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| Registros recuperados: 501 | |
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| Fraser, Dylan J; Department of Biology, Dalhousie University; dylan.fraser@dal.ca; Coon, Thomas; Cree Trapper's Association; tourism@nation.mistissini.qc.ca; Prince, Michael R.; Cree Nation of Mistissini, Quebec; tourism@nation.mistissini.qc.ca; Dion, Rene; Grand Council of the Crees of Quebec; rdion@gcc.ca; Bernatchez, Louis; Department of Biology, Laval University; louis.bernatchez@bio.ulaval.ca. |
| Despite their dual importance in the assessment of endangered/threatened species, there have been few attempts to integrate traditional ecological knowledge (TEK) and evolutionary biology knowledge (EBK) at the population level. We contrasted long-term aboriginal TEK with previously obtained EBK in the context of seasonal migratory habits and population biology of a salmonid fish, brook charr, (Salvelinus fontinalis) inhabiting a large, remote postglacial lake. Compilation of TEK spanning four decades involved analytical workshops, semidirective interviews, and collaborative fieldwork with local aboriginal informants and fishing guides. We found that TEK complemented EBK of brook charr by providing concordant and additional information about (1) population... |
| Tipo: Peer-Reviewed Reports |
Palavras-chave: Biodiversity; Conservation; Cree; Evolutionary biology; Fish; James Bay; Local ecological knowledge; Migration; Northern research; Traditional ecological knowledge; Traditional knowledge.. |
| Ano: 2006 |
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| Scheffer, Marten; Wageningen Agricultural University; Marten.Scheffer@wur.nl. |
| Despite the huge scientific progress of the last century, the dynamics of complex systems such as the atmosphere, human societies, and ecosystems remain difficult to understand and predict. Nonetheless, our ability to carve the future depends largely on our insight into the functioning of such complex systems. Complex systems are the focus of considerable mathematical theory. Rather than referring to any particular part of the world, such theory addresses what seems to be another world: a world of strange attractors, catastrophe folds, torus destruction, and homoclinic bifurcations. So disparate is the language and notation in this discipline that it is hard to imagine that it has any thing to do with reality as we know it. Indeed, it deals with a kind of... |
| Tipo: Peer-Reviewed Reports |
Palavras-chave: Bifurcation; Catastrophe; Chaos; Cycle; Daphnia; Fish; Macrophyte; Model; Multiple stable states; Plankton; Predation; Trophic cascade. |
| Ano: 1999 |
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| Modenutti,Beatriz; Albariño,Ricardo; Bastidas Navarro,Marcela; Díaz Villanueva,Verónica; Souza,María Sol; Trochine,Carolina; Laspoumaderes,Cecilia; Cuassolo,Florencia; Mariluán,Gustavo; Buria,Leonardo; Balseiro,Esteban. |
| North Andean Patagonian aquatic systems include a number of deep and shallow oligotrophic lakes with a profuse hydrographic net. In this contribution we present a review of the researches carried out during the last decade in the food webs of North Patagonian water bodies. Food webs in these systems were studied based on field surveys, combining with field and laboratory experiments. Deep and shallow lakes were analyzed in relation to light, organic matter, and nutrient constraints as limiting interacting factors. In addition, we have also extended our knowledge on the structure and dynamics of stream food webs by analyzing different aspects of biotic interactions occurring both through the autotrophic and heterotrophic pathways. Since Andean lakes were... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Bacterioplankton; Phytoplankton; Zooplankton; Fish; Insects; Lakes and rivers. |
| Ano: 2010 |
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S1667-782X2010000200003 |
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| Gonçalves,Rodrigo J; Souza,María Sol; Aigo,Juana; Modenutti,Beatriz; Balseiro,Esteban; Villafañe,Virginia E; Cussac,Víctor; Helbling,E Walter. |
| In the last decades, both temperature and UVB (280-315 nm) radiation on the surface of the Earth increased at growing rates as a result of human activities. Many studies had evaluated the effects of temperature on aquatic ecosystems, but now the field broadens as the combination and variations of temperature and radiation gains especial importance. In this work we attempt to revisit some of our knowledge about the effects of UVR and temperature on marine and freshwater plankton and fish from temperate regions (defined here as latitudes between 30-60º), especially from the Patagonia area, due to the special characteristics found in these sites. UVR affects (often negatively) almost all processes, from carbon fixation to behavior; and certainly all trophic... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Climate change; Bacterioplankton; Phytoplankton; Zooplankton; Fish; Oxidative stress; Upper mixed layer. |
| Ano: 2010 |
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S1667-782X2010000200005 |
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| Zayas,Marcelo A; Cordiviola,Elly. |
