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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Girinos de espécies do gênero Ololygon pertencentes ao grupo "Catharinae" no Estado do Rio de Janeiro (Amphibia, Anura, Hylidae)

Carvalho-e-Silva, Sergio Potsch de January 1986 (has links)
Submitted by Alberto Vieira (martins_vieira@ibest.com.br) on 2017-10-18T20:43:03Z No. of bitstreams: 1 200885.pdf: 5771245 bytes, checksum: 78ce10d3d1c6cfa5d881b3a033ed2847 (MD5) / Made available in DSpace on 2017-10-18T20:43:03Z (GMT). No. of bitstreams: 1 200885.pdf: 5771245 bytes, checksum: 78ce10d3d1c6cfa5d881b3a033ed2847 (MD5) Previous issue date: 1986 / O estudo da morfologia e dos hábitos das larvas e do comportamento reprodutivo de seis espécies do gênero Ololygon pertencentes ao grupo “catharinae” no Estado do Rio de Janeiro, como sejam albicans, argyneornata, flavoguttata, humilis, obtriangulata e trapicheiroi, demonstrou que elas constituem espécies plenas. Quatro subgrupos podem ser reconhecidos: “argyreornata” incluindo argyneornata e humilis, “trapicheiroi” incluindo albicans trapicheiroi, “flavoguttata” incluindo apenas flavoguttata, e “obtriangulata” com apenas obtriangulata. Aspectos da morfologia, como sejam o tamanho das narinas e do espiráculo, assim como a quantidade de papilas na margem da boca, são confrontados com as características das coleções de água em que vivem as larvas, respectivamente. As larvas de todas as espécies envolvidas vivem no fundo de águas límpidas e frias nas matas ou em seu bordo. / The study of morphology and habits of tadpoles and of the reprodutive behaviour of six species of the “catharinae” group of the genus Ololygon in the State of Rio de Janeiro, viz: albicans, argyneornata, flavoguttata, humilis, obtriangulata and trapicheiroi demonstrated that they are all full species. Four subgroups are identified: “argyreornata”, including argyneornata and humilis, “trapicheiroi” including albicans trapicheiroi, “flavoguttata” including only flavoguttata, and “obtriangulata”. Some aspects of morphology, such as the size of the nostrils and of the spiracle opening as well as the number of labial papilae are confronted with the features of the water in which the tadpoles live, respectively. All the tadpoles studied here live in the bottom of clear and cool water, inside the forests or in their border.
32

Comportamento reprodutivo de Scinax albicans (Bokermann, 1967) (Anura, Hylidae), na Floresta Pluvial Montana no sudeste do Brasil

Nascimento, Denise Souza do 26 September 2003 (has links)
Submitted by Alberto Vieira (martins_vieira@ibest.com.br) on 2018-01-12T15:30:38Z No. of bitstreams: 1 840569.pdf: 4998582 bytes, checksum: 4e3a03db8f038d32b20e091659ad3c0c (MD5) / Made available in DSpace on 2018-01-12T15:30:39Z (GMT). No. of bitstreams: 1 840569.pdf: 4998582 bytes, checksum: 4e3a03db8f038d32b20e091659ad3c0c (MD5) Previous issue date: 2003-09-26 / Estudo da biologia reprodutiva de Scinax albicans, incluindo aspectos do hábito de vida, territorialidade, recrutamento, sobrevivência, parâmetros demográficos, organização social dos machos e os fatores ambientais que afetaram a atividade reprodutiva e de vocalização, foi realizado em um trecho de um afluente do rio Paquequer, no município de Teresópolis no estado do Rio de Janeiro de setembro de 2001 a setembro de 2002. As excursões foram realizadas em média duas vezes por mês, totalizando 26 excursões e 72 dias de permanência no campo. O sistema reprodutivo de Scinax albicans é do tipo prolongado. Com exceção de setembro de 2002 houve atividade reprodutiva, evidenciada pela formação de coro e/ou ocorrência de desovas, em todos os meses do ano, sendo fortemente influenciada por fatores ambientais como chuva, correnteza do riacho e altas temperaturas. O número médio de noites em que os machos permaneceram no coro foi de 5,4 noites, representando 7,5 % do total de noites amostradas. O número de fêmeas não foi significativamente correlacionado com o número de machos e a razão sexual operacional (RSO) foi negativamente correlacionada com o número de machos no coro. O número de ovos foi positivamente correlacionado com o tamanho das fêmeas. O tamanho populacional médio da agregação foi de 23,3 machos. A mortalidade foi baixa e o recrutamento foi muito variável ao longo do ano, sem nenhum padrão sazonal claro. A variação do tamanho populacional foi melhor explicada pela mortalidade do que pelo recrutamento. A mortalidade observada na agregação não parece estar relacionada diretamente à disponibilidade de recursos para a população como um todo, e pode refletir a alta vulnerabilidade dos machos a predação, quando se agregam para a reprodução. / Study of the reproductive biology of Scinax albicans, including aspects of life habits, territoriality, recruiting, survivorship, demographic parameters, male social organization, and environmental factors that affect the reproductive activity and vocalization, was performed in a section of a tributary to the Paquequer river, in the Municipality of Teresópolis, State of Rio de Janeiro, from September 2001 to September 2002. Fieldwork was done twice a month, totalizing 26 excursions and 72 days of field. Scinax albicans reproductive system is of the prolongued type. Reproductive activity occurred through the whole year, except for September 2002, as shown by the presence of the chorus or cluthes. The activity reproductive was strongly influenced by enviromentals factors such as rainfall, stream velocity and high temperatures. The avarege number of night in wich males remained in the chorus was 5.4 nights, representing 7.5% of the total number of nights sampled. The number of females was not significanthy correlated with the number of males and the operational sexual ratio (OSR) was negatively correlated with the number of males in the chorus. The number of eggs was positvely correlated with the size of the females. The average population size ofthe aggregation was 23.3 males. The mortality was low and recruiting was very variable through the year, with no clear sazonal pattern. The population size variation was better explained by mortality than recruiting. The observed mortality in the aggregation does not appear to be directly related to the resource availability of the population as whole and may reflect a high vulnerability of the males to predation, when they aggregate to reproduction.
33

