Resumen: Los humedales son considerados sistemas biológicos dinámicos y productivos, debido a que el agua se encarga de producir un ambiente mixto. Las algas tienen un rol importante desde los servicios ecosistémicos que desarrollan, entre ellos los de soporte y regulación, vinculados a la producción primaria, al ciclaje de nutrientes, a la producción de oxígeno atmosférico y a la purificación del agua. El objetivo de este trabajo fue aportar información respecto a la riqueza y composición de especies de la ficoflora del departamento de Ñeembucú. Para ello se tomaron muestras de agua en los distritos Tacuaras y Villa Franca, del departamento de Ñeembucú - Paraguay, en ocho campañas de muestreo, durante los meses de octubre de 2020 a julio de 2021. Se colectaron 32 muestras, incluyendo tomas directas de agua y muestras filtradas con red de plancton provenientes de cuerpos de agua temporales y permanentes, conservadas en lugol acético para su posterior observación. Para el recuento e identificación de las algas se utilizó el método de sedimentación de Utermölh. Se encontraron 185 especies de algas distribuidas en siete phylum: Bacillariophyta (63 especies), Charophyta (53 especies), Chlorophyta (41 especies), Cryptophyta (una especie), Cyanophyta (ocho especies), Euglenophyta (17 especies), y Ochrophyta (dos especies). La mayoría de las especies identificadas corresponden a medios dulceacuícolas oligotróficos. Este trabajo representa un aporte para aumentar el conocimiento de la diversidad algal del departamento de Ñeembucú.

Abstract: Wetlands are considered dynamic and productive biological systems, due to the water, which is responsible for producing a mixed environment. Algae play an important role in the ecosystem services they provide, including support and regulation, linked to primary production, nutrient cycling, atmospheric oxygen production and water purification. The objective of this work was to provide information on the species richness and composition of the phycoflora of the department of Ñeembucú. For this purpose, water samples were taken in the Tacuaras and Villa Franca districts, in the department of Ñeembucú - Paraguay, in eight sampling cam- paigns, during the months of October 2020 to July 2021. Thirty-two samples were collected, including direct water samples and samples filtered with plankton nets from temporary and permanent water bodies, preserved in acetic lugol for later observation. The Utermölh sedimentation method was used to count and identify the algae. We found 185 species of algae distributed in seven phylum: Bacillariophyta (63 species), Charophyta (53 species), Chlorophyta (41 species), Cryptophyta (one species), Cyanophyta (eight species), Euglenophyta (17 species), and Ochrophyta (two species). Most of the species identified correspond to oligotrophic freshwater environments. This work represents a contribution to increase the knowledge of the algal diversity of the department of Ñeembucú.

RESUMO Apresentamos um inventário com 23 táxons da flora ficológica bentônica em praias da costa nordeste do estado do Pará, na Amazônia brasileira, uma região raramente amostrada para algas. As coletas foram realizadas em substratos como matacões no município de Salinópolis, e em troncos, galhos e pneumatóforos de Laguncularia racemosa e substratos artificiais no município de Marapanim. Apesar das limitações da amostragem, nós registramos dez novas citações de algas marinhas e estuarinas bentônicas para a costa do estado do Pará: seis Chlorophyta (Bryopsis pennata, Cladophora coelothrix, C. conferta,Gayralia brasiliensis, Pseudorhizoclonium africanum e Ulva chaetomorphoides), duas Rhodophyta (Caloglossa confusa e Centroceras gasparrinii), uma Ochrophyta (Bachelotia antillarum) e uma Cyanophyta (Coleofasciculus chthonoplastes).

ABSTRACT We present a checklist with 23 taxa of the benthic phycological flora on three beaches on the northeast coast of Pará state, in the Brazilian Amazon, a rarely surveyed area for algae. Collections were made on substrates like rocky outcrops at Salinópolis municipality, and on trunks, branches and pneumatophores of Laguncularia racemosa and artificial substrates at Marapanim municipality. Despite the limited geographic scale of the sampling, we provide ten new citations for the benthic, marine and estuarine algal taxa of the Pará state coast: six Chlorophyta (Bryopsis pennata, Cladophora coelothrix, C. conferta, Gayralia brasiliensis, Pseudorhizoclonium africanum and Ulva chaetomorphoides), two Rhodophyta (Caloglossa confusa, Centroceras gasparrinii), one Ochrophyta (Bachelotia antillarum) and one Cyanophyta (Coleofasciculus chthonoplastes).