| The fish conservation was quantified by means of the index SUMIN, composed by the summation of 12 outstanding variables for the species survival and/or conservation. An arranged list of 53 species was obtained according to a gradient of conservation necessity. The species determined as vulnerable of maximum priority: Salminus brasiliensis, Pygocentrus nattereri, Serrasalmus marginatus and S. rhombeus; species vulnerable of special attention: Brycon orbygnianus, Triportheus paranensis, Serrasalmus serrulatus, S. spilopleura, Piaractus mesopotamicus, Hemigrammus mattei, Cynopotamus argenteus, Astyanax correntinus, Gymnocorymbus ternetzi, Hyphessobrycon anisitsi and Mylossoma orbignyanus. The remaining species, were qualified as not threatened: Poptella... |
| Tipo: Journal article |
Palavras-chave: Conservation; Fish; Characidae; South America. |
| Ano: 2007 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-65382007000200006 |
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| Nirchio,Mauro; Martinez,Emanuel Ricardo Monteiro; Foresti,Fausto; Oliveira,Claudio. |
| Despite their ecological and economical importance, fishes of the family Ariidae are still genetically and cytogenetically poorly studied. Among the 133 known species of ariids, only eight have been karyotyped. Cytogenetic analyses performed on Genidens barbus and Sciades herzbergii revealed that both species have 2n = 56 chromosomes and Cathorops aff. mapale has 2n = 52 chromosomes: Genidens barbus has 10 Metacentrics (M), 14 Submetacentrics (SM), 26 Subtelocentrics (ST), and 6 Acrocentrics (A), Sciades herzbergii has 14M, 20SM, 18ST and 4A, whereas Cathorops aff. mapale has 14M, 20SM, and 18ST. The nucleolus organizer regions (NORs) were found in a single chromosome pair on the short arm of a large-sized ST pair in Genidens barbus and on the short arm of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cytogenetics; Ag-NORs; Chromosome evolution; Chromosome rearrangements; Fish. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572010000200011 |
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| Carvalho,Margarida Lima; Oliveira,Claudio; Foresti,Fausto. |
| The family Gasteropelecidae is composed of three genera and eight species. This study shows that Thoracocharax cf. stellatus has 2n = 52 chromosomes for both sexes. The five males studied showed 8 metacentric, 16 submetacentric, 4 subtelocentric, and 24 acrocentric chromosomes; the seven females showed only one submetacentric chromosome, belonging to pair 11, and one extra acrocentric chromosome, smaller than all the other chromosomes, characterizing the presence of a ZZ/ZW sex chromosome system in this species. Nucleolus organizing regions (NORs) were detected on the short arms of the subtelocentric chromosome pair 13. Constitutive heterochromatin was identified at pericentromeric and terminal positions in almost all chromosomes. The W chromosome was... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Sex chromosomes; ZW; DNA content; Fish; Evolution. |
| Ano: 2002 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572002000300008 |
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| Fonteles,Soraia B.A.; Lopes,Carlos E.; Akama,Alberto; Fernandes,Flora M.C.; Porto-Foresti,Fábio; Senhorini,José A.; Daniel-Silva,Maria de Fátima Z.; Foresti,Fausto; Almeida-Toledo,Lurdes Foresti de. |
| A karyotype analysis of the electric eel, Electrophorus electricus (Teleostei, Gymnotiformes), a strongly electric fish from northern South America, is presented. Two female specimens were analyzed, one from the Amazon River and one from the Araguaia River. The specimens had a chromosomal number of 2n = 52 (42M-SM + 10A). C-bands were present in a centromeric and pericentromeric position on part of the chromosomes; some interstitial C-bands were also present. Heteromorphic nucleolus organizer regions (NORs) were detected in two chromosome pairs of the specimen from the Amazon River. The chromosome number and karyotype characteristics are similar to those of other Gymnotidae species. The genera Electrophorus and Gymnotus are positioned as the basal lineages... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chromosome; Fish; Gymnotidae; Electric eel. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572008000200010 |
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| Abreu,Marcia Matos de; Pereira,Luiz Henrique Garcia; Vila,Vilma Barretto; Foresti,Fausto; Oliveira,Claudio. |
| Catfishes of the genus Pseudoplatystoma are very important species due to both their high commercial value and their ecological role as voracious predators. They undertake lengthy migratory movements during their life-cycle, this including reproductive migration which occurs from October to December in the rainy season. In the present study, seven microsatellite loci were analyzed to access genetic variability in two samples of P. reticulatum from the Upper Paraguay Basin. The loci were highly polymorphic (mean = 7.28). According to all analysis, the two samples of P. reticulatum revealed pronounced genetic differentiation. Fst value was 0.2290, Rst value 0.1067 and AMOVA 22.90% (Fst) and 10.67% (Rst), all being highly significant (p < 0.001). The... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Fish; Population genetics; Microsatellite; Homing; Population structure. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572009000400032 |
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| Gross,Maria Claudia; Schneider,Carlos Henrique; Matiello,Mara Cristina de Almeida; Leite,Maysa de Lima; Bertollo,Luiz Antonio Carlos; Artoni,Roberto Ferreira. |
