Non-marine algae of Australia : 2. Some conspicuous tuft-forming Cyanobacteria

Skinner, Stephen; Entwisle, Timothy J.

doi:10.7751/telopea20024008

Cited by 3 publications

(3 citation statements)

References 4 publications

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“…However, the structure of filaments is not always quite similar (cell size in the main filament, cell size in branches, stratification), but it is difficult to evaluate if the variations are really meaningful. A critical review of different Stigonema ocellatum descriptions and illustrations found in literature (Frémy 1930, Geitler 1932, Skinner & Entwisle 2001, Komárek & Hauer 2011 corroborates that a very wide morphological range is recorded for the species, even though most of the populations can be correctly identified on the basis of the species original description. The present results from morphological and molecular studies and the available data in literature allow considering that S. ocellatum is probably a complex of species rather than a well delimited species.…”

Section: Discussionmentioning

confidence: 84%

True branched nostocalean cyanobacteria from tropical aerophytic habitats and molecular assessment of two species from field samples

Ferreira

Branco

Kaštovský

2013

RBT

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Aerophytic cyanobacteria are commonly found growing on rocks, tree trunks and soil, but the diversity of these organisms is still poorly known. This complex group is very problematic considering the taxonomic arrangement and species circumscription, especially when taking into account tropical populations. In this work, 20 samples of aerophytic cyanobacteria from 15 distinct sampling sites were collected along a tropical rainforest area at the São Paulo State (Brazil). Samples were dried at room temperature after the collection, and once in the laboratory, they were rehydrated and analyzed. The taxonomic study resulted in the record and description of nine species of true-branched cyanobacteria pertaining to the genera Spelaeopogon (one specie), Hapalosiphon (two species) and Stigonema (six species). The similarity of the flora found when compared to surveys conducted in other geographical regions was relatively low. These differences could be addressed to ecological conditions of the habitats, to the extension of the area surveyed or even to taxonomic misinterpretations. The molecular assessment of 16S rDNA on the basis of field material was successful for two morphospecies, Hapalosiphon sp. and Stigonema ocellatum; however, their relationships with other populations and species revealed to be uncertain. The results of the floristic survey and of the molecular approach evidenced the fragile delimitation of some genera and species in the true branched group of cyanobacteria.

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Section: Discussionmentioning

confidence: 84%

True branched nostocalean cyanobacteria from tropical aerophytic habitats and molecular assessment of two species from field samples

Ferreira

Branco

Kaštovský

2013

RBT

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“…Branco & Necchi 1996. Muitas dessas macroalgas apresentam hábito de crescimento similar a tufos emaranhados, algumas vezes com uma ampla capa gelatinosa, e que se desenvolvem de modo mais conspícuo em regiões de pequenas corredeiras (Skinner & Entwisle 2001).…”

Section: Introductionunclassified

“…O tricoma heteropolar apresenta falsas ramificações com heterocitos apicais ou menos frequentemente intercalares (Branco et al 2009). A presença de T. distorta tem sido reportada para as mais diversas regiões do mundo: América do Norte (Sheath & Cole 1992), Austrália (Skinner & Entwisle 2001), Europa (Holmes & Whitton 1981). No Brasil essa alga também já foi observada ocorrendo em riachos principalmente da região sudeste do país (p.ex.…”

Section: Introductionunclassified

Microhabitat de Tolypothrix distorta Kütz. ex Bornet & Flahault (Microchaetaceae, Cyanophyta) em dois riachos da região Centro-Sul do Estado do Paraná, Brasil

