ABSTRACT This study aimed to determine if there are any differences in the attributes and composition of the phytoplankton and epiphyton communities between organic (OF) and conventional (CF) rice fields. We also strove to identify if there were any variations in these communities by comparing samples taken from two different periods (12 and 35 days) after the application of the herbicide clomazone and penoxsulam in CF. The farms are located in the Pampa Biome, Southern Brazil. Phytoplankton samples from the subsurface water and epiphyton samples from the rice stems were analyzed using the Utermöhl method. The CF and OF had distinct environmental conditions (pH, conductivity, and turbidity values), and the residual concentration of the herbicides decreased over time. There were no significant differences in epiphyton and phytoplankton density, or in phytoplankton richness, between the rice fields; only the epiphyton richness and taxonomic composition showed differences between the rice fields. Cyanobacteria and Chlorophyceae comprised a large proportion of the epiphytic density in CF and OF, respectively. However, Bacillariophyceae and Chlorophyceae had greater phytoplankton densities in CF and OF, respectively. The taxonomic composition of communities should be considered an effective tool to show the differences between the two cultivation systems.

Abstract The BIOTA/FAPESP Program made the “São Paulo State algal flora” possible through a very intensive sampling program that aimed at (1) collecting as equally as possible from lentic, semi-lentic, and lotic environments, (2) performing the most uniform possible coverage of the state’s territory, and (3) fostering the collection of periphytic and surface sediments materials that had been extremely neglected till then. The study of all this material made it clear that the biodiversity of the Zygnematophyceae increased by 100%, the Euglenophyceae by 34%, and the Chlorophyceae by 97%, the last being only due to the study of the Chlorococcales. The Bacillariophyceae are in the final phase of their floristic survey, but it is already possible to see an increase in biodiversity of over 700%. Byproducts from the BIOTA/FAPESP algae are a key for the taxonomic identification of freshwater algal genera occurring in Brazil in its third edition, and the production of the most complete algal flora ever carried out in Brazil, that of the Ipiranga River Sources State Park that already totals 919 taxa.

Resumo O Programa BIOTA/FAPESP possibilitou a organização da “Flora ficológica do Estado de São Paulo” com o desenvolvimento de um programa intensivo de coleta que visou (1) amostrar de forma equivalente os ambientes lêntico, semilêntico e lótico, (2) realizar da forma mais uniforme possível a cobertura do território do Estado e (3) privilegiar a coleta de materiais perifítico e de sedimentos superficiais, que haviam sido extremamente negligenciados até então. O estudo de todo esse material mostrou que as Zygnematophyceae apresentaram aumento de 100% de sua biodiversidade, as Euglenophyceae de 34% e as Chlorophyceae de 97%, porcentual este, entretanto, devido à conclusão apenas do estudo das Chlorococcales. As Bacillariophyceae estão na fase de conclusão de seu levantamento florístico, mostrando que o aumento da biodiversidade deverá suplantar os 700%. Há, finalmente, produtos laterais gerados pelo Programa BIOTA/FAPESP representados pela publicação de uma chave para identificação dos gêneros de algas de águas continentais que ocorrem no Brasil, que se encontra na terceira edição; e a realização da flora ficológica mais completa já produzida em nível brasileiro, a do Parque Estadual das Fontes do Ipiranga que soma, em fase de finalização, 919 táxons.

Survey was carried out of family Bacillariaceae (Bacillariophyceae) in the Parque Estadual das Fontes do Ipiranga, São Paulo, southeast Brazil, based on 28 samples. Analysis of specimens from the morphological point of view was made utilizing light microscope after oxidation and preparation of permanent slides. Four genera, 27 species and three varieties that are not the typical of their respective species were identified, from which nine are new registers for the State São Paulo [Nitzschia acicularis Hustedt, N. acidoclinata Lange-Bertalot, N. clausii Hantzsch, N. dissipata (Kützing) Rabenhorst, N. intermedia Hantzsch, N. palea (Kützing) W. Smith var. tenuirostris Grunow, N. subacicularis Hustedt, Tryblionella debilis Arnott ex O’Meara, and T. victoriae Grunow], and two are new records for the Brazilian territory [Grunowia solgensis (Cleve-Euler) Aboal and N. dissipata (Kützing) Rabenhorst var. borneensis Kützing]. Each identification was based on population samples, is presented by their morphological description and measurements, and is illustrated by photomicrographs.

