130 resultados para Sotalia fluviatilis


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The findings are presented of a study conducted to use autochthonously obtained, nonpathogenic heterotrophic marine bacteria as a substitute feed for microalgae in rearing larval Penaeus monodon. Eleven strains were isolated: Micrococcus (MCC), Staphylococcus, Streptococcus, Bacillus (two strains; BAC-1, BAC-2), Pseudomonas (two strains; PSM-1, PSM-2), Vibrio parahemolyticus, V. fluviatilis, Moraxella (MOR) and Flavobacterium. Six nonhemolytic strains were then chosen for the Penaeus monodon larval feed trials: BAC-1, BAC-2, PSM-1, PSM-2, MCC and MOR. The study demonstrates that bacterial biomass could be further investigated as a partial substitute for microalgae in penaeid shrimp larval rearing.

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Electrophoretic and serological studies of foot muscle protein of three species of Cerithiacea (Telescopium telescopium, Cerithidea fluviatilis and C. obtusum) were carried out to understand their relationships. Living specimens were collected from mud flats and mangrove swamps off Portonovo. Polyacrylamide electrophoresis of proteins from foot muscle extract of T. telescopium, C. fluviatilis and C. obtusum showed that the former had a different densitometric profile as well as more number of protein bands; but the later two species showed a closer related pattern as well as lesser number of protein bands. At the same time these two species are distinguished from each other in their total number of bands and Rf values. Immunological studies using micro-Ouchterlony double diffusion tests which absorbed antiserum indicated that C. fluviatilis and C. obtusum were more closely related as revealed by an identity reactions than T. telesopium as shown by non-identity reactions. Results are discussed in relation to ecological and morphological adaptations

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Previously we suggested that four proteins including aldolase and triose phosphate isomerase (TPI) evolved with approximately constant rates over long periods covering the whole animal phyla. The constant rates of aldolase and TPI evolution were reexamined based on three different models for estimating evolutionary distances, It was shown that the evolutionary rates remain essentially unchanged in comparisons not only between different classes of vertebrates but also between vertebrates and arthropods and even between animals and plants, irrespective of the models used, Thus these enzymes might be useful molecular clocks for inferring divergence times of animal phyla, To know the divergence time of Parazoa and Eumetazoa and that of Cephalochordata and Vertebrata, the aldolase cDNAs from Ephydatia fluviatilis, a freshwater sponge, and the TPI cDNAs from Ephydatia fluviatilis and Branchiostoma belcheri an amphioxus, have been cloned and sequenced, Comparisons of the deduced amino acid sequences of aldolase and TPI from the freshwater sponge with known sequences revealed that the Parazoa-Eumetazoa split occurred about 940 million years ago (Ma) as determined by the average of two proteins and three models, Similarly, the aldolase and TPI clocks suggest that vertebrates and amphioxus last shared a common ancestor around 700 Ma and they possibly diverged shortly after the divergence of deuterostomes and protostomes.

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This article documents the addition of 220 microsatellite marker loci to the Molecular Ecology Resources Database. Loci were developed for the following species: Allanblackia floribunda, Amblyraja radiata, Bactrocera cucurbitae, Brachycaudus helichrysi, Calopogonium mucunoides, Dissodactylus primitivus, Elodea canadensis, Ephydatia fluviatilis, Galapaganus howdenae howdenae, Hoplostethus atlanticus, Ischnura elegans, Larimichthys polyactis, Opheodrys vernalis, Pelteobagrus fulvidraco, Phragmidium violaceum, Pistacia vera, and Thunnus thynnus. These loci were cross-tested on the following species: Allanblackia gabonensis, Allanblackia stanerana, Neoceratitis cyanescens, Dacus ciliatus, Dacus demmerezi, Bactrocera zonata, Ceratitis capitata, Ceratitis rosa, Ceratits catoirii, Dacus punctatifrons, Ephydatia mülleri, Spongilla lacustris, Geodia cydonium, Axinella sp. Ischnura graellsii, Ischnura ramburii, Ischnura pumilio, Pistacia integerrima and Pistacia terebinthus. © 2010 Blackwell Publishing Ltd.

