Ecologia e Recursos Naturais

This study has aims to determine the age and to estimate the growth parameters using scales of the species. Individuals of Piaractus mesopotamicus (Holmberg, 1887) used in this study were captured in the commercial fishery conducted in the region, along the year 2006. The model selected to express the growth of the species was the von Bertalanffy Sl= Sl∞*[1-exp-k(t-to)]. To determine if scales are suitable for studying the growth of pacu, we analyzed the relation between standard length (Sl) and the radius of the scales through linear regression. The period of annuli formation was determined analyzing the variations in the marginal increment and evaluating the consistency of the readings through the analysis of the coefficient of variations (CVs) for the average standard lengths of each age (number of rings) observed in the scales. The relationship between Ls of the fish and the radius of the scales showed that scales can be used to study the age and growth of P. mesopotamicus (R= 0.79). CVs were always below 20%, demonstrating the consistency of the readings. Annuli formation occurred in February, probably related to trophic migration that occurs in this month in the region. Equations that represents the growth in length obtained for P. mesopotamicus are Sl=50.00*[1-exp-0.18(t-(-3.00)] for males and Sl=59.23*[1-exp-0.14(t-(-3.36)] for females. The growth parameters obtained in this study were lower compared to other studies previously conducted for the same species and can related to overexploitation that species is submitted by fishing in the region. These values show also that females of pacu attain greater asymptotic length than males that growth faster.

Age and growth parameters of cachara Pseudoplatystoma reticulatum (Eigenmann & Eigenmann, 1889) (Siluriformes, Pimelodidae) (males and females) were estimated through the analysis of growth rings in spines of pectoral fins. Fish were collected from January to December 2007, in the area directly influenced by the Aproveitamento Múltiplo de Manso (APM Manso) and in the Cuiabá River (upper parts of the Pantanal). The maximum number of growth rings was seven for males, and eight, for females. The analysis of temporal variations in mean marginal increment showed that rings found in the spines were formed annually, in December. Growth rings were associated to spawning (in the study region from November to March) of the species. The growth curve in length was obtained by the von Bertalanffy model adjusted by the Ford-Walford transformation. The equations are: Ls = 72.7*[1-e-0.44(t+1.5974)] for males, and Ls = 84.5*[1-e-0.33(t+2.0943)] for females. The equations that describe the growth curve in weight are: Wt = 4991.61*[1-e-0.44 (t+1.5974] 2.70 for males and Wt = 7503.17*[1-e-0.33 (t+2.0943] 2.99 for females.

Marmosets of the genus Callithrix are specialized in the consumption of tree exudates to obtain essential nutritional resource by boring holes into bark with teeth. However, marmoset preferences for particular tree species, location, type, and other suitable factors that aid in exudate acquisition need further research. In the current study, the intensity of exudate use from Anadenanthera peregrina var. peregrina trees by hybrid marmosets Callithrix spp. groups was studied in five forest fragments in Vic¸osa, in the state of Minas, Brazil. Thirty-nine A. peregrina var. peregrina trees were examined and 8,765 active and non-active holes were analyzed. The trunk of A. peregrina var. peregrina had a lower number of holes than the canopy: 11% were found on the trunk and 89% were found on the canopy. The upper canopy was the preferred area by Callithrix spp. for obtaining exudates. The intensity of tree exploitation by marmosets showed a moderate-to-weak correlation with diameter at breast height (DBH) and total tree height. The overall results indicate that Anadenanthera peregrina var. peregrina provides food resources for hybrid marmosets (Callithrix spp.) and these animals prefer to explore this resource on the apical parts of the plant, where the thickness, location, and age of the branches are the main features involved in the acquisition of exudates.

*Evaluation of potential impact ecotoxicological of liquid waste from a
slaughterhouse refrigerator using "Daphnia magna"*: Considering the complexity of substances in liquid effluent it appears that in many cases, the effluent toxicity remains after treatment in conventional systems. This work aims to propose the use of ecotoxicological tests as a parameter to estimate the impact of effluent from a slaughterhouse refrigerator using Daphnia magna microcrustacean as bioindicator of toxicity. The final effluent, represented by the Decantation Lagoon, showed a CE(50) of 82.03%. The estimate of the possible toxic effects on aquatic ecosystem allows the use of mathematical models based on the critical flow rate (Q7,10 e Q95%) of watercourse. By the model was determined the minimum dilution needed of the effluent (D.E.R) to preventing deleterious effects on aquatic life in 0.82%, value is not satisfied for the situations studied (61.41% and 65.56% ), condition requiring the reduction of effluent toxicity.

