Thelma Veiga Ludwig

Thelma Veiga Ludwig
Universidade Federal do Paraná | UFPR · Department of Botany

Doctor

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152
Publications
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Publications

Publications (152)
Article
Epilithic diatom species in eight sampling sites of the Cascavel River, Southern Brazil, were taxonomically analyzed. The studied streams are located in a predominantly urban micro-watershed, with distroferric red latosol (rich in Fe and Al), being characterized by distinct metals, predominantly acidic pH, and high conductivity. Overall, 221 diatom...
Article
Actinella guianensis Grunow (Eunotiaceae): analysis of the type material and the description of Actinella cordiformis sp. nov. Abstract: The taxonomic concept of Actinella guianensis Grunow is well-established in the literature. However, during the analysis of recent samples from two Amazon blackwater habitats, we found an uncommon and oddly shaped...
Article
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The genus Simonsenia is characterized by the raphe system that opens into a longitudinal channel over a marginal keel, and small circular areolae, occluded by hymens. So far, the occurrence of Simonsenia species in Brazil is known only by two records of S. delognei, documented in light microscopy. Here, are described three new species of Simonsenia...
Article
Actinella gessneri Hustedt is a rare and poorly known Amazonian diatom species. Low records and restricted distribution to acid waters suggest that this species may be threatened with extinction. We record a new occurrence of Actinella gessneri Hustedt in Amazonian blackwaters, providing detailed images on LM and SEM, and approaching ecological asp...
Article
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Diatoms constitute a representative portion of the algal community of freshwater aquatic environments, but their studies are centered mostly in the south and southern regions of Brazil, making the microalgae biodiversity of water bodies in the semiarid practically unknown. In the state of Ceará, the few records of the Bacillariaceae are centered in...
Article
Abstract: The genus Humidophila is mainly characterized by small cells, striae often composed by one elongated areola occluded by thin hymenes. Species are distributed globally and are common in moist sub–aerial habitats. We identified five Humidophila species found in the well–conserved freshwater bodies and subaerial wet habitats from the mountai...
Article
In a Brazilian karst environment, composed predominantly of carbonate rocks, diatoms were collected in periphytic habitat (epiphyton, epilithon, epipsammon) in lentic and lotic water bodies from the Serra da Bodoquena. This Pantanal region is known for its tourist and scenic value, covering springs and rivers with extensive formation of active lime...
Article
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Abstract The Paranaguá Estuarine Complex (PEC) is one of Brazil's largest southwest Atlantic estuarine systems, possessing a rich microalgae diversity that remains to be fully explored. Therefore, due to the increasing interest in the microalgae biotechnological potential, this study isolated and identified diatoms found in the PEC. The diatoms wer...
Article
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Temporal stability in beta diversity does not guarantee surrogacy or compositional stability in a micro-phytoplankton metacommunity Temporal stability in beta diversity does not guarantee surrogacy or compositional stability in a micro-phytoplankton meta-community. In this study, we evaluated phytoplankton community organization (i.e., microalgae f...
Article
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Associating anthropogenic effects with variations in biodiversity is key to understanding how anthropogenic impacts are extrapolated in public supply micro-watersheds. The structure and dynamics of metacommunities in aquatic environments depend not only on the river network itself, but on a multitude of factors. Therefore, we associate the density...
Article
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The Caatinga is the largest tropical dry forest region in South America and harbors an impressive biological diversity. However, efforts in the studies of many groups of organisms, especially aquatic ones, are very small compared to other Brazilian regions. The state of Ceará stands out due to the major concentration of surface water in the semi-ar...
Article
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The biotechnological potential of microalgae has been the target of a range of research aimed at using its potential to produce macromolecules with high added value. Particular focus has been given to biofuels' production, such as biohydrogen, biodiesel, and bioethanol from lipids and carbohydrates extracted from microalgal biomass. Bioprospecting...
Article
The samples for this study were collected from terrestrial mosses and lichens growing on palm tree trunks and concrete walls in the city of Rio de Janeiro, south-eastern Brazil. During the investigation on diatom diversity, a new species from the genus Luticola was found. The new species occurred individually at all sampling sites. The aim of this...
Article
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Abstract: During a survey on freshwater epilithic diatoms from subtropical lotic environments belonging to the Cascavel River microbasin, Paraná State, Brazil, we observed populations of a new Nupela Vyverman et Compère species. Morphological and meristic analyses were performed using light and scanning electron microscopy, resulting in the descrip...
