Made available in DSpace on 2014-06-11T19:30:55Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-06-02Bitstream added on 2014-06-13T19:40:26Z : No. of bitstreams: 1 santos_lrs_dr_sjrp.pdf: 23003034 bytes, checksum: 250b19c5b31c24c66f01695e3507c19f (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Os vertebrados ectotérmicos apresentam um desenvolvido sistema de células com pigmentos melânicos em seu citoplasma, localizadas em diversos órgãos e estruturas formando um sistema pigmentar extracutâneo. Esses tipos celulares são grandes e irregulares, com o citoplasma abundante e intensamente pigmentado e variam de um aspecto estrelado ao puntiforme. São encontrados também associados ao aparelho reprodutor de algumas espécies de anuros, conferindo uma tonalidade escura. Esta característica anatômica de coloração testicular faz parte da arquitetura somática do órgão e na literatura não há qualquer dado que aponte para uma inter-relação entre estes componentes. Células contendo pigmentos melânicos são encontradas também no fígado, onde apresentam atividade fagocítica, sendo denominadas melanomacrófagos ou células de Kupffer, e não eram incluídas na classificação de célula pigmentar, pois se pensava que os macrófagos presentes no fígado e baço apenas fagocitavam os melanossomos, e não os sintetizavam. Entretanto, análises sobre a função melanogênica das células pigmentares nesses órgãos em algumas espécies demonstraram que há melanogênese. Para os anfíbios anuros, os estudos relativos aos melanócitos viscerais e aos melanomacrófagos são recentes e se referem à poucas espécies. Alguns estudos demonstraram que alterações do sistema melanogênico pode estar relacionado ao aumento da pigmentação no fígado e a hemocaterese hepática. Há também, trabalhos que relatam modificações metabólicas e estruturais das células hepáticas durante o inverno, não sendo descritas funções para as células pigmentares presentes nos demais órgãos. Assim, neste trabalho objetivamos analisar a resposta das células... / Ectothermic vertebrates present a well-developed system composed of cells with melanin in its cytoplasm. These cells are distributed in several organs and tissues constituting an extracutaneous pigmentary system. These cells types are big and irregular, with shapes that vary from a star-shaped to a punctiform format. In addition, its cytoplasm is abundantly pigmented. In anuran amphibians this pigmented cells are also found associated to the reproductive system, what gives to the gonads a dark coloration. This coloration makes part of the somatic architecture of the organ, but there is no data in the literature that suggest a function for this pigmentation. Melanin-contemning cells are also found on the liver, where show phagocytic activity, being called melanomacrophages or Kupffer cells, and were not included in the classification of pigmentary cell, since it was thought that the macrophages in the liver and spleen only phagocyted the melanosomes, not synthesizing them. However, some analysis about the melanogenic function of these pigmentary cells in these organs show that melanogenesis indeed takes place. To anuran amphibians, the studies concerning to the viceral melanocytes and to the melanomacrophages are recent and refer to just a few species. Some studies show that changes in the melanogenic system can be related to the increase in the pigmentation on the liver and to the hepatic hemocateresis. Furthermore, some studies report modifications both metabolic and structural in hepatic cells during the winter, but not designating any function for the pigmented cells present in other organs. Our aim in this study was to analyze the response of the cells of the extracutaneous pigmentar system of the anuran Eupemphix nattereri to a varying thermal condition... (Complete abstract click electronic access below)

Made available in DSpace on 2014-06-11T19:22:56Z (GMT). No. of bitstreams: 0 Previous issue date: 2004-12-17Bitstream added on 2014-06-13T20:10:11Z : No. of bitstreams: 1 zieri_r_me_sjrp.pdf: 2224009 bytes, checksum: f31e2003cdc028d7117086382535f9bd (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O presente estudo analisa as características estruturais e ultra-estruturais dos testículos, bem como as características do sistema pigmentar extracutâneo e sua relação com as outras estruturas, nos anuros Physalaemus nattereri (Steindachner, 1963) e P. fuscomaculatus (Steindachner, 1964). Dez machos adultos de cada espécie foram coletados em Nova Itapirema, distrito de Nova Aliança - SP e processados para análises em microscopia de luz e microscopia eletrônica de transmissão. Os testículos apresentaram numerosas células contendo pigmentos, aleatoriamente distribuídas na túnica albugínea e interstício, dando ao órgão uma coloração marrom escura. Essas células são estruturalmente semelhantes a melanócitos, e se caracterizam pela enorme quantidade de pigmentos melânicos no interior de corpúsculos elétron-densos contendo melanina, os melanossomos. Durante a espermiogênese ocorre condensação da cromatina e alongamento nuclear, além da perda de material citoplasmático. As células de Sertoli apresentam em seu citoplasma grande quantidade de microtúbulos e grânulos de glicogênio. O espermatozóide é fusiforme, contém uma capa acrossômica e perfuratorium na região anterior do núcleo e a peça intermediária contém uma bainha citoplasmática com mitocôndrias. O flagelo apresenta o axonema, fibra justaxonemal e membrana ondulante, e bastão axial ausente. Esta organização é