Biologia alimentar da ictiofauna na área de influência do reservatório da usina Mogi Guaçu e lagoas marginais da Estação Ecológica - Fazenda Campininha (SP)
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Data
2007-05-08
Autores
Gonçalves, Cristina da Silva [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
Estudos sobre alimentação natural de peixes contribuem para o conhecimento básico da biologia das espécies, compreensão da organização trófica do ecossistema e conhecimento das interações entre as espécies. O presente estudo visou estudar a biologia alimentar da ictiofauna na área de influência do reservatório da usina Mogi Guaçu e nas lagoas marginais naturais da Estação Ecológica (fazenda Campininha), município de Mogi Guaçu-SP, com o intuito de responder as seguintes questões: (1) quais recursos alimentares as espécies estão utilizando? (2) existe alguma preferência alimentar para as espécies? (3) ocorrem alterações sazonais na dieta das espécies? Para a captura dos peixes, foram utilizadas redes de espera, puçá e armadilhas do tipo covo. Foram capturados 2341 exemplares de 41 espécies pertencentes a cinco ordens e 15 famílias. A ictiofauna nos ambientes estudados foi composta por peixes típicos da bacia do alto Paraná indicando uma condição que, embora alterada, apresenta espécies essencialmente nativas desta região. Foram analisados 370 estômagos provenientes de 1900 exemplares de peixes pertencentes a 14 espécies nos dois ambientes. Entre os itens consumidos pelos peixes, detritos e insetos (fragmentos) foram os que mais contribuíram para a alimentação das espécies no reservatório e nas lagoas marginais, respectivamente. Verificou-se que a dieta das espécies no reservatório e nas lagoas marginais foi significativamente correlacionada entre os períodos seco e chuvoso não ocorrendo, portanto, alterações sazonais. Os itens de origem autóctone tiveram uma participação maior na dieta das espécies, incluindo algas, insetos aquáticos e detritos entre os mais freqüentes. Foram determinadas cinco guildas tróficas para as 17 espécies analisadas. No reservatório os curimatídeos compuseram a guilda...
Studies involving fishes natural feeding habits increases the knowledge about species biology, understanding the trophic structure and species interaction. This work was conducted to study the feeding biology of fishes from Mogi Guaçu reservoir and some oxbow lakes from a protected area known by fazenda Campininha (Mogi Guaçu municipality), to answer the following questions: (1) which food resources fishes are using? (2) is there any food resource preferred for them? (3) seasonal alterations occur in fishes diets? Fishes were sampled using simple gillnets with different meshes sizes and traps. We captured 2341 fishes from 41 species belonging five orders and 15 families. The fish fauna composition revealed typical species from high Paraná river system indicating the presence of native species although the human alterations in the region. We analyzed 370 stomachs from 1900 individuals (14 species from both areas). They consumed mostly detritus and insects (fragments). Fishes diet on reservoir and oxbow lakes were significantly correlated between the seasons and no changes were observed. The majority items consumed were from autochthonous origin, including algae, aquatic insects and detritus that appeared frequently. Five trophic guilds were determined to the 17 species sampled. Curimatidae were the most abundant species corresponding to detritivorous fishes, followed by omnivorous, invertivorous, piscivorous and herbivorous fishes. Four trophic guilds were found in oxbow lakes where the invertivorous fishes were the most abundant (Hoplosternum littorale, Hyphessobrycon bifasciatus and Hyphessobrycon eques), followed by detritivorous, omnivorous and piscivorous fishes. The frequencies obtained from stomach repletion, fat accumulation and gonadal maturation degrees were related with fish's conditions.
Studies involving fishes natural feeding habits increases the knowledge about species biology, understanding the trophic structure and species interaction. This work was conducted to study the feeding biology of fishes from Mogi Guaçu reservoir and some oxbow lakes from a protected area known by fazenda Campininha (Mogi Guaçu municipality), to answer the following questions: (1) which food resources fishes are using? (2) is there any food resource preferred for them? (3) seasonal alterations occur in fishes diets? Fishes were sampled using simple gillnets with different meshes sizes and traps. We captured 2341 fishes from 41 species belonging five orders and 15 families. The fish fauna composition revealed typical species from high Paraná river system indicating the presence of native species although the human alterations in the region. We analyzed 370 stomachs from 1900 individuals (14 species from both areas). They consumed mostly detritus and insects (fragments). Fishes diet on reservoir and oxbow lakes were significantly correlated between the seasons and no changes were observed. The majority items consumed were from autochthonous origin, including algae, aquatic insects and detritus that appeared frequently. Five trophic guilds were determined to the 17 species sampled. Curimatidae were the most abundant species corresponding to detritivorous fishes, followed by omnivorous, invertivorous, piscivorous and herbivorous fishes. Four trophic guilds were found in oxbow lakes where the invertivorous fishes were the most abundant (Hoplosternum littorale, Hyphessobrycon bifasciatus and Hyphessobrycon eques), followed by detritivorous, omnivorous and piscivorous fishes. The frequencies obtained from stomach repletion, fat accumulation and gonadal maturation degrees were related with fish's conditions.
Descrição
Palavras-chave
Peixe, Fishes, Oxbow lakes
Como citar
GONÇALVES, Cristina da Silva. Biologia alimentar da ictiofauna na área de influência do reservatório da usina Mogi Guaçu e lagoas marginais da Estação Ecológica - Fazenda Campininha (SP). 2007. v, 120 f. Dissertação (mestrado) - Universidade Estadual Paulista, Instituto de Biociências de Rio Claro, 2007.