Biologia reprodutiva de Scinax longilineus (B. Lutz, 1968) (Anura, Hylidae) no Parque das Mangabeiras, município de Belo Horizonte, Minas Gerais

Carvalho Júnior , Ronald Rezende 04 1900 (has links)
Submitted by Alberto Vieira (martins_vieira@ibest.com.br) on 2018-01-18T20:25:40Z No. of bitstreams: 1 542884.pdf: 7863821 bytes, checksum: 5d78f32d61ba973782961143e07054f1 (MD5) / Made available in DSpace on 2018-01-18T20:25:40Z (GMT). No. of bitstreams: 1 542884.pdf: 7863821 bytes, checksum: 5d78f32d61ba973782961143e07054f1 (MD5) Previous issue date: 2001-04 / O presente trabalho teve por objetivo o estudo da biologia reprodutiva de Scinax longilineus no Parque das Mangabeiras (19º 55' 57" S e 43º 56' 32" N), área de reserva florestal localizada no município de Belo Horizonte, Minas Gerais. Foram selecionados quatro pontos de amostragem na área do parque, sendo a coleta regular de dados realizada entre agosto de 1996 e agosto de 1997, com observações adicionais de junho a agosto de 1999 e fevereiro a outubro de 2000. Alguns fatores abióticos ( chuva, temperatura e luminosidade) interferiram na atividade reprodutiva da espécie, principalmente a precipitação. As fêmeas são maiores e mais pesadas que os machos. Os indivíduos de S. longilineus ocorrem em áreas de borda e interior de mata, mas preferencialmente nas margens de riachos no interior de mata. Um total de 322 indivíduos foram marcados, sendo 147 sub-adultos, 96 fêmeas, 67 machos e 12 imagos. Foram realizadas 69 recapturas e houve recrutamento constante durante todo o ano... / The objective of the present study was to describe the reproductive biology of the treefrog Scinax longilineus in Parque das Mangabeiras (19º 55' 57" S and 43º 56' 32" N), a reserve forest area in municipality of Belo Horizonte, State of Minas Gerais. Four sample areas were selected in the park. Field observations were realized in the period between August 1996-August 1997. Additional observations were made at the intervals of June-August 1999 -and February- October 2000. The reproductive activity of S. longilineus was influenced by some abiotic factors (rainfall, temperature, and luminosity). Females were larger and heavier than males. The individuals occurs preferentially near the streams in a forested or near forested areas. Three hundred and twenty two individuals were marked during the study. Sixty nines recaptures were realized and a constant recruitment was observed...
34

Comportamento reprodutivo de Phyllomedusa rohdei Mertens, 1926 (Amphibia, Anura, Hylidae), na região de Saquarema, Estado do Rio de Janeiro, Sudeste do Brasil / Reproductive behavior of Phyllomedusa rohdei Mertens, 1926 (Amphibia, Anura, Hylidae), in the region of Saquarema, State of Rio de Janeiro, Southeastern Brazil

Wogel , Henrique 14 March 2001 (has links)
Submitted by Alberto Vieira (martins_vieira@ibest.com.br) on 2018-01-19T13:43:31Z No. of bitstreams: 1 493550.pdf: 4439289 bytes, checksum: 46a00bf7efe5e74fce0a2afe49066d41 (MD5) / Made available in DSpace on 2018-01-19T13:43:31Z (GMT). No. of bitstreams: 1 493550.pdf: 4439289 bytes, checksum: 46a00bf7efe5e74fce0a2afe49066d41 (MD5) Previous issue date: 2001-03-14 / FUJB / FAPERJ / CAPES / A atividade reprodutiva de Phyllomedusa rohdei foi observada em uma poça temporária, localizada no município de Saquarema, Região dos Lagos, Estado do Rio de Janeiro, entre julho de 1999 a julho de 2000. O período reprodutivo se estendeu de dezembro a fevereiro (época chuvosa). As fêmeas foram maiores e mais pesadas que os machos. Machos permaneceram poucas noites em atividade de vocalização nos coros, considerando a duração da estação reprodutiva. Os números de machos e de fêmeas presentes na poça apresentaram-se positivamente correlacionados, contudo não houve correlação entre o número de machos e as razões sexuais operacionais. Machos maiores predominaram nos coros quando havia água na poça, enquanto machos menores predominaram quando a poça estava seca. A formação de casais não foi aleatória com relação às seguintes variáveis medidas para os machos: comprimento rostro-anal, massas inicial e final, número de noites presentes no coro e tempo de permanência na poça no mês de dezembro. Os machos apresentaram uma distribuição espacial agregada dentro da poça e reuniram-se preferencialmente em locais com sítios de oviposição disponíveis. Durante a corte, machos não só emitiam vocalizações como também patrulhavam a área a procura de fêmeas. Estas, por sua vez, não escolheram seus parceiros e a seleção sexual resultou da competição entre machos. / The breedind activity of Phyllomedusa rohdei was observed in a temporary pond, located at Saquarema, Rio de Janeiro State, Brazil from July, 1999 to July, 2000. The reproductive period extended from December to February (wet season). Females were larger and heavier than males. Males spent relatively few nights in activity call in the chorus, with respect to the length of the breeding season. The number of males and females present in the pond was positively correlated, but no correlation was revealed between the number of males and the operational sex ratio. Larger males predominated in the chorus when there was water in the pond, while smaller males predominated when the pond was dry. The matings were non-random in relation to the following variables measured on males: snout-vent length, initial and final mass, number of nights present in the chorus and the period of permanence in the pond in December. The spatial distribution of males in the pond was clustered, the meeting occurring preferentially in places with oviposition sites. During the courtship behavior, males call and patrol the area in search of females. Females did not choose mates and the sexual selection results from male-male competition.
35

