Ictiofauna nos trechos médio e baixo rio Pardo, Alto Paraná: inventário
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Data
2008-07-29
Autores
Castagnolli, Marcelo Carrão [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
O presente estudo visa inventariar as espécies de peixe e caracterizar as comunidades ictiicas ao longo de um padrão longitudinal nos trechos médio e baixo do rio Pardo, desde a Usina hidrelétrica de Itaipava até sua foz no rio Grande. A pesca exploratória, dividida em duas etapas, época seca, entre setembro e outubro de 2004, e final da época chuvosa, em março de 2005. Com duas baterias de redes de espera, 110 m de comprimento e 1,5 m de altura, malhas 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 e 12 cm entre nós opostos, em 8 locais de amostragem em 3 rios, Pardo (5), Mogi-Guaçú (1) e Grande (2). Capturados, 928 peixes pertencentes a 4 ordens, 15 famílias, 40 gêneros e 53 espécies com biomassa total de 95,581 kg. Evidenciam o predomínio de Characiformes (28 espécies – 52,83%) e Siluriformes (15 espécies – 28,30%) e a presença de Gymnotiformes (4 espécies – 7,55%) e Perciformes (6 espécies – 11,32%). Maior número de peixes capturados na época chuvosa, menores índices de diversidade no início do trecho médio e na foz do rio Pardo e índices mais elevados nos trechos intermediários evidenciam que este se apresenta dentro da normalidade. A biodiversidade das espécies de peixe não foi fortemente impactada, conforme noticiado, em virtude do acidente com melaço ocorrido em 29 de setembro de 2003. O rio Pardo apresenta uma grande riqueza de espécies, apesar da perda da mata ciliar e do lançamento de esgoto. A composição da ictiofauna variou ao longo das estações do ano e entre os locais de amostragem. Estudos mais complexos devem ser conduzidos objetivando a coleta e a análise conjunta de um universo maior de dados para ampliar o conhecimento destes ambientes lóticos.
This study aims to identify fish species and characterize the fish communities over a longitudinal pattern in the low and middle Pardo river stream, from the Itaipava hydroelectric to its mouth in the Grande river. The exploratory fishing was divided into two stages, dry season, between September and October of 2004 and end of the rainy season in March 2005. Fish were caught with two fishnet batteries with 110 m long and 1.5 m high (meshes of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 and 12 cm between opposed knots), among 8 sampling points located on 3 rivers, Pardo river (5), Mogi Guaçu river (1) and Grande river (2). There were caught, 928 fishes belonging to 4 orders, 15 families, 40 genera and 53 species in 95.581 kg of total biomass. The data shows the predominance of Characiformes (28 species - 52.83%) and Siluriformes (15 species - 28.30%) and the presence of Gymnotiformes (4 species - 7.55%) and Perciformes (6 species - 11, 32%). The number of fish caught was higher in the rainy season, lower diversity were obtained at the upper Pardo river and at it’s mouth and high ones in the intermediaries show that this river presents itself within the normal range. The biodiversity of fish species was not heavily impacted, as reported by local media, because the accident occurred with molasses in September 29, 2003. The Pardo river presents a wealth of species, despite the loss of riparian forest and the sewage launch. The composition of the fish fauna varied over the seasons and between the local sampling. Studies should be conducted more complex aiming to collect and joint analysis of a larger universe of data in order to expand the knowledge of these environments.
This study aims to identify fish species and characterize the fish communities over a longitudinal pattern in the low and middle Pardo river stream, from the Itaipava hydroelectric to its mouth in the Grande river. The exploratory fishing was divided into two stages, dry season, between September and October of 2004 and end of the rainy season in March 2005. Fish were caught with two fishnet batteries with 110 m long and 1.5 m high (meshes of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 and 12 cm between opposed knots), among 8 sampling points located on 3 rivers, Pardo river (5), Mogi Guaçu river (1) and Grande river (2). There were caught, 928 fishes belonging to 4 orders, 15 families, 40 genera and 53 species in 95.581 kg of total biomass. The data shows the predominance of Characiformes (28 species - 52.83%) and Siluriformes (15 species - 28.30%) and the presence of Gymnotiformes (4 species - 7.55%) and Perciformes (6 species - 11, 32%). The number of fish caught was higher in the rainy season, lower diversity were obtained at the upper Pardo river and at it’s mouth and high ones in the intermediaries show that this river presents itself within the normal range. The biodiversity of fish species was not heavily impacted, as reported by local media, because the accident occurred with molasses in September 29, 2003. The Pardo river presents a wealth of species, despite the loss of riparian forest and the sewage launch. The composition of the fish fauna varied over the seasons and between the local sampling. Studies should be conducted more complex aiming to collect and joint analysis of a larger universe of data in order to expand the knowledge of these environments.
Descrição
Palavras-chave
Peixe de agua doce, Pardo, Rio (MG e SP), Parana, Rio, Ictiofauna, Ichthyofauna
Como citar
CASTAGNOLLI, Marcelo Carrão. Ictiofauna nos trechos médio e baixo rio Pardo, Alto Paraná: inventário. 2008. x, 83 f. Dissertação (mestrado) - Universidade Estadual Paulista, Centro de Aqüicultura, 2008.