Article
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O presente estudo teve como objetivo realizar um levantamento florístico para conhecer as espécies do gênero Pinnularia Ehrenberg (Bacillariophyceae) encontradas no lago Jurucuí, município de Belterra, estado do Pará. A pesquisa baseou-se em amostras obtidas no sedimento, plâncton e perifíton em junho de 2018. No presente estudo, o gênero Pinnulari...
Research
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A Caatinga é a maior região de floresta tropical seca da América do Sul e abriga uma diversidade biológica impressionante. Porém, ainda há grandes lacunas em relação aos estudos de diversos grupos de organismos, principalmente os aquáticos, se comparados a outras regiões brasileiras. A flora de diatomáceas é praticamente desconhecida no estado do C...
Chapter
In this chapter, we reviewed the main studies on freshwater ecosystems of the Atlantic Forest, Brazil. We have firstly provided a list of the hydrographic basins that cross the Atlantic Forest and propose a classification of Atlantic Forest freshwaters based on a proposed wetland classification for Brazil. Anthropogenic disturbances and freshwater...
Article
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Eunotia species from a stream located in the surrounding area of the Iguaçu National Park conservation unit were analyzed. Samples were monthly collected from September 2012 to August 2013. The periphytic material, manually obtained by squeezing aquatic macrophytes, was oxidized and analyzed under light and scanning electron microscopy. Twenty-one...
Conference Paper
Abstract—Surveys studies carried out in different countries demonstrated that about 75% of lake water samples contain toxic cyanobacteria [4, 5]. The toxin that is must recurrent in Brazilian water bodies are the microcystin [6]. Microcystins are hepatotoxins produced by some species of cyanobacteria, and act by inflicting damage to cells from the...
Article
We evaluated the response of diatom community relative to environmental changes with the aim of characterizing and comparing, along a linear gradient, three environments across the Cascavel River microbasin with distinct land-uses. In June 2016, 10 substrates were collected for periphyton extraction in locations with different land-uses (conservati...
Conference Paper
Cianobactérias são organismos que podem ocorrer em reservatórios e mananciais. Algumas espécies podem produzir toxinas, nocivas por contato ou ingestão, podendo causar até morte. A lei exige análises periódicas da água destinada à população, para monitorar e controlar a qualidade. O processo de identificação e contagem das células de cianobactérias...
Article
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Diatom growth strategies, which are used as a proxy to analyze disturbances and environmental impacts, can also provide reliable information about environmental gradients. In this study, we used diatom communities and biological traits to assess the structure of epilithic diatoms after an oil spill in a large tributary of the Iguaçu River (Paraná,...
Article
In the present study, we analyzed the taxonomy and ecology of fourteen species of Luticola registered in oligo-to hyper-eutrophic 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 simi...
Article
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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...
Article
In the present study, two new species of Nitzschia Hassall, Nitzschia pusilluhasta sp. nov. and Nitzschia australodesertorum sp. nov. are described from reservoirs in the state of São Paulo southeast Brazil. The morphology of the new species was analysed using light and electron microscopy. Nitzschia pusilluhasta is distinguished from morphological...
Article
In the present study, two new species of Nitzschia Hassall, Nitzschia pusilluhasta sp. nov. and Nitzschia australodesertorum sp. nov. are described from reservoirs in the state of São Paulo southeast Brazil. The morphology of the new species was analysed using light and electron microscopy. Nitzschia pusilluhasta is distinguished from morphological...
Article
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Floodplains are heterogeneous ecosystems that occupy a large area in the neotropic regions, which show great diatom diversity. During a floristic survey of periphytic and sedimentary samples in a swamp from the Upper Paraná River Floodplain in Brazil, a new species of Actinella Lewis and Gomphonema Ehrenberg (Bacillariophyceae) were found. We detai...
Article
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Type material of Navicula kotschyi was studied, and this species was transferred to Dorofeyukea gen. nov. as D. kotschyi comb. nov. Dorofeyukea was described on the basis of DNA sequence and morphological data. Additional species assigned to this genus that were previously included in Navicula include: D. ancisa comb. nov., D. grimmei comb. nov., D...
Article
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Aim Relationships between species composition and variation patterns in diatom assemblages over six tropical reservoirs located in Southeast Brazil were explored. Methods Surface-sediment and phytoplankton diatom assemblages were determined and Canonical Correspondence Analysis was used to verify the set of environmental variables that best explain...
Article
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The morphology of three Stauroneis species from midwestern karstic Brazilian formations was illustrated under light and electron microscopy. Two new Stauroneis are described and compared with similar species in the genus. Stauroneis cav-alcantei Tremarin, Tusset & T. Ludwig is characterized by lanceolate valves with subtly protracted apices, and S....