semelhante à encontrada em outros anfíbios como P. biligonigerus, P. gracilis e P. fuscomaculatus. / This paper was analyses the structural and ultra-structural characteristics of the testis, and the extracutaneous pigmentary system characteristics and the relationship with other structures, in the anurans Physalaemus nattereri (Steindachner, 1963) and P. fuscomaculatus (Steindachner, 1964). Ten males adults of each species were collected in Nova Itapirema, district of Nova Aliança - SP and processed for analyses in light and transmission electron microscopy. The testis presented numerous pigment-containing cells, randomly distributed in the albuginea tunic and interstitium, giving the organ a dark brown coloration. The intense pigmentation observed in the testis is due to great amount of cellular types containing granules of brown coloration and long citoplasmic processes, characterized by the synthesis and accumulation of great amount of melanin pigment inside of melanosomes. Spermiogenesis in the anuran P. nattereri involves chromatin condensation and nuclear elongation, with visible cytoplasmic eliminations. In this stage it can also be seen inside Sertoli cell citoplasm, surrounding each spermatid, a great amount of microtubules and glycogen. The anterior region of the nucleous presented an acrossome and perfuratorium. A mitochondrial sleeve is found around the proximal portion of the tail. The tail presents an axonema with a 9+2 axoneme pattern, a justaxonemal fiber, undulating membrane and absence of axial rod. This organization is similar to that found in other amphibians such as P. biligonigerus, P. gracilis and P. fuscomaculatus.

Orientador: Denise de Cerqueira Rossa-Feres / Resumo: As interações entre espécies influenciam a estrutura de comunidades, a dinâmica das populações, a morfologia, a fisiologia e o comportamento das espécies. A mortalidade é um efeito direto promovido pelo predador, mas também há outros efeitos indiretos decorrentes da presença do predador, como alterações no comportamento da presa. Nos ambientes aquáticos a presa pode detectar o risco de predação por meio de sinais visuais, mecânicos e químicos. Ao detectar o predador, a presa pode usar estratégias, como formação de cardume, mudança no padrão de uso de habitat e diminuição da atividade natatória para reduzir a predação. Apesar de diminuir a taxa de predação, as estratégias antipredatórias tem custos para as presas e configuram um trade-off. Os comportamentos que aumentam a chance de escapar do predador prejudicam a atividade e o forrageamento dos girinos, diminuindo seu crescimento e suas chances de sobrevivência. Os aspectos morfológicos e fisiológicos são importantes na ocupação da coluna d’água por girinos, mas, será que a predação também é uma pressão que determina o modo como os girinos ocupam a coluna d’água? Entender como a predação influencia o comportamento dos girinos pode elucidar aspectos da dinâmica populacional e estruturação de comunidades, bem como dos mecanismos que regulam o padrão evolutivo dos anuros. Nesse contexto, esta dissertação, apresentada na forma de manuscrito, apresenta um estudo no qual foi testado experimentalmente como um predador aquático (náia... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Interactions between species influence community structure, population dynamics, morphology, physiology and species’ behavior. Mortality is a direct effect caused by the interaction with a predator, but even the simple presence of predators can lead to other indirect effects such as alterations on prey’s behavior. In aquatic environments, prey may detect predation risk by visual, mechanical, and chemical cues. When detecting a predator, the prey can use strategies to escape predation such as shoal formation, changes on habitat use pattern, and reduction on swimming activity. Despite decreasing predation rates, the antipredatory strategies have costs for the prey and set up a trade-off. For example, the same behavior that raises the prey’s chance to escape from a predator, decreases its foraging activity, leading thus to a reduction in the prey’s growth and survivorship. Among tadpoles, morphological and physiological aspects are important to determine water column occupation. But could predation also be an important pressure that determines the way tadpoles occupy the water column? Understanding how predation influences tadpoles’ behavior may elucidate populational dynamics and community structuring aspects, as well as the mechanisms that regulate anuran evolutionary patterns. In this sense, this dissertation presents a study, in a manuscript form, that tested experimentally the influence of an aquatic predator (Odonata water nymph; Micrathyria sp.) on the use of space, activ... (Complete abstract click electronic access below) / Mestre