O levantamento florístico da família Bacillariaceae (Bacillariophyceae) foi realizado para a área do Parque Estadual das Fontes do Ipiranga, São Paulo, Brasil, com base em 28 unidades amostrais. O exame do material do ponto de vista morfológico foi realizado ao microscópio óptico após oxidação e confecção de lâminas permanentes. Quatro gêneros, 27 espécies e três variedades que não são as típicas de suas respectivas espécies foram identificados. Nove desses táxons foram registrados pioneiramente para o Estado de São Paulo [Nitzschia acicularis Hustedt, N. acidoclinata Lange-Bertalot, N. clausii Hantzsch, N. dissipata (Kützing) Rabenhorst, N. intermedia Hantzsch, N. palea (Kützing) W. Smith var. tenuirostris Grunow, N. subacicularis Hustedt, Tryblionella debilis Arnott ex O’Meara e T. victoriae Grunow] e dois para o Brasil [Grunowia solgensis (Cleve-Euler) Aboal e N. dissipata (Kützing) Rabenhorst var. borneensis Kützing]. Todo material foi identificado com base em amostras populacionais, descrito através de suas características morfológicas e medidas e ilustrado por fotomicrografias.

RESUMO Criptógamos do Parque Estadual das Fontes do Ipiranga, São Paulo, SP. Algae 46: Bacillariophyceae (Bacillariaceae). O levantamento florístico da família Bacillariaceae (Bacillariophyceae) foi realizado para a área do Parque Estadual das Fontes do Ipiranga, São Paulo, Brasil, com base em 28 unidades amostrais. O exame do material do ponto de vista morfológico foi realizado ao microscópio óptico após oxidação e confecção de lâminas permanentes. Quatro gêneros, 27 espécies e três variedades que não são as típicas de suas respectivas espécies foram identificados. Nove desses táxons foram registrados pioneiramente para o Estado de São Paulo [Nitzschia acicularis Hustedt, N. acidoclinata Lange-Bertalot, N. clausii Hantzsch, N. dissipata (Kützing) Rabenhorst, N. intermedia Hantzsch, N. palea (Kützing) W. Smith var. tenuirostris Grunow, N. subacicularis Hustedt, Tryblionella debilis Arnott ex O’Meara e T. victoriae Grunow] e dois para o Brasil [Grunowia solgensis (Cleve-Euler) Aboal e N. dissipata (Kützing) Rabenhorst var. borneensis Kützing]. Todo material foi identificado com base em amostras populacionais, descrito através de suas características morfológicas e medidas e ilustrado por fotomicrografias.

ABSTRACT Cryptogams of the Parque Estadual das Fontes do Ipiranga, São Paulo, SP. Algae, 46: Bacillariophyceae (Bacillariaceae). Survey was carried out of family Bacillariaceae (Bacillariophyceae) in the Parque Estadual das Fontes do Ipiranga, São Paulo, southeast Brazil, based on 28 samples. Analysis of specimens from the morphological point of view was made utilizing light microscope after oxidation and preparation of permanent slides. Four genera, 27 species and three varieties that are not the typical of their respective species were identified, from which nine are new registers for the State São Paulo [Nitzschia acicularis Hustedt, N. acidoclinata Lange-Bertalot, N. clausii Hantzsch, N. dissipata (Kützing) Rabenhorst, N. intermedia Hantzsch, N. palea (Kützing) W. Smith var. tenuirostris Grunow, N. subacicularis Hustedt, Tryblionella debilis Arnott ex O’Meara, and T. victoriae Grunow], and two are new records for the Brazilian territory [Grunowia solgensis (Cleve-Euler) Aboal and N. dissipata (Kützing) Rabenhorst var. borneensis Kützing]. Each identification was based on population samples, is presented by their morphological description and measurements, and is illustrated by photomicrographs.

