Las Gemelas Seamount, located about 50km southwest of Isla del Coco, Costa Rica using a manned submersible to survey the seafloor habitats. The goal of the exploration was to characterize the habitats and biota, and conduct quantitative surveys of the deepwater portions of Isla del Coco National Park and Las Gemelas. We completed a total of 22 successful submersible dives, spanning more than 80hr underwater, and collected a total of 36hr of video. With respect to invertebrates, our objectives were to gather quantitative information on species composition, density, distribution and habitat associations as well as to compare the invertebrate communities between the two sites. A total of 7 172 invertebrates were counted from analysis of the video collected on this project. Larger organisms were counted and placed into 27 taxonomic groups to characterize the deepwater invertebrate fauna of Las Gemelas Seamount and Isla del Coco National Park. The Shannon-Weiner Index for biodiversity (H’) was calculated to be 0.14 ± 0.02 for Isla del Coco and 0.07 ± 0.03 for Las Gemelas surveys. Although richness was fairly equal between the two sites...

Heavy metals in fish and invertebrates from the Gulf of Paria, Venezuela

LEMUS,Mairin; CASTAÑEDA,Julián; CHUNG,Kyung
Fonte: Centro de Ciencias de la Atmósfera, UNAM Publicador: Centro de Ciencias de la Atmósfera, UNAM
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2014 EN
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The concentration of Hg, Cu, Cd, Cr and Ni was estimated in fish and invertebrates captured in the Gulf of Paria coastal zone, Venezuela. The results show that invertebrates have a higher bioaccumulation of metals in relation to fish, particularly C. virginica that had the highest concentrations of Hg, Cu and Cd and the snail A. deflorata with the highest values of Cr, Ni and Pb. In relation to fishes, C. spixii (catfish) presented the highest values of all metals tested. The metals tested in the species do not exceed the maximum permissible values indicated by the WHO for human consumption. However, heavy metals are present in the Gulf of Paria.