Estratégia alimentar e colonização de peixes : efeitos de longo prazo no sucesso de invasões.

• Ano de defesa: 2017
• Autor(a) principal: Tonella, Lívia Helena
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Estadual de Maringá; Brasil; Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais; UEM; Maringá; Departamento de Biologia
• Palavras-chave em Português: Invasões biológicas; Ecologia; Peixes de água doce; Plasticidade fenotípica; Espécies invasoras; Invasão biológica; Colonização; Neotropical; Planície de inundação; Alto rio Paraná; Brasil.; Biological invasion; Ecology; Freshwater fishes; Phenotypic plasticity; Colonization; Floodplain; Upper Paraná River; Brazil.; Ciências Biológicas
• Link de acesso: http://repositorio.uem.br:8080/jspui/handle/1/4814

Dams alter the physical structure of water systems, increasing the occurrence of lentic environments, which favors species with adaptations for this type of biotopes. Changes in the taxonomic structure of communities determined by impoundments are increased by the suppression of geographical barriers and consequent introduction of exotic species, widening their geographical distributions. The consequent process of invasion is related to traits of the life history of the species, especially phenotypic plasticity, conspicuous characteristic of invasive species. The hypothesis of this work is that the feeding habits of the species influence its success as biological invaders. For that, we tested the following predictions: (i) The species with the greatest amplitudes of food items consumed in their original geographic distributions are favored in the long term of a invasion process; (ii) species with feeding specialization are only favored in the invasion process if they consume resources of low trophic levels, such as organic debris. For that it was evaluated the feeding strategies of nine fish species within an invaded area (upper Paraná River floodplain) in relation to their original geographic distribution (Cuiabá River basin). The results confirm the predictions that the most successful species in the invasion process are those with high trophic plasticity (omnivores), as well as the ones that present high variability of items within specific trophic guilds (piscivores), or specialization for items of lower energetic value (organic debris). The high availability of food resources used by these species, which are rarely limited in aquatic ecosystems, should be a determining factor for their success in colonizing invaded environments. Understanding the factors that determine the success of invasive species in the colonization of environments is fundamental for determining effective practices that minimize the impacts caused by biological invasions.