Ciclo reprodutivo de machos de Dendropsophus minutus (Anura, Hylidae)

Santos, Lia Raquel de Souza [UNESP] 24 February 2006 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:22:56Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-02-24Bitstream added on 2014-06-13T20:29:23Z : No. of bitstreams: 1 santos_lrs_me_sjrp.pdf: 2514640 bytes, checksum: 8920d8cebd5e6c418cf59dcb095bf86b (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Poli(etilenoglicol) (PEG) é um polímero neutro hidrossolúvel, e brometo de dioctadecildimetilamônio (DODAB) e diododecildimetilamônio (DDAB) são surfactantes catiônicos dialquilados, C18 e C12, respectivamente, derivados da amônia quaternária, formadores de vesículas. As suas propriedades físicas, em solução aquosa, são bem conhecidas. No entanto, as propriedades de misturas desse polímero com esses surfactantes não o são. Investigamos a interação de PEG com DODAB e DDAB em solução aquosa, numa faixa de concentração total dos componentes até 1% em peso, e construímos diagramas de fases, com especial destaque para a fase vesicular. Utilizamos PEG com massa molecular entre 200 Da e 2 MDa e os diagramas de fases foram construídos a 25oC, isto é, acima da temperatura de transição gel-líquido cristal (Tm) de DDAB (Tm = 16oC) e abaixo da Tm de DODAB (Tm = 45oC). DODAB e DDAB têm a característica comum de formar vesículas unilamelares em baixas concentrações do surfactante e vesículas multilamelares em concentrações mais elevadas; em regiões intermediárias, vesículas uni e multilamelares coexistem em equilíbrio na solução. A fronteira entre essas regiões de vesículas não é muito bem definida e observamos, neste estudo, que o efeito de PEG na estrutura de agregados de DODAB e DDAB em água depende da massa molecular do polímero. Além disso, PEG favorece a formação de vesículas unilamelares em concentrações mais elevadas de DODAB e DDAB, quando predominam as vesículas multilamelares de DODAB puro (sem o polímero), possibilitando a formação de vesículas mistas de DODAB/PEG e DDAB/PEG em água e concentrações relativamente grandes desses surfactantes. Dentre os métodos experimentais empregados nesse estudo, destacamos, turbidimetria, fluorescência de estado estacionário, calorimetria diferencial... / Poly (ethyleneglycol) (PEG) is a water soluble neutral polymer, and dioctadecyldimethylammonium (DODAB) and diododecyldimethylammonium (DDAB) bromide are double chain cationic surfactants derived from the quaternary ammonium that have been widely investigated due to their high application potential in different areas of the science and technology. The physical properties of PEG, DODAB and DDAB in aqueous solution are well-known. However, the properties of mixtures of the polymer with those surfactants are not. We investigated the interaction of PEG with DODAB and DDAB in aqueous solution, within a range of total concentration of the components of 0-1 wt%, and the phase diagrams built up, with special interest for the vesicular phases. We used PEG with molecular mass between 200 Da and 2 MDa and the phase diagrams were built up at 25°C, that is, above the melting temperature (Tm) of DDAB (Tm = 16°C) and below Tm of DODAB (Tm = 45°C). DODAB and DDAB have the common characteristic of forming unilamellar vesicles at low surfactant concentrations and umultilamellar vesicles at higher concentrations; at intermediate concentrations, uni- and multilamellar vesicles coexist in solution. The borders of these different vesicle phases are not well defined. We observed in this Thesis that the effect of PEG on the structures of DODAB and DDAB aggregates in water depends on the molecular mass of the polymer. Besides, PEG stabilizes the unilamellar vesicles at high concentrations of DODAB, where the multilamellar vesicles are the dominant structures present in solution, thus allowing the formation of mixed DODAB/PEG and DDAB/PEG vesicles in water at relatively high concentrations of these surfactants. The experimental methods used in this investigation include turbidimetry, steady-state fluorescence, differential scanning calorimetry (DSC), isothermal titration... (Complete abstract click electronic access below)
36

Estudo Químico e Biológico da Secreção Cutânea de Hypsiboas cinerascens e H. geographicus