RESUMEN Clorófitas y cianófitas son organismos fotosintéticos que se caracterizan por su plasticidad bioquímica, lo que les ha permitido desarrollarse en diferentes ambientes y tener una tasa de crecimiento más rápida que las plantas. Dependiendo de la especie y las condiciones ambientales, estos organismos pueden producir enzimas nitrogenadas para la fijación del nitrógeno atmosférico; fosfatasas que solubilizan el fósforo; fitohormonas que promueven el crecimiento de las plantas; y polisacáridos higroscópicos que evitan la erosión y mejoran las características del suelo. En este sentido, el objetivo de esta revisión fue analizar la información disponible sobre el uso de cianófitas y clorófitas como biofertilizantes, y su posible aplicación en la producción de alimentos orgánicos. Múltiples estudios e investigaciones fueron encontrados demostrando las ventajas del uso de estos microorganismos para mejorar la productividad de las plantas, y que a su vez conducen a una agricultura sostenible respetuosa con el medio ambiente. Sin embargo, su alto costo de producción se ha convertido en un factor limitante para su comercialización.

ABSTRACT Chlorophyta and Cyanophyta are photosynthetic organisms characterized by their biochemical plasticity, which has allowed them to develop in different environments and have a faster growth rate than plants. Depending on the species and environmental conditions, these organisms can produce nitrogenous enzymes, for atmospheric nitrogen fixation; phosphatases, that solubilize phosphorus; phytohormones, that promote plant growth; and hygroscopic polysaccharides, that prevent erosion and improve soil characteristics. In this sense, the aim of this review was to analyze the available information on the use of Chlorophyta and Cyanophyta as biofertilizers and their potential application in organic food production. Multiple studies and researches were found demonstrating the advantages of these microorganisms when being used to improve plants productivity, and also at the same time, leading to sustainable agriculture that is respectful to the environment. However, their high production cost has become a limiting factor for their commercialization.

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 El desarrollo masivo de cianobacterias y la contaminación por cianotoxinas constituyen una problemática ambiental de especial interés en los sistemas acuáticos, debido a los diversos impactos negativos que los florecimientos (blooms) de cianobacterias pueden ocasionar. Dada la importancia recreacional y de abastecimiento de los embalses Abreo - Malpaso, Peñol - Guatapé y Playas, ubicados en el oriente de Antioquia - Colombia, en este estudio, se estimó la densidad de cianobacterias planctónicas y otros organismos del fitoplancton, así como el biovolumen geométrico, la relación superficie volumen (S/V) y la dimensión lineal máxima (DLM), a través de cuatro muestreos, en tres estaciones, para cada uno de los embalses. Se identificaron, dentro del phylum Cyanobacteria, con potencial de producción de cianotoxinas, el complejo Microcystis, los géneros Woronichinia, Aphanocapsa y Oscillatoria y la especie Radiocystis fernandoi. Al aplicar la prueba no parámetrica Kruskal - Wallis, no se encontraron diferencias significativas entre los embalses estudiados (p>0,05); sin embargo, el embalse El Peñol - Guatapé presentó la mayor biomasa algal y densidad de cianobacterias, por lo que, según los niveles de riesgo planteados para los embalses estudiados y de acuerdo con las características morfológicas de estos organismos, este embalse presenta un nivel de riesgo Medio Alto con relación a la presencia y morfología de las cianobacterias, mientras que los embalses Abreo - Malpaso y Playas están asociados a un riesgo Medio Bajo. Se sugiere establecer medidas de control y de prevención, con el fin de evitar un desarrollo masivo de cianobacterias, una potencial presencia de cianotoxinas y afectaciones graves a seres humanos y animales.

ABSTRACT Cyanotoxin contamination is of special interest in water bodies, especially those for human use, due to the various negative effects that blooms of potentially toxic cyanobacteria can cause on human health. Given the recreational and supply importance of the Abreo - Malpaso, Peñol - Guatapé and Playas reservoirs in the Department of Antioquia, Colombia. This study has estimated the biomass of the planktonic cyanobacteria, their geometric biovolume, the surface volume ratio (S / V) and the maximum linear dimension (MLD), during four sampling seasons in three different stations for each of these bodies. Water. We have identified from the Cyanophyta division with the production of cyanotoxins, the Microcystis complex and generates Woronichinia, Aphanocapsa and Oscillatoria, as well as the species Radiocystis fernandoi. When applying the nonparametric Kruskal - Wallis test, no significant differences were found between the studied reservoirs (p> 0.05); however, the Peñol - Guatapé reservoir presented the highest algae biomass and density of cyanobacteria, therefore, according to the levels of risk posed for the reservoirs studied and according to the morphological characteristics of these organisms, this reservoir presents a High Medium risk level in relation to the presence and morphology of the cyanobacteria, while the Abreo-Malpaso and Playas reservoirs are associated with a Medium Low risk. It is suggested to establish control and prevention measures to avoid a massive development of cyanobacteria, a possible presence of cyanotoxins and serious affectations in humans and animals.