Resumen El fitoperifíton es una de las comunidades más importantes en las ciénagas o lagos de planos inundables por el papel que desempeña en el flujo de la energía, el ciclo de nutrientes y la productividad primaria de estos importantes ecosistemas. En este estudio se analizó la comunidad fitoperifítica asociada con tres especies de macrófitas (Ludwigia sedoides Humb. and Bonpl. Hara 1953, Nymphoides indica L. Kuntze, 1891 y Eichhornia azurea Swartz. Kunth, 1843) en una ciénaga tropical de la cuenca del río Atrato, Chocó, Colombia. Los muestreos se realizaron entre mayo y agosto del 2014 mediante la recolección de muestras de fitoperifíton de raíces de tres ejemplares de cada especie estudiada. Simultáneamente se midieron algunas variables físicas y químicas del agua circundante. Se registró una densidad de 1.160,63 ind.cm-2, distribuida en 82 morfoespecies, 26 familias, 16 órdenes y ocho clases, siendo la clase Bacillariophyceae la más abundante en las tres especies estudiadas. L. sedoides presentó la mayor densidad y riqueza fitoperifítica asociada. Se registraron diferencias en los valores de densidad, riqueza, diversidad y dominancia del fitoperifíton de las macrófitas estudiadas (p<0,05). El análisis de agrupamiento basado en el índice de Jaccard indicó poca similitud en la composición de la comunidad perifítica entre las especies de macrófitas, así como un marcado efecto del periodo hidrológico. En el estudio se establece la línea de base para el conocimiento de las comunidades fitoperifíticas asociadas con macrófitas en las ciénagas de zonas bajas tropicales como las del río Atrato.

Abstract The phytoperiphyton is one of the main communities in swamps or floodplains given its fundamental role in the energy flow, the nutrient cycle, and the primary productivity of these ecosystems. In the present study, I analyzed the phytoperiphytic community associated with three macrophyte species (Ludwigia sedoides Humb. and Bonpl. Hara 1953, Nymphoides indica L. Kuntze, 1891, and Eichhornia azurea Swartz. Kunth, 1843) in a tropical swamp in the Atrato River basin, Chocó-Colombia. I collected the phytoperiphyton samples between May and August 2014 from the roots of three specimens of each of the species under study, and I measured some physical and chemical variables of the surrounding water. I registered a density of 1160.63 ind.cm-2 distributed in 82 morphospecies, 26 families, 16 orders, and eight classes, the Bacillariophyceae class being the most abundant. L. sedoides presented the highest density and associated phytoperiphytic richness. I found differences in the density, richness, diversity, and dominance of the phytoperiphyton among the studied macrophytes (p<0.05). Clustering analysis based on the Jaccard index indicated a low similarity in the composition of the phytoperiphytic community among the macrophyte species, as well as a marked effect of the hydrological period. The present study constitutes a baseline for the knowledge of the phytoperiphytic communities associated with macrophytes in the swamps of low tropical areas such as the Atrato River basin.