| Morphological and chromosomal markers were used to infer the structure and genetic variability of a population of fish of the genus Astyanax, geographically isolated at sinkhole 2 of Vila Velha State Park, Paraná, Brazil. Two morphotypes types were observed, the standard phenotype I and phenotype II which showed an anatomical alteration probably due to an inbreeding process. Fluctuating asymmetry (FA) analysis of different characters showed low levels of morphological variation among the population from sinkhole 2 and in another population from the Tibagi river (Paraná, Brazil). The Astyanax karyotype was characterized in terms of chromosomal morphology, constitutive heterochromatin and nucleolar organizer regions. Males and females presented similar... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Fish; Astyanax sp.; Fluctuating asymmetry; Karyotype structure; Triploidy; Genetic conservation. |
| Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572004000400011 |
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| Grisolia,Cesar Koppe; Oliveira,Adriano Barros Barata de; Bonfim,Helder; Klautau-Guimarães,Maria de Nazaré. |
| An evaluation of the genotoxicity of domestic sewage was carried out in a municipal wastewater treatment plant. The study was carried out using Allium cepa root tip cells through cytological parameters such as aberrant cells in anaphase-telophase and the mitotic index, and the fish species Oreochromis niloticus and Tilapia rendalli, through the index of micronuclei in peripheral erythrocytes. In the Allium test, each of the four stages of the wasterwater treatment routine was analyzed, i.e., crude sewage, primary effluent, secondary effluent, and tertiary effluent. O. niloticus and T. rendalli specimens were maintained in an aquarium continuously receiving the final effluent, in an open system, before being discharged into Lake Paranoá. For micronuclei... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Allium cepa; Biomonitoring; Domestic sewage; Fish; Micronuclei; Mutagenicity. |
| Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572005000200026 |
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| Klingelfus,Tatiane; Costa,Paula Moiana da; Scherer,Marcos; Cestari,Marta Margarete. |
| Abstract Even though aluminum is the third most common element present in the earth's crust, information regarding its toxicity remains scarce. It is known that in certain cases, aluminum is neurotoxic, but its effect in other tissues is unknown. The aim of this work was to analyze the genotoxic potential of aluminum sulfate in kidney tissue of the fish Rhamdia quelen after trophic contamination for 60 days. Sixty four fish were subdivided into the following groups: negative control, 5 mg, 50 mg and 500 mg of aluminum sulfate per kg of fish. Samples of the posterior kidney were taken and prepared to obtain mitotic metaphase, as well as the comet assay. The three types of chromosomal abnormalities (CA) found were categorized as chromatid breaks,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Fish; Metal contamination; Chromosomal abnormalities; Comet assay. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572015000400499 |
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| Leuzzi,Maria Sueli Papa; Almeida,Fernanda Simões de; Orsi,Mário Luís; Sodré,Leda Maria Koelblinger. |
| In this study, the RAPD technique was used to analyze the genetic structure of populations of the fish Astyanax altiparanae (Characidae, Tetragonopterinae) living in the lower, middle and upper Paranapanema River, Brazil. The aim was to assess this structure regarding fish handling and conservation programs. The genetic variability (P) was found to be 42.64%, 75% and 75% in the low, middle and upper reaches, respectively. The dendrogram of genetic similarity, obtained by comparative analysis of the sets of samples from the three sites, showed the formation of three clusters. All of the genetic parameters used indicate that the population in the lower Paranapanema is genetically different from those in the middle and upper sections. The theta P test shows... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Astyanax altiparanae; RAPD; Genetic structure; Genetic conservation; Fish. |
| Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572004000300009 |
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| Martinez,Emanuel Ricardo Monteiro; Nirchio,Mauro; Granado,Angel; Foresti,Fausto; Oliveira,Claudio. |
| Cytogenetic analyses performed in Cephalosilurus apurensis, Microglanis aff. cottoides and Pseudopimelodus bufonius revealed that the three species have 2n = 54 chromosomes: C. apurensis presented six metacentric (M), 28 submetacentric (SM), 14 subtelolocentric (ST), and six acrocentric (A) chromosomes, while M. aff. cottoides showed 10M, 32SM, 10ST and 2A, and P. bufonius had 12M, 30SM and 12ST. The nucleolus organizer regions (NORs) were present on the short arm of a middle-sized ST pair, identified as pair 19, in C. apurensis NORs were found on the short arm of a middle-sized ST (pair 23) and on the long arm of a middle-sized ST (pair 22) in M. aff. cotttoides and on the short arm of three middle-sized ST pairs, identified as pairs 9, 10 and 11, in P.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Karyotype; Chromosomes; C-banding; Ag-NOR; Fish. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572008000400015 |
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| Registros recuperados: 501 | |
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