Spatial variation in the strength of mutualism between a jumping spider and a terrestrial bromeliad: Evidence from the stable isotope N-15

Psecas chapoda, a neotropical jumping spider strictly associated with the terrestrial bromeliad Bromelia balansae in cerrados and semi-deciduous forests in South America, effectively contributes to plant nutrition and growth. In this study, our goal was to investigate if spider density caused spatial variations in the strength of this spider-plant mutualism. We found a positive significant relationship between spider density and delta N-15 values for bromeliad leaves in different forest fragments. Open grassland Bromeliads were associated with spiders and had higher delta N-15 values compared to forest bromeliads. Although forest bromeliads had no association with spiders their total N concentrations were higher. These results suggest that bromeliad nutrition is likely more litter-based in forests and more spider-based in open grasslands. This study is one of the few to show nutrient provisioning and conditionality in a spider-plant system. (c) 2008 Elsevier Masson SAS. All rights reserved.

A PHYLOGENETIC ANALYSIS of SYNOECA DE SAUSSURE, 1852, A NEOTROPICAL GENUS of SOCIAL WASPS (HYMENOPTERA: VESPIDAE: EPIPONINI)

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

Morphological and morphometric characteristics of the epididymis in the Neotropical bats Eumops glaucinus and Molossus molossus (Chiroptera: Molossidae).

The ability of certain species of bats to store viable spermatozoa in the cauda epididymis, for periods of many months beyond the end of spermatogenesis was first recognized over a century ago. However, information about the bat epididymis is still scarce or absent. Thus, this study aimed to characterize and to compare morphologically and morphometrically the regional histology of the epididymis of Eumops glaucinus and Molossus molossus (Chiroptera: Molossidae). Histologically, the epididymis of both species was subdivided into 4 segments: initial segment, caput, corpus and cauda. In comparing the two species, it was observed that the tubular and luminal diameters and percentage of interstitial tissue showed significant differences in all segments. The epithelial height, in both, is greater in the initial segment with a decrease until the cauda epididymis. In relation to the luminal diameter, both species showed a gradual increase from the initial segment to the cauda. The percentage of epithelium, lumen and interstitial tissue varied between both, sometimes M. molossus showing a significantly higher percentage, and other times, E. glaucinus. In both species, the principal cell was the most abundant (> 77%), followed by basal cells at approximately 13% and apical cells at 4% in all segments. Spermatozoa were observed in greater amounts in corpus and cauda epididymis segments. In summary, ours results show that, despite that the species analyzed belong to different genera and have different breeding cycles, the epididymis exhibits similarities in the two species and morphometric and composition differences compared to the majority of mammals.

Environmental evaluation of metals in sediments and dragonflies due to sugar cane cultivation in neotropical streams

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Evaluating the use of predatory insects as bioindicators of metals contamination due to sugarcane cultivation in neotropical streams

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

An adaptive view of caste differentiation in the neotropical wasp Polybia (Trichothorax) sericea Olivier (Hymenoptera: Vespidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Recursos alimentares explorados pelos cupins (Insecta: Isoptera)

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

Surprising genomic diversity in the Neotropical fish Synbranchus marmoratus (Teleostei: Synbranchidae): how many species?

Os cromossomos e a variação de conteúdo de DNA nuclear foram estudados em sete amostras de Synbranchus marmoratus das bacias dos rios Paraguai e Paraná com o objetivo de avaliar se diferenças no cariótipo e no conteúdo de DNA nuclear poderiam fornecer informações para a caracterização de linhagens evolutivas independentes no gênero e para a elaboração de hipóteses evolutivas e biogeográficas. A ocorrência de diferentes cariótipos já foi descrita para essa espécie, entretanto, um novo citótipo foi encontrado no rio Miranda. O conteúdo de DNA nuclear mostrou uma ampla variação entre as amostras e indivíduos, com valores entre 5,2 a 9,1 pg de DNA/núcleo. Uma análise de variância confirmou a ocorrência de diferenças significativas entre as amostras. em uma série de análises, um padrão multimodal foi encontrado na distribuição do conteúdo de DNA nuclear, pelo qual várias unidades, mais ou menos discretas, foram identificadas. Combinando a fórmula cariotípica com o conteúdo de DNA nuclear, uma relação complexa entre os rios foi observada. Com base nos dados disponíveis, sugerimos que existem várias linhagens evolutivas independentes de Synbranchus marmoratus nos rios amostrados. Hipóteses biogeográficas são propostas e discutidas.

Environmental factors predicting fish community structure in two neotropical rivers in Brazil

Com o objetivo de identificar os padrões de organização das comunidades de peixes dos rios Jogui e Iguatemi nós amostramos peixes através de redes de espera trimestralmente entre Novembro/1999 e Agosto/2000. Hypostomus ancistroides e Parauchenipterus galeatus foram as espécies de peixes mais abundantes nos rios Jogui e Iguatemi, respectivamente. A variação longitudinal foi mais importante que a sazonal na determinação da composição de espécies em ambos os rios e a diferença entre estações não foi significativa. A altitude foi o fator mais importante na determinação da distribuição das espécies.

Meso and microhabitat analysis and feeding habits of small nektonic characins (Teleostei: Characiformes) in Neotropical streams

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

Neotropical monogenoidea. 25. Anacanthorus penilabiatus n. sp. (Dactylogyridae, Anacanthorinae) from Piaractus mesopotamicus (Osteichthyes, Serrasalmidae), cultivated in the State of São Paulo, Brazil

Anacanthorus penilabiatus n. sp. is described from the serrasalmid fish, Piaractus mesopotamicus (Holmberg, 1887), cultivated in the Centro de Aqüicultura, Universidade Estadual Paulista. The new species is characterized by having a relatively straight copulatory organ with a long lip on the distal margin and a median longitudinal flap, and a copulatory ligament. The large size of the infrapopulations of this species of parasite indicates that it should be considered a potential agent causing losses in aquaculture of the fish host.

Nuclear DNA content determination in Characiformes fish (Teleostei, Ostariophysi) from the Neotropical region

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

Karyotype description of two Neotropical Psittacidae species: the endangered Hyacinth Macaw, Anodorhynchus hyacinthinus, and the Hawk-headed Parrot, Deroptyus accipitrinus (Psittaciformes: Aves), and its significance for conservation plans

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Nuclear DNA content in 20 species of Siluriformes (Teleostei: Ostariophysi) from the Neotropical region

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

Karyological characterization of four Neotropical fish species of the genus Hisonotus (Teleostei, Loricariidae, Hypoptopomatinae) from distinct Brazilian river basins

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