Diversity and ecological considerations on pigmented euglenophyceae in the state park of the Jacuí Delta, Rio Grande do Sul, Southern Brazil

Autores

  • Sandra Maria Alves-da-Silva
  • Guilherme Hermany
  • Maria Angélica Oliveira

Resumo

Qualitative samples were taken from both lotic and lentic environments, in the State Park of the Jacuí Delta, located in the vicinity of the capital of Rio Grande do Sul State (29°56’ e 30°03’S e 51°12’e 51°18’W), collected between May 1998 and September 1999, along the shore of an island, five bays (“sacos”) and one canal. The analysis revealed a high diversity of pigmented Euglenophyceae, with 130 taxa identified to genus, species infra-species levels. Amongst these, 42 taxa were new citations of the genus Trachelomonas for the Park. Twinspan classification analysis identified four groups. The study of the pigmented Euglenophyceae population composition and its relationship with environmental variables revealed a group of taxa (group B) with preference for habitats strongly changed by human action, with high levels of organic contamination and ammonium salts, as well as nitrite ions and orthophosphate, indicating moderately polluted waters (β-α mesossaprobic). Additionally, the environmental preferences of species never before described in the literature as characteristic of the conditions listed above, are given for the first time in Brazil.
Keywords: pigmented Euglenophyceae, diversity, ecology, southern Brazil.

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Publicado

2007-11-26

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