Browsing by Autor "Simone Wengrat"

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Ecology and distribution of<i>Aulacoseira</i>species (Bacillariophyta) in tropical reservoirs from Brazil
(Taylor & Francis, 2016) Denise C. Bicudo; Priscila Izabel Tremarin; Pryscilla D. Almeida; Stéfano Zorzal‐Almeida; Simone Wengrat; Samantha B Faustino; Lívia F. Costa; Elaine Cristina Rodrigues Bartozek; Angélica Cristina Righetti da Rocha; Carlos Eduardo de Mattos Bicudo
Ecological preferences and distribution of Aulacoseira species in southeastern Brazilian reservoirs with varying trophic states were studied. One hundred and fourteen plankton samples (winter and summer) from 57 sites located in 16 reservoirs were analysed. Ten water quality parameters were measured. Ten Aulacoseira species were identified using light, scanning and transmission electron microscopy, and new information on their ecological preferences is provided here. Our results indicate that trophic gradient is the main driver of species distribution. Principal components analysis and calculation of weighted average nutrient optima revealed three indicator taxa, Aulacoseira tenella characteristic for oligotrophic waters and two varieties of Aulacoseira granulata (nominate and var. angustissima) typical for eutrophic reservoirs. This is the first ecological study of Aulacoseira in Brazil, adding information on the distribution of this genus in the tropics, and highlighting the need for species-level identification and regional studies to improve the use of diatoms in water quality assessment.
Taxonomy and ecology of Fragilaria billingsii sp. nov. and analysis of type material of Synedra rumpens var. fusa (Fragilariaceae, Bacillariophyta) from Brazil
(2026) Simone Wengrat; Eduardo A. Morales; Carlos E. Wetzel; Pryscilla D. Almeida; Luc Ector; Denise Campos Bicudo
Taxonomy and ecology of Fragilaria billingsii sp. nov. and analysis of type material of Synedra rumpens var. fusa (Fragilariaceae, Bacillariophyta) from Brazil
(Q15088586, 2016) Simone Wengrat; Eduardo A. Morales; Carlos E. Wetzel; Pryscilla D. Almeida; Luc Éctor; Denise C. Bicudo
Synedra rumpens var. fusa was originally described by Patrick, but there are only a few subsequent records of this variety in the literature. Analysis of samples from Brazilian reservoirs containing a morphologically similar taxon led us to the analysis of the type material of S. rumpens var. fusa, performed using light (LM) and scanning electron microscopy (SEM). In the present manuscript, an amendment to the description of the var. fusa is made and its transfer to the genus Fragilaria as F. fusa comb. et stat. nov. is proposed. Moreover, Fragilaria billingsii sp. nov. is described from a large multipurpose reservoir from the State of São Paulo, Brazil. Comparative discussions with morphologically related taxa found in the literature are presented. Regarding ecological preferences, the new species was found living in slightly acidic and meso-eutrophic waters.