Repositório RCAAP

Cracids are generalist frugivores, which often exploit plant food resources such as flowers and leaves, mainly when fruit production declines. The Chaco chachalaca (Ortalis canicollis) is the most abundant cracid in the Pantanal (Brazil), and particularly common in the gallery forests. However, the factors related to their occurrence in this habitat type are unclear. In this study I describe the feeding habits and feeding niche breadth fluctuations of the Chaco chachalaca in relation to food resources abundance and diversity at the Miranda river gallery forest (Southern Pantanal). I also analyzed the relationships between Chaco chachalacas feeding activity and food resources abundance. This parameter (flowers and fruits) exhibited significant seasonal differences of abundance in which flowers were plentiful at the end of the dry, while fruits were abundant during the early wet season. However, food resources diversity to Chaco chachalacas exhibited no seasonal difference. Their feeding activity paralleled the availability of food resources, so that when some items were massively available an enhanced number of Chaco chachalacas foraged in the gallery forest, particularly during the prolonged dry season when they extensively used flowers and Genipa americana fruits. In fact, the Chaco chachalaca feeding niche breadth value presented low values in this period, while high values were common in the rest of the year. The flexible diet of this cracid, potentially favors their year round presence in the gallery forest, mainly during the prolonged dry season when the propensity for famine might be high. Since the Chaco chachalaca is among the largest and most abundant canopy frugivores in the gallery forest, it may contribute to forest regeneration, an underscored role due to the impact of annual floods and meandering dynamics on tree loss.

Interaction among species, like ants and plants through extrafloral nectaries (EFNs), are important components of ecological communities’ evolution. However, the effect of human disturbance on such specific interactions and its ecological consequences is poorly understood. This study evaluated the outcomes of mutualism between ants and the EFN-bearing plant Stachytarpheta glabra under anthropogenic disturbance. We compared the arthropod fauna composition between two groups of twenty plant individuals, one in an area disturbed by human activities and one in a preserved area. We also check the plant investment in herbivory defense and the consequential leaf damage by herbivore. Our results indicate that such disturbances cause simplification of the associated fauna and lack of proper ant mutualist. This led to four times more herbivory on plants of disturbed areas, despite the equal amount of EFN and ant visitors and low abundance of herbivores. The high pressure of herbivory may difficult the re-establishment of S. glabra, an important pioneer species in ferruginous fields, therefore it may affect resilience of this fragile ecological community.

The aim of this study was to evaluate the phenolic and flavonoids contents and the antioxidant and antitumoral activity of leaf and calyx methanolic extracts from Hibiscus sabdariffa (roselle) cultivated with poultry litter and organosuper® under three modes of application. The total phenolic content in the each extract was determined using the Folin-Ciocalteu reagent and for aluminium chloride flavonoids. The antioxidant parameters were analyzed using a 2, 2-diphenyl-1-picrylhydrazyl (DPPH.) free radical scavenging assay. An antitumor colorimetric assay using sulforhodamine B. The highest contents of phenolic and flavonoids were observed in leaf extracts (389.98 and 104.52 mg g–1, respectively) and calyx extracts (474.09 and 148.35 mg g–1, respectively) from plants cultivated with organosuper®, although these values did not differ significantly from those observed for the other treatments. The average IC50 of leaves (43.48 μg mL–1) and calyces (37.15 μg mL–1) demonstrated that both have substances that may contribute to free radical scavenging action. The methanol extract from calyces showed significant selective activity against a leukemia line (K-562), with IC50 values of 0.12 mg mL–1 (organosuper®) and 1.16 mg mL–1 (poultry litter), with concentration-dependent, cytotoxic and cytocidal effects.

Butia purpurascens is an endemic and threatened palm tree species that occurs in open areas of the Brazilian Cerrado, predominantly in southwestern Goiás. The leaves of this palm tree are harvested by local people to fabricate brooms. This study evaluated changes in vegetative and reproductive phenology in two different natural populations of this palm tree: one population with leaf harvesting and another non-harvested population. Twenty plants were monitored in each area for 23 months. The phenophases were related to the temperature and precipitation averages for a 30-year period. Leaf sprouting occurred throughout the year, with a slight reduction in periods of low temperatures and low rainfall. The first spathes emerged in March and flowering began during the dry season (June), continuing until January of the following year, concurrent with the period of most intense fruiting. Flowering and fruiting appear to be triggered by periods of drought, which are commonly observed in the Cerrado. The harvested sites produced significantly fewer leaves, spathes, inflorescences and infructescences than the non-harvested sites. Thus, the supply of resources to the local fauna is possibly reduced in sites under leaf exploitation, which in the long term can represent damage to the palm tree population’s structure and dynamics. Other socioeconomic and ecological studies about the effects of leaf harvesting in B. purpurascens are necessary to enable strategies for sustainable use, devise management alternatives and conserve this threatened palm species.