Diurnal behavior of the leaf beetle "Chrysolina sanguinolenta" L. in Chinese cabbage ("Brassica rapa" L. subsp. "pekinensis" (Lour.) Hanelt) beds: Potential to support ecological management: Aiming to contribute to the knowledge production that support the ecological management of leaf beetles, the diurnal behavior of the leaf beetle "Chrysolina sanguinolenta" L. was investigated during the cultivation cycle of Chinese cabbage ("Brassica rapa" L. subsp. "pekinensis" (Lour.)) Hanelt “beds”. Five field campaigns were performed in order to collect data throughout the cultivation cycle (47 days). Biological and behavioral data of beetle and microclimate data were recorded. Ethnoecological data were also obtained from the owner farmer. Data analysis showed patterns in two distinct time scales: (1) along the cropping cycle and (2) throughout the day (nictemeral). The observed patterns suggest a relationship of the activity of "C. sanguinolenta" with the microclimate nictemeral cycle and the beetle life cycle with the "B. rapa" cultivation cycle. Understanding these patterns can support decisions about the management and control of harmful insects.

Bibliometric analysis of production on environmental literacy: A field of research in a consolidation process - This study aimed to carry out a bibliometric analysis of bibliographic production on environmental literacy, with special attention to authorship and co-authorship data. Bibliometric data were recovered using the Scopus platform for each of the keyword: “ecoliteracy”, “ecological literacy”, “environmental literacy”, “environmental literacy” AND (method* OR practic*). The results of descriptive data and bibliometric coupling networks maps based on co-authorship are presented. The results reveal that the researched words are part of a very recent investigation branch, with a dominance of “environmental literacy” concept in the literature. The main areas that correspond to the vast majority of publications are those of Social Sciences, followed by Environmental Sciences. Co-authorships tend to be established between authors within closed collaboration networks, with relative geographic and temporal isolation. And there is an inequality on a global and national scale in academic production. Publications on methodologies and practices of environmental literacy form an important part of the production. However, questions remain open about the effectiveness of the methodological approaches used, among others, possibly because “environmental literacy” is a very young field of knowledge and has not yet formed a unified body in terms of theoretical and methodological scope.

guided trail in Rincão Gaia: Integrated approaches in the experience of complex environmental themes - This report aim to share the lived experience as a guide on a guided trail for about 6 years in a recovering area of an old quarry in the Pampa biome. The guided trail includes a set of different approaches that are combined to tell a story and convey concepts and notions about important processes to understand the current environmental context. Some concepts and processes are complex, and their understanding is facilitated by the multiple approaches adopted that complement each other. The application of this “multiple approach” with audiences of different age, level of education/academic background and socioeconomic status profiles generally leads to the perception of a positive impact on participants at the end of the meeting. However, the adoption of the methodology by the reporter, despite the advantage of versatility and adaptability to different audiences, requires some important challenges. Considering that the activities reported were developed in a privileged location for environmental education, it is not possible to state that this is a methodological approach to be applied in any situation. It is recommended that the approach reported here be tested in other contexts. It is recommended that the approach reported here be tested in other contexts and submitted for validation.

Pesticides in the Anthropocene: Evaluative essay on pesticides in the context of planetary boundaries - The essay explores the human trajectory on Earth, its approximation to the limits of sustainability on the planet and the role of pesticides as an important component of the planetary boundaries of new entities.

guided trail in Rincão Gaia: Integrated approaches in the experience of complex environmental themes - This report aim to share the lived experience as a guide on a guided trail for about 6 years in a recovering area of an old quarry in the Pampa biome. The guided trail includes a set of different approaches that are combined to tell a story and convey concepts and notions about important processes to understand the current environmental context. Some concepts and processes are complex, and their understanding is facilitated by the multiple approaches adopted that complement each other. The application of this “multiple approach” with audiences of different age, level of education/academic background and socioeconomic status profiles generally leads to the perception of a positive impact on participants at the end of the meeting. However, the adoption of the methodology by the reporter, despite the advantage of versatility and adaptability to different audiences, requires some important challenges. Considering that the activities reported were developed in a privileged location for environmental education, it is not possible to state that this is a methodological approach to be applied in any situation. It is recommended that the approach reported here be tested in other contexts. It is recommended that the approach reported here be tested in other contexts and submitted for validation.

<p class="aresumo">The present study examined the behavior of a reservoir located on subtropical latitude (Dona Francisca reservoir). The limnological variables measured were dissolved oxygen, temperature, pH and electric conductivity. Measurements were taken quarterly at different<em> </em>sampling sites along the reservoir. The results indicated the formation of longitudinal zones regarding circulation patterns and stratification, beyond the influence from the water masses of the main tributary. The vertical profiles were obtained. The behavior of the reservoir is similar to others previously studied in the country, but with shorter time-lag stratification and a narrower range, possibly due to the shorter residence time of the water, and to the latitude, where summer is shorter.</p>