Almeida, Richardson Alves de 20 December 2015 (has links)
Submitted by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2017-02-14T15:49:46Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Tese -Richardson Alves de Almeida.pdf: 6059708 bytes, checksum: aa22a530cee33dcce7f300d9cc1d7452 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2017-02-14T15:50:01Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Tese -Richardson Alves de Almeida.pdf: 6059708 bytes, checksum: aa22a530cee33dcce7f300d9cc1d7452 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2017-02-14T15:50:17Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Tese -Richardson Alves de Almeida.pdf: 6059708 bytes, checksum: aa22a530cee33dcce7f300d9cc1d7452 (MD5) / Made available in DSpace on 2017-02-14T15:50:17Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Tese -Richardson Alves de Almeida.pdf: 6059708 bytes, checksum: aa22a530cee33dcce7f300d9cc1d7452 (MD5) Previous issue date: 2015-12-20 / FAPEAM - Fundação de Amparo à Pesquisa do Estado do Amazonas / Peptides identified in frogs exhibit various biological activities the main one being the antimicrobial activity (bacteria and/or pathogenic fungi). Antimicrobial peptides known to AMPs represent a promising source of active compounds to overcome the problem of the increase in resistant strains to antibiotics used. AMPs Identification requires the use of sensitive analytical techniques since the amount of material is limited. In this regard, mass spectrometry (MS) coupled chromatographic techniques play an important role in identification peptides. MS modern techniques such as image by mass spectrometry and molecular biology tools such as deoxyribonucleic acid sequencing are also used in combination to provide quick identification / sequencing novel peptides. In this work the study of skin secretion of two species of frogs, Hypsiboas cinerascens and H. geographicus. At the time of H. geographicus species were identified 4 new peptides, which showed significant identity with biologically active peptides of amphibians, and 3 of them presented with homologous fragments of the protein bombesin. For H. cinerascens species was identified 36 new peptides, which were organized in distinct groups according to the similarity of their sequences, some of which showed significant identity with deposited in the database. These 36 peptides only 3 were had their sequences confirmed by MS and c-DNA and one of them was synthesized having activity against fungi and bacteria. / Peptídeos identificados em anuros exibem diversas atividades biológicas sendo a principal delas a atividade antimicrobiana (bactérias e/ou fungos patogênicos). Peptídeos antimicrobianos conhecidos com PAMs representam uma promissora fonte de compostos ativos para superar o problema do aumento de cepas resistentes aos antibióticos utilizados. A identificação de PAMs requer a utilização de técnicas analíticas sensíveis uma vez que a quantidade de material é limitada. Neste sentido, espectrometria de massa (MS) acoplada a técnicas cromatográficas desempenham um papel importante para identificação de peptídeos. Técnicas modernas de MS tais como imagem por espectrometria de massa e ferramentas de biologia molecular como o sequenciamento do ácido desoxirribonucleico também são utilizados em combinação para proporcionar a rápida identificação/sequenciamento de novos peptídeos. Neste trabalho foi realizado o estudo da secreção cutânea de duas espécies de anuros, Hypsiboas cinerascens e H. geographicus. Até o momento da espécie H. geographicus foi possível identificar 4 novos peptídeos, que apresentaram identidade significativa com peptídeos biologicamente ativos de anfíbios, sendo que 3 deles apresentaram-se com homólogos a fragmentos da proteína bombesina. Em relação a espécie H. cinerascens foi possível identificar 36 novos peptídeos, que foram organizados em grupos distintos de acordo com a similaridade de suas sequências, sendo que alguns apresentaram identidade significativa com os depositados em banco de dados. Desses 36 peptídeos 3 tiveram suas sequências confirmadas por MS e c-DNA, sendo que um deles foi sintetizado tendo atividade contra fungos e bactérias.
37

Variabilidade genetica e relações interpopulacionais de Dendropsophus minutus do Brasil / Morphological variation and mitochondrial DNA diversity in natural populations of Dendropsophus minutus (Anura: Hylidae)

Egito, Gabriel Toselli Barbosa Tabosa do 05 November 2009 (has links)
Orientador: Shirlei Maira Recco Pimentel / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-14T11:03:41Z (GMT). No. of bitstreams: 1 Egito_GabrielToselliBarbosaTabosado_M.pdf: 537508 bytes, checksum: e9fd34e6de85068aa05990a955acff88 (MD5) Previous issue date: 2009 / Resumo: Dendropsophus minutus está amplamente distribuído ao Leste dos Andes, na América do Sul e possui uma grande diversidade acústica e morfológica, o que sugere que possa haver mais de uma espécie sob esse nome. Sua coloração dorsal pode ser classificada em dois padrões principais, hourglass e bivittata. No presente estudo, 14 parâmetros morfométricos e seqüências de DNA com 357 pares de bases do gene citocromo b mitocondrial foram analisados objetivando um melhor entendimento acerca da variação de D. minutus no Brasil. Tanto os resultados moleculares quanto os fenotípicos revelaram a presença de uma alta estruturação da diversidade dessa espécie, mostrando que a divergência entre populações é, geralmente, proporcional à distância geográfica, exceto no estado de São Paulo, sudeste do Brasil. Nessa região, a Serra do Mar está aparentemente agindo como uma barreira geográfica para o fluxo gênico, isolando duas linhagens. A primeira, formada pelas populações da Mata Atlântica, tem padrão hourglass de coloração dorsal. A segunda, do interior de São Paulo, assim como a população do Rio Grande do Sul, possui padrão bivittata de coloração dorsal. Esses resultados corroboram a hipótese de que o táxon D. minutus contém duas linhagens crípticas. Apesar disso, uma amostragem maior se faz necessária, bem como um melhor estudo de caracteres para defini-las como espécies ou não. / Abstract: In despite of its complex reproductive behavior, Dendropsophus minutus has a large distribution at East of Andes, South America and show high acoustic and morphologic diversity, suggesting that possibly more than one species may exist under this name. Its dorsum coloration has basically two main patterns, hourglass or bivittata. Here, 14 morphometric parameters and partial mitochondrial cytochrome b gene sequences (357 base pairs) were analyzed aiming to understand more about Brazilian D. minutus variation. Both molecular and morphologic results agree with a high structuration of this species diversity, showing population divergence generally proportional to their geographic distance, except in São Paulo State, southeastern Brazil. At this region, Serra do Mar high mountains are apparently acting as a barrier for dispersion, isolating two lineages. The first of them, formed by populations from Atlantic Rainforest domain, has an hourglass dorsum pattern, whereas the second, comprising inner São Paulo State populations gathered with D. minutus from Rio Grande do Sul (South Brazil), shows bivittata dorsum coloration pattern. These results corroborate the hypothesis that D. minutus could comprise more than one species, revealing two cryptic lineages. However, these lineages should not be defined as different species before sampling enlargement to the present study. / Mestrado / Biologia Celular / Mestre em Biologia Celular e Estrutural
38