Resumen En el presente estudio se evaluaron la diversidad y la distribución de la comunidad fitoperifítica de un río andino amazónico, el río Hacha (en el municipio de Florencia, Caquetá), mediante el análisis de esta comunidad asociada con un sustrato rocoso en cuatro estaciones del gradiente altitudinal del río en periodos de alta y baja precipitación. En cada periodo climático se analizó la variación espacial de la composición y la abundancia del fitoperifiton, así como los factores ambientales que pueden ser responsables de dicha variación, y se contrastaron a partir de pruebas de comparación múltiple, un Anova y un análisis de ordenación. Se evidenció un aumento aguas abajo de la temperatura, la turbidez, y la demanda biológica de oxígeno y amonio, y una disminución de oxígeno disuelto a medida que se pasaba de las mayores altitudes a las menores durante los dos períodos analizados. Las variables de turbidez, temperatura y conductividad influyeron positivamente sobre la abundancia y la biomasa. El índice de Shannon tuvo una relación inversa significativa con las variables de demanda biológica de oxígeno y amonio y una positiva con las variables de pH y oxígeno disuelto. La clase Bacillariophyceae fue la de mayor distribución altitudinal, así como de morfoespecies registradas (52,3 %), y las estaciones A1 y A2 presentaron la mayor diversidad fitoperifítica en los muestreos. La estación Puente López (A4) registró los menores valores de riqueza y valores elevados de demanda biológica de oxígeno y amonio en las dos épocas de muestreo.

Abstract In the present study, we evaluated the diversity and distribution of the phytoperiphytic community of the Hacha River, an Andean-Amazonian river in the Florencia (Caquetá) associated with a rocky substrate in four stations along the altitudinal gradient of the river during periods of high and low precipitation. In each season, we analyzed the spatial variation of the composition and the abundance of the phytoperiphyton, as well as the environmental factors that may be responsible for this variation, contrasting them through various tests, an Anova, and management analysis. We registered an increasing gradient downstream of temperature, turbidity, and biological demand for oxygen and ammonium, as well as decreasing values of dissolved oxygen from the highest altitudes to the lowest during the two periods analyzed. The turbidity, temperature, and conductivity variables positively influenced biomass and ammonia abundance. The Shannon index presented a significant inverse relationship with the biological oxygen demand and ammonia, and a positive one with pH and dissolved oxygen. The Bacillariophyceae class had the highest altitudinal distribution and stations A1 and A2 presented the greatest phytoperiphytic diversity among samplings. The Puente López station (A4) registered the lowest richness and high values of biological demand of oxygen and ammonium in the two sampling periods.

The floristic survey of Brachysira Kützing (Naviculales) of the Parque Estadual das Fontes do Ipiranga (PEFI), São Paulo, São Paulo State, Brazil, resulted from the analysis of 31 permanent preparations of diatom material collected between years 1991 and 2017. The water and substrate samples (macrophytes and rocks) from lentic systems, streams and the hydrophytoterium were collected and subsequently were oxidized for analysis under light microscope. Nine species and one morphotype were identified from 15 diatom slides, of which four species are new records for Brazil (Brachysira cf. calcicola Lange-Bertalot, Brachysira frenguellii (Manguin) Lange-Bertalot &amp; Moser, Brachysira huitotarum Vouilloud, Sala &amp; Núñez-Avellaneda and Brachysira intermedia (Østrup) Lange-Bertalot). Brachysira subrostrata Lange-Bertalot was registered for the first time in the State of São Paulo

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 &amp; Moser, Brachysira huitotarum Vouilloud, Sala &amp; Núñez-Avellaneda e Brachysira intermedia (Østrup) Lange-Bertalot). Brachysira subrostrata Lange-Bertalot foi registrada pela primeira vez no Estado de São Paulo.

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.

ABSTRACT (Cryptogams of the Parque Estadual das Fontes do Ipiranga, São Paulo, São Paulo State, Brazil. Algae, 45: Bacillariophyceae (Naviculales: Brachysira)). The floristic survey of Brachysira Kützing (Naviculales) of the Parque Estadual das Fontes do Ipiranga (PEFI), São Paulo, São Paulo State, Brazil, resulted from the analysis of 31 permanent preparations of diatom material collected between years 1991 and 2017. The water and substrate samples (macrophytes and rocks) from lentic systems, streams and the hydrophytoterium were collected and subsequently were oxidized for analysis under light microscope. Nine species and one morphotype were identified from 15 diatom slides, of which four species are new records for Brazil (Brachysira cf. calcicola Lange-Bertalot, Brachysira frenguellii (Manguin) Lange-Bertalot & Moser, Brachysira huitotarum Vouilloud, Sala & Núñez-Avellaneda and Brachysira intermedia (Østrup) Lange-Bertalot). Brachysira subrostrata Lange-Bertalot was registered for the first time in the State of São Paulo.