RESUMO Estudos taxonômicos do fitoplâncton são importantes ferramentas para advertir a qualidade da água, possibilitando o monitoramento das águas utilizadas para fins múltiplos. Assim, este trabalho visou estudar a composição e a distribuição fitoplanctônica em trechos da Bacia do Rio Piranhas-Açu, na região semiárida do Nordeste brasileiro, de 2010 a 2011, com 13 pontos amostrais, em rios e reservatórios. Foram identificados 81 táxons infragenéricos, os quais foram distribuídos em 9 classes: Cyanophyceae , Chlorophyceae , Bacillariophyceae , Trebouxiophyceae , Euglenophyceae , Coscinodiscophyceae , Zygnematophyceae , Mediophyceae e Klebsormidiophyceae . As divisões Chlorophyta e Cyanophyta foram as mais representativas, com 30 (37%) e 24 (30%) táxons, respectivamente. Contudo, elas estiveram dominantes durante o período de estudo. Em alguns pontos de amostragem, as cianobactérias apresentaram densidades com valores limites acima de 20.000 células/mL, e, portanto, necessitaram monitoramento semanal como disposto pela Portaria 2.914, de 12 de dezembro de 2011, do Ministério da Saúde. Dentre as espécies com alto índice de abundância, destacam-se aquelas potencialmente produtoras de toxinas, representadas por Cylindrospermopsis raciborskii , Pseudanabaena limnetica , Microcystis sp., Dolichospermum sp. e Oscillatoria sp. Os dados indicam um potencial risco à saúde da população beneficiada por essas águas.

ABSTRACT Phytoplankton taxonomic studies are important tools to analyze the quality of water, allowing the monitoring of waters used for multiple purposes. Thus, this work aimed at studying the formation and distribution of phytoplankton in stretches of the Piranhas-Açu River Basin, in the semiarid region of Northeastern Brazil, from 2010 to 2011, with 13 sampling points in river and reservoirs. We identified 81 infrageneric taxa, distributed into 9 classes: Cyanophyceae , Chlorophyceae , Bacillariophyceae , Trebouxiophyceae , Euglenophyceae , Coscinodiscophyceae , Zygnematophyceae , Mediophyceae , and Klebsormidiophyceae . The Chlorophyta and Cyanophyta divisions were the most representative, with 30 (37%) and 24 (30%) taxa, respectively. However, the cyanobacteria were more seen throughout the study period. In some sampling points, they had limits above 20.000 cells/mL, requiring weekly monitoring as provided by Decree 2914 from December 12, 2011, of the Brazilian Ministry of Health. The species with high abundance are those producing toxins, represented by Cylindrospermopsis raciborskii , Pseudanabaena limnetic , Microcystis sp. Dolichospermum sp., and Oscillatoria sp. The data indicate a potential health risk to the population served by these waters.

Se presentan datos recabados entre los meses de junio a agosto, 2016 de la floración algal nociva (FAN) ocurrida en la laguna Alalay (Cochabamba, Bolivia), que en marzo del mismo año causó la muerte masiva de peces y aves. Esta FAN estuvo dominada continuamente por Arthrospira fusiformis, Anabaenopsis milleri y Aphanocapsa sp., tres cianobacterias que se reportan en la literatura como altamente tóxicas y cuyas adaptaciones morfológicas, autecología, uso efectivo de nutrientes, espacio y luz, y las consecuencias de su actividad fisiológica en el ecosistema determinaron su prevalencia en la laguna. Los resultados físicos y químicos denotan el estado hipereutrófico de la laguna y un cambio en la limitación de la productividad en el ecosistema del nitrógeno hacia el fósforo. La incorporación de nitrógeno atmosférico y el reciclaje de nutrientes en la columna de agua y sedimentos así como la reutilización de la materia orgánica producida por las algas han resultado en una densidad algal pocas veces reportada en la literatura. Los análisis multivariados muestran que aunque solo poco más del 77% de la varianza en la abundancia algal es explicada por los parámetros físicos y químicos medidos durante el estudio, nitratos, fósforo total, carbonates, sulfatos y conductividad son las variables que determinan en mayor grado los patrones de variación espacio-temporal observados en los tres puntos de muestreo estudiados. Estas variaciones confirman resultados anteriores obtenidos con variables ambientales y comunidades de diatomeas que muestran que la laguna está afectada de manera distinta en los tres puntos de estudio por las actividades antrópicas en la cuenca. La identidad confirmada de Arthrospira fusiformis y Anabaenopsis milleri, su alta abundancia durante marzo y meses subsecuentes, las características del deceso masivo de animales y los datos físicos y químicos históricos, sugieren que ese deceso fue producido por cianotoxinas y no así por descensos en el tenor de oxígeno disuelto o la presencia de sulfuro de hidrógeno en la columna de agua. Los resultados aquí reportados tienen implicaciones para el desarrollo de protocolos de recuperación y manejo de la laguna, aspecto que se discute en el contexto de los datos recabados y de la literatura.