Amphibians are hosts for a wide variety of ecto- and endoparasites, such as protozoans and parasitic worms. Naididae is a family of Oligochaeta whose species live on a wide range of substrates, including mollusks, aquatic macrophytes, sponges, mosses, liverworts, and filamentous algae. However, some species are known as endoparasitic from vertebrates, such as Dero (Allodero) lutzi, which is parasitic of the urinary tracts of frogs, but also have a free-living stage. Specimens in the parasitic stage lack dorsal setae, branchial fossa, and gills. Here we report the occurrence of D. (A.) lutzi associated with anuran Scinax fuscovarius from Semi-deciduous Atlantic Rain Forest in southern Brazil. The study took place at the Caiuá Ecological Station, Diamante do Norte, Paraná, southern Brazil. Seven specimens of S. fuscovarius were examined for parasites but only one was infected. Parasites occurred in ureters and urinary bladder. Previous records of this D. (A.) lutzi include the Brazilian States of Santa Catarina, São Paulo, Rio de Janeiro, and Minas Gerais, as well as Cuba and North America. This is a new locality record for this species in Brazil. Reports of Dero (Allodero) lutzi are rare, due to difficulty of observation, and such events are restricted only the fortuitous cases. It is important to emphasize the necessity of future studies, which are fundamental to the understanding of biological and ecological aspects of this species.

Two groups of pygmy marmoset (Cebuella pygmaea) were rescued along the left bank of the Madeira River during the formation of Santo Antônio Hydroelectric Dam reservoir in the state of Rondônia, Northern Brazil. Reintroduction of both groups occurred in areas of open Tropical rainforest located within the project´s Permanent Preservation Area. A post-release monitoring was conducted for three months using radio-telemetry. Individuals of each group remained together and settled in stable home ranges near their respective release sites. The mortality rate of translocated animals was about 7%. This seems to be the first report documenting the complete group translocation of C. pygmaea and the first to successfully employ radio-telemetry techniques in monitoring this species. This study demonstrated the feasibility of translocation and the use of radio-telemetry in monitoring C. pygmaea.

Dinoflagellates of the genus Ceratium are generally marine organisms, but rare occurrences in freshwater have been observed in Brazil. In this paper we are recording for the first time the presence of Ceratium furcoides, an invasive species, in a shallow, natural intermittent pool formed at a high-altitude at the southern end of the Iron Quadrangle, an iron-mining district of Minas Gerais State (Southeast Brazil). Samples were collected in October and November of 2010 (rainy period). The population density of this organism observed in Lagoa Seca (“Dry Pool”) was very low, at most 4 ind L–1. Mountain lakes are extremely vulnerable to atmospheric deposition of organisms, making them valuable witnesses both of the many forms of impact arising from human activities and of the extended global connections that facilitate the dispersion and introduction of new species over great distances. Studies on the population dynamics of C. furcoides in natural tropical systems are still rare and very recent to the brazilian scenario and hence the monitoring of its dynamics and the potential impact on aquatic communities of its becoming established are essential to an understanding of the process of bioinvasion by this species.

The objective of this study was to verify the occurrence of Dioscorea trifida in Brazil and to obtain information concerning its distribution, management and diversity. Farmers from 21 communities were interviewed in the states of São Paulo, Santa Catarina and Mato Grosso. During the visits, semi-structured interviews were conducted to collect socio-economic, management and diversity data for this crop. Fifty-one collected accessions, plus two accessions obtained at local markets of Amazonas, were characterized using 12 morphological traits. Most the interviewed farmers were men (75%) with a mean age of 59.5 years. Just a few young people and labor force were available for agricultural activities, with an average of only three individuals per farm. Most farmers (56%) grew only one variety of D. trifida, although 44% had more than one variety in their fields, which aims to provide greater assurance at harvest. Many popular names were observed for D. trifida, and cará roxo (purple yam) was the name most used by farmers (43.4%). Characters referring to the tuber, such as skin and flesh color, were most relevant for the distinction of the accessions. The results of this study may collaborate to develop strategies for conservation, both ex situ and in situ, within the view of on farm conservation.