Resumo: Objetivo Monitoramento do fitoplâncton como bioindicador para avaliar a condição do reservatório de Nasarawa e também avaliar a relação entre o fitoplâncton e as variáveis ambientais do reservatório. Métodos Amostras de fitoplâncton e água do reservatório de Nasarawa (Nigéria) foram coletadas e analisadas de forma padronizada durante dez meses (fevereiro de 2018 a novembro de 2018) em cinco locais de amostragem. Resultados Foram registrados 38 gêneros pertencentes a cinco principais famílias: Bacillariophyceae (42%), Chlorophyceae (24%) Cyanophyceae (13%), Deemidiaceae (18%) e Euglenophyceae (3%). Quatro classes de fitoplâncton; Bacillariophyta, Chlorophyta Cyanophyta e Desmidiaceae mostram relação positiva com oxigênio dissolvido, pH, transparência e sólidos totais dissolvidos. A densidade total de fitoplâncton no reservatório foi maior na estação seca do que na estação chuvosa. O índice de poluição de Palmer foi empregado para avaliar a qualidade da água do reservatório. A pontuação total foi calculada em 25, mostrando evidências de poluição orgânica elevada. Conclusões A presença de indicadores de poluição orgânica Closterium sp, Navicula sp, Nitzschia sp, Synedra sp, Chlamydomonas sp, Cyclotella sp e Anacystis sp é um sinal de alerta para a deterioração das condições da qualidade da água do reservatório. Medidas são necessárias para reduzir a taxa de poluição do reservatório decorrente das atividades humanas na bacia hidrográfica do reservatório.

Abstract: Aim Phytoplankton monitoring as bioindicators to assess the health of the Nasarawa reservoir and also to evaluate the relationship between phytoplankton and reservoir environmental variables. Methods Phytoplankton and water samples from Nasarawa reservoir (Nigeria) were collected and analysed for ten months (February, 2018 to November, 2018) using standard methods at five sampling sites. Results A total of 38 genera belonging to five major families such as: Bacillariophyceae (42%), Chlorophyceae (24%) Cyanophyceae (13%), Deemidiaceae (18%) and Euglenophyceae (3%) were recorded. Four Phytoplankton classes; Bacillariophyta, Chlorophyta Cyanophyta, and Desmidiaceae show positive close relation with dissolved oxygen, pH, transparency, and total dissolved solids. The overall phytoplankton density in the reservoir was higher in dry season than the wet season. Palmer pollution index was employed to study the water quality of the reservoir. The total score was calculated to be 25, showing evidence of high organic pollution. Conclusions The presence of organic pollution indicators Closterium sp, Navicula sp, Nitzschia sp, Synedra sp, Chlamydomonas sp, Cyclotella sp and Anacystis sp is a warning sign of the deteriorating condition of the water quality in the reservoir. Measures need to be enforced to reduce the rate of pollution of the reservoir arising from the human activities in the catchment of the reservoir.