We present data collected during June to August, 2016 for the harmful algal bloom (HAB) developing in Alalay shallow lake, Cochabamba Bolivia; bloom that caused the massive kill of fish and birds early in March of the same year. The bloom was continuously dominated by Arthrospira fusiformis, Anabaenopsis milleri and Aphanocapsa sp., three cyanobacteria reportedly highly toxic and which morphological and autecological adaptations, effective use of nutrients, space and light, and the ecological consequences of their physiological activities determined their prevalence in the lake. Atmospheric nitrogen fixation and the recycling of nutrients from the water column and sediments, as well as the reuse of organic matter produced by photosynthetic organisms resulted in algal densities that are seldom reported in the literature. Water chemistry shows that the lake is hypereutrophic and that it has shifted from a nitrogen to a phosphorus limitation. Multivariate analyses showed that although only about 77% of the algal abundance variance is explained by measured water chemistry variables, nitrates, total phosphorus, carbonates, sulfatos, and conductivity are the parameters explaining observed variation in algal abundance in the three selected sampling sites. Such variations confirm previous results obtained by analysis of environmental variables and diatom assemblages, showing that the three sampling points are affected differently by anthropic activities in the drainage basin. The confirmed identity of Arthrospira fusiformis and Anabaenopsis milleri, their high abundance during March and subsequent months, the features of the fish and bird kills, and the historical water chemistry data suggest that the kills were produced by cyanotoxins and not by low dissolved oxygen and presence of hydrogen sulfide, as reported in the local and national press. The results shown here have implications for the development of recuperation and management protocols, aspects that are discussed in the context of our data and reports in the literature.

Abstract: There are 3,256 species of phytoplankton reported in Mexico. In the southeast region, particularly in the basins of the Tonalá and Grijalva-Usumacinta rivers, between 155 and 300 species of phytoplankton have been reported. This number of species is considered low for a watershed with the largest water reservoir in Mexico; consequently, this study was focused to the phytoplankton species present in the tropical wetland Chaschoc, located in the basin of the Usumacinta River. Hence, phytoplankton was collected during the low flow of the flooding cycle in 2014 by oblique tows. A total of 129 morphospecies and 6 taxonomic groups were recorded: Cyanophyta (Cyanoprocaryota), Bacillariophyta, Chlorophyta, Cryptophyta, Euglenophyta (Euglenozoa) and Dinophyta (Dinoflagellata). Regarding the number of species, Chlorophyta was the best represented, while the group Cryptophyta was the less represented. In addition, 40 new records are reported for the Grijalva and Usumacinta basins, of which 13 are considered potentially toxic and 42 indicators of pollution and eutrophication. However, it is expected that the registration of species increases with samples in different seasons of the hydrological cycle and other wetlands associated with the Usumacinta River and its tributaries.

Resumen: En México existen 3,256 especies de fitoplancton reportadas. En la región sureste, particularmente en las cuencas de los ríos Tonalá y Grijalva-Usumacinta, el registro varía entre 155 y 300 especies. Este número de especies se considera bajo para una de las cuencas con mayor reserva de agua en el país. Por tal motivo, se planteó el objetivo de reportar las especies de fitoplancton presentes en el humedal tropical Chaschoc, ubicado en la cuenca del río Usumacinta. Para ello, el fitoplancton se recolectó durante el flujo bajo del ciclo de inundación en 2014 mediante arrastres oblicuos. Se registraron 129 morfoespecies de 6 grupos taxonómicos: Cyanophyta (Cyanoprocaryota), Bacillariophyta, Chlorophyta, Cryptophyta, Euglenophyta (Euglenozoa) y Dinophyta (Dinoflagellata). Entre estos, las Chlorophyta fueron el grupo mejor representado, mientras que las Cryptophyta resultaron el grupo con menos especies. En la lista florística se reportan 40 nuevos registros para la cuenca baja del río Usumacinta, 13 especies potencialmente tóxicas y 42 indicadoras de contaminación por materia orgánica o eutrofización. Sin embargo, es esperable que el registro de especies aumente con muestreos en las diferentes temporadas del ciclo hidrológico y otros humedales asociados con el río Usumacinta y sus tributarios.

