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Morphological caste differences in the neotropical swarm-founding polistinae wasps: Agelaia m. a. multipicta and a. p. pallipes (hymenoptera vespidae)
(1997-10-01)
Distinct size dimorphism was found between queens (inseminated egglayers) and workers (uninseminated non egg-layers) sampled from mature colonies of Agelaia pallipes and A. A. multipicta. In both species, among 22 measured ...
An experimental assessment of landscape configuration effects on frog and toad abundance and diversity in tropical agro-savannah landscapes of southeastern Brazil
(Springer, 2012-01-01)
Amphibians are an imperiled group of vertebrate animals that typically have biphasic life histories involving a shift from aquatic larval habitats to terrestrial adult habitats. Habitat loss is the greatest threat to ...
Bromeliad architectural complexity and vertical distribution predict spider abundance and richness
(Wiley-Blackwell, 2011-06-01)
Habitat complexity is a main predictor of the distribution of arthropods on vegetation. However, it remains poorly known whether plant architecture and fine-scale spatial distribution affect the species richness and ...
Water quality index as a simple indicator of aquaculture effects on aquatic bodies
(Elsevier B.V., 2008-09-01)
This paper proposes a water quality index (WQI) to subsidize management actions in the Medio Paranapanema Watershed in São Paulo State, Brazil, as a simple pollution indicator for aquaculture activity. Water quality of the ...
A model for the plankton system of the Broa reservoir, Sao Carlos, Brazil
(Elsevier B.V., 2000-02-28)
In this paper a model, called ELLOBO running in STELLA II, was set to describe the plankton system of the Broa reservoir (SP). The three state variables of the model are: phytoplankton, zooplankton, and the fish Astyanax ...
Factors regulating diversity and abundance of fish communities in Pantanal lagoons, Brazil
(Blackwell Publishing, 2004-02-01)
The factors effecting fish species richness, evenness and relative abundance in 19 floodplain lagoons in the Pantanal (Brazil) were examined. Richness and evenness were strongly correlated with the lagoon's: (i) isolation ...
Testing the quick meal hypothesis: the effect of pulp on hoarding and seed predation of Hymenaea courbaril by red-rumped agoutis (Dasyprocta leporina)
(Blackwell Publishing, 2006-02-01)
Red-rumped agoutis (Dasyprocta leporina) are important seed dispersers/predators of Neotropical large-seeded plants. Several species of seeds cached by agoutis have an edible reward, in contrast to temperate rodent-dispersed ...
Winged leaf-cutting ants on nuptial flights used as transport by Attacobius spiders for dispersal
(Wiley-Blackwell, 2004-10-01)
1. Sexuals of a leaf-cutting ant, Atta bisphaerica Forel, left their nest for nuptial flights in October to December.2. When leaving a nest, 53 of the 479 winged sexuals (or alates) observed (11.1%) carried up to three ...
Comparing river basins world-wide and contrasting inland fisheries in Africa and Central Amazonia
(1998-04-01)
An analysis of covariance relating basin area (A, km2) to river length (L, km) and discharge rate (D, m3 s-1) was performed for two continents and showed that the two covariates (L and D) were highly significant and that ...
Mesocosm experiment on the impact of invertebrate predation on zooplankton of a tropical lake
(Springer, 2007-12-01)
Invertebrate predation on zooplankton was investigated in mesocosms in the shallow tropical Lake Monte Alegre, Sauo Paulo State, Brazil, in the summer of 1999. Two treatments were applied: one with natural densities of ...