The rhizomatous Cyperus giganteus, abundant in the Pantanal wetland, can dominate extense floodable areas as monodominant communities. The Jacadigo lake has a large area of C. giganteus, where we performed an evaluation on community structure during two months in 2010, before it was hit by a wildfire which top-killed the vegetation, compared to ten months post-fire. We utilized 40 plots of 1m × 1m, along permanent trails, assessing two strata: the upper, near the inflorescence of adult plants, and the lower, close to the water level. Our results show that fire does not affect dominance of C. giganteus, as it maintained the same cover as before fire; species richness is not much altered either - 28 before fire and 34 thereafter. Fire changed the floristic composition, due to the annual variation of species and the ability of some plants to colonize gaps and to regrow after fire from underground organs and seeds. The stratification of the vegetation with characteristic species of upper and lower strata was similar after fire.

The amendments to the Forest Law proposed by the Brazilian government that allow partial substitution of forested areas by agricultural activities raised deep concern about the integrity of aquatic ecosystems. To assess the impacts of this alteration in land uses on the watershed, diffuse loads of total nitrogen (Nt) and total phosphorus (Pt) were estimated in Lobo Stream watershed, southeastern Brazil, based on export coefficients of the Model of Correlation between Land Use and Water Quality (MQUAL). Three scenarios were generated: scenario 1 (present scenario), with 30-meter-wide permanent preservation areas along the shore of water bodies and 50-meter-radius in springs; scenario 2, conservative, with 100-meter-wide permanent preservation areas along water bodies; and scenario 3, with the substitution of 20% of natural forest by agricultural activities. Results indicate that a suppression of 20% of forest cover would cause an increase in nutrient loads as well as in the trophic state of aquatic ecosystems of the watershed. This could result in losses of ecosystem services and compromise the quality of water and its supply for the basin. This study underlines the importance of forest cover for the maintenance of water quality in Lobo Stream watershed.

Corbicula fluminea is an invasive bivalve responsible for several environmental and financial problems around the globe. Despite the invasive potential of this species, it suffers certain restrictions in lentic environments due to natural phenomena that significantly affect its population structure (e.g. water column fluctuation and sunlight exposure). The present study addresses how temporal decline of the water level in a Neotropical reservoir and exposure to sunlight affect the population structure of C. fluminea. Samplings were carried out twice in the reservoir of Furnas Hydroelectric Power Station (HPS) (Minas Gerais, Brazil), in 2011 and 2012. Population density, spatial distribution and mean shell length of C. fluminea were estimated for each year after sampling in 51 quadrats (0.0625m2) placed on three transects at different distances along the reservoir margins (0, 10 and 20 m from a fixed-point). We observed a predominance of C. fluminea in both years, with a simultaneous gradual decrease in density and richness of native species in the sampling area. Significant differences in density of C. fluminea were registered at different distances from the margin, and are related to the temporal variability of physical conditions of the sediment and water in these environments. We also registered a trend toward an increase in the density and aggregation of C. fluminea as we moved away from the margin, due to the greater stability of these areas (>10 m). The mean shell length of C. fluminea showed significant difference between the distinct distances from the margin and during the years, as well as the interaction of these factors (Distances vs.Years). These results were associated with the reproductive and invasive capacity of this species. This study reveals that these temporal events (especially water column fluctuation) may cause alterations in density, spatial distribution and mean shell length of C. fluminea and the composition of the native malacofauna in Neotropical lentic environments.

Alterations in aquatic systems and changes in water levels, whether due to rains or dam-mediated control can cause changes in community structure, forcing the community to readjust to the new environment. This study tested the hypothesis that there is an increase in the richness and abundance of aquatic insects during the rainy season in the Serra da Mesa Reservoir, with the premise that increasing the reservoir level provides greater external material input and habitat diversity, and, therefore, conditions that promote colonization by more species. We used the paired t test to test the differences in richness, beta diversity, and abundance, and a Non-metric Multidimensional Scaling (NMDS) was performed to identify patterns in the community under study. Additionally, Pearson correlations were analyzed between the richness, abundance, and beta diversity and the level of the reservoir. We collected 35,028 aquatic insect larvae (9,513 in dry period and 25,515 in the rainy season), predominantly of the Chironomidae family, followed by orders Ephemeroptera, Trichoptera, and Odonata. Among the 33 families collected, only 12 occurred in the dry season, while all occurred in the rainy season. These families are common in lentic environments, and the dominance of Chironomidae was associated with its fast colonization, their behavior of living at high densities and the great tolerance to low levels of oxygen in the environment. The hypothesis was confirmed, as the richness, beta diversity, and abundance were positively affected by the increase in water levels due to the rainy season, which most likely led to greater external material input, greater heterogeneity of habitat, and better conditions for colonization by several families.