Resumo O conhecimento da composição da dieta do molusco de água doce Diplodon enno é de extrema importância para a sua cultura e propagação, permitindo desta forma a recuperação de populações em perigo de extinção no Brasil. As microalgas são a principal fonte de alimento para moluscos filtradores e os uniónidos sendo selecionadas por estes com base nas suas características celulares. O principal objectivo deste trabalho é analisar a composição fitoplanctônica da água e do conteúdo gastrointestinal do molusco D. enno, de forma a desenvolver uma dieta apropriada ao seu cultivo. Para isso, amostras de água e espécimes de bivalves foram recolhidos do rio São Francisco, cidade de Paulo Afonso, Bahia, Brasil. A composição de microalgas encontrada na água e no conteúdo do estômago/intestino foi muito diversa, sendo representada pelas seguintes divisões: Cyanophyta, Chlorophyta, Dinophyta e Heterokontophyta (diatomáceas). Atendendo à abundância relativa de cada divisão de microalgas, podemos afirmar que na água e no trato gastrointestinal Cyanophyta representa 15% e 14%, Chlorophyta 54% em ambos, Heterokontophyta 31% e 27% e Dinophyta 0% and 5%, respectivamente. De acordo com o critério CETESB de classificação de espécies de fitoplâncton, 50% das espécies de Cyanophyta e 15% das de Chlorophyta observadas nas amostras de água foram classificadas como “muito frequentes”, tal como aconteceu para 68% das espécies de Heterokontophyta e 33% das de Chlorophyta nas amostras do conteúdo do trato gastrointestinal. Realçando as espécies presentes, apesar de apenas Coelastrum sp. e Chroococcus sp. terem sido observadas em 100% e 75% das amostras de água, respectivamente, nas amostras de trato gastrointestinal Staurastrum sp., Aulacoseira sp., Scenedesmus sp. e Fragilaria crotonensis foram identificadas em entre 80% e 100% das amostras. Os resultados deste estudo mostram que D. enno se alimenta não apenas de pequenas microalgas clorófitas, devido ao seu pequeno tamanho que possibilita maiores taxas de filtração, como também de diatomáceas maiores, devido a uma possível vantagem nutricional para os bivalves. Assim sendo, uma dieta composta por diatomáceas e pequenas clorófitas poderá ser considerada a mais indicada para a manutenção de populações de D. enno.

Abstract The knowledge on diet composition of the freshwater mussel Diplodon enno (Ortmann) would aid in its culture and propagation allowing, this way, the replacement of natural endangered populations in Brazil. Microalgae are the main food source for captive mussels and unionids have displayed an ability to sort algae based on the cellular characteristics prior to ingestion. The main objective of the present work is to analyze the phytoplankton composition of the water from and of the gastrointestinal contents of the mussel D. enno, as an initial step for development of a suitable rearing diet. Therefore, water samples and bivalve specimens were collected from S. Francisco River, city of Paulo Afonso, Bahia, Brazil. The microalgal composition found in water and stomach/gut content samples was very diverse being represented by the following divisions: Cyanophyta, Chlorophyta, Dinophyta and Heterokontophyta (Diatoms). Concerning the relative abundance of microalgae divisions, it is possible to state, for the water and gastrointestinal contents, that Cyanophyta represents 15% and 14%, Chlorophyta 54% in both, Heterokontophyta 31% and 27% and Dinophyta 0% and 5%, respectively. According to the Brazilian CETESB criteria for phytoplankton species classification, 50% of Cyanophyta and 15% of Chlorophyta species observed in the water samples were classified as “very frequent”, as were 68% of Heterokontophyta and 33% of Chlorophyta species in the gut/stomach tract samples. Focusing at a species level, although in the water only Coelastrum sp. and Chroococcus sp. were observed in 100% and 75% of the samples, respectively, in the gastrointestinal tract the species Staurastrum sp., Aulacoseira sp., Scenedesmus sp. and Fragilaria crotonensis occurred in 80% to 100% of the samples. The present results showed that D. enno feeds not only on small chlorophytes microalgae, due to their convenient size that facilitates higher feeding rates, but also on large size diatoms, due to a possible nutritional advantage for the bivalves. Thus, a diet composed by large diatoms and small chlorophytes microalgae may be considered as the most reasonable for the maintenance of D. enno populations.