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Recent climatic change has been recorded across the globe. Although environmental change is a characteristic feature of life on Earth and has played a major role in the evolution and global distribution of biodiversity, predicted future rates of climatic change, especially in temperature, are such that they will exceed any that has occurred over recent geological time. Climate change is considered as a key threat to biodiversity and to the structure and function of ecosystems that may already be subject to significant anthropogenic stress. The current understanding of climate change and its likely consequences for the fishes of Britain and Ireland and the surrounding seas are reviewed through a series of case studies detailing the likely response of several marine, diadromous and freshwater fishes to climate change. Changes in climate, and in particular, temperature have and will continue to affect fish at all levels of biological organization: cellular, individual, population, species, community and ecosystem, influencing physiological and ecological processes in a number of direct, indirect and complex ways. The response of fishes and of other aquatic taxa will vary according to their tolerances and life stage and are complex and difficult to predict. Fishes may respond directly to climate-change-related shifts in environmental processes or indirectly to other influences, such as community-level interactions with other taxa. However, the ability to adapt to the predicted changes in climate will vary between species and between habitats and there will be winners and losers. In marine habitats, recent changes in fish community structure will continue as fishes shift their distributions relative to their temperature preferences. This may lead to the loss of some economically important cold-adapted species such as Gadus morhua and Clupea harengus from some areas around Britain and Ireland, and the establishment of some new, warm-adapted species. Increased temperatures are likely to favour cool-adapted (e.g. Perca fluviatilis) and warm-adapted freshwater fishes (e.g. roach Rutilus rutilus and other cyprinids) whose distribution and reproductive success may currently be constrained by temperature rather than by cold-adapted species (e.g. salmonids). Species that occur in Britain and Ireland that are at the edge of their distribution will be most affected, both negatively and positively. Populations of conservation importance (e.g. Salvelinus alpinus and Coregonus spp.) may decline irreversibly. However, changes in food-web dynamics and physiological adaptation, for example because of climate change, may obscure or alter predicted responses. The residual inertia in climate systems is such that even a complete cessation in emissions would still leave fishes exposed to continued climate change for at least half a century. Hence, regardless of the success or failure of programmes aimed at curbing climate change, major changes in fish communities can be expected over the next 50 years with a concomitant need to adapt management strategies accordingly.

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Tachykinins were purified from extracts of gastrointestinal tissues of the urodele, Amphiuma tridacrylum (three-toed amphiuma), and the elasmobranch Sphyrna lewini (hammerhead shark), and from the brain of the agnathan Lampetra fluviatilis (river lamprey). The amphiuma substance P (SP) (DNPSVGQFYGLM-NH2) contains 12 amino residues compared with 11 for mammalian SP and lacks the Arg/Lys-Pro-Xaa-Pro motif that is characteristic of NK, receptor-selective agonists. Lampetra SP (RKPHPKEFVGLM-NH2) is identical to SP from the sea lamprey and the shark SP-related peptide (AKFDKFYGLM-NH2) is identical to dogfish scyliorhinin L. Amphiuma neurokinin A (NKA) (HKDAFIGLM-NH2) and lamprey NKA (HFDEFVGLM-NH2) contain 9 amino acid residues compared with 10 for mammalian NKA. The shark NKA-related peptide (ASGPTQAGIV(10)GRKRQKGEMF(20)VGLM-NH2) shows limited structural similarity to mammalian neuropeptide gamma and the teleost tachykinin, carassin but contains 24 rather than 21 amino acid residues. The data show that the primary structures of the tachykinins have been very poorly conserved during vertebrate evolution and that pressure has acted only to maintain the functionally important sequence -Phe-Xaa-Gly- Leu-Met-NH2 at the COOH-termini of the peptides.