Production de bois et autres ressources (gibier, champignons,...), conservation de la biodiversité et gestion des paysages, la forêt a suscité de riches débats depuis quelques années, le Grenelle de l'Environnement ayant révélé des intérêts parfois contradictoires. Si le gestionnaire forestier tente de développer autant que possible une gestion multifonctionnelle de ses forêts, il reste dépendant des connaissances fragmentaires sur les interactions dans les écosystèmes forestiers. La politique actuelle, qui vise à concilier la production de bois et la préservation des espèces, repose plus sur des expériences de terrain que sur des études étayées scientifiquement. Les Chiroptères comptent des espèces candidates pour étudier l'influence de la gestion forestière sur la biodiversité : le jour, elles occupent des gîtes arboricoles et, la nuit, elles exploitent des habitats forestiers pour chasser leurs proies, qui dépendent elles-mêmes de micro-habitats forestiers. Pour aider le gestionnaire à mettre en œuvre une stratégie de gestion conservatoire, nous avons étudié l'utilisation des ressources de la forêt par trois espèces : Myotis bechsteinii, Myotis nattereri et Plecotus auritus. La radio-localisation a permis d'identifier des réseaux d'arbres-gîte dont l'occupation varie selon les espèces, leur statut reproducteur et l'implication dans le comportement de fission-fusion des colonies de parturition. Les différentes utilisations des gîtes impliquent une stratégie de gestion propre à chaque espèce, voire à chaque colonie de reproduction. Procurant a priori de potentiels gîtes et proies, le bois mort debout favorise la richesse spécifique des Chiroptères forestiers à partir de 25 m3 à l'hectare, mais une stratification de la végétation pourrait être un objectif de gestion, la réponse des espèces était essentiellement liée à la structure forestière des trouées induites par le bois mort. Ce travail a ensuite nécessité de s'intéresser aux méthodes permettant de comprendre l'utilisation de l'espace par chaque individu (domaine vital) et la façon dont chacun d'eux fréquente ses terrains de chasse (sélection de l'habitat). Compte tenu des limites technologiques, le Kernel semble actuellement la meilleure méthode de représentation et de calcul de surface du domaine vital alors que la K-select a livré des résultats significatifs pour mettre en évidence des facteurs de sélection d'habitat. Les surfaces des domaines vitaux et des centres d'activité varient selon les espèces, Myotis bechsteinii associe de petites surfaces à un comportement territorial, surtout en période d'allaitement. M. nattereri et Plecotus auritus peuvent exploiter de grands espaces sur lesquels ils se limitent à de petits centres d'activité. Les colonies de ces dernières pourront plus facilement se déplacer dans leur domaine vital au gré des itinéraires de gestion mis en œuvre. Les caractéristiques des habitats forestiers utilisés comme terrains de chasse varient selon les espèces, voire le sexe, l'âge et le statut reproducteur des individus, mais toutes trois montrent une forte sélectivité pour les peuplements forestiers présentant un fort encombrement végétal, des gros arbres et une forte structuration du peuplement. Cinq principes de gestion dans un contexte fort de production de bois sont développés en conclusion des résultats avec deux exemples de stratégies de gestion destinée au maintien des Chiroptères. / The forest is the center of many interests that fuel the debates of our society. These debates are particularly exacerbated since the french " Grenelle de l'Environnement " in 2008. Among the various expectations, forest produce wood that is the subject of attentions, both by an increased demand for certain types of trees and by the naturalist world which sees in it one of last refuges for biodiversity in our modified landscapes. Thus, if the forest manager is trying to develop a management that is as much multifunctional as possible, it remains dependent on fragmented knowledge on the link between biodiversity and the forest ecosystem. Despite the establishment of a conservation policy that seeks to balance timber production and species preservation, the way to conduct such a policy is based on concrete field experiences yet scientifically unsubstantiated. Bats are good candidate species to study the response of biodiversity to forest management: they select networks of tree-roosts in which they form breeding colonies composed of several dozen individuals and they exploit forest habitats to hunt their prey, prey which themselves depend on forest microhabitats. However, their study is recent in forest and provides very vague management guidelines. To help managers implement a conservation management strategy, we thus studied the behavior of forest usage by three species of gleaning bats, Myotis bechsteinii, Myotis nattereri and Plecotus auritus. This work required to focus on the methods available to understand the use of space by each individual (home range) and how each individual selects its hunting habitats. We showed that each species had a unique response to available habitats and that the status of individuals (sex, age and reproductive status) intervenes in explaining the selection of tree roosts and hunting grounds. Both compartments are constrained by the availability of suitable habitat, helping to explain the structuring of habitat selection factors and the shape and surface of individual home ranges. Furthermore, the way networks of tree-roost are used partly explains the types of roosts selected. These different results means that it is necessary to lay down specific management strategies for each species, even each breeding colony. Finally, we studied the role of deadwood to explain the presence of bats in forests. We have shown that species richness increased from standing deadwood of 25m3 per hectare, while the response of species to deadwood was mainly restricted to forest habitat structure produced by the gaps resulting from the deadwood patch, favoring particularly edge-foraging species. Some species do however clearly benefit from insects emerging from deadwood. Five recommendations are proposed for the conservation of these species in a context of strong wood production.