Resumen Las microalgas bentónicas tienen la capacidad natural de adherirse a diversos sustratos fijos sumergidos para formar biopelículas, las cuales tienen roles importantes no solo en ecosistemas naturales sino también en sistemas de producción acuícolas. Se llevó a cabo una investigación experimental para evaluar la capacidad formadora de biopelículas de dos microalgas bentónicas (Navicula incerta y Navicula sp.) en tres diferentes sustratos (malla plástica, tela y madera), bajo condiciones controladas de temperatura y luz. Los sustratos fueron arreglados a manera de cortinas suspendidas de un tubo de PVC dentro de acuarios de plástico (45 L de capacidad) con agua marina enriquecida con el medio F/2. El experimento se llevó hasta que la fase de crecimiento exponencial de la microalga fue alcanzada. Posteriormente la biomasa incorporada fue calculada gravimétricamente, y su composición bioquímica fue determinada por métodos estándar. La mayor cantidad de materia seca se observó para N. incerta en el sustrato de tela y la menor se encontró en el de madera. El mayor número de células asociadas a la biopelícula fue registrado para Navicula sp. en malla plástica (1.24 x 109 cel/m2), mientras que el menor se encontró para Navicula sp. en madera (1.43 x 108 cels/m2). Diferencias significativas en cuanto a materia orgánica se encontraron entre los sustratos y las especies, con valores más altos para N. incerta en tela (3.22 g/m2) y más bajos para Navicula sp. en madera (0.02 ± 0.05 g/m2). Los mejores perfiles bioquímicos para las biopelículas correspondieron a las formadas por N. incerta sobre malla plástica y Navicula sp. sobre tela. La red de plástico se consideró el mejor sustrato debido a la estabilidad de la biopelícula y la facilidad para cosechar la biomasa.

Abstract Benthic microalgae have the natural capacity to adhere to a diversity of fixed submerged substrates to form biofilms, which have important roles not only in natural ecosystems, but also in aquaculture systems. An experimental investigation was performed to assess the biofilm-forming capacity of two microalgae (Navicula incerta and Navicula sp.) on three different substrates (plastic net, fabric, and wood) under controlled temperature and light conditions. The substrates were arranged on curtains suspended from a wood stick, into plastic aquariums (45 L in capacity) filled with filtered marine water enriched with F/2 medium. The trial was carried out until the exponential growing phase of the microalgae was reached. After that, the incorporated biomass was gravimetrically calculated, and its biochemical composition was determined by standard methods. The greatest amount of incorporated dry matter was observed for Navicula sp. on fabric and the lowest was observed for wood. The highest number of cells associated with the biofilm was obtained for Navicula sp. on the plastic net (1.24 x 109 cells/m2), while the lowest was recorded for Navicula sp. on the wood (1.43 x 108 cells/m2). Significant differences in organic matter were found among the substrates, with the highest values for N. incerta on the fabric (3.22 g/m2) and the lowest for Navicula sp. on the wood (0.02 g/m2). The best biochemical profiles among the formed biofilms were observed for N. incerta on the plastic net and Navicula sp. on the fabric. The plastic net was considered the best substrate because of the stability of the biofilm and the easiness of harvesting the biomass.

RESUMEN La vegetación riparia es primordial para el funcionamiento de los ecosistemas acuáticos al aportar materia orgánica. Dado que el perifiton juega un rol indispensable en la dinámica de estos ecosistemas y existen pocos trabajos sobre su ecología en el Neotrópico, se planteó la pregunta: ¿Cómo afecta el tipo de cobertura vegetal de la zona riparia, la estructura del fitoperifiton de humedales de la Orinoquía? En noviembre de 2016 se estudiaron 15 humedales con cobertura boscosa y 15 humedales con vegetación herbácea en su zona riparia. Los humedales están ubicados en la zona periurbana de Villavicencio, Meta (Colombia). Se comparó la diversidad algal entre coberturas riparias y se realizaron análisis de Redundancia para determinar que variables ambientales explicaban la composición del fitoperifiton. Se encontraron 467 morfotipos de algas, el 36,2 % perteneció a la clase Zygnematophyceae, 35,3 % a Bacillariophyceae y 16 % a Chlorophyceae. En cuanto a las diatomeas, se encontraron 165 morfoespecies distribuidas en 30 géneros. Eunotia y Pinnularia fueron los más representativos. Los análisis multivariados indicaron que la composición de diatomeas se relacionó con la cobertura vegetal litoral y el carbono orgánico total. El resto del fitoperifiton fue explicado por la temperatura y la conductividad. Modelos de regresión lineal mostraron que la diversidad de diatomeas fue explicada por el número de sustratos, la temporalidad y la cobertura vegetal riparia. Los resultados permiten concluir que en humedales antropizados de la Orinoquía colombiana, el tipo de cobertura vegetal riparia afecta la composición y diversidad de las diatomeas.

