In the present study, we describe feeding habits of Deuterodon sp. from the Ubatiba River and explore if diet changes according to a temporal cycle of dry and wet seasons. We observed that Deuterodon sp. fed on an extremely high diversity of items ranging from organic matter, sediment (sand plus quartz parts), algae, seeds and leaves to animal organisms, such as, crustaceans, oligochaets and several life stages of terrestrial and aquatic insects, indicating an omnivorous diet. An important shift in the use of feeding resources was also registered; animal and vegetal items had alternated importance between both seasons. Allochthonous vs. autochthonous items analysis showed predominance of allochthonous items during dry season while no significant differences were registered during wet season. Neste estudo descrevemos o hábito alimentar de Deuterodon sp. do rio Ubatiba e exploramos a hipótese de que as variações da dieta são função da alternância das estações seca e chuvosa. Observamos que Deuterodon sp. ingere ampla variedade de items, que variam desde matéria orgânica, sedimento (areia e partículas de quartzo), algas, sementes e folhas até organismos animais, tais como crustáceos, oligoquetas e diversos estágios de vida de insetos terrestres e aquáticos, sugerindo uma dieta onívora. Foi registrada importante alternação no uso dos recursos alimentares; itens animais e vegetais alternaram a importância durante as estações. Quanto aos recursos de origem autóctone e alóctone, registramos maior ocorrência dos últimos na estação seca e ausência de diferenças significativas para os primeiros na estação chuvosa.

ResumoEsse estudo foi realizado no Córrego Andorinha, localizado na vertente oceânica da Ilha Grande (23°05', 23°15'S e 44°06 e 44°23'W) e teve como objetivo determinar a dieta de B. microcephalus, bem como suas variações entre jovens e adultos. As coletas foram realizadas entre nov/99 e out/00 através de rede de espera e arrastinho (malhas 5mm e 10mm) em um trecho do riacho onde a vegetação marginal cobre 100% da localidade, o substrato é formado por areia, cascalho, rochas e folhiço. A cada ocasião de coleta 20 exemplares eram amostrados e o conteúdo estomacal analisado sob microscópio estereoscópico através do método da Freqüência Numérica. A dieta da espécie é baseada em larvas de insetos aquáticos (autóctones) e insetos terrestres (alóctones). A participação dos itens autóctones e alóctones variam sazonalmente (r Spearman =0,296; p=0,325) sendo que os ítens alóctones predominaram na estação seca. Considerando-se a importância relativa dos itens alóctones e autóctone na dieta de jovens e adultos, separadamente, observamos predomínio de itens alóctones entre os primeiros (teste t; t = 2,51; gl = 30; p = 0,018) e ausência de diferença entre os adultos (teste t; t = 0,79; gl = 84; p = 0.429). O valor médio do Quociente Intestinal (QI) foi 0,77, sem diferenças entre jovens e adultos (teste t; t = -0,62; gl = 85; p=0,45), e sugere dieta onívora fato não corroborado pela dieta registrada. Isso pode ser explicado pela pontualidade das amostras realizadas em uma localidade de baixa produção primária decorrente da baixa insolação (100% cobertura); no entanto, como migradores, esses exemplares certamente utilizam outros recursos (e.g. algas filamentosas e/ou vegetais superiores) em outras localidades onde a produção primária é incrementada pela insolação (áreas abertas), justificando a pré-adaptação anatômica da população (QI de onívoro). AstractThe present study was developed at córrego Andorinha in the oceanic slope of Ilha Grande (23°05', 23°15'S e 44°06 e 44°23'W) and aimed to determine B. microcephalus feeding habits as well as their differences between adult and juvenile specimens. Sampling were carried out between Nov/99 and Oct/00, by waiting nets (5-10 mm mesh) and sieves in a stream strech characterized by 100% of canopy and sand, gravel, rocks and debris substrata. At each sampling ocasion, 20 specimens were collected and their gut content analysed under stereoscopic microscopic following the Numerical Frequency method. Diet was based mainly on aquatic insect larvaes (autochthonous) and terrestrial insects (allochthonous). The participation of allochthonous and autochthonous itens varied seasonally (r spearman = 0.296; p=0.325), being allochthonous itens predominant during dry season. Considering the relative participation of allochthonous and autochthonous itens in the diet of juvenile and adult, separatelly, we found predominance of allochthonous itens among juveniles (t test; t=2.51, df=30; p=0.01) and absence of differences among adult specimens (t test; t=0.79, df=84; p=0.43). Mean value of Intestinal...

