Fishes from the rio da Dona, a threatened environment in the Recôncavo Sul basin, Bahia, Brazil

The rio da Dona is an important water body in the Recôncavo Sul basin used as a water supply for the neighboring towns and for agriculture, recreation and subsistence fishing. The knowledge about the ichthyofauna of this river is scarce. In this paper, an inventory of the fish fauna from rio da Dona basin and an identification key for the species recorded are presented. Additionally, taxonomic and conservationist issues are discussed. The specimens were collected in different sites along the upper, middle and lower courses of the rio da Dona. The fishes were anesthetized, fixed in formalin, conserved in ethanol, and identified. In addition to the material collected, specimens previously deposited in the ichthyological collection of the Museu de História Natural da Bahia were also analyzed. Twenty species, distributed into 16 genera, ten families, and four orders were recorded. One of these species, Aspidoras kiriri, is endemic to the rio da Dona. Four species, Cichla pinima, Coptodon rendalli, Poecilia reticulata and Serrasalmus brandtii, have been introduced into the river. Higher richness of native species has been recorded in the upper course of the rio da Dona, while in the middle and lower parts non-native species were also representative. Along the river, a series of anthropic impacts were observed, such as deforestation of native forest including the riparian vegetation, silting and dams, which can probably compromised the resident ichthyofauna.

Fishes from the rio da Dona, a threatened environment in the Recôncavo Sul basin, Bahia, Brazil

The rio da Dona is an important water body in the Recôncavo Sul basin used as a water supply for the neighboring towns and for agriculture, recreation and subsistence fishing. The knowledge about the ichthyofauna of this river is scarce. In this paper, an inventory of the fish fauna from rio da Dona basin and an identification key for the species recorded are presented. Additionally, taxonomic and conservationist issues are discussed. The specimens were collected in different sites along the upper, middle and lower courses of the rio da Dona. The fishes were anesthetized, fixed in formalin, conserved in ethanol, and identified. In addition to the material collected, specimens previously deposited in the ichthyological collection of the Museu de História Natural da Bahia were also analyzed. Twenty species, distributed into 16 genera, ten families, and four orders were recorded. One of these species, Aspidoras kiriri, is endemic to the rio da Dona. Four species, Cichla pinima, Coptodon rendalli, Poecilia reticulata and Serrasalmus brandtii, have been introduced into the river. Higher richness of native species has been recorded in the upper course of the rio da Dona, while in the middle and lower parts non-native species were also representative. Along the river, a series of anthropic impacts were observed, such as deforestation of native forest including the riparian vegetation, silting and dams, which can probably compromised the resident ichthyofauna.(AU)

Alternatives for the prevention and control of pathogens in fish farming / Alternativas para a prevenção e o controle de patógenos em piscicultura

The use of nutritional factors and phytotherapics considered imunostimulant are an important alternative in the prevention and control of pathogens in fish farming in substitution to the use of chemical and antibiotic products that, besides being toxic to the fish are harmful to the environment, generate resistance and can affect the health of the consumer. Control of different species of bacteria of the genus Pseudomonas and Aeromonas, reduction of fungus infection, control of Trichodina spp. and Ichthyophthirius multifiliis and the reduction of the occurrence of monogenetic in several species of fish are obtained with the use of nutritional factors and some phytotherapics that stimulate the not-specific response of the immunologic system and increase the resistance of the fish. These products become alternative of low cost to the producer and minimum impact in the environment.

A utilização de fatores nutricionais e fitoterápicos, considerados imunoestimulantes, é uma importante alternativa na prevenção e controle de patógenos em piscicultura em substituição ao uso de produtos químicos e antibióticos, que, além de serem tóxicos ao peixe, são nocivos ao ambiente, geram resistência e podem afetar a saúde do consumidor. Controle de diferentes espécies de bactérias dos gêneros Pseudomonas e Aeromonas, redução de infecção por fungos, controle de Trichodina spp. e de Ichthyophthirius multifiliis e diminuição da ocorrência de monogenéticos em diversas espécies de peixes são conseguidos com o uso de fatores nutricionais e de vários fitoterápicos, que estimulam as respostas não-específicas do sistema imunológico e aumentam a resistência dos peixes. Estes produtos tornam-se alternativas de baixo custo ao produtor e de mínimo impacto ao ambiente.

Alternatives for the prevention and control of pathogens in fish farming / Alternativas para a prevenção e o controle de patógenos em piscicultura

The use of nutritional factors and phytotherapics considered imunostimulant are an important alternative in the prevention and control of pathogens in fish farming in substitution to the use of chemical and antibiotic products that, besides being toxic to the fish are harmful to the environment, generate resistance and can affect the health of the consumer. Control of different species of bacteria of the genus Pseudomonas and Aeromonas, reduction of fungus infection, control of Trichodina spp. and Ichthyophthirius multifiliis and the reduction of the occurrence of monogenetic in several species of fish are obtained with the use of nutritional factors and some phytotherapics that stimulate the not-specific response of the immunologic system and increase the resistance of the fish. These products become alternative of low cost to the producer and minimum impact in the environment.