Leaf area estimation is an important biometrical trait for evaluating leaf development and plant growth in field and pot experiments. We developed a non-destructive model to estimate the leaf area (LA) of Vernonia ferruginea using the length (L) and width (W) leaf dimensions. Different combinations of linear equations were obtained from L, L2, W, W2, LW and L2W2. The linear regressions using the product of LW dimensions were more efficient to estimate the LA of V. ferruginea than models based on a single dimension (L, W, L2 or W2). Therefore, the linear regression “LA=0.463+0.676WL” provided the most accurate estimate of V. ferruginea leaf area. Validation of the selected model showed that the correlation between real measured leaf area and estimated leaf area was very high.

The choice of sampling gears to assess benthic macroinvertebrate communities depends on environmental characteristics, study objectives, and cost effectiveness. Because of the high foraging capacity and diverse habitats and behaviors of benthophagous fishes, their stomach contents may offer a useful sampling tool in studies of benthic macroinvertebrates, especially in large, deep, fast rivers that are difficult to sample with traditional sediment sampling gear. Our objective was to compare the benthic macroinvertebrate communities sampled from sediments with those sampled from fish stomachs. We collected benthic macroinvertebrates and fish from three different habitat types (backwater, beach, riffle) in the wet season, drying season, and dry season along a single reach of the Grande River (Paraná River Basin, southeast Brazil). We sampled sediments through use of a Petersen dredge (total of 216 grabs) and used gill nets to sample fish (total of 36 samples). We analyzed the stomach contents of three commonly occurring benthophagous fish species (Eigenmannia virescens, Iheringichthys labrosus, Leporinus amblyrhynchus). Chironomids dominated in both sampling methods. Macroinvertebrate taxonomic composition and abundances from fish stomachs differed from those from sediment samples, but less so from riffles than from backwater and beach habitats. Macroinvertebrate taxa from E. virescens stomachs were more strongly correlated with sediment samples from all three habitats than were those from the other two species. The species accumulation curves and higher mean dispersion values, compared with with sediment samples suggest that E. virescens is more efficient than sediment samples and the other fish studied at collecting benthic taxa. We conclude that by analyzing the stomach contents of benthophagous fishes it is possible to assess important characteristics of benthic communities (dispersion, taxonomic composition and diversity). This is especially true for studies that only sample fish assemblages to evaluate aquatic ecosystem impacts. Therefore, this approach can be useful to amplify assessments of human impacts, and to incorporate additional bioindicators.

The Ibirité reservoir is an urban and eutrophic environment, with regular occurrences of cyanobacteria blooms. The reservoir is warm monomict and remains stratified most of the year, circulating in the dry season (winter). During the hydrological cycle of October/07 to October/08 there were four scenarios with different environmental conditions, which influenced the structure of the zooplankton community, as confirmed in a previous study. Changes in the zooplankton community structure between the scenarios were studied, aiming at analyzing the stability and persistence of this community. The Spearman’s coefficient of correlation was used to measure the stability; the persistence was evaluated through a cluster analysis and changes in community composition were estimated by the "temporal" β diversity index. Considering the distribution patterns of abundance, the community was stable only in the transition between scenarios 1 and 2 (n = 30, r = 0.71, p = 0.00001), when there were no cyanobacteria blooms. The persistence of zooplankton between the scenarios was low, showing a distinct species composition for each scenario. The highest variations in species composition, observed by the values of temporal β diversity index, were the transitions between scenarios 3-0 (1.45) and 0-1 (1.05), and the lowest variations occurred in the transition between scenarios 1-2 (0.57). The results suggest that the cyanobacteria blooms at Ibirité reservoir are be acting as "selective filters", and are, thus, disturbances with sufficient ability to change the structure of the zooplankton community. Keywords Urban Reservoir, zooplankton, bloom of cyanobacteria, stability, persistence.

Clinodiplosis bellum sp. nov. associated with Diplopterys pubipetala (A.Juss.) Anderson and Davis (Malpighiaceae) from Brazil are described. This is the first species of Clinodiplosis described to State of São Paulo and the first formal description of Diplopterys pubipetala (Malpighiaceae) as host plant of Cecidomyiidae species. Description and illustration of the Clinodiplosis bellum sp. nov. (Diptera: Cecidomyiidae) are given.