Krupek

Branco

Peres

2013

Hoehnea

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-(Microhabitat of Tolypothrix distorta Kütz. ex Bornet & Flahault (Microchaetaceae, Cyanophyta) in two streams from midsouthern region of Paraná State, Brazil). This study aimed to evaluate some microhabitat characteristics of two populations of Tolypothrix distorta in streams from midsouthern region of Paraná State on a seasonal period. Each population was monthly investigated for the abundance of T. distorta and environmental variables such as depth, current velocity, irradiance, richness, and substrate diversity (H') using the quadrat technique for each sample unit (n = 7-10). For each segment the following physical and chemical water variables were also measured: temperature, oxygen saturation, specific conductance, pH, and turbidity. The seasonal period of higher abundance (percent cover) occurred during the months corresponding to summer/fall for both populations. The analyses also showed that populations had lower niche width and wide variation under the environmental conditions, characterizing the species as a generalist in the use of resources. Faster water flow and larger substrates favored the development of T. distorta, which may be related to the species morphological characteristics, thallus type that consists of tangled filaments formed by tuft and covered with thick gelatinous coats. Key words: autoecology, macroalgae, Tolypothrix distorta, seasonal variation RESUMO -(Microhabitat de Tolypothrix distorta Kütz. ex Bornet & Flahault (Microchaetaceae, Cyanophyta) em dois riachos da região Centro-Sul do Estado do Paraná, Brasil). O presente estudo teve por objetivo avaliar temporalmente algumas características de microhabitat de duas populações de Tolypothrix distorta em riachos da região Centro-Sul do Estado do Paraná. As populações foram avaliadas mensalmente, através da técnica de quadrados, quanto à abundância de T. distorta e as variáveis microambientais profundidade, velocidade da correnteza, irradiância, riqueza e diversidade (H') do substrato para cada unidade amostral (n = 7-10). Para cada trecho foram ainda medidas as seguintes variáveis físicas e químicas da água: temperatura, saturação de oxigênio, condutividade, pH e turbidez. O período sazonal de maior abundância (cobertura percentual) ocorreu, para ambas as populações, durante os meses correspondentes ao verão/outono. As análises mostraram que as populações apresentaram baixa largura de nicho e ampla variação nas condições ambientais ocorrentes, caracterizando a espécie como generalista quanto ao uso dos recursos. Os resultados sugerem que a elevada velocidade da correnteza e os substratos de maior tamanho favoreceram o desenvolvimento de T. distorta, que pode estar relacionado com as características morfológicas, talo tipo tufo formado por filamentos emaranhados e coberto com ampla capa gelatinosa da espécie.

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Stream macroalgal flora from Parnaíba River Basin, Brazil: reducing Wallacean shortfall

2019

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The global biodiversity loss is a consensus. The biodiversity conservations shortfalls make conservation of biological diversity even more challenging. For many taxa, the knowledge about their distributions is deficient, and this is called the Wallacean shortfall. This situation is no different within algae biodiversity, especially in Brazil. There is still an enormous inequity of sample effort, as is the case of the Parnaíba River Basin (Northeast region), which had only 10 algal species in published (the lowest number of algal species reported among the main Brazilian basins). The present work had the objective of increasing the knowledge of algal flora in Brazil by conducting a taxonomic study of the stream macroalgal species of the Parnaíba River Basin. The sampling of macroalgae was carried out in 21 segments of streams from the Middle and Lower Parnaíba Basin, in the Piauí and Maranhão states. Macroalgae were manually removed and preserved in 4% formaldehyde. Environmental characteristics of each segment were measured in order to describe the sampling sites. The taxonomic survey of the macroalgal communities resulted in the identification of 38 taxa in total, of which 32 at a specific level; three vegetative groups; two sporophytic stages of red algae and one unidentified species. Among the 38 species recorded, 37 are new records for the Parnaíba River Basin. Following the same pattern, 23 species are new records for the Brazilian Northeast region, and Microcoleus lacustris represented the first report in Brazil. Despite the fact that it remains the Brazilian basin with the lowest number of algal species documented, this study contributed to the increase of almost five times the number of species sampled in the Parnaíba River Basin (from only 10 to 47 species). These data reinforce that the differences presented in algal diversity in the Brazilian regions are more related to the sampling effort than other factors (e.g. environmental characteristics, geographic distribution, biomes, among others). In addition, this survey illustrates not only the group's lack of information in the region but also shows the importance of this type of study as a tool for expanding the knowledge about biodiversity and its conservation.

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Non-marine algae of Australia : 2. Some conspicuous tuft-forming Cyanobacteria

Cited by 3 publications

References 4 publications

True branched nostocalean cyanobacteria from tropical aerophytic habitats and molecular assessment of two species from field samples

True branched nostocalean cyanobacteria from tropical aerophytic habitats and molecular assessment of two species from field samples

Microhabitat de Tolypothrix distorta Kütz. ex Bornet & Flahault (Microchaetaceae, Cyanophyta) em dois riachos da região Centro-Sul do Estado do Paraná, Brasil

Stream macroalgal flora from Parnaíba River Basin, Brazil: reducing Wallacean shortfall

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