ABSTRACT Riparian vegetation is essential for the functioning of aquatic ecosystems by providing organic matter. Given that periphyton plays an indispensable role in the dynamics of these ecosystems and there are few works on its ecology in the Neotropic our research question was: How does the riparian vegetation cover affect the structure of the phytoperiphyton in wetlands of the Orinoquía? In November 2016, we sampled 15 wetlands covered by forest and 15 wetlands covered by herbaceous vegetation in the riparian zone. The wetlands are located in the peri-urban area of Villavicencio, Meta (Colombia). The algal diversity between coverage types was compared and Redundancy Analyses were carried out to determine which environmental variables explain the phytoperiphyton composition. 467 morphotypes of microalgae were found, 36.2 % belonged to the Zygnematophyceae Class, 35.3 % to Bacillariophyceae, and 16 % to Chlorophyceae. 165 morpho-species of diatom distributed in 30 genera were found. Eunotia and Pinnularia were the most representative. The multivariate analyzes indicate that the composition of diatoms was related to the littoral vegetation coverage and the total organic carbon. The rest of the phytoperifiton was explained by temperature and conductivity. Linear regression models showed that the diversity of diatoms was explained by the number of substrates, temporality and the type of riparian coverage. We conclude that in anthropogenic wetlands of the Colombian Orinoquía, the type of riparian vegetation affects the composition and diversity of diatoms.

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).

ABSTRACT A survey of Epithemia (Bacillariophyceae) was carried out in the Parque Estadual das Fontes do Ipiranga (PEFI), São Paulo, SP, Brazil, in order to know the taxonomic diversity and the morphological variability of the genus. A total of 31 diatoms slides were analyzed of which five were used in this study. Five species were identified: E. proboscidea Kützing, E. gibba (Ehrenberg) Kützing, E. gibberula (Ehrenberg) Kützing, E. operculata (C. Agardh) Ruck & Nakov and Epithemia sp., with the dominance of periphytic species. One taxon was recorded for the first time in Brazil (E. proboscidea Kützing) and two taxa in the PEFI area (E. gibba (Ehrenberg) Kützing and E. operculata (C. Agardh) Ruck & Nakov).

Diatoms (Bacillariophyceae) are an important component of aquatic taxocenosis that can live in a wide variety of habitats, which are very common and abundant organ-isms in NOA's lotic ecosystems. The objective of this work was to present 20 new records of these microalgae: 3 new citations for the country, 5 for the Northwest region and 12 new records for Tucumán. Seasonal samplings were carried out from 2012 to 2014 in Calimayo and Mista streams (both belonging to the Sali river basin). Biological data (epilithon and phy-toplankton) were collected "in situ". Abiotic factors were measured according to conventional methodologies. Descriptions of the species were made and morphometric characteristics were obtained, the geographic distribution and autoecological traits of the taxa registered for the first time for the NOA and the country were analyzed. Microphotographs (MO) of the cited species were incorporated. This contribution allowed to increase the knowledge, distribution and autoecology of the diatom species analyzed.

Las diatomeas (Bacillariophyceae) constituyen un importante componente de las taxocenosis acuáticas, pueden vivir en una amplia variedad de hábitats, son organismos muy comunes y abundantes en los sistemas lóticos del Noroeste Argentino (NOA). El objetivo propuesto en este trabajo fue dar a conocer 20 nuevos registros de estas microalgas: 3 nuevas citas para el país, 5 para la región del noroeste y 12 nuevos registros para Tucumán. Se realizaron muestreos estacionales en los arroyos: Calimayo y Mista (ambos pertenecientes a la cuenca del río Sali) desde 2012 a 2014, se recolectaron datos biológicos (epiliton y fitoplancton) e "in situ" se midieron variables abióticas según metodologías convencionales. Se efectuaron descripciones de las especies, se obtuvieron características morfométricas, se analizó la distribución geográfica y rasgos autoecológicos de los taxones registrados por primera vez para el NOA y el país. Se incorporan microfotografías (MO) de las especies citadas. Esta contribución permitió incrementar el conocimiento, la distribución y la autoecología de los taxones de diatomeas considerados.