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The present work comprises studies on the salinity tolerance and respiratory metabolism of a mood-boring sphaeromid, Sphaeroma annandalei, Stabbing and two free living,foulers of the family Cirolanidae, Cirolana fluviatilis Stabbing and C. uilleyi Stabbing. Except for the systematic accounts and general observations by Pillai (1961) and the preliminary studies on the salinity tolerance and respiration of C. fluviatilis by Nagabhushanam and Gopalakrishnamurthy (1965, 1965a) very little is known about these isopods From Indian waters. Studies by John (1968) on the habits, structure, and development of Sphaeroma terebrans and by Cheriyan (1973) on the eoéphysiology of the same are the recent major contributions on this interesting group of animals. 5. annandalei is closely related to S. terebrans and has been reported to occur on timber along with the latter (Pillai, 1951). s. gggandalei is a serious pest attacking wood along the Kerala coast, but detailed works on this species have not been undertaken so Far

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En el marc d'un projecte més ampli sobre la comunitat de peixos de la conca lacustre de Banyoles, s'ha estudiat la distribució espacial de les diferents espècies així com l'ús que aquestes fan de l'hàbitat. El poblament piscícola de l'estany de Banyoles és el resultat d'un llarg historial d'introducció d'espècies exòtiques i extinció de les poblacions autòctones locals. S'ha revisat la seva composició actual detectant un total de 18 espècies (4 autòctones i 14 introduïdes) de les quals només 13 presenten una població estable. L'estudi de l'hàbitat s'ha centrat a l'Estany, l'element principal del sistema lacustre, analitzant per separat la zona litoral i la zona limnètica. En el primer cas s'han realitzat les captures d'individus mitjançant pesca elèctrica des d'una embarcació adaptada per aquesta pràctica. La totalitat del litoral ha estat dividida en trams de característiques homogènies on s'han obtingut les captures per unitat d'esforç per cada espècie. El mostreig s'ha desenvolupat entre l'estiu de 1997 i la primavera del 2000 realitzant un total de 10 campanyes de pesca. Les espècies més abundants al litoral són la perca americana (Micropterus salmoides) i el peix sol (Lepomis gibbosus), essent també presents la perca (Perca fluviatilis), carpa (Cyprinus carpio) i el gardí (Scardinius erythrophthalmus). S'han capturat altres espècies com ara anguila (Anguilla anguilla), bagra (Squalius cephalus), sandra (Sander lucioperca), carpí (Carassius auratus) i madrilleta vera (Rutilus rutilus), però són molt menys abundants en nombre. S'ha examinat, per cadascuna de les espècies, si existeix selecció de l'hàbitat i en cas afirmatiu, quin és el preferent en base a la classificació del litoral en sis tipus de vegetació predominant. Les espècies més abundants, perca americana i peix sol, ocupen tots els hàbitats disponibles però amb una densitat diferent. La perca mostra també una clara selecció de l'hàbitat a favor de les zones molt estructurades amb abundant presència de jonca litoral. Carpa i gardí seleccionen els ambients més fondos amb major presència de matèria orgànica d'origen vegetal procedent del bogar. En general els individus ocupen les zones amb una densitat de vegetació intermèdia, majoritàriament zones de jonca a l'estiu i zones amb mansega a l'hivern, on troben refugi i els recursos tròfics necessaris. La perca americana, a més, presenta una elevada fidelitat a un mateix punt del litoral al llarg de la seva vida. La zona limnètica ha estat prospectada mensualment mitjançant ecosondació, realitzant transectes perpendiculars a l'eix principal de l'Estany, cobrint la seva totalitat. La composició d'espècies s'ha obtingut a partir de les captures fetes amb xarxes (tresmalls) amb periodicitat estacional. L'anàlisi geoestadística de la densitat de peixos ha permès descriure l'estructura espacial d'aquesta a partir dels variogrames, així com la seva variabilitat tant espacial com temporal, i obtenir els mapes de densitat. A l'hivern, la densitat de peixos a la zona limnètica assoleix els seus valors mínims i els individus es troben formant agregats dispersos, pels diferents estrats de fondària. A partir de la primavera la densitat augmenta, pel reclutament i la major freqüència d'individus que abandonen el litoral; la densitat esdevé més homogènia a les primer capes de fondària. A l'estiu la densitat és màxima i l'estrat més homogeni coincideix amb la posició de la termoclina. Aquest estructura varia en disminuir la temperatura i barrejar-se la columna d'aigua, tornant a la situació hivernal. La perca i la madrilleta vera són les espècies predominants en aquest ambient, juntament amb la carpa. La seva distribució no és homogènia i respon a les característiques limnològiques de les diferents cubetes de l'Estany. Una particularitat d'aquest, relacionada amb el seu origen càrstic, es la formació d'una ploma hidrotermal que afecta la distribució dels peixos, probablement en augmentar la terbolesa. S'ha integrat l'ús de l'hàbitat de les espècies que ocupen tant la zona limnètica com la litoral a partir del seguiment d'individus, concretament de perca i bagra. S'ha utilitzat un sistema automàtic de posicionament que estima la localització dels individus marcats amb transmissor de telemetria acústica. L'anàlisi dels desplaçaments mostra un rang superior per la bagra en comparació amb la perca. Ambdues espècies mostren una orientació en els seus desplaçaments. La perca ocupa el litoral a la nit i es desplaça a la zona limnètica de dia, amb un ritme d'activitat marcat per dos màxims coincidint amb la sortida i posta de sol; en canvi la bagra mostra una major activitat nocturna amb zones de repòs properes al litoral. S'ha estimat igualment els dominis vital de cada individu marcat.