A utilização de fatores nutricionais e fitoterápicos, considerados imunoestimulantes, é uma importante alternativa na prevenção e controle de patógenos em piscicultura em substituição ao uso de produtos químicos e antibióticos, que, além de serem tóxicos ao peixe, são nocivos ao ambiente, geram resistência e podem afetar a saúde do consumidor. Controle de diferentes espécies de bactérias dos gêneros Pseudomonas e Aeromonas, redução de infecção por fungos, controle de Trichodina spp. e de Ichthyophthirius multifiliis e diminuição da ocorrência de monogenéticos em diversas espécies de peixes são conseguidos com o uso de fatores nutricionais e de vários fitoterápicos, que estimulam as respostas não-específicas do sistema imunológico e aumentam a resistência dos peixes. Estes produtos tornam-se alternativas de baixo custo ao produtor e de mínimo impacto ao ambiente.

Comparative limnology of South American floodplain lakes and lagoons / Limnologia comparada de lagos e lagoas de planícies de inundação da América do Sul

The primary purpose of this study was to compare different lagoons from eight floodplains in South America (Amazon, the Upper Paraná, the Middle Paraná, Mogi-Guaçu, Araguaia, Pantanal, São Francisco and Orinoco floodplains). Secondly, the effect of water level upon selected limnological variables (important and frequently used variables in limnological studies) was evaluated. Data were obtained from published articles and dissertations. Some unpublished data from Upper Paraná, Amazon and Araguaia floodplains were also used. Despite the general differences among the floodplains such as climate, geology and limnological characteristics of the main river, certain constant patterns were found. Oxygen concentration was always higher during low water phase and, in general, the lagoons have an acid water independently of the period. By comparing the Amazon, Paraná and Araguaia floodplains, whose data are more abundant, high variability in chemical factors was found during the low water phase when measured by the variation coefficient. This result supports the hypothesis that the flood pulse acts as a regional process that increases similarity among the lagoons

O objetivo principal deste estudo foi comparar diferentes lagoas de oito planícies de inundação da América do Sul (planícies do Amazonas, Alto Paraná, Médio Paraná, Moji-Guaçu, Araguaia, Pantanal, São Francisco e Orinoco). Posteriormente, foi avaliado o efeito do nível da água sobre as variáveis limnológicas selecionadas (variáveis importantes e freqüentemente utilizadas nos estudos limnológicos). Os dados foram obtidos de artigos publicados e dissertações. Também foram utilizados alguns dados inéditos das planícies do Alto Paraná, Amazônia e Araguaia. Apesar das diferenças nos climas, aspectos geológicos e características limnológicas dos rios principais das planícies, alguns padrões limnológicos foram observados. As maiores concentrações de oxigênio foram observadas durante o período de águas baixas, e em geral todas as lagoas apresentam baixos valores de pH, independentemente do período hidrológico. Comparando-se apenas as planícies do Amazonas, Alto Paraná e Araguaia, que possuem o maior número de dados, a maior variabilidade limnológica, medida pelo coeficiente de variação, foi encontrada durante o período de águas baixas. Este resultado corrobora a hipótese de que a inundação age como um processo regional, aumentando a similaridade entre as lagoas

Comparative limnology of South American floodplain lakes and lagoons / Limnologia comparada de lagos e lagoas de planícies de inundação da América do Sul

The primary purpose of this study was to compare different lagoons from eight floodplains in South America (Amazon, the Upper Paraná, the Middle Paraná, Mogi-Guaçu, Araguaia, Pantanal, São Francisco and Orinoco floodplains). Secondly, the effect of water level upon selected limnological variables (important and frequently used variables in limnological studies) was evaluated. Data were obtained from published articles and dissertations. Some unpublished data from Upper Paraná, Amazon and Araguaia floodplains were also used. Despite the general differences among the floodplains such as climate, geology and limnological characteristics of the main river, certain constant patterns were found. Oxygen concentration was always higher during low water phase and, in general, the lagoons have an acid water independently of the period. By comparing the Amazon, Paraná and Araguaia floodplains, whose data are more abundant, high variability in chemical factors was found during the low water phase when measured by the variation coefficient. This result supports the hypothesis that the flood pulse acts as a regional process that increases similarity among the lagoons

O objetivo principal deste estudo foi comparar diferentes lagoas de oito planícies de inundação da América do Sul (planícies do Amazonas, Alto Paraná, Médio Paraná, Moji-Guaçu, Araguaia, Pantanal, São Francisco e Orinoco). Posteriormente, foi avaliado o efeito do nível da água sobre as variáveis limnológicas selecionadas (variáveis importantes e freqüentemente utilizadas nos estudos limnológicos). Os dados foram obtidos de artigos publicados e dissertações. Também foram utilizados alguns dados inéditos das planícies do Alto Paraná, Amazônia e Araguaia. Apesar das diferenças nos climas, aspectos geológicos e características limnológicas dos rios principais das planícies, alguns padrões limnológicos foram observados. As maiores concentrações de oxigênio foram observadas durante o período de águas baixas, e em geral todas as lagoas apresentam baixos valores de pH, independentemente do período hidrológico. Comparando-se apenas as planícies do Amazonas, Alto Paraná e Araguaia, que possuem o maior número de dados, a maior variabilidade limnológica, medida pelo coeficiente de variação, foi encontrada durante o período de águas baixas. Este resultado corrobora a hipótese de que a inundação age como um processo regional, aumentando a similaridade entre as lagoas