RESUMEN Objetivo. Se caracterizó la composición y estructura del Fitoperifiton de la cuenca media y baja del río Cesar y su relación con las variables físicas y químicas. Materiales y métodos. Los muestreos se realizaron entre febrero-septiembre de 2011. Se recolectaron muestras de sustratos naturales disponibles (rocas, sedimento y restos vegetales), se midieron variables físicas y químicas In situ e In vivo. Resultados. Se encontraron 110 morfoespecies representadas en 9 clases y 22 órdenes, las Bacillariophyceae presentaron la mayor densidad con un 48% (45 especies), Cyanophyceae con 35% (18 especies), seguida de Fragilariophyceae con 7% (9 especies), Chlorophyceae con 2% (11 especies), Euglenophyceae con 2% (5 especies), Coscinodiscophyceae y Trebouxiophyceae con 4% y 1% (4 y 3 especies respectivamente) y por ultimo Ulvophyceae con 0.00005% (1 especie). Las morfoespecies más representativas Anabaena sp.1 (136.70 Cel/cm2), Oscillatoria vaucher (129.80 Cel/cm2) y Oscillatoria sp.1 (90.20 Cel/cm2). Se realizó un análisis de Componentes Principales (ACP) donde se observó una sectorización de algunos tramos del río Cesar y del fitoperifiton, para caracterizar las estaciones por sus particularidades se observaron crecimiento excesivos de especies en zonas donde se encuentran vertimientos de aguas residuales con alto contenido de materia orgánica como las algas verde-azules. Conclusiones. Las Cyanophyceae se asociaron negativamente con el oxígeno según el ACC. Se evidencio que el sector de Puente Salguero es caracterizado por alta concentración de fósforo orgánico, además el Fitoperifiton del río Cesar, identifico este sector como el punto más crítico de contaminación orgánica del sistema y sus influencia estaciones río abajo.

ABSTRACT Objective. The composition and structure of Fitoperifiton the middle and lower basin of the Cesar River and its relationship to the physical and chemical variables were characterized. Materials and methods. Sampling was conducted between February to September 2011. Samples available natural substrates (rocks, sediment and plant debris) were collected, physical and chemical variables in situ and in vivo were measured. Results. 110 Morphospecies classes represented in 9 and 22 orders were found, the Bacillariophyceae had the highest density with 48% (45 species), Cyanophyceae with 35% (18 species), followed by Fragilariophyceae with 7% (9 species), Chlorophyceae 2 % (11 species), Euglenophyceae with 2% (5 species) and Trebouxiophyceae Coscinodiscophyceae with 4% and 1% (respectively 4 and 3 species) and finally with Ulvophyceae 0.00005% (1 species). The most representative Anabaena sp.1 Morphospecies (136.70 Cel/cm2), Oscillatoria Vaucher (129.80 Cel/cm2) and Oscillatoria sp.1 (90.20 Cel/cm2). an analysis of principal components (ACP) where segmentation of some sections of the Cesar River and fitoperifiton was observed to characterize the stations for their peculiarities was made excessive growth of species in areas where they are wastewater discharges high were observed organic matter such as blue-green algae. Conclusions. The Cyanophyceae were negatively associated with oxygen according to the ACC. It was evident that the sector Puente Salguero is characterized by high concentration of organic phosphorus, plus the Fitoperifiton the Cesar River, identified this sector as the most critical point of organic contamination of the system and its influence stations downstream.