The Sinos River encompasses a wide area of natural habitats and, at the same time, supports one of the highest population densities of southern Brazil. Consequently, natural habitats along the Basin ...present a high degree of habitat disturbance. Despite of the existence of threatened species, information about diversity of amphibians in that area is scarce. Thus, we aimed to catalogue the amphibian species of the Sinos River Basin from records in scientific collections and compilation of published articles. We recorded 52 species, all with geographic coordinates validated at the collection point, indicating that the Sinos River Basin harbours about 50% of the amphibian species of the State of Rio Grande do Sul. Three anuran species were classified as having some degree of threat:
Melanophryniscus cambaraensis
,
Melanophryniscus dorsalis
and
Thoropa saxatilis
. We also expected other 18 species with a high probability of occurrence in the Basin. This work shows that, despite the intense human impact, the Sinos River Basin has a relevant role for the maintenance of a considerable fraction of the amphibian biodiversity in southern Brazil.
Sixty specimens of the “cururu” toad,
Rhinella icterica
(Spix 1824) (Bufonidae), were collected in Campo Belo do Sul, State of Santa Catarina, Brazil, between May 2009 and January 2011, and were ...examined for the presence of helminth parasites. Nine species of adult helminths were found:
Catadiscus cohni
,
Rudolphitrema rudolphii
,
Cylindrotaenia
sp.,
Rhabdias fuelleborni
,
Strongyloides
sp.,
Cosmocerca rara
,
Cosmocerca brasiliensis
,
Aplectana elenae
, and
Oxyascaris
sp., in addition to an unidentified adult nematode species. Females of cosmocercid nematodes, proteocephalan plerocercoid, and acanthocephalan cystacanth were found but not identified for lack absolute of taxonomic characters. The sex of the anurans had no influence on prevalence, abundance, and richness of helminth species. Length and body mass of hosts did not influence the prevalence and richness of helminths, while the abundance of
R
.
fuelleborni
was significantly correlated with both parameters.
The recovery of microalgae by means of coagulation-flocculation is efficient, simple and low operating costs. The addition of coagulants makes it possible to destabilize the microalgae surface loads ...and recover their biomass. Chemical coagulants can contaminate the environment and negatively affect human health. Thus, the exploration of natural coagulants, such as Moringa oleifera and Guazuma ulmifolia, are innovative. Thus, this study aimed to evaluate the efficiency of biomass separation from the microalgae Scenedesmus obliquuos by means of coagulation-flocculation. M. oleifera and G. ulmifolia were used in order to optimize the variables dose, pH and settling time, through a central composite rotational design, which presented recovery efficiencies above 80.0% and 60.0%, respectively. In relation to M. oleifera, optimum regions were obtained for biomass recovery at both pH 4.0 with a dose of 40.0 mg L−1 and pH 9.0 with a dose of 80.0 mg L−1, both in 30 min of settling times. For G. ulmifolia, an optimum dose of 30.0 mg L−1 at pH 4.0 with a 3 min settling time demonstrated that this new coagulant for microalgae recovery has potential for application. Thus, these natural coagulants are promising and can be used in coagulation-flocculation to recover biomass from Scenedesmus obliquuos and, thus, minimize the use of synthetic or metallic products.
•Coagulation and biomass separation from Scenedesmus obliquuos were studied.•Dose, pH and settling time were optimized using natural coagulants.•Recovery efficiencies above 80% (M. oleifera) and 60% (G. ulmifolia) were reached.•Optimum regions was found to promote greater recovery.
Background
Raptor distributions and abundances are poorly known in southern Brazil. Given that raptors have low population densities, methods typically applied to census birds are usually ...inappropriate for surveying raptors. Roadside surveys allow large areas to be searched at a relatively low cost and are often applied to count raptors. We conducted eight paired roadside surveys (roadside point transects and roadside strip transects of 54.5 ~ 58.6 km long) to assess the species richness and abundance of raptors in two grassland landscapes of southern Brazil and to compare results of the two methods.
Results
In total, 1,890 observations of 18 raptor species (118.13 individuals (ind.)/transect) were recorded. Raptor abundances were higher in the altitudinal grasslands (299.25 ± 48.91 ind./transect) than in the coastal plain (86.63 ± 44.04 ind./transect). Abundances were higher when raptors were surveyed with point transects (9.38 ind. · 10 km
2
−1
· h
−1
) than with strip transects (3.55 ind. · 10 km
2
−1
· h
−1
). No significant differences were found in relation to species richness, although five species were exclusively recorded with point transects versus one with strip transects.
Conclusions
Roadside point transects may reduce bias due to differences in species detection caused by habitat features and in abundance estimates resulting from survey habitat being disproportional to their availability. Point counts may enhance the quality of the search for raptors in a surveyed area, increasing the detection probability. The choice of survey method depends on the objectives of the study, but our results favor the use of point transects rather than strip transects to survey raptors in open landscapes.