Estudos cromossômicos em anuros das famílias Hylidae rafinesque, 1815 e Leptodactylidae werner, 1896 (Amphibia: Anura)

SUAREZ, Pablo January 2010 (has links)
Submitted by Edisangela Bastos (edisangela@ufpa.br) on 2013-11-14T18:06:50Z No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Tese_EstudosCromossomicosAnuros.pdf: 2376687 bytes, checksum: 47c08d5fecec451c4a49b4ad47ae4e09 (MD5) / Approved for entry into archive by Ana Rosa Silva(arosa@ufpa.br) on 2013-11-22T14:29:43Z (GMT) No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Tese_EstudosCromossomicosAnuros.pdf: 2376687 bytes, checksum: 47c08d5fecec451c4a49b4ad47ae4e09 (MD5) / Made available in DSpace on 2013-11-22T14:29:43Z (GMT). No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Tese_EstudosCromossomicosAnuros.pdf: 2376687 bytes, checksum: 47c08d5fecec451c4a49b4ad47ae4e09 (MD5) Previous issue date: 2010 / Embora exista uma grande diversidade de complementos cromossômicos em Leptodactylidae (2n = 18 a 2n = 26) e Hylidae (2n = 20 a 2n = 32), a elevada fragmentação de dados limita o acesso a informações sobre as origens e os mecanismos responsáveis por esta diversidade. Isto provavelmente tem influenciado que os dados citogenéticos tenham sido principalmente utilizados na caracterização do status de espécies mais do que incluídos amplamente em análises filogenéticas. Este trabalho aborda, por meio de dados citogenéticos, aspectos evolutivos de três grandes grupos de anuros de ampla distribuição na região Neotropical. O gênero Leptodactylus é agrupado com Hydrolaetare, Paratelmatobius e Scythrophrys na família Leptodactylidae. Os antecedentes cromossômicos neste gênero indicam variações nos números diplóides de 2n = 18 a 2n = 26, assim como variações nos números fundamentais (número de braços autossômicos, NF) e nas posições das Regiões Organizadoras do Nucléolo (NOR). Os resultados das análises de 26 espécies de Leptodactylus empregando diversas técnicas representa, provavelmente, a análise citogenética mais inclusiva realizada no gênero Leptodactylus até o momento, e os resultados constituem um marco para a proposição de hipóteses consistentes de evolução cromossômica no gênero. A tribo Lophyiohylini agrupa atualmente 81 espécies distribuídas em 10 gêneros. A informação citogenética é escassa e restrita apenas a 12 espécies. São aqui apresentados comparativamente dados citogenéticos em espécies dos gêneros Argenteohyla, Itapotihyla, Phyllodytes, Trachycephalus e Osteocephalus. Os resultados indicam que, com exceção de O. buckleyi (2n = 26; NF = 50) e P. edelmoi (2n = 22; NF = 44), todas as demais espécies analisadas coincidem com os dados citogenéticos disponíveis, que indicam um 2n = 24 (NF = 48) na maioria das espécies cariotipadas, com NOR e constrições secundarias (CS) localizadas no par 11. Entretanto, em Phyllodytes edelmoi e Argentohyla siemersi pederseni, essas regiões localizam-se nos pares 2 e 5, respectivamente. Blocos heterocromáticos foram associados às CS adicionais (sítios frágeis) em Osteocephalus, mas não em Trachycephalus. Dados citogenéticos nos gêneros Nyctimantis e Tepuihyla, assim como técnicas com maior poder de resolução e estudos mais inclusivos, são necessários para compreender melhor a evolução cromossômica da tribo. A tribo Dendropsophini atualmente agrupa os gêneros Scinax, Pseudis, Scarthyla, Sphaenorhynchus, Xenohyla e Dendropsophus. Os dados citogenéticos registrados em todos os gêneros revelaram uma elevada diversidade cariotípica com grandes variações nos números diplóides (2n = 22 em Scarthyla; 2n = 24 em Scinax e Xenohyla; 2n = 24, 24 +1-2B e 26 em Sphaenorhynchus; 2n = 24 e 28 em Pseudis; e, 2n = 30 em Dendropsophus). O 2n = 24 observado em X. truncata indica que o 2n = 30constitui uma sinapomorfia do gênero Dendropsophus. A localização das NOR no par 7 é uma característica compartilhada por espécies dos gêneros Scarthyla, Xenohyla, Pseudis e Sphaenorhynchus, com algumas exceções nos dois últimos (P. caraya e S. carneus). Entretanto, o gênero Dendropsophus exibe uma interessante diversidade em relação a número e localização das NOR. Por outro lado, a distribuição de heterocromatina apresentou padrões variáveis, particularmente gênero Pseudis. Embora exista uma excepcional variação cromossômica neste grupo, a informação fragmentária em alguns gêneros dificulta a formulação de hipóteses consistentes sobre o papel dos cromossomos na evolução do grupo. / Although there exists a large variety of chromosomal complements in Leptodactylidae (2n = 18 to 2n = 26) and Hylidae (2n = 20 to 2n = 32), the high fragmentation of data limits the access to the information about the origins and underlying mechanisms of its diversity. This, probably, had influence on the use of cytogenetic data on the characterization of species status more than been widely included in phylogenetic analyses. This work approaches, through cytogenetic data, some evolutionary aspects of three maior groups of anurans widely distributed in the Neotropical region. The genus Leptodactylus is clustered with Hydrolaetare, Paratelmatobius and Scythrophrys in the family Leptodactylidae. The chromosomal background in the genus indicates variation of the diploid numbers from 2n = 18 to 2n = 26, as well as, variation on the fundamental numbers (number of autosomic arms, FN) and on the position of Nucleolus Organizer Regions (NOR). Results of the analysis of 26 species of Leptodactylus, using several techniques, probably represents the most inclusive cytogenetic analyses on the genus Leptodactylus until now and its results provides appropriate bases to establish consistent relationships of chromosomal evolution on the genus Leptodactylus. Actually the Lophyiohylini tribe cluster 81 species distributed in 10 genera. The cytogenetic information is scarce and restrict to only 12 species. In the present study, are presented, comparatively, cytogenetic data of species from Argenteohyla, Itapotihyla, Phyllodytes, Trachycephalus and Osteocephalus genera. With exception of O. buckleyi (2n = 26; NF = 50) and P. edelmoi (2n = 22; NF = 44), the results indicate that all the others analyzed species coincide with cytogenetic data available, that indicates 2n = 24 (NF = 48) on the majority of karyotyped species, with NOR and secondary constrictions (SC) located on the 11 pair. However, in Phyllodytes edelmoi and Argentohyla siemersi pederseni, these regions are located on pairs 2 and 5, respectively. Heterochromatic blocks were associated to additional SC (fragile sites) in Osteocephalus, but not in Trachycephalus. Cytogenetic data on the Nyctimantis and Tepuihyla genera, techniques with techniques with higher resolution and more inclusive studies are necessary to better comprehend the chromosomal evolution of the tribe. The Dendropsophini tribe actually clusters the Scinax, Pseudis, Scarthyla, Sphaenorhynchus, Xenohyla and Dendropsophus genera. The registered cytogenetic data of all the genera revealed high karyotype diversity with great variation on the diploid numbers (2n = 22 in Scarthyla; 2n = 24 in Scinax and Xenohyla; 2n = 24, 24 +1- 2B e 26 in Sphaenorhynchus; 2n = 24 and 28 in Pseudis; and, 2n = 30 in Dendropsophus). The 2n=24 observed in X. truncata indicates that 2n=30 constitute a synapomorphy of the Dendropsophus genus. The NOR localization on the pair 7 is a characteristic shared by species of Scarthyla, Xenohyla, Pseudis and Sphenorhynchus, with some exceptions in the last two genera (P. caraya and S. carneus). However, the Dendropsophus genus displays an interesting diversity related to the number and its localization. On the other hand, the heterochromatin distribution presented standard variables, particularly on genus Pseudis. Although there is an exceptional chromosome variation in this group, fragmentary information in some genera made difficult to formulate consistent hypotheses about the role of chromosomes in the evolution of the group.
39

