Categorização functional trófica das comunidades de macroinvertebrados de dois reservatórios na região centro-oeste do Estado de São Paulo, Brasil

The use of the concept of guild can be useful for the functional trophic categorization of communities, because there is no requirement identification of organisms in the level of species and not to treat each species as a separate entity. The aim of this study was to analyze the functional feeding groups (collectors-gatherers, collectors-filterers, shredders, predators and grazer-scrapers) of the macroinvertebrate communities of two reservoirs in the Midwestern region of São Paulo State. Sampling was carried out in rainy (March/April - 2001) and dry (July/August - 2001) seasons and the data obtained indicate that 'collectors-gatherers' is the most frequent guild. This fact suggests a great importance of organic matter as a food source in the diet of the macroinvertebrates analyzed.

Socialists vs. fascists and communists in Italian São Paulo in the 1920s

The action of São Paulo's Italian reformist socialists at the beginning of the 20th century had a political impact on the way of considering the question of democracy both in the state of São Paulo and the whole of Brazil. In fact not only did the socialists oppose the fascist political project and the symbolic roots of its aggressive behavior, but they also faced the opposition of the theoretical proposals coming from other leftist groups. This article intends to present the main interlocutors of these socialists and understand how this theoretical dispute has developed.

Comparative feeding kinematics of tropical hylid tadpoles

Anuran larvae, which are otherwise simple in shape, typically have complex keratinized mouthparts (i.e. labial teeth and jaw sheaths) that allow them to graze upon surfaces. The diversity in these structures among species presumably reflects specializations that allow for maximal feeding efficiency on different types of food. However, we lack a general understanding of how these oral structures function during feeding. We used high-speed digital imaging (500 Hz) to observe tadpoles of six species from the anuran family Hylidae grazing on a standardized food-covered substrate. Tadpoles of these species vary in the number of labial tooth rows, belong to two different feeding guilds (benthic and nektonic), and inhabit ponds and streams. We confirmed that the labial teeth in these species serve two functions: anchoring the mouth to the substrate and raking material off of the substrate. In general, tadpoles with a larger maximum gape or those with fewer labial tooth rows opened and closed their mouths slower than tadpoles with smaller gape or more tooth rows. Nektonic feeding tadpoles released each of their tooth rows proportionally earlier in the gape cycle compared with benthic feeding tadpoles. Lastly, we found some support for the idea that deformation of the jaw sheaths during a feeding cycle is predictable based on tadpole feeding guild. Collectively, our data show that anatomical (e.g. number of labial teeth) and ecological features (e.g. feeding guild) of tadpoles significantly influence how tadpoles open and close their mouths during feeding. © 2013. Published by The Company of Biologists Ltd.

Dynamics and coexistence in a system with intraguild mutualism

It is a tenet of ecological theory that two competing consumers cannot stably coexist on a single limiting resource in a homogeneous environment. Many mechanisms and processes have since been evoked and studied, empirically and theoretically, to explain species coexistence and the observed biological diversity. Facilitative interactions clearly have the potential to enhance coexistence. Yet, even though mutual facilitation between species of the same guild is widely documented empirically, the subject has received very little theoretical attention. Here, we study one form of intraguild mutualism in the simplest possibly community module of one resource and two consumers. We incorporate mutualism as enhanced consumption in the presence of the other consumers. We find that intraguild mutualism can (a) significantly enhance coexistence of consumers, (b) induce cyclic dynamics, and (c) give rise to a bi-stability (a 'joint' Allee effect) and potentially catastrophic collapse of both consumer species. © 2012 Elsevier B.V.

Pollination ecology of the Cerrado species Eschweilera nana (Lecythidaceae subfam. Lecythidoideae)

Eschweilera nana is pollinated by a guild of pollinators consisting of mostly bees. Effective pollinators are large bees able to force their way into the closed androecium to access nectar. The morphology of the flowers diminishes self pollination and promotes cross-pollination. Although many pollinators make diurnal visits to the flowers, fruit set was very low in comparison with the number of flowers produced. Breeding system tests yielded only two fruits, one produced by xenogamy and another one in the control test. The results of this study are consistent with studies of other Cerrado plants pollinated by guilds of insects and support the conclusion of other pollination studies of Lecythidaceae that fruit set is low in comparison with the high numbers of flowers produced. © 2013 The New York Botanical Garden.