Resumo No nordeste do Brasil, as lagoas de estabilização são muito adequadas para o tratamento de águas residuárias por causa da disponibilidade relativamente grande de terra e das condições ambientais (por exemplo, altas temperaturas) favoráveis ao melhor desenvolvimento dos microorganismos. Entretanto, florações de cianobactérias potencialmente tóxicas podem afetar o uso dessas lagoas de tratamento, devido à consequente qualidade inferior do efluente. O objetivo deste estudo foi avaliar a dinâmica das comunidades de fitoplâncton e a ocorrência de cianobactérias em uma lagoa de maturação situada após duas lagoas em série. Temperatura, oxigênio dissolvido, pH, DBO, N e P foram medidos durante um período de quatro meses, durante o qual amostras foram coletadas na superfície e fundo em sete pontos de amostragem da lagoa. As comunidades de fitoplâncton das amostras coletadas foram também identificadas e classificadas utilizando-se um microscópio óptico convencional. Para avaliar os resultados utilizou-se a análise de variância e o teste de Tukey. Para as três divisões de fitoplâncton encontradas (Cyanophyta, Chlorophyta e Euglenophyta), não houve diferença significativa para as amostras de superfície e de fundo de um mesmo mês. Entretanto, ocorreu grande variação para as amostras dos diferentes meses; nos meses de abril e outubro houve uma predominância de Cyanophyta, ao passo que em setembro o predomínio na lagoa foi de Chlorophyta. Os fatores determinantes que favoreceram o predomínio de Cyanophyta foram a baixa carga orgânica superficial aplicada (entre 78 e 109 kg DBO.ha–1.d–1) e N:P ≤ 10. A presença de duas das espécies de Cyanophyta, Oscillatoria sp. e Microcystisaeruginosa, consideradas potencialmente tóxicas, indica que é necessária precaução quando se considera o destino final do efluente tratado e sugere a necessidade de avaliar os riscos e benefícios associados ao uso da tecnologia de tratamento.

Abstract In northeastern Brazil, stabilization ponds are very suitable for wastewater treatment because of the relative great land availability and environmental conditions (e.g., high temperature) favorable for microorganism optimal development. However, blooms of potentially toxic cyanobacteria may affect the use of these treatment ponds due to resulting effluent poor quality. The objective of this study was to evaluate the dynamics of phytoplankton communities and the occurrence of cyanobacteria in a maturation pond located immediately after a series of two ponds. Temperature, dissolved oxygen, pH, BOD, N, and P were measured during a period of four months when samples were collected from the surface and the bottom of 7 sampling points distributed inside the pond. The phytoplankton of collected samples was also identified and classified using a conventional optical microscopy. Analysis of variance and Tukey test were used to evaluate the results. The three phytoplankton divisions found (Cyanophyta, Chlorophyta, and Euglenophyta) did not change considerably through surface and bottom. However, they changed greatly over the sampled months; great dominance of Cyanophyta was found at April and October, while Chlorophyta dominated the lagoon in September. Low superficial organic loads (between 78 and 109 kg BOD.ha–1.d–1) and N:P ≤ 10 were the determinant factors that favored the predominance of Cyanophyta. The presence of two potentially toxic species of Cyanophyta, Oscillatoria sp. and Microcystis aeruginosa, indicates that caution is required when considering the final destination of treated effluent and suggests a need to assess the risks and benefits associated with the use of the treatment technology.

The present work registers for the first time the cyanobacteria Sphaerocavum brasiliense Azevedo y Sant’Anna and Microcystis wesenbergii (Komárek) Komárek in Kondrateva (Microcystaceae, Cyanophyceae) in an algal bloom on Huacachina lagoon (Ica), including the first report of Sphaerocavum for Peru. We suggest the necessity of monitoring these bloom-forming cyanobacteria.

En el presente trabajo se registra por primera vez a las cianobacterias Sphaerocavum brasiliense Azevedo y Sant’Anna y Microcystis wesenbergii (Komárek) Komárek in Kondrateva (Microcystaceae, Cyanophyceae) en una floración algal de la laguna Huacachina (Ica), incluyendo el primer reporte del género Sphaerocavum para el Perú. Se sugiere el monitoreo de estas cianobacterias por ser formadoras de floraciones algales.