Diversity and phylogeography of eastern Guiana Shield frogs

Fouquet, Antoine January 2008 (has links)
The Guiana Shield is a sub-region of Amazonia, one of the richest areas on earth in terms of species number. It is also one of the most pristine areas and is still largely unexplored. Species number, distribution, boundaries and their evolutionary histories remain at least unclear but most of the time largely unknown. This is the case for most Anurans, a group which is recognized as threatened globally and is disappearing even from pristine tropical forests. Given the pace of forest destruction and the growing concerns about climate change it is urgently necessary to obtain a better estimate of regional biodiversity in Amazonian frogs as well as a better understanding of the origin and distribution of Anuran diversity. Furthermore, given their sensitivity to climatic conditions, amphibians are a good model to investigate the influence of paleoclimatic events on Neotropical diversification which was supposedly the driving force on biotic evolution during Pleistocene in the Guiana Shield. I first test species boundaries in two species Scinax ruber and Rhinella margaritifera. These species are widely distributed, abundant and largely recognized as species complexes. I used an original species delineation method based on the combined use of mitochondrial and nuclear DNA in phylogenetic and phylogeographic analyses. Phylogenetic analyses demonstrated the polyphyly of Scinax ruber and Rhinella margaritifera. These species consist of multiple lineages that may all merit species status. Conflicting signals of mitochondrial and nuclear markers indicated the possibility of ongoing hybridization processes. Phylogeographic analyses added further information in support of the specific status of these lineages. Our results highlight the utility of combining phylogenetic and phylogeographic methods, as well as the use of both mitochondrial and nuclear markers within one study. This approach helped to better understand the evolutionary history of taxonomically complex groups of species. The assessment of the geographic distribution of genetic diversity in tropical amphibian communities can lead to conclusions that differ strongly from prior analyses based on the occurrence of currently recognized species alone. Such studies, therefore, hold the potential to contribute to a more objective assessment of amphibian conservation priorities in tropical areas. Subsequently, I tested if these first results on cryptic species are generalisable, questioning what would potentially be a minimum estimate of the number of cryptic frog species in Amazonia and the Guiana Shield, using mtDNA with multiple complementary approaches. I also combined isolation by distance, phylogenetic analyses, and comparison of molecular distances to evaluate threshold values for the identification of candidate species among these frogs. In most cases, geographically distant populations belong to genetically highly distinct lineages that could be considered as candidate new species. This was not universal among the taxa studied and thus widespread species of Neotropical frogs really do exist, contra to previous assumptions. Moreover, the many instances of paraphyly and the wide overlap between distributions of inter- and intra-specific distances reinforce the hypothesis that many cryptic species remain to be described. In our data set, pairwise genetic distances below 0.02 are strongly correlated with geographical distances. This correlation remains statistically significant until genetic distance is 0.05, with no such relation thereafter. This suggests that for higher genetic distances allopatric and sympatric cryptic species prevail. Based on our analyses, we propose a more inclusive pairwise genetic distance of 0.03 between taxa to target lineages that could correspond to candidate species. Using this approach, we identify 129 candidate species, two-fold greater than the 60 species included in the current study. This leads to estimates of around 170 to 460 frog taxa unrecognized in Amazonia-Guianas. As a consequence the global amphibian decline detected especially in the Neotropics may be worse than realised. The Rhinella margaritifera complex is characterisized by the presence of many cryptic species throughout its wide distribution, ranging from Panama to Bolivia and almost entire Amazonia. French Guiana has long been thought to harbor two species of this group, though molecular data analysed in previous chapters indicated as many as five lineages. I tested whether morphological measurements are correlated or not with genetic data using discriminant analysis and if diagnostic characteristics among the previously determined lineages can be used to describe these new species. This is a novel integrative method which can lead to a facilitation of the description of cryptic species that have been detected by phylogenetic and/or phylogeographic studies. These analyses, combined with published data of other Rhinella species, indicated that two of these lineages represent previously unnamed species. Two of the remaining are allocable to R. margaritifera while the status of the fifth is still unclear because so far it is morphologically indistinguishable from R. castaneotica. Determining if codistributed species responded to climate change in an independent or concerted manner is a basic objective of comparative phylogeography. Species boundaries, histories, ecologies and their geographical ranges are still to be explored in the Guiana Shield. According to the refugia hypothesis this region was supposed to host a forest refugium during climatic oscillations of the Pleistocene but the causes and timing for this have been criticized. We investigated patterns of genetic structure within 18 frog species in the eastern Guiana Shield to explore species boundaries and their evolutionary history. We used mtDNA and nuclear DNA and complementary methods to compare the genetic diversity spatially and temporally. With one exception all the species studied diversified repeatedly within the eastern Guiana Shield during the last 4 million years. Instead of one Pleistocene forest refugium the Guiana Shield has probably hosted multiple refugia during late Pliocene and Pleistocene. Most of these Pleistocene refugia were probably situated on the coast of French Guiana, Amapà, Suriname and Guyana. This diversification likely resulted from forest fragmentation. Many species deserve taxonomic revisions and their ranges to be reconsidered. The local endemism of the Anuran fauna of the Guiana Shield is likely to be much higher and some areas consequently deserve more conservation efforts. Specifically I questioned whether major intraspecific diversification started before the Pleistocene and occurred within the Guiana Shield or ex situ. According to ecological characteristics of the species involved I will test different diversification hypotheses. The consequences on the diversity and the endemism of the Guiana Shield will be explored. My results demonstrate that we have been grossly underestimating local biological diversity in the Guiana Shield but also in Amazonia in general. The order of magnitude for potential species richness means that the eastern Guiana Shield hosts one of the richest frog fauna on earth. In most of the species studied high levels of mtDNA differentiation between populations call for a reassessment of the taxonomic status of what is being recognised as single species. Most species display deep divergence between eastern Guiana Shield populations and Amazonian ones. This emphasizes that the local endemism in the Guiana Shield of these zones is higher than previously recognized and must be prioritised elements taken into account in conservation planning. Nevertheless, a few other species appear widely distributed showing that widespread species do exist. This underlines the fact that some species have efficient dispersal abilities and that the frog fauna of the eastern Guiana Shield is a mixture of old Guianan endemic lineages that diversified in situ mostly during late Pliocene and Pleistocene and more recently exchanged lineages with the rest of Amazonia. Recognizing this strong historical component is necessary and timely for local conservation as these zones are likely to be irremediably modified in the near future.
40