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In the present study, cadmium and lead in the muscle, lung, liver and kidney of dolphins (Sotalia guianensis and Stenella clymene) of the Bahia coast in the northwest of Brazil were determined by graphite furnace atomic absorption spectrometry. Samples were digested using a diluted oxidant mixture (HNO(3) + H(2)O(2)) with a microwave heating program performed in five steps. The optimized temperatures and chemical modifier for the pyrolysis and atomization were 700 degrees C, 1400 degrees C and Pd plus Mg for Cd, and 900 degrees C, 1800 degrees C and NH(4)H(2)PO(4) for Pb, respectively. Characteristic masses and limits of detections (n = 20, 3 sigma) for Cd and Pb were 1.6 and 9.0 pg and 0.82 ng g(-1) and 0.50 ng g(-1), respectively. Repeatability ranged from 0.87 to 8.22% for Cd and 4.31 to 8.09% for Pb. The found concentrations presented no statistical differences at the 95% confidence level when compared with the ICP OES methods. Addition and recovery tests were also performed and the results ranged between 87 and 112% for both elements. Samples of cetacean Dolphinidae (S. guianensis and S. clymene) were analyzed, and the higher concentrations ranged from 0.09 to 46.2 mu g g(-1) for Cd and 0.04 to 0.47 mu g g(-1) for Pb in liver, and from 0.133 to 277 mu g g(-1) for Cd in the kidney. (C) 2010 Elsevier By. All rights reserved.

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Os sistemas de monitoramento utilizando diatomáceas foram desenvolvidos, em sua maioria, para monitorar os efeitos da poluição orgânica e da eutrofização, adotando como parâmetros de referência a demanda biológica de oxigênio após cinco dias e a concentração de fósforo total. Entretanto, vários fatores naturais têm sido apontados como causadores de variação na composição destas comunidades em rios. Por isso, grandes mudanças estruturais não provam necessariamente a hipótese de que tenha ocorrido algum evento poluidor. Neste contexto, a partir da relação entre a estrutura da comunidade de diatomáceas epilíticas da microbacia do arroio Schmidt, RS, Brasil, mudanças na qualidade da água e alterações físicas do meio, como fluxo, sombreamento ripário, largura e profundidade, objetivou-se colher subsídios para aplicação em programas de manejo e conservação de ecossistemas aquáticos. Durante os meses de janeiro e fevereiro de 2004, foram realizadas quatro excursões científicas a seis estações, totalizando 24 amostragens, para medição das seguintes variáveis: condutividade elétrica, oxigênio dissolvido em saturação, pH, turbidez, demanda biológica de oxigênio em cinco dias (DBO5), demanda química de oxigênio (DQO), fósforo total, nitrato, sólidos totais dissolvidos, sólidos suspensos, sílica, profundidade de submersão do substrato, velocidade da correnteza, diâmetro dos seixos, largura do rio e sombreamento em função da vegetação ripária. Para as análises qualitativas e quantitativas das diatomáceas epilíticas, uma área de 25 cm2 foi raspada de cinco replicatas O material foi oxidado com dicromato de potássio, ácido sulfúrico e clorídrico para confecção de lâminas permanentes. Padrões de distribuição e abundância das espécies foram explorados através da Análise de Espécies Indicadoras e os fatores ambientais responsáveis por esta distribuição foram evidenciados pela Análise de Correspondência Canônica. Os resultados confirmaram a preferência de Cymbella e Encyonema por águas lentas e elevada luminosidade, bem como a adaptabilidade de Cocconeis ao sombreamento. Nitzschia acicularis, Surirella tenera e Planothidium rupestoides revelaram-se indicadoras de ambientes meso-eutróficos. Encyonema perpusilum destacou-se no habitat oligo/β- mesossapróbico, e Sellaphora pupula no sítio de maior concentração de eletrólitos. Pelo cruzamento das respostas das espécies à saturação de oxigênio, DBO5, DQO, condutividade, fósforo total, sólidos totais dissolvidos e turbidez, foi possível estabelecer dois grupos sinalizadores de qualidade: Achnanthes sp. 3, Cocconeis fluviatilis, Navicula angusta, Nitzschia acicularis, Tryblionella victoriae, Pinnularia cf. obscura, Planothidium rupestoides, Sellaphora pupula, Stenopterobia sp. e Surirella tenera, relacionadas com maior impacto antropogênico, e Achnanthes sp. 2, Encyonema perpusilum, Geissleria aikenensis, Luticola goeppertiana, Navicula symmetrica e Nitzschia amphibia, referindo-se a ambientes mais oxigenados, pouco mineralizados e com reduzidos teores de compostos orgânicos. Estas informações também constituem subsídios para estudos paleolimnológicos envolvendo a reconstituição de paleoambientes (e.g. maior abundância de Cymbella indicando ambientes lênticos) e a concentração de paleonutrientes (e.g. Nitzschia acicularis designando períodos de maior eutrofização).