Tucumán is known for its richness in natural and water resources. Previous phycological studies focused mainly on the phytoplankton, but little was done in relation to the epilithic phycoflora. The aim of this research was to analyze the epilithic taxocenosis and physicochemical variables of Calimayo stream during an annual cycle, and to contribute to the taxonomic knowledge of the phycoflora in Northwestern Argentina. Physicochemical and biological samples collected in 2012-2013 were studied. The water was alkaline, bicarbonate-calcium, oligosaprobic in summer/13 and oligo-β-mesosaprobic in the other seasons. Mineralization was average and the stream was well oxygenated. The Bacillariohyceae class presented 69 taxa followed by Divisions Cyanophyta (10), Chlorophyta (5) and Rhodophyta (1). The following species were always present: Amphipleura lindheimerii, Cocconeis placentula var. lineata, Cymbella affinis, Gomphonema olivaceum, G. parvulum, Luticola mutica, Navicula tripunctata, Nitzschia palea, Orthoseira roeseana, Planothidium frequentissimum, P. lanceolatum, Reimeria uniseriata, Rhoicosphenia abbreviata, Ulnaria ulna, Oedogonium sp., Lyngbya sp. 1, Myxosarcina spectabilis, Oscillatoria sp. 1 y 2. Of a total of 85 taxa, 70 are cited for the first time for epilithon and Myxosarcina spectabilis is a new record for Tucuman. Phycoflora composition was influenced by temperature, depth, precipitation and pH.

Tucumán se destaca por sus riquezas en recursos naturales e hídricos. Los estudios ficológicos se basaron principalmente en el fitoplancton, siendo escaso el análisis de la ficoflora epilítica. Los objetivos fueron analizar la taxocenosis epilítica y variables fisicoquímicas del arroyo durante un ciclo anual y contribuir al conocimiento de la ficoflora del NOA. Se estudiaron muestras fisicoquímicas y biológicas recolectadas durante 2012-2013. El agua tuvo un pH alcalino, se caracterizó como bicarbonatada-cálcica, oligosapróbica (verano/13) y oligo-β-mesosapróbica en las otras estaciones. La mineralización fue media y el arroyo estuvo bien oxigenado. La Clase Bacillariohyceae presentó 69 taxones seguida de las Divisiones Cyanophyta (10), Chlorophyta (5) y Rhodophyta (1). Las especies siempre presentes fueron: Amphipleura lindheimerii, Cocconeis placentula var. lineata, Cymbella affinis, Gomphonema olivaceum, G. parvulum, Luticola mutica, Navicula tripunctata, Nitzschia palea, Orthoseira roeseana, Planothidium lanceolatum, P. frequentissimum, Reimeria uniseriata, Rhoicosphenia abbreviata, Ulnaria ulna, Oedogonium sp., Lyngbya sp.1, Myxosarcina spectabilis, Oscillatoria sp. 1 y 2. Las mayores densidades se presentaron en época invernal. De un total de 85 taxones, 70 se citan por primera vez para el epiliton y Myxosarcina spectabilis es un nuevo registro para Tucumán. La composición de la ficoflora estuvo influenciada por: temperatura, profundidad, precipitaciones y pH.

We studied the adaptability of the alga Cyanophyta Spirulina (Arthrospira) platensis (Geitl) grown in conical tubular photobio-reactor under ambient conditions with 0.28 m² on the upper surface of the Cone (0.7 m x 0.6 m top diameter) constructed with PVC (polyvinyl chloride) pipe transparent (12 mm diameter, 34 m long for the 34 coils forming the cone and 7 m for the cooler) reinforced with a metal frame and lined with aluminum foil; (total volume = 5.3 L). The inner surface of the Cone (0.71 m²) was exposed to sunlight with 11700 lux illuminance and solar radiation mean equal to 774 W/m²from June 24 to July 12, 2013. Agitation and aeration of the photobioreactor culture was carried out with an air pump to an average flow of 0.002 L/s which resulted in a rate ofproduction of dry biomass of 0,298 g/m²/day, chlorophyll "a" 0.0023 g/m²/day and carotenoids in 0.0011 g/m²/day. The growth of S. platensis in conical tubular photobioreactor was adjusted to a mathematical model of growth "Potential" in 18 days, with statistical adjustment of the model (R² = 0. 937; F = 119.216).

Se estudió la adaptabilidad del alga Cyanophyta Spirulina (Arthrospira)platensis (Geitl) cultivada en fotobiorreactor tubular cónico bajo condiciones ambientales con 0,28 m² en la superficie superior del cono (0,7 m de alto x 0,6 m diámetro superior) construido con tubo de PVC (Policloruro de Vinilo) transparente (12 mm de diámetro, 34 m de largo para las 34 espiras que forman el cono y 7 m para el enfriador), reforzado con una estructura metálica y forrado con hojas de aluminio (volumen total = 5,3 L). La superficie interna del cono (0,71 m²) fue expuesta a luz solar con iluminancia de 11.700 lux y radiación solar media igual a 774 W/m² desde el 24 de junio al 12 julio de 2013. La agitación y aireación del cultivo en el fotobiorreactor se realizó con una bomba de aire a un caudal medio de 0,002 L/s, la misma que dio como resultado una tasa de producción de biomasa seca de 0,298 g/m²/día, clorofila-"a" de 0,0023 g/m²/día y carotenoides de 0,0011 g/m²/día. El crecimiento de S. platensis en fotobiorreactor tubular cónico se ajustó a un modelo matemático de crecimiento "Potencial" en 18 días, con estadísticos de ajuste del modelo de (R²=0,937; F = 119,216).