Article
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Gomphonema Ehrenberg is a genus well represented in periphytic algal flora of epicontinental environments. The substrate colonization is facilitated by the secretion of mucilage by the pore field, allowing cell adhesion. Samples were scraped off and analyzed from vegetative portions of the macrophyte Eichhornia azurea Kunth, collected in São Franci...
Conference Paper
Full-text available
Diatomáceas são comumente utilizadas como bioindicadores da qualidade da água em ambientes aquáticos dulcícolas, uma vez que sua ocorrência possui intrínseca relação com as condições ambientais. Para o estudo, realizaram-se coletas de fitoplâncton no ribeirão Coati Chico, afluente do rio Cascavel, na área rural próximo a uma das três estações de tr...
Article
Diatoms grow under very specific physical and chemical conditions, and eutrophication may cause community variation. We aimed to describe spatial and temporal variation in diatom community diversity in two urban reservoirs of different throphic status at different spatial scales. We collected samples of epiphytic diatoms from aquatic macrophytes fr...
Article
The genus Luticola is characterized mainly by valves with an internal longitudinal channel located at the valve face/mantle junction, rounded areolae and an isolated pore (stigma) near the central area. Studies on Luticola species that occur in Brazil are scarce. Therefore, this paper illustrates and describes the morphology of 18 species of Lutico...
Article
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Dinoflagellate taxonomy has been undergoing a comprehensive review in recent decades. Knowledge on Brazilian dinoflagellate flora remains quite incomplete, particularly regarding the size of the country. This study is the first taxonomic survey of freshwater dinoflagellates in the State of Paraná, southern Brazil. Forty– one freshwater environments...
Article
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A taxonomic study of species of the genus Gomphonema Ehrenberg (Bacillariophyceae) was performed in alotic environment (Ipoitã Channel) of the Upper Paraná River Floodplain. Samplings were performed in June, September and December 2013 and February 2014. Two petioles of Eichhornia azurea (Sw) Kunth were sampled at three different sites in the chann...
Article
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Six species of Adlafia Moser, Lange-Bertalot et Metzeltin from Brazilian freshwater environments were investigated under light and electron microscopes. Two new taxa are described. Adlafia decora Tusset, Tremarin & T. Ludwig is characterized mainly by linear-lanceolate valves and rostrate ends, and A. triundulata Tusset, Tremarin & T. Ludwig shows...
Article
Six species of Adlafia Moser, Lange-Bertalot et Metzeltin from Brazilian freshwater environments were investigated under light and electron microscopes. Two new taxa are described. Adlafia decora Tusset, Tremarin & T. Ludwig is characterized mainly by linear-lanceolate valves and rostrate ends, and A. triundulata Tusset, Tremarin & T. Ludwig shows...
Article
Catalogue of diatom names resurrected: diatombase will be the new authority resource for diatom names and more.
Article
The structure of epiphytic diatom communities in a reservoir and a stream were studied with regard to different taxonomic levels (species, genera, and families) and biological traits (strategies of attachment to the substrate). We expected that strongly attached diatoms would abound in the stream, and those employing a loosely attached strategy sho...
Article
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The evaluation of abiotic and biotic variables can provide information for understanding the structure and function of lotic systems. To obtain this information, measurements of 15 chemical and physical variables and of phytoplankton were conducted at two sampling stations. The present study aims to evaluate the temporal and spatial variation of pl...
Article
Actinella leontopithecus-rosalia is a poorly known diatom described from southeast Brazil. Its similarity with other Actinella taxa and the lack of morphological data make it difficult the species recognition by researchers. This study addresses unpublished morphologic and morphometric details of frustule and expands the geographic distribution of...
Article
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We conducted a taxonomical study of epiphytic diatoms on the macrophytes Polygonum hydropiperoides, Ludwigia peruviana and Alternanthera philoxeroides collected in the mesotrophic reservoir Piraquara II flooded in 2009, located in the state of Paraná. A total of 135 infrageneric taxa were identified, among them five at generic level and other five...
Article
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The study of the genus Melosira in plankton samples from the lower Iguaçu River revealed the presence of four taxa: Melosira undulata (Ehrenberg) Kützing var. undulata, M. undulata var. normanni Arnott, M. varians C. Agardh and M. muscigena Iwahashi. We present illustrations of the frustules using light microscopy (LM), descriptions, and comments a...
Article
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Fragilaria longifusiformis (Hains & Sebring) Siver et al. is a planktonic diatom distributed widely aroud the world, with rare published records or information on its occurrence in Brazil. We believe that the valve face ornamentations, inconspicuous under light microscopy, hinder the accurate identification of the species, leading to misidentificat...
