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Estudo da influência de parâmetros ambientais no desenvolvimento larvar de Pelophylax perezi
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Resumo(s)
Os anfíbios apresentam variações geográficas em vários aspectos das histórias de vida. Investigaram-se as causas das variações num gradiente de altitudes, no estádio larvar de Pelophylax perezi, de modo a perceber se eram provocadas por adaptação local ou plasticidade fenotípica. Utilizaram-se características das histórias de vida, de forma a tentar destrinçar a componente genética da ambiental. Os tamanhos e a diferenciação dos girinos foram medidos, mensalmente, em charcos naturais e em experiências de common garden no laboratório, em que se usaram dois níveis de temperatura. Na maioria dos casos, observou-se uma resposta semelhante das características consoante a origem e a temperatura, tendo-se apenas prolongado o período larvar na temperatura mais elevada. Não parecem existir diferenças genéticas entre as populações, mas observou-se um efeito ambiental, em que diferentes temperaturas da água influenciam o desenvolvimento dos girinos.
Amphibians have geographic variations in many aspects of life history. The causes of variation in an altitudinal gradient in the larval stage of Pelophylax perezi have been investigated in order to see whether they were caused by local adaptation or phenotypic plasticity. We used life history traits in order to try to disentangle the genetic component from the environment component. Size and differentiation of tadpoles were measured monthly in natural ponds and in common garden experiments in the laboratory, where were used two levels of temperature. In most cases, traits responded similarly according to the origin and temperature and only the larval period at higher temperature was prolonged. There seem to be no genetic differences between populations, but an environmental effect, where different water temperatures influence the development of tadpoles.
Amphibians have geographic variations in many aspects of life history. The causes of variation in an altitudinal gradient in the larval stage of Pelophylax perezi have been investigated in order to see whether they were caused by local adaptation or phenotypic plasticity. We used life history traits in order to try to disentangle the genetic component from the environment component. Size and differentiation of tadpoles were measured monthly in natural ponds and in common garden experiments in the laboratory, where were used two levels of temperature. In most cases, traits responded similarly according to the origin and temperature and only the larval period at higher temperature was prolonged. There seem to be no genetic differences between populations, but an environmental effect, where different water temperatures influence the development of tadpoles.
Descrição
Tese de mestrado. Biologia (Biologia Evolutiva e do Desenvolvimento). Universidade de Lisboa, Faculdade de Ciências, 2009
Palavras-chave
Herpetologia Anfíbios Pelophylax perezi Teses de mestrado - 2009