The cyanophyta are a diverse group prokaryotic photosynthetic microorganisms, distributed in different terrestrial and aquatic environments. Some species of cyanophyta, can form toxic or harmful algal bloom. The objective of this study was to identify the species composition of cyanophyta in fluvio-lagoon systems Pom-Atasta (PA) and East Palisade (PE). Water samples were collected in ten sampling sites in each lagoon, with a van Dorn bottle at the surface and in the middle of the water column, in February, 2011. Twenty one were identified, of which seven species are bloom-forming as: Pseudanabaena catenata, P. limnetica, Anabaenopsis circularis, A. elenkinii, Aphanizomenon cf. ovalisporum, Ap. schindleri and Dolichospermum circinalis. Also, two new records reported: Aphanizomenon cf. ovalisporum y A. schindleri.

Las cianofitas son un grupo muy diverso de microorganismos procariontes fotosintetizadores, con una amplia distribución en diferentes ambientes tanto terrestres como acuáticos. Algunas especies pueden formar florecimientos algales nocivos o tóxicos. El objetivo de este estudio consistió en identificar la composición de las especies de cianofitas en los sistemas fluvio-lagunares Pom-Atasta (PA) y Palizada del Este (PE). Se recolectaron muestras de agua tanto en superficie como medio fondo para cada laguna, en febrero del 2011, en 10 sitios utilizando una botella van Dorn. Se identificaron 21 taxones, de las cuales siete especies forman florecimientos algales como: Pseudanabaena catenata, P. limnetica, Anabaenopsis circularis, A. elenkinii, Aphanizomenon cf. ovalisporum, Ap. schindleri y Dolichospermum circinalis. Además, se reportan dos nuevos registros correspondientes a Aphanizomenon cf. ovalisporum y A. schindleri.

A bacia de drenagem do rio Cascavel encontra-se quase que inteiramente dentro do perímetro urbano do município de Guarapuava, Estado do Paraná, Brasil. Foram amostrados sete segmentos de riachos em duas estações do ano (verão e inverno). Foram encontrados 12 táxons de macroalgas com dominância de Chlorophyta (sete táxons) seguido de Cyanophyta (três táxons), Heterokontophyta e Rhodophyta (um táxon cada). Riqueza, índice de diversidade e equidade foram mais elevados durante o período de inverno enquanto a abundância e dominância foram mais elevadas no verão. Entre as características microambientais, a velocidade da correnteza foi a única que diferiu significativamente entre os períodos climáticos. A Análise de Regressão revelou que a riqueza do substrato foi responsável pela variação de riqueza, diversidade, equidade e dominância de espécies durante o período de verão. Durante o inverno, a velocidade da correnteza foi responsável pela variação da diversidade de espécies. A análise de agrupamento das comunidades de macroalgas não reuniu pontos do mesmo período temporal. A Análise de Correspondência Canônica (CCA) mostrou que os segmentos aproximaram-se devido à ocorrência de uma ou poucas espécies em comum. Os padrões de distribuição espacial e temporal de macroalgas lóticas parecem fortemente influenciados por características de microhabitat em diferentes escalas, porém apoiadas em variáveis mais regionais.

The drainage basin of Cascavel River is almost entirely within the urban perimeter of Guarapuava, Paraná State, Brazil. Seven stream segments were sampled in two seasons (summer and winter). We found 12 taxa of macroalgae with a dominance of Chlorophyta (seven taxa) followed by Cyanophyta (three taxa), Heterokontophyta and Rhodophyta (one taxon each). Richness, diversity, and evenness were higher during the winter while the abundance and dominance were higher in the summer. Among the microenvironmental characteristics, the current velocity was the only one that differed significantly between the periods. The regression analysis revealed that the richness of the substrate was responsible for the variation in richness, diversity, evenness, and dominance during the summer period. During the winter the current velocity was responsible for the variation of species diversity. A cluster analysis of macroalgal communities did not group points in the same temporal period. The Canonical Correspondence Analysis (CCA) showed that the segments were close to each other because of the occurrence of one or a few species in common. The patterns of spatial and temporal distribution of stream macroalgae seem to be strongly influenced by microhabitat characteristics at different scales.However, they aresupported by regional variables.