Species composition and spatial distribution of a stream fish assemblage in the east coast of Brazil: comparison of two field study methodologies

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Abundance and distribution of juvenile pink shrimps Farfantepenaeus spp. in a mangrove estuary and adjacent bay on the northern shore of São Paulo State, southeastern Brazil

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

Bathymetric distribution of the shrimp Rimapenaeus constrictus (Stimpson, 1874) (Decapoda, Penaeidae) in two locations off the southeastern Brazilian coast

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

Seed dispersal and spatial distribution of Attalea geraensis (Arecaceae) in two remnants of Cerrado in Southeastern Brazil

The seed dispersal system of Attalea geraensis (Arecaceae), an acaulescent palm, was investigated during one year in two Cerrado fragments in the state of São Paulo, southeastern Brazil. A. geraensis had inflorescences and infrutescences throughout the year. Two scatter-hoarding rodents (the spiny rat, Clyomys bishopi and agoutis, Dasyptocta azarae) were identified as seed predators/dispersers, able to move seeds up to 30 in from the palms, although most of the fruits (57.5%) were dispersed less than 2 in. The removal rates were high and after 20 days, 97.2% of the fruits were removed. Fruit fate was not related to fruit mass, length and diameter. The application of Morisita's index showed a more clumped distribution of adults in the smaller fragment, probably because of the absence of agoutis. Higher seed removal by rodents in the large Cerrado remnant may decrease seed predation by beetles. (C) 2007 Elsevier Masson SAS. All rights reserved.

Radioautographic study of the seasonal distribution of leukocytes in turtles Phrynops hilarii (Chelonia Chelidae)

The aim of this study was to present a morphological description of the leukocytes of Phrynops hilarii turtles according to the seasonal distribution of these cells and to show their replacement in the blood circulation using a radioautographic method. Five animals of both sexes weighing 600-1200 g were used. The animal's blood was aspirated, smeared on glass slides, and stained with the Romanowsky stain, and 500 cells of each animal were counted during each season. The results obtained were analyzed statistically by analysis of variance followed by the Bonferrom test (NCSS), with the level of significance set at p < 0.05. The radioautographic analysis of turtle blood exposed to 1000 mu Ci of H-3-thymidine and developed after 30 days showed a large number of silver grains incorporated into the cells, except for basophils, with cell renewal occurring every seven days. Quantitative data demonstrated a seasonal influence on the distribution of some leukocyte types, with the following p values: heterophils (p = 0.0007), basophils (p = 0.0002), monocytes (p = 0.0016), eosinophils (p = 0.0073). However, using this statistical method, it was not possible to detect a significant difference related to seasonal influence on lymphocytes (p = 0. 16295) or thrombocytes (p = 0. 1046). Using this experimental animal model, a seasonal influence on the distribution of some leukocyte types was observed, and the radioautographic method revealed a cell renewal system occurring every seven days, except for basophils. (C) 2008 Elsevier Ltd. All rights reserved.

Distribution of Rickettsia rickettsii in ovary cells of Rhipicephalus sanguineus (Latreille1806) (Acari: Ixodidae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Spatial-temporal distribution of fire-protected savanna physiognomies in Southeastern Brazil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Soil profile, relief features and their relation to structure and distribution of Brazilian Atlantic rain forest trees

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

Spatial distribution of nests of Nasutitermes sp (Isoptera : Termitidae) in a Cerrado area in southeastern Brazil

The density and aggregation patterns of nests of a species of Nasutitermes were determined in an area of 12,750 m(2). We found 131 nests in this area, and the distribution pattern was regular, with a density equaling 102.74 nests per hectare. Nest volume was determined from the height and diameter of 105 nests and varied from 1.59 to 192.46 dm(3). of the colonies, 70.5% had a volume below the mean value: 51.4% of these had volumes lower than 9 dm(3). Regression between the mean volumes and the distance of the 2 nearest nests was positive and significant (P < 0.001), suggesting competition between colonies.

Density and Spatial Distribution of Buffy-tufted-ear Marmosets (Callithrix aurita) in a Continuous Atlantic Forest

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

How to not inflate population estimates? Spatial density distribution of white-lipped peccaries in a continuous Atlantic forest

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

Spatio-temporal segregation and size distribution of fish assemblages as related to non-native species occurrence in the middle rio Doce Valley, MG, Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Diversity and distribution of crustaceans from 13 sheltered sandy beaches along Sao Sebastiao Channel, south-eastern Brazil

The crustacean species composition in the intertidal zones of 13 sheltered unconsolidated marine beaches in south-eastern Brazil is described. Fifty-three crustacean species were collected, adding 46 species to the total reported by previous studies in the same region. Decapods dominated the community, in contrast to exposed sandy beaches where peracarids normally predominate. The species were distributed irregularly among the beaches. Richness varied markedly among sites, and was positively related to a combination of factors such as fine sand grains, high organic matter content, and relatively low silt-clay content. The presence of rock fragments enabled both rocky shore and sandy beach crustaceans to occur oil the same beaches. Richness and abundance of crustaceans showed no clear relationship to sediment grain size and slope, in contrast to the norm for exposed sandy beaches. The dominance of the tanaid Kalliapseudes schubarti in sonic areas may be a result of organic matter pollution in the region. These beaches showed higher species richness than typical sheltered and exposed sandy beaches, indicating that this sheltered, highly heterogeneous seascape is an important area for conservation.

Larval competition for patchy resources in Chrysomya megacephala (Dipt., Calliphoridae): implications of the spatial distribution of immatures

In the present study, a single procedure was established to investigate the effect of the spatial distribution of immatures in patchy resources, on the outcome of larval competition for food. in experimental populations of Chrysomya megacephala. A theoretical model of intraspecific competition was extended and applied to experimental data on survival to adulthood for 20 larval densities, to obtain the theoretical mean number of individuals that will survive, considering a hypothetical previous random adult oviposition in a system of homogeneous patches. The survival curve obtained suggests that the larval competition for food in C. megacephala is of the scramble/exploitative type, which corroborates results from previous studies, although the latter did not consider the correlation between local and global abundances. The present model allows that experimental data could be perfectly applicable, and it incorporates fundamental assumptions about the spatial context of competition for patchy resources in blowflies, and may be applied to the optimization of mass rearing techniques and to the maintenance of insect colonies under experimental conditions.

Predicting the potential distribution of the alien invasive American bullfrog (Lithobates catesbeianus) in Brazil

The non-native invasive anuran Lithobates catesbeianus is presently distributed in Brazil, especially in the Atlantic Rainforest biodiversity hotspot. Here, we use a maximum entropy ecological niche modeling algorithm (i) to model the North American native geographic distribution of this species and (ii) to project that model onto the whole of Brazil. After applying a threshold value that balances commission and omission errors, the projection results suggested high probabilities of occurrence mostly in southern and southeastern Brazil. We also present the first report on the species known distribution in Brazil, showing good agreement with model predictions. If the predictive map is interpreted as depicting invasiveness potential of L. catesbeianus, strategies to prevent further invasion in Brazil should be focused especially in the Atlantic Rainforest biodiversity hotspot.