Composição dos organismos aquáticos e relações tróficas das assembléias de peixes: regime lótico versus lêntico em sistemas hidrológicos neotropicais

• Ano de defesa: 2015
• Autor(a) principal: Souto, Ana Carolina [UNESP]
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Estadual Paulista (Unesp)
• Palavras-chave em Português: Ictiofauna - Paranapanema, Rio, Bacia (SP e PR); Peixe - Distribuição sazonal; Organismos aquaticos; Ichthyology
• Link de acesso: http://hdl.handle.net/11449/142963; http://www.athena.biblioteca.unesp.br/exlibris/bd/cathedra/05-07-2016/000865793.pdf

The large Neotropical rivers, with their main channels, their secondary channels, oxbow lake connected and isolated from water courses have a high diversity of habitats. The large variety of habitats provides the formation of spatially heterogeneous environmental gradients, considered of great importance for biodiversity. An environmental diversity is commonly found in freshwater Neotropical, more specifically in South America, for example, in the basins of the Amazon and Paraná. Space compartments are of great importance for the development of life cycle of aquatic communities, and several studies suggest that lagoons can play a key role in reproduction, feeding and growth of numerous species of fish and other aquatic organisms. However, little is known about the dynamics of those bodies in river systems and oxbow lake systems and possible interactions in the same time scale. The objective of this study was to analyze and compare the structure of aquatic organisms and trophic dynamics of fish assemblages in a lotic system (main river channel) versus one contiguous lentic system (oxbow lake), in the dry and rainy seasons. The selected site for this study was the main river channel front to an oxbow lake, in the Upper Paranapanema River basin. It is considered one of the most important tributaries of the upper Paraná River, with its source located in the Paranapiacaba Mountain, State of São Paulo, Southeastern Brazil. The set of aquatic organisms responsible for primary and secondary production, such as phytoplankton, zooplankton, macrophytes and macroinvertebrates showed some differences in its composition compared to biota of the main river channel with that of the oxbow lake, as well as in the two seasons. In general, the higher rate richness occurred in the oxbow lake. The structure of fish assemblages also showed some differences when comparing the environments and periods of the year. A greater diversity of species in the main ...