The functional biogeography of species: Biogeographical species roles of birds in Wallacea and the West Indies

Biogeographical systems can be analyzed as networks of species and geographical units. Within such a biogeographical network, individual species may differ fundamentally in their linkage pattern, and therefore hold different topological roles. To advance our understanding of the relationship between species traits and large-scale species distribution patterns in archipelagos, we use a network approach to classify birds as one of four biogeographical species roles: peripherals, connectors, module hubs, and network hubs. These roles are based upon the position of species within the modular network of islands and species in Wallacea and the West Indies. We test whether species traits - including habitat requirements, altitudinal range-span, feeding guild, trophic level, and body length - correlate with species roles. In both archipelagos, habitat requirements, altitudinal range-span and body length show strong relations to species roles. In particular, species that occupy coastal- and open habitats, as well as habitat generalists, show higher proportions of connectors and network hubs and thus tend to span several biogeographical modules (i.e. subregions). Likewise, large body size and a wide altitudinal range-span are related to a wide distribution on many islands and across several biogeographical modules. On the other hand, species restricted to interior forest are mainly characterized as peripherals and, thus, have narrow and localized distributions within biogeographical modules rather than across the archipelago-wide network. These results suggest that the ecological amplitude of a species is highly related to its geographical distribution within and across bio geographical subregions and furthermore supports the idea that large-scale species distributions relate to distributions at the local community level. We finally discuss how our biogeographical species roles may correspond to the stages of the taxon cycle and other prominent theories of species assembly. © 2013 The Authors.

Interference of cage fish farm on diet, condition factor and numeric abundance on wild fish in a Neotropical reservoir

Historically, the ichthyofauna of large Brazilian rivers has been subject to anthropogenic interference, such as impoundments. Currently, cage fish farming systems are a new source of impact on aquatic ecosystems. The objective of this study was to characterise the impact of freshwater fish farms on the feeding of five species of Neotropical freshwater fish. Specimens of Astyanax altiparanae, Galeocharax knerii, Iheringicthys labrosus, Pimelodus maculatus and Plagioscion squamosissimus were sampled in areas around two systems of cage fish farming (CF), and two control areas (CT) that were not influenced by this activity. Results show that there were significant changes in the diet of trophic generalist species (A. altiparanae, P. maculatus and I. labrosus) accompanied by a related increase in the condition factor values of these species in cage areas. Trophic specialist species, such as the carnivorous fish species G. knerii and P. squamosissimus, presented small differences between the CF and CT areas with regard to diet and showed no differences in other analyses performed. In conclusion, cage fish farms can affect the natural diet of trophic generalist fish species, directly affecting the nutritional status (condition factor), where food wastes was found to be one of the principal items consumed by this trophic guild. Results indicate that these species are responsible for recycling a great quantity of organic matter transferred by this type of activity, which, along with local fishery activities, contribute to mitigation of associated processes of eutrophication. © 2013 Elsevier B.V.

Avifauna da Ilha Queimada Grande, SP: diversidade, estrutura trófica e sazonalidade

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

A estrutura trófica da ictiofauna de riachos reflete a estrutura física do habitat?

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estrutura de comunidades e influência da heterogeneidade ambiente na diversidade de anuros em área de pastagem no sudeste do Brasil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Uso de habitats e ecomorfologia de girinos na Serra da Mantiqueira, SP

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Ecologia da polinização de Eschweilera nana Miers, uma Lecythidaceae do cerrado

Pós-graduação em Ciências Biológicas (Biologia Vegetal) - IBRC

O pensamento de Che Guevara: um homem novo, trabalho e consciência na Revolução Cubana

Pós-graduação em Ciências Sociais - FFC

Entre o semear e a próxima colheita: uma análise dos escritos de Lenin sobre a questão agrário-camponesa

Pós-graduação em Ciências Sociais - FFC

A reestruturação das instituições de controle das empresas estatais chinesas (1978-2003)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)