Rezende, C.F. Community structure of macroinvertebrates associated with leaf litter from riffles and pools from Central Amazon streams. Biota Neotrop. May/Aug 2007 vol. 7, no. 2 http://www.biotaneotropica. org.br/v7n2/pt/abstract?short-communication+bn01607022007 ISSN 1676-0603.Considering that the composition and distribution of freshwater macroinvertebrates is related to several environmental factors, especially water flow and type of substratum I hypothesized that composition, richness and abundance of macroinvertebrates that occur in both environments with distinct hydrological characteristics (riffle and pool) were different between these areas. Specimens were sampled in three streams where five traps were arranged in stretches from pools and riffles totalizing 30 traps. In the laboratory the macroinvertebrates were identified to family level. An analysis of variance in blocks was made in order to verify possible effects of habitat and stream type on the richness and abundance of macroinvertebrates. Shannon´s diversity index was applied, followed by a t-test. The Bray-Curtis cluster analysis was performed to verify the similarity between different habitats. A total of 132 specimens were collected, 97 in riffles and 35 in pools. Among sixteen families collected, six colonized only riffles, two colonized only pools and eight colonized both environments. An effect of the habitat (pools or riffles) upon the richness and abundance of macroinvertebrates was detected. On the contrary, no difference was found among streams (igarapés). The Shannon diversity index was higher in riffles than in pools. The riffle stretches formed a single group on the Bray-Curtis cluster analysis. I conclude that composition and abundance were distinct between the community of macroinvertebrates of riffles and pools. The explaining hypothesis for these results is that the community structure of both environments is distinct due to variations associated with water flow, that allows the existence of groups with different ecological and behavioral features.Keywords: colonization, water flow, aquatic invertebrates. ResumoRezende, C.F. Estrutura da comunidade de macroinvertebrados associados ao folhiço submerso de remanso e correnteza em igarapés da Amazônia Central. Biota Neotrop. May/Aug 2007 vol. 7, no. 2 http:// www.biotaneotropica.org.br/v7n2/pt/abstract?short-communication+bn01607022007 ISSN 1676-0603.Considerando que a composição e a distribuição de macroinvertebrados de água doce é relacionada a diversos fatores ambientais, destacando-se a velocidade da corrente e o tipo de substrato tive como hipótese de trabalho que a composição, riqueza, e abundância de macroinvertebrados que ocorrem em dois ambientes com características hidrológicas distintas (correnteza e remanso) fossem diferentes entre essas áreas. A amostragem foi realizada em três igarapés onde foram dispostas cinco armadilhas em trechos de remanso e cinco em correnteza, totalizando 30 armadilhas. No laboratório os macroinvertebrados foram identificados em ordens e ...

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Substantially higher rates of protein and fluid volume transport for microfiltration of yeast suspensions were possible with improved hydrodynamics using centrifugal fluid instabilities called Dean vortices. Under constant permeate flux operation with suspended yeast cells, a helical module exhibited 19 times the filtration capacity of a linear module. For feed containing both BSA and beer yeast under constant transmembrane pressure with diafiltration, about twice as much protein (BSA and other proteins from cell lysis) was transported out of the feed by the helical module as compared with the linear module. The volumetric permeation flux improvements for the helical over the linear module ranged from 18 to 43% for yeast concentrations up to 4.5 dry wt %.

The ecology of fish from intermittent streams in the Brazilian semi-arid region is still little known. In the past twenty years, the number of researchers dedicated to this topic has increased considerably. However, significant gaps still exist when compared to the perennial streams of other regions of Brazil. Questions that address seasonal variations come up against the determination of capture methods and techniques that are efficient in the different phases of the hydrological cycle. In addition, techniques widely used in perennial systems, such as electrofishing, in most cases, have not been effective. Aspects related to biology, physiology, behavior, functional and taxonomic ecology of fish still need to be investigated taking into account seasonal and spatial scale variations. In view of the growing transformation imposed on the Brazilian semi-arid region by the extensive use of natural resources and by climate change, aquatic environments and their biodiversity are threatened by the transformation of riparian vegetation, the sewage release, the species introduction, the modification of its course and artificial perennialization. Thus, we will present and discuss, in this paper, the studies developed on the ecology of fish in the intermittent streams of the Brazilian semi-arid region and the gaps and challenges to be faced by future research.

