A ictiofauna de cabeceiras do rio Tietê, São Paulo, Brasil
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Data
2011-09-01
Autores
Marceniuk, Alexandre Pires
Hilsdorf, Alexandre Wagner da Silva
Langeani, Francisco [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Instituto Virtual da Biodiversidade (BIOTA/FAPESP)
Resumo
Uma síntese das espécies de peixes de cabeceiras do rio Tietê é apresentada com base em material de coleções zoológicas e novas coletas realizadas. São referidas para região 56 espécies pertencentes a sete ordens e 16 famílias, aumentando significativamente números anteriores. Os resultados mostram que as cabeceiras do rio Tietê possuem uma composição ictiofaunistica bastante peculiar, distinta daquela encontrada no restante do Alto rio Paraná, mostrando acentuado grau de endemismo e grande similaridade com bacias hidrográficas litorâneas, corroborando a hipótese de captura de rios da região por drenagens costeiras e vice e versa no passado. Dentre as espécies encontradas na região, oito são endêmicas (14,3%), 13 são encontradas nas cabeceiras do rio Tietê e drenagens litorâneas da região sudeste do Brasil (23,2%), dez ocorrem em todo Alto rio Paraná (17,9%), cinco são encontradas no Alto rio Paraná e drenagens litorâneas da região sudeste do Brasil (8,9%), enquanto 13 espécies mostram uma ampla distribuição na América do Sul (23,2%), das quais parte ainda precisa ter a identidade confirmada. A diversidade de espécies é acrescida de pelo menos cinco espécies novas pertencentes aos gêneros Cyphocharax, Characidium, Astyanax, Pareiorhina e Australoheros e quatro novos registros são feitos para Characidium cf. zebra, Scleromystax barbatus, Crenicicla britskii e Synbranchus cf. marmoratus. Pelo menos sete espécies introduzidas estão estabelecidas na região, enquanto outras dez espécies são relacionadas em listas de espécies ameaçadas.
A synthesis of the ichthyofauna of the headwaters of the rio Tietê, based on material from zoological collections and new samplings, is presented. Fifty six species belonging to seven orders and 16 families are recorded to the drainage, increasing previous numbers significantly. The current results show that the headwaters of the rio Tietê possess a singular ichthyofauna composition, diverse from that found in the remaining of the upper Paraná basin, with high level of endemic species and great similarity to the species from coastal drainages. This finding corroborates the hypothesis of past river capture between streams and rivers in both drainages. Among the species occurring in the area surveyed, eight are endemic (14.3%), 13 are found in the headwaters of rio Tietê and in the coastal drainages of southeastern Brazil (23.2%), 10 are present throughout the upper Paraná basin (17.9%), five are found in the upper Paraná basin and in the coastal drainages of southeastern Brazil (8.9%), while 13 show a broader distribution in the South America drainages (23.2%), part of which still remains to be identified. Species diversity increased with the discovery of at least five new species belonging to the genera Cyphocharax, Characidium, Astyanax, Pareiorhina and Australoheros, and four new records for Characidium cf. zebra, Scleromystax barbatus, Crenicicla britskii and Synbranchus cf. marmoratus. At least, seven non-native species are recognized to be established in the region, while 10 other are included in red books.
A synthesis of the ichthyofauna of the headwaters of the rio Tietê, based on material from zoological collections and new samplings, is presented. Fifty six species belonging to seven orders and 16 families are recorded to the drainage, increasing previous numbers significantly. The current results show that the headwaters of the rio Tietê possess a singular ichthyofauna composition, diverse from that found in the remaining of the upper Paraná basin, with high level of endemic species and great similarity to the species from coastal drainages. This finding corroborates the hypothesis of past river capture between streams and rivers in both drainages. Among the species occurring in the area surveyed, eight are endemic (14.3%), 13 are found in the headwaters of rio Tietê and in the coastal drainages of southeastern Brazil (23.2%), 10 are present throughout the upper Paraná basin (17.9%), five are found in the upper Paraná basin and in the coastal drainages of southeastern Brazil (8.9%), while 13 show a broader distribution in the South America drainages (23.2%), part of which still remains to be identified. Species diversity increased with the discovery of at least five new species belonging to the genera Cyphocharax, Characidium, Astyanax, Pareiorhina and Australoheros, and four new records for Characidium cf. zebra, Scleromystax barbatus, Crenicicla britskii and Synbranchus cf. marmoratus. At least, seven non-native species are recognized to be established in the region, while 10 other are included in red books.
Descrição
Palavras-chave
Biodiversity, new species, new records, identification key, Conservation, Biodiversidade, novas espécies, novos registros, chave de identificação, conservação
Como citar
Biota Neotropica. Instituto Virtual da Biodiversidade | BIOTA - FAPESP, v. 11, n. 3, p. 217-236, 2011.