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Strandings of live or dead aquatic mammals constitute an important instrument to provide information regarding the occurrence, biology and ecology of these species. The aim of this study was to register the stranded species of cetaceans, the frequency and the spatial-temporal distribution of theses strandings during the period of 1984 to 2005, in the coast of Rio Grande do Norte. Data was acquired through the monitoring of strandings in the north, north-west and south coast of RN, and through information obtained from institutions and newspaper archives of the State. A total of 122 strandings of cetaceans were registered along the coast of Rio Grande do Norte. Of the 14 species of cetaceans registered, four species had higher frequencies: Sotalia guianensis (n= 65), Steno bredanensis (n = 6), Globicephala macrorhynchus (n = 6) and Physeter macrocephalus (n = 7). Out of 118 strandings, 93 occurred in the south coast (78.8 %), 23 in the north coast (19.5%) and 2 (1.7%) in the north-west coast of the State. The highest frequency of strandings occurred during the months of August to March and the maximum number of strandings occurred from 2000 onwards, as a consequence of the intense monitoring of the Pequenos Cetáceos Project in Rio Grande do Norte

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Estudou-se a anatomia de raízes, caules, folhas e escapos de Eriocaulon elichrysoides, Leiothrix fluitans, Paepalanthus obtusifolius, Philodice hoffmannseggii, Syngonanthus caulescens e Tonina fluviatilis,espécies aquáticas de Eriocaulaceae que ocorrem em diferentes ecossistemas brasileiros, visando a caracterização anatômica das mesmas e também a interpretação das adaptações ao ambiente. Essas plantas caracterizam-se por apresentarem raízes com aspecto esponjoso e esbranquiçado; acúmulo de ar no córtex; epiderme unisseriada, de paredes finas; córtex externo, mediano e interno; endoderme unisseriada e periciclo unisseriado ou multisseriado. em L. fluitans, P. obtusifolius e T. fluviatilis foram observadas raízes absorventes com aerênquima e raízes fixadoras sem aerênquima. Caules aéreos ou rizomatosos, com ou sem espessamentos causados pelo periciclo. Folhas e escapos com células epidérmicas de paredes finas, estômatos somente na face abaxial, parênquima clorofiliano frouxo, tecido de sustentação pouco desenvolvido e feixes vasculares colaterais. Essas estruturas anatômicas são típicas de plantas de ambientes úmidos ou aquáticos, e ocorrem de forma convergente em diferentes gêneros de Eriocaulaceae.