River networks are among Earth’s most threatened hot-spots of biodiversity and provide key ecosystem services (e.g., supply drinking water and food, climate regulation) essential to sustaining human well-being. Climate change and increased human water use are causing more rivers and streams to dry, with devastating impacts on biodiversity and ecosystem services. Currently, more than a half of the global river networks consist of drying channels, and these are expanding dramatically. However, drying river networks (DRNs) have received little attention from scientists and policy makers, and the public is unaware of their importance. Consequently, there is no effective integrated biodiversity conservation or ecosystem management strategy of DRNs. A multidisciplinary team of 25 experts from 11 countries in Europe, South America, China and the USA will build on EU efforts to assess the cascading effects of climate change on biodiversity, ecosystem functions and ecosystem services of DRNs through changes in flow regimes and water use. DRYvER (DRYing riVER networks) will gather and upscale empirical and modelling data from nine focal DRNs (case studies) in Europe (EU) and Community of Latin American and Caribbean States (CELAC) to develop a meta-system framework applicable to Europe and worldwide. It will also generate crucial knowledge-based strategies, tools and guidelines for economically-efficient adaptive management of DRNs. Working closely with stakeholders and end-users, DRYvER will co-develop strategies to mitigate and adapt to climate change impacts in DRNs, integrating hydrological, ecological (including nature-based solutions), socio-economic and policy perspectives. The end results of DRYvER will contribute to reaching the objectives of the Paris Agreement and placing Europe at the forefront of research on climate change.

Os trabalhos de Lindeman (1942), seguidos pelos trabalhos de Odum (1956, 1957), desperteam o interesse de ecólogos sobre questões a cerca da produção biótica e do fl uxo de energia em sistemas aquáticos. A ecologia energética ocupa-se fundamentalmente da forma como a energia transita no interior do sistema. Ao nível ecossistêmico o fl uxo de energia desenvolve uma série de reações químicas que podem liberar ou absorver calor. Essas funções atuam primeiramente ao nível individual, populacional (Odum & Smalley 1959) e, posteriormente, ecossistêmico (Odum 2001). Odum foi o primeiro a desenvolver uma abordagem para medir o estado de maturidade do sistema que era atingido quando observado incremento de biomassa. Essa avaliação termodinâmica media o estágio de maturidade dos ecossistemas, e verifi cava o desempenho de cada componente, alicerçado ao manejo de populações naturais. A aplicação da teoria de Odum pode ser desenvolvida com análises sobre redes trófi cas que permitem quantifi car o estágio de evolução de um ecossistema, através das propriedades emergentes. A ausência de dados quantitativos (biomassa) englobando todos os organismos do ecossistema junto com a difi culdade de se encontrar ferramentas para o desenvolvimento desses trabalhos tem sido uma das principais difi culdades dessas abordagens. A presente revisão tem como objetivo traçar um histórico da ecologia energética em sistemas aquáticos, enfatizando as principais metodologias utilizadas para verifi car o fl uxo de energia nos sistemas ecológicos. Palavras-chave: Ecologia energética, rios, peixes, teias trófi cas ABSTRACT ENERGY FLOW IN AQUATIC COMMUNITIES, EMPHASIZING LOTIC SYSTEMS. A series of studies by Lindeman and Odum attracted scientifi c attention to the matter of biotic production and energy fl ow in aquatic ecosystems. Energy fl ow ecology fundamentally deals with how energy is transferred in a given system. The fl ow of energy generates a series of chemical reactions which may absorb or release heat, and these heat variations occur at the level of the individual, with subsequent effects over the entire population and ecosystem. Odum was the fi rst author to develop a thermodynamic method to measure the state of maturity reached by a given system following biomass increment. This method was used to evaluate the individual performance of each of the ecosystem's parts based on the natural processes intrinsic to populations. Odum's theory can be further developed by including trophic web analysis, thus allowing assessment of the evolutionary stage of ecosystems based on emergent properties. The greatest obstacles for such an approach is the lack of quantitative data (biomass) that would include all organisms of any given ecosystem and the diffi culty in fi nding useful tools to develop these studies. The objective of the present review is to present an historical account of the energy fl ow ecology in aquatic ecosystems, focusing on the main methodologies employed.