Community ecology of metazoan parasites of the sairú Cyphocharax nagelii from the Peixe River

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

Reproductive ecology and size of sexual maturity in the anomuran crab Aegla parana (Decapoda: Aeglidae)

In Southern Brazil, Aegla parana Schmitt, 1942 is characterized by a broad distribution throughout the Iguacu River basin, particularly between the southern state of Parana and the northern state of Santa Catarina, preferentially inhabiting streams with rocky substrates. Although there has been an increase in the number of studies about the population biology of Aeglidae, many aspects about the reproductive biology of A. parana are still unknown. Therefore, the present study aimed to investigate the size at sexual maturity, reproductive seasonality and recruitment of A. parana from November, 2008 to December, 2009, in a tributary of the Iguacu River located in Uniao da Vitoria, Parana, Brazil. Basic environmental factors were investigated to determine their influence on the reproductive cycle of this species. Gonadal stages were characterized macroscopically, and the presence or absence of embryos in females (ovigerous females) from monthly samples was recorded. The entire sample was composed of 436 males and 211 females. Although the smallest ovigerous female was 16.2 mm, the average size (carapace length, CL) at sexual maturity (CL50%) was calculated at 17.4 mm. The greatest percentage of females with developed (mature, near spawning) gonads stage was observed from January to June, 2009, while ovigerous females were recorded from April to July, 2009, after which the reproductive period ended. Recruitment occurred from October to December, 2009. The presence of ovigerous females was negatively correlated with temperature (Spearman, p < 0.05). Females carrying embryos were generally collected during periods of lower temperatures, whereas recruits entered the population during periods of higher temperatures, when food for them is more abundant in the region studied.

Landscape Diversity Influences Dispersal and Establishment of Pest with Complex Nutritional Ecology

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

Diet and ecomorphology of Leporinus reticulatus (Characiformes: Anostomidae) from the upper Rio Juruena, MT, Brazil: ontogenetic shifts related to the feeding ecology

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

Induced fractional valley number in graphene with topological defects

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Ecology of the Skink, Mabuya arajara Reboucas-Spieker, 1981, in the Araripe Plateau, Northeastern Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Agro-ecology as a mediating science between the training of the agronomist and sustainable agriculture

Agro-ecology plays an important role in the implementation of sustainable development, and an agronomist can be a leading agent in the dissemination of that culture. In this perspective, a survey was carried out with the attendants of the course in Agronomy at the Instituto Federal de Educacao, Ciencia e Tecnologia do Mato Grosso, Campus Campo Novo do Parecis, Brazil. The object of the study was to analyze the participation of the academics in agro-ecological activities, seeking to observe the acceptance, perceptions and possible indications of incorporation of these principles in the training. The survey was conducted during the period July-December 2011. The approach was the qualitative method and the instruments used in data collection were participant observation and interviews during the activities. The results revealed the satisfaction of students in engaging in agro-ecological activities: Students developed concepts and incorporated the proposal of agro-ecology throughout the project. The contents of the agronomy course offered at the institution, in the perception of students, is strongly linked to the principles of conventional farming, not fully considering training to meet the challenges, and current and emerging demands of agriculture.

Population ecology of the planktonic shrimp lucifer faxoni borradaile, 1915 (crustacea, sergestoidea, luciferidae) of the southeastern coast of brazil

Luciferid shrimps have short life spans and a rapid turnover of generations, engage in sequential spawning, and protect their eggs during incubation. This study investigates the ecology of Lucifer faxoni Borradaile, 1915 in the littoral zone, Ubatuba region, São Paulo. Sampling was conducted monthly from July 2005 to December 2006 using a Renfro net trawled over a distance of 50 m for a total sampling effort of 50 m² at each station. Nine stations were sampled, ranging from 1 to 15 m deep. Three stations each were grouped into zones 1, 2 and 3 (Z1, Z2 and Z3). Monthly values of salinity, temperature and rainfall were recorded at each station. The pre-buccal somite length (SL) of each specimen was measured. The results showed that in shallower zones (Z1 and Z2), 6306 individuals were captured, whereas in the deeper zone (Z3), 3808 specimens were captured, but no significant differences in SL was detected between the specimens from Z1 and Z2 and those from Z3 (ANOVA, p=0.25). The abundance of shrimps did not differ significantly between seasons (Tukey’s test, p=0.02) except in the spring. The sex ratio differed significantly over the seasons (χ², p<0.05). The results were closely associated with environmental factors with respect to the spatial and seasonal distribution of L. faxoni. Rainfall affected salinity directly, and contributed to the displacement of these shrimps to deeper areas.

Correlating soil porosity and respective geological unit in Paraíba do sul Valley, Brazil: a geostatistical methodology proposal

This manuscript aims proposing a methodology for correlating soil porosity to the respective geological units using geostatistical analysis techniques, including interpolation data by kriging. The site studied was in Lorena municipality, Paraíba do Sul Valley, southeastern Brazil. Specifically all studies were carried out within an area of 12 km2 located at Santa Edwirges farm. The database comprehended 41 soil samples taken at different geological and geomorphologic units at three different depths: surface, 50 cm and 100 cm depth. The geostatistical analyses results were correlated to a geological mapping specifically elaborated for the site. This mapping accounts for two different geological formations and a geological contact characterized by a shearing zone. The results indicate the existence of a significant relationship between the soil porosity and the respective geological units. The studies revealed that the residual soils from weathered granitic rocks tend to have higher porosities than the residual soils from weathered biotite gneiss rocks, while the soil porosity within the shearing zone is relatively un-sensitive to the respective geological formation. The spatial patterns observed were efficient to evaluate the relationship between the soil porosity, geology unit and the and geomorphology showing a good potential for correlating with others soil properties such as hydraulic conductivity, soil water retention curves and erosion potentials.

The use of artificial neural networks in analysing the nutritional ecology of Chrysomya megacephala (F.) (Diptera: Calliphoridae), compared with a statistical model

Artificial neural networks (ANNs) have been widely applied to the resolution of complex biological problems. An important feature of neural models is that their implementation is not precluded by the theoretical distribution shape of the data used. Frequently, the performance of ANNs over linear or non-linear regression-based statistical methods is deemed to be significantly superior if suitable sample sizes are provided, especially in multidimensional and non-linear processes. The current work was aimed at utilising three well-known neural network methods in order to evaluate whether these models would be able to provide more accurate outcomes in relation to a conventional regression method in pupal weight predictions of Chrysomya megacephala, a species of blowfly (Diptera: Calliphoridae), using larval density (i.e. the initial number of larvae), amount of available food and pupal size as input data. It was possible to notice that the neural networks yielded more accurate performances in comparison with the statistical model (multiple regression). Assessing the three types of networks utilised (Multi-layer Perceptron, Radial Basis Function and Generalised Regression Neural Network), no considerable differences between these models were detected. The superiority of these neural models over a classical statistical method represents an important fact, because more accurate models may clarify several intricate aspects concerning the nutritional ecology of blowflies.