Diversity and phylogeography of eastern Guiana Shield frogs

Fouquet, Antoine January 2008 (has links)
The Guiana Shield is a sub-region of Amazonia, one of the richest areas on earth in terms of species number. It is also one of the most pristine areas and is still largely unexplored. Species number, distribution, boundaries and their evolutionary histories remain at least unclear but most of the time largely unknown. This is the case for most Anurans, a group which is recognized as threatened globally and is disappearing even from pristine tropical forests. Given the pace of forest destruction and the growing concerns about climate change it is urgently necessary to obtain a better estimate of regional biodiversity in Amazonian frogs as well as a better understanding of the origin and distribution of Anuran diversity. Furthermore, given their sensitivity to climatic conditions, amphibians are a good model to investigate the influence of paleoclimatic events on Neotropical diversification which was supposedly the driving force on biotic evolution during Pleistocene in the Guiana Shield. I first test species boundaries in two species Scinax ruber and Rhinella margaritifera. These species are widely distributed, abundant and largely recognized as species complexes. I used an original species delineation method based on the combined use of mitochondrial and nuclear DNA in phylogenetic and phylogeographic analyses. Phylogenetic analyses demonstrated the polyphyly of Scinax ruber and Rhinella margaritifera. These species consist of multiple lineages that may all merit species status. Conflicting signals of mitochondrial and nuclear markers indicated the possibility of ongoing hybridization processes. Phylogeographic analyses added further information in support of the specific status of these lineages. Our results highlight the utility of combining phylogenetic and phylogeographic methods, as well as the use of both mitochondrial and nuclear markers within one study. This approach helped to better understand the evolutionary history of taxonomically complex groups of species. The assessment of the geographic distribution of genetic diversity in tropical amphibian communities can lead to conclusions that differ strongly from prior analyses based on the occurrence of currently recognized species alone. Such studies, therefore, hold the potential to contribute to a more objective assessment of amphibian conservation priorities in tropical areas. Subsequently, I tested if these first results on cryptic species are generalisable, questioning what would potentially be a minimum estimate of the number of cryptic frog species in Amazonia and the Guiana Shield, using mtDNA with multiple complementary approaches. I also combined isolation by distance, phylogenetic analyses, and comparison of molecular distances to evaluate threshold values for the identification of candidate species among these frogs. In most cases, geographically distant populations belong to genetically highly distinct lineages that could be considered as candidate new species. This was not universal among the taxa studied and thus widespread species of Neotropical frogs really do exist, contra to previous assumptions. Moreover, the many instances of paraphyly and the wide overlap between distributions of inter- and intra-specific distances reinforce the hypothesis that many cryptic species remain to be described. In our data set, pairwise genetic distances below 0.02 are strongly correlated with geographical distances. This correlation remains statistically significant until genetic distance is 0.05, with no such relation thereafter. This suggests that for higher genetic distances allopatric and sympatric cryptic species prevail. Based on our analyses, we propose a more inclusive pairwise genetic distance of 0.03 between taxa to target lineages that could correspond to candidate species. Using this approach, we identify 129 candidate species, two-fold greater than the 60 species included in the current study. This leads to estimates of around 170 to 460 frog taxa unrecognized in Amazonia-Guianas. As a consequence the global amphibian decline detected especially in the Neotropics may be worse than realised. The Rhinella margaritifera complex is characterisized by the presence of many cryptic species throughout its wide distribution, ranging from Panama to Bolivia and almost entire Amazonia. French Guiana has long been thought to harbor two species of this group, though molecular data analysed in previous chapters indicated as many as five lineages. I tested whether morphological measurements are correlated or not with genetic data using discriminant analysis and if diagnostic characteristics among the previously determined lineages can be used to describe these new species. This is a novel integrative method which can lead to a facilitation of the description of cryptic species that have been detected by phylogenetic and/or phylogeographic studies. These analyses, combined with published data of other Rhinella species, indicated that two of these lineages represent previously unnamed species. Two of the remaining are allocable to R. margaritifera while the status of the fifth is still unclear because so far it is morphologically indistinguishable from R. castaneotica. Determining if codistributed species responded to climate change in an independent or concerted manner is a basic objective of comparative phylogeography. Species boundaries, histories, ecologies and their geographical ranges are still to be explored in the Guiana Shield. According to the refugia hypothesis this region was supposed to host a forest refugium during climatic oscillations of the Pleistocene but the causes and timing for this have been criticized. We investigated patterns of genetic structure within 18 frog species in the eastern Guiana Shield to explore species boundaries and their evolutionary history. We used mtDNA and nuclear DNA and complementary methods to compare the genetic diversity spatially and temporally. With one exception all the species studied diversified repeatedly within the eastern Guiana Shield during the last 4 million years. Instead of one Pleistocene forest refugium the Guiana Shield has probably hosted multiple refugia during late Pliocene and Pleistocene. Most of these Pleistocene refugia were probably situated on the coast of French Guiana, Amapà, Suriname and Guyana. This diversification likely resulted from forest fragmentation. Many species deserve taxonomic revisions and their ranges to be reconsidered. The local endemism of the Anuran fauna of the Guiana Shield is likely to be much higher and some areas consequently deserve more conservation efforts. Specifically I questioned whether major intraspecific diversification started before the Pleistocene and occurred within the Guiana Shield or ex situ. According to ecological characteristics of the species involved I will test different diversification hypotheses. The consequences on the diversity and the endemism of the Guiana Shield will be explored. My results demonstrate that we have been grossly underestimating local biological diversity in the Guiana Shield but also in Amazonia in general. The order of magnitude for potential species richness means that the eastern Guiana Shield hosts one of the richest frog fauna on earth. In most of the species studied high levels of mtDNA differentiation between populations call for a reassessment of the taxonomic status of what is being recognised as single species. Most species display deep divergence between eastern Guiana Shield populations and Amazonian ones. This emphasizes that the local endemism in the Guiana Shield of these zones is higher than previously recognized and must be prioritised elements taken into account in conservation planning. Nevertheless, a few other species appear widely distributed showing that widespread species do exist. This underlines the fact that some species have efficient dispersal abilities and that the frog fauna of the eastern Guiana Shield is a mixture of old Guianan endemic lineages that diversified in situ mostly during late Pliocene and Pleistocene and more recently exchanged lineages with the rest of Amazonia. Recognizing this strong historical component is necessary and timely for local conservation as these zones are likely to be irremediably modified in the near future.

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