Fish assemblage structure and aquatic pollution in a Brazilian stream: some limitations of diversity indices and models for environmental impact studies

The aim of this study was to describe and quantify the effect of aquatic pollution on the fish assemblage structure of the Corumbatai River (Brazil), by comparing two sites with different water quality characteristics. The results revealed that abundance of individuals was low at the polluted site (B). However, the two sites did not differ significantly in species richness (total and average). This fact contradicts theories stating that portions where the transverse area of the channel is larger should present a higher biological richness. It was also observed that the ichthyofauna of site B had higher evenness, and, consequently, a tendency to a higher diversity than that at site A. This demonstrates that diversity estimates should be used cautiously in environmental impact studies, as they do not necessarily indicate better conditions of communities living in more preserved environments.

Phylogeny, Ecology, and Heart Position in Snakes

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

Habitat Split as a Cause of Local Population Declines of Amphibians with Aquatic Larvae

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

Solar Radiation Effect on the Complexation Capacity of Aquatic Humic Substances with Metals

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

Water quality index as a simple indicator of aquaculture effects on aquatic bodies

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 Macuco and Queixada rivers was investigated for 2 years (from May 2003 to May 2005). The index proposed in this work is composed of three measurable environmental parameters-turbidity, total phosphorus and dissolved oxygen. Concentrations of these three variables were normalized on a scale from 0 to 100 and translated into statements of water quality (excellent, good, regular, fair and poor). The index was applied to seventeen monitoring points in the aquatic bodies described above and compared to others, one being that used by the Environmental Protection Agency of United States and proposed for the National Sanitation Foundation, other employing minimal index and the last one considering the minimum operator concept. The results show that the degradation in this watershed from aquaculture activity can be easily inferred with this index, which is more restricted than the others routinely used to infer water quality. (C) 2007 Elsevier Ltd. All rights reserved.

Development of a simple and versatile ultrafiltration system for the fractionation of aquatic humic substances

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

An experimental assessment of landscape configuration effects on frog and toad abundance and diversity in tropical agro-savannah landscapes of southeastern Brazil

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

Community structure of aquatic insects (Ephemeroptera, Plecoptera, and Trichoptera) in Cerrado streams of Paraguay, Paraná, and São Francisco river basins

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

Influence of Seasonality on the Interaction of Mercury with Aquatic Humic Substances Extracted from the Middle Negro River Basin (Amazon)

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

Changes in optical properties caused by UV-irradiation of aquatic humic substances from the amazon river basin: Seasonal variability evaluation

Aquatic humic substances (AHS) isolated from two characteristic seasons of the Negro river, winter and summer corresponding to floody and dry periods, were structurally characterized by (13)C nuclear magnetic ressonance. Subsequently, AHS aqueous solutions were irradiated with a polychromatic lamp (290-475 nm) and monitored by its total organic carbon (TOC) content, ultraviolet-visible (UV-vis) absorbance, fluorescence and Fourier transformed infrared spectroscopy (FTIR). As a result, a photobleaching upto 80% after irradiation of 48 h was observed. Conformational rearrangements and formation of low molecular complexity structures were formed during the irradiation, as deduced from the pH decrement and the fluorescence shifting to lower wavelengths. Additionally a significant mineralization with the formation of CO(2), CO, and inorganic carbon compounds was registered, as assumed by TOC losses of up to 70%. The differences in photodegradation between samples expressed by photobleaching efficiency were enhanced in the summer sample and related to its elevated aromatic content. Aromatic structures are assumed to have high autosensitization capacity effects mediated by the free radical generation from quinone and phenolic moieties.

Bioaccumulation of metals in aquatic insects of streams located in areas with sugar cane cultivation

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

Lability of Cd, Cr, Cu, Mn and Pb complexed by aquatic humic substances

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

Behavior of cardiac variables in animals exposed to cigarette smoke

OBJECTIVE: To assess the behavior of cardiac variables in animals exposed to cigarette smoke. METHODS: Two groups of Wistar rats were studied as follows: control group (C), comprising 28 animals; and smoking group (S), comprising 23 animals exposed to cigarette smoke for 30 days. Left ventricular cardiac function was assessed in vivo with transthoracic echocardiography, and myocardial performance was analyzed in vitro in preparations of isolated left ventricular papillary muscle. The cardiac muscle was assessed in isometric contractions with an extracellular calcium concentration of 2.5 mmol/L. RESULTS: No statistical difference was observed in the values of the body variables of the rats and in the mechanical data obtained from the papillary muscle between the control and smoking groups. The values of left ventricular systolic diameter were significantly greater in the smoking animals than in the control animals (C= 3.39 ± 0.4 mm and S= 3.71 ± 0.51 mm, P=0.02). A significant reduction was observed in systolic shortening fraction (C= 56.7 ± 4.2% and S= 53.5 ± 5.3%, P=0.02) and in ejection fraction (C= 0.92 ± 0.02 and S= 0.89 ± 0.04, P=0.01). CONCLUSION: The rats exposed to cigarette smoke had a reduction in left ventricular systolic function, although their myocardial function was preserved.

Photosynthetic rate of the aquatic macrophyte Egeria densa Planch. (Hydrocharitaceae) in two rivers from the Itanhaém River Basin in São Paulo State, Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Giardia survey in live-trapped small domestic and wild mammals in four regions in the southwest region of the State of São Paulo, Brazil

For the first time, a survey on Giardia in the live-trapped small domestic and wild mammals was perfomed in four regions of state of the São Paulo, Brazil, with special attention to the parasitism of Rattus rattus rattus by Giardia. This species was found infected in all studied sites: Botucatu (15.4%), Conchas (28.5%), Itaporanga (38.7%) and São Roque (100 %). Two new hosts and their frequency of infection were described for Giardia in Nectomys squamipes, an aquatic rodent and in Bolomys lasiurus, a forest rodent (100 % and 14.3 %, respectively). Both G. muris and G. duodenalis groups were found in scrapings of intestinal mucosa of those rodents. Mixed infection was observed in some animals. It is important to emphasize the infection by G. duodenalis in the black rat as this species lives as a comensal with man and in N. squamipes as it may contaminate small streams used for domestic consumption. Therefore, further investigation will be necessary to elucidate the potential of these rodents to act as reservoirs of Giardia for man.