Knowledge of biodiversity in oligotrophic aquatic ecosystems is fundamental to plan conservation strategies for protected areas. This study assessed the diatom diversity from an urban reservoir with oligotrophic conditions. The Piraquara I reservoir is located in an Environmental Protection Area and is responsible for the public supply of Curitiba city and the metropolitan region. Samples were collected seasonally between October 2007 and August 2008. Periphytic samples were obtained by removing the biofilm attached to Polygonum hydropiperoides stems and to glass slides. The taxonomic study resulted in the identification of 87 diatom taxa. The most representative genera regarding the species richness were Pinnularia (15 species) and Eunotia (14 species). Five species were registered for the first time in Brazil and seven in the State of Paraná. Taxonomic and ecological comments of the species registered are provided.
In the present study, we analyzed the taxonomy and ecology of fourteen species of Luticola registered in oligo- to hypereutrophic reservoirs of southeastern Brazil. Two new species were described using light and scanning electron microscopy. Luticola bartolomeii sp. nov. and Luticola iporangensis sp. nov. are distinguished from morphologically similar species by a combination of valve outline and dimensions. In addition, L. bartolomeii showed occluded isolated areolae that have a different shape and location, hitherto not observed in other Luticola species. We also compared the morphology of the new species with similar taxa and provided information on their ecological preferences. Luticola panamaensis is first recorded in Brazil, and another eight species are recorded for the first time for the state of São Paulo. This study expanded the distribution of species and added new information to the ecology of Luticola, as well as provided the first SEM images for some already known species. Information on the co-occurrence of other diatom species in the samples is also included.
O ensaio objetiva refletir de que maneira as microalgas podem ser teoricamente concebidas e metodologicamente utilizadas como instrumento biotecnológico de sensoriamento responsável por aumentar capacidade de percepção/ação/cognição e comunicação acerca das dinâmicas antrópicas da natureza – considerando, em termos epistemológicos, que a razão científica se afasta do senso comum na medida em que gera experiências instrumentalizadas entre sujeito-objeto do conhecimento. Também ampliam e corrigem as experiências fenomenológicas limitadas às capacidades humanas circunscritas a regras neurofisiológicas e neuropsicológicas do corpo humano, ou às lógicas técnico-científicas de outras áreas do saber ligadas à política. Elas funcionam como biotecnologias capazes de fazer crescer e de corrigir a inteligência e a sensibilidade de sistemas teórico-metodológicos aplicados em planos de diagnóstico, monitoramento e ajustes ambientais. Enquanto biotecnologias, as microalgas funcionam como prolongamentos e potencializadores dos corpos e dos cérebros dos cientistas ou das comunidades acadêmicas reunidas no interior das Ciências do Ambiente. Por fim, considera alguns obstáculos epistemológicos que impedem a participação dos bioindicadores na esfera das políticas voltadas à gestão ambiental.
A bstract: The actual status of the progress and the main aspects of diatom studies in Brazil remain unknown. This paper describes a survey of published studies addressing material of Brazilian origin in non-marine aquatic environments. Our objectives are to (1) summarize and categorize diatom research topics, (2) to describe how related studies evolved and developed over time, as well as respective journals, (3) to identify the most studied regions and environments, and (4) to indicate the main institutions and works addressing diatom research and related interactions. We conducted a systematic review selecting 478 studies. Since the early studies, the approach on diatom fl oristic exclusively was the most frequent, even though, ecological studies have been increasing since the 2000s. However, these concentrate in the southern and southeastern. It was only in the last decades that other Brazilian regions became the setting of more extensive samplings, thus refl ecting on the interactions between authors and institutions from the collection sites. However, the actual biodiversity scenario of diatoms in Brazil still seems to be underestimated, which may infl uence further conservation measures. Finally, we indicate some suggestions aimed at fi lling the sampling gaps presented/highlighted in this study.
RESUMO Foi realizado um levantamento florístico de Epithemia (Bacillariophyceae) na área do Parque Estadual das Fontes do Ipiranga (PEFI), São Paulo, SP, Brasil, com o objetivo de conhecer a diversidade taxonômica e a variabilidade morfológica do gênero. Ao total, 31 lâminas de diatomáceas foram examinadas das quais cinco foram usadas no presente estudo. Cinco espécies foram identificadas: E. proboscidea Kützing, E. gibba (Ehrenberg) Kützing, E. gibberula (Ehrenberg) Kützing, E. operculata (C. Agardh) Ruck & Nakov e Epithemia sp., com dominância de espécies perifíticas. Um táxon foi registrado pela primeira vez para o Brasil (E. proboscidea Kützing) e dois táxons para a área do PEFI (E. gibba (Ehrenberg) Kützing e E. operculata (C. Agardh) Ruck & Nakov).
RESUMO (Criptógamos do Parque Estadual das Fontes do Ipiranga, São Paulo, SP, Brasil. Algae, 45: Bacillariophyceae (Naviculales: Brachysira)). O levantamento florístico do gênero Brachysira Kützing (Naviculales) do Parque Estadual das Fontes do Ipiranga (PEFI), São Paulo, SP, Brasil, resultou da análise de 31 preparações permanentes de material coletado entre 1991 e 2017. As amostras de água e de substratos (macrófitas e rochas) de sistemas lênticos, riachos e do hidrofitotério foram coletadas e posteriormente oxidadas para análise ao microscópio de luz. Nove espécies e um morfotipo foram encontrados em 15 amostras de material do PEFI, sendo quatro novas citações para o Brasil (Brachysira cf. calcicola Lange-Bertalot, Brachysira frenguellii (Manguin) Lange-Bertalot & Moser, Brachysira huitotarum Vouilloud, Sala & Núñez-Avellaneda e Brachysira intermedia (Østrup) Lange-Bertalot). Brachysira subrostrata Lange-Bertalot foi registrada pela primeira vez no Estado de São Paulo.
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