Article
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Fragilaria longifusiformis (Hains & Sebring) Siver et al. (Diatomeae) in subtropical rivers and reservoirs. Fragilaria longifusiformis (Hains & Sebring) Siver et al. is a planktonic diatom distributed widely aroud the world, with rare published records or information on its occurrence in Brazil. We believe that the valve face ornamentations, incons...
Article
Full-text available
A taxonomic survey was carried out of the genus Eunotia in the Hercílio River, state of Santa Catarina, southern Brazil. Trimestral collections were made (April, July and October 2009) at four sampling stations, totaling 12 samples. The survey of the genus Eunotia resulted in the identification of 30 taxa, four of which were determined at generic l...
Article
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Specimens belonging to the Cymbella affinis / Cymbella tumidula / Cymbella turgidula species complex have many taxonomic problems, due to their high morphological variability and lack of type designations. Fifteen taxon names of this complex, distributed in five species, were re-evaluated concerning their taxonomic status, and lectotypified based o...
Article
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The genus Nupelais characterized mainly by structure of the areola and raphe system. Many species were described from tropical regions; however, few studies have been conducted on Brazilian environments. The goal of this article is to identify and describe the morphology of Nupela species, under light and electron microscopy, found in the rivers of...
Article
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Acanthoceras Honigmann and Urosolenia Round & Crawford emend. Rott, Kling & McGregor species were studied based on samples of 19 hydroelectric power plants reservoirs located in the State of Paraná, Southern Brazil. Autoecological informations of Urosolenia species complement the study. One Acanthoceras and four Urosolenia species were identified:...
Article
Full-text available
The most distinctive feature of Capartogramma Kufferath is the x-shaped thickening of silica at valve center, namely the tigillate stauro. In addition, pseudosepta at the valve apices and uniseriate striae composed by rounded areolae characterize the genus. Seven species have been described to date, including Capartogramma paradisiaca Novelo, Taver...
Article
ABSTRACT - Fragilaria longifusiformis (Hains & Sebring) Siver et al. (Diatomeae) in subtropical rivers and reservoirs. Fragilaria longifusiformis (Hains & Sebring) Siver et al. is a planktonic diatom distributed widely aroud the world, with rare published records or information on its occurrence in Brazil. We believe that the valve face ornamentati...
Article
The most distinctive feature of Capartogramma Kufferath is the x-shaped thickening of silica at valve center, namely the tigillate stauro. In addition, pseudosepta at the valve apices and uniseriate striae composed by rounded areolae characterize the genus. Seven species have been described to date, including Capartogramma paradisiaca Novelo, Taver...
Article
Full-text available
The most distinctive feature of Capartogramma Kufferath is the x-shaped thickening of silica at valve center, namely the tigillate stauro. In addition, pseudosepta at the valve apices and uniseriate striae composed by rounded areolae characterize the genus. Seven species have been described to date, including Capartogramma paradisiaca Novelo, Taver...
Article
Full-text available
Eunotia is a highly diverse diatom genus in the Neotropics. Considerable morphological variability of the valve showed in several species of the genus resulted in a quite confused taxonomy. Twelve Eunotia taxa attached to Podostemum spp. were investigated using the light microscopy (LM). Additionally, scanning electron microscopy (SEM) was used in...
Article
Full-text available
Examination of samples from different aquatic environments from Brazil revealed the presence of a new Aulacoseiraspecies. Aulacoseira veraluciae Tremarin, Torgan & T. Ludwig is described and illustrated with light and scanning electron microscopy, and its morphology compared with that of similar species, such as A. muzzanensis (Meister) Krammer, A....
Article
Full-text available
Eunotia is a highly diverse diatom genus in the Neotropics. Considerable morphological variability of the valve showed in several species of the genus resulted in a quite confused taxonomy. Twelve Eunotia taxa attached to Podostemum spp. were investigated using the light microscopy (LM). Additionally, scanning electron microscopy (SEM) was used in...
Article
Examination of samples from two lakes in the Matogrossense Pantanal, midwest Brazil, revealed the presence of four new Aulacoseira species, A. minuscula Tremarin, Torgan & T. Ludwig, A. pantanalensis Tremarin, Torgan & T. Ludwig, A. samariana Tremarin, Torgan & T. Ludwig and A. simoniae Tremarin, Torgan & T. Ludwig. These are described and illustra...
Article
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A taxonomic survey was carried out on Coscinodiscophyceae and Fragilariophyceae found in the Iguaçu River catchment area within Iguaçu National Park, in the state of Paraná, Brazil. Between September 2007 and August 2008, we collected 24 samples from two stations on the Iguaçu River, upstream and downstream of the falls. We identified 37 taxa, incl...