Aquatic macroinvertebrates (AMI) play an important role in the ecology of wetlands, either by their job as regulators of the cycles of matter, as for their energy storage function represented in their biomass, which is transferred to higher trophic levels. To answer the question of how biomass of different AMI trophic guilds is related with physicochemical variables in the wetland Jaboque (Bogotá, Colombia), four samplings were achieved between April 2009 and January 2010, according to periods of rain and drought in the region. The AMI biomass values obtained were rated as of intermediate rank. No temporal but spatial significant differences were found. Apparently these spatial differences appear to be associated with variations in anthropogenic pressure, which differs in each area of the wetland. In dry months (January and August), biomass was greater and dominated by detritivores. We observed a positive relationship between the specific conductance of water and the biomass of predators and detritivores and between water temperature and the biomass of detritivores and shredders. These relationships suggest that the physical and chemical variables influence the distribution, abundance, and biomass of functional groups. The physical and chemical conditions of water exhibited spatiotemporal fluctuations related to changes in the concentration of organic matter and nutrients, which presumably were related to the affluents discharges and the high impact of local human populations.

Suitability of degraded areas as breeding habitats can be tested through assessment of nest predation rates. In this study we estimated nest success in relation to several potential predictors of nest survival in the Stripe-tailed Yellow-finch (Sicalis citrina) breeding in abandoned mining pits at Brasília National Park. We monitored 73 nests during the 2007-breeding season. Predation was the main cause of nest failure (n = 48, 66%); while six nests were abandoned (8%) and 19 nests produced young (26%). Mayfield’s daily survival rates and nest success were 0.94 and 23%, respectively. Our results from nest survival models on program MARK indicated that daily survival rates increase linearly towards the end of the breeding season and decrease as nests aged. None of the nest individual covariates we tested - nest height, nest size, nest substrate, and edge effect - were important predictors of nest survival; however, nests placed on the most common plant tended to have higher survival probabilities. Also, there was no observer effect on daily survival rates. Our study suggests that abandoned mining pits may be suitable alternative breeding habitats for Striped-tailed Yellow-finches since nest survival rates were similar to other studies in the central cerrado region.

The epipelagic flyingfish, Hirundichthys affinis is a major artisanal fishery resource from the Northeastern coastal waters of Brazil. However, biological information about this species has been poorly documented. This paper presents data on the length-weight relationship, sex ratio, length at first sexual maturity, gonadal development and fecundity of H. affinis sampled from the coastal waters of Rio Grande do Norte, Brazil. The total body length and weight for both sexes ranged from 23.4 to 29.4 cm and from 89 to 188g, respectively. The allometric coefficient of males was 2.208 and that of females was 2.985, indicating negatively allometric growth. The sex ratio was 1M:1.6F thus differing from the expected ratio of 1:1 (χ2 = 18.63). The total length at first sexual maturity was estimated at 27.3 cm for males and 27.1 cm for females. The macroscopic characteristics of the gonads indicated four maturation stages. Histological studies of gonads of H. affinis showed seven phases of oocyte development and four phases of spermatocyte development. The mean absolute fecundity was 9092 vitelogenic oocytes. Spawning occurred during the months of March to July. The microscopic descriptions of the stages of gonad maturation indicate that the study area is an important spawning ground of H. affinis.

We carried out a six-year study aimed at evaluating if and how a Brazilian Atlantic Forest small mammal community responded to the presence of the invasive exotic species Artocarpus heterophyllus, the jackfruit tree. In the surroundings of Vila Dois Rios, Ilha Grande, RJ, 18 grids were established, 10 where the jackfruit tree was present and eight were it was absent. Previous results indicated that the composition and abundance of this small mammal community were altered by the presence and density of A. heterophyllus. One observed effect was the increased population size of the spiny-rat Trinomys dimidiatus within the grids where the jackfruit trees were present. Therefore we decided to create a mathematical model for this species, based on the Verhulst-Pearl logistic equation. Our objectives were i) to calculate the carrying capacity K based on real data of the involved species and the environment; ii) propose and evaluate a mathematical model to estimate the population size of T. dimidiatus based on the monthly seed production of jackfruit tree, Artocarpus heterophyllus and iii) determinate the minimum jackfruit tree seed production to maintain at least two T. dimidiatus individuals in one study grid. Our results indicated that the predicted values by the model for the carrying capacity K were significantly correlated with real data. The best fit was found considering 20~35% energy transfer efficiency between trophic levels. Within the scope of assumed premises, our model showed itself to be an adequate simulator for Trinomys dimidiatus populations where the invasive jackfruit tree is present.