Residual biomass obtained after microalgae lipid extraction is rich in carbon and nutrients and has great potential for use as a substrate in anaerobic digestion, microalgae cultivation, and plant ...cultivation. However, residues from organic solvents can make it unfeasible to use the biomass in these applications. In this work, ethyl acetate (EA) and hexane-ethanol mixture (HE) were used to evaluate the yield and quality of lipids extracted from the microalga Scenedesmus obliquus BR003. Also, the toxicity of these solvents to anaerobic digestion, microalgae cultivation, and seed germination was evaluated at concentrations similar to those found in the residual biomass after lipid extraction. Lipid yields were 83.1% and 55.4% for HE and EA, respectively, where EA extracted mostly neutral lipids. In the HE mixture, hexane showed no significant effect in toxicity assays due to its low solubility in the aqueous fraction. However, ethanol in this mixture migrates to the aqueous phase, and the effective concentrations at 50% (EC50) were 3.78, 26.97, and 4.97 g L−1 for methanogenic archaea, S. obliquus, and lettuce seeds, respectively. The EA showed EC50 values of 18.74, 18.02, and 5.85 g L−1 for methanogenic archaea, S. obliquus, and lettuce seeds, respectively. The EA was less toxic to anaerobic microorganisms and lettuce seeds when compared to ethanol, which was less toxic to S. obliquus, making EA an environmentally friendly solvent for industrial use. Our study provides novel information on the criteria of solvent selection when aiming at resource recovery from residual microalgae biomass after lipid extraction.
•- Ethyl acetate extracts lipid from Scenedesmus obliquus microalgae, with predominance of triacylglycerol.•- Ethanol in residual biomass showed a lower toxicity for further microalgae cultivation.•- Ethyl acetate showed a lower toxicity for anaerobic digestion and microalgae cultivation.•- Ethyl acetate is an environmentally friendly solvent for extraction of lipids from microalgae and exhibits low toxicity.
Reptile diversity of Sinos River Basin Moser, Camila Fernanda; Avila, Fernanda Rodrigues de; Oliveira, Roberto Baptista de ...
Biota Neotropica,
01/2018, Volume:
18, Issue:
3
Journal Article
Peer reviewed
Open access
Abstract This work aimed to catalog the species of reptiles of the Sinos River Basin based on records from scientific collections and data collected in the field. We recorded 65 species, including 46 ...snakes, nine lizards, five turtles, four amphisbaenians and one caiman. Snakes composed most of the recorded specimens (91.3%), and the three most representative are venomous and of medical importance. The most urban region of the basin (Lowland) has the highest number of records. This fact may be a reflection of the high human population density in this region, which would have favored the encounter of specimens and their sending to scientific collections and research centers. It is worth highlighting that most species with few specimens in the collections are also rarely observed in the wild, such as Clelia hussani and Urostrophus vautieri. This observation makes it feasible that these populations are small or that they are declining.
Resumo Este trabalho teve como objetivo catalogar as espécies de répteis da Bacia Hidrográfica do Rio Sinos com base em registros de coleções científicas e dados coletados em campo. Registramos 65 espécies, incluindo 46 serpentes, nove lagartos, cinco tartarugas, quatro anfisbenas e um jacaré. As serpentes compuseram a maioria dos espécimes registrados (91,3%), e as três espécies mais representativas são peçonhentas e de importância médica. A região mais urbana da bacia (planície) possui o maior número de registros. Este fato pode ser um reflexo da alta densidade populacional humana nesta região, o que teria favorecido o encontro de espécimes e seu envio para coleções científicas e centros de pesquisa. Vale ressaltar que a maioria das espécies com poucos exemplares nas coleções também são raramente observadas na natureza, como Clelia hussani e Urostrophus vautieri. Esta observação torna viável que essas populações sejam pequenas ou que estejam em declínio.
Synthetic or natural cationic polymers, such as polyacrylamide and chitosan, are exploited as coagulants due to their characteristics, such as a high positive surface charge. Due to variations in ...culture conditions, such as species and cell concentration, different interactions of coagulants with microalgae occur, affecting the efficiency of biomass recovery. Thus, in this study, the separation efficiency of biomass of the microalgae
Scenedesmus obliquus
was evaluated by coagulation-flocculation with the synthetic polymer polyacrylamide and natural polymer chitosan to optimize the dose and pH by means of a rotational central composite design. Biomass removal efficiencies greater than 90% and greater than 70% were observed for the synthetic polymer and chitosan, respectively. Notably, the reduced optical density and biological nature of microalgae make the use of response surface methodology challenging. Optimal regions with doses of 12.8 mg of synthetic polymer and 5.0 mg of chitosan were obtained per liter of microalgae sample. An optimal pH of 6.5, falling within the natural range of culture conditions was indicated for both coagulants, minimizing reagent costs. The interaction with microalgae and the potential application of chitosan and other natural coagulants that are efficient and economically viable should be explored.
Many endemic plant species from Brazil’s Legal Amazon present soil organisms in their rhizosphere. These organisms play a key role in the physiological traits, plant performance, and resistance ...against drought, and herbivory. Our aim here was to present a quantitative analysis of the arbuscular mycorrhizal fungi (AMF) species, and soil nematodes associated with endemic plant species from the Brazil’s Legal Amazon, Rio Branco, Acre. We found four main groups considering the similarities on soil microbiota community structure: i)
T. cacao, M. flexuosa
, and
G. weberbaueri
showed high AMF and soil nematode richness; ii)
S. officinarum
and
V. unguiculata
showed high herbivore nematode abundance and low Ambisporaceae and Claroideoglomeraceae sporulation; iii)
H. brasiliensis
and
E. guineensis
showed the low abundance of Gigasporaceae spores and lack of herbivore nematodes; and iv)
E. precatoria
showed the high abundance of
A. colombiana, Monanchus
, and
Tripyla
. The results of our study highlight the importance of considering endemic tree species as potential hosts for a solid and diverse soil food web on a sustainable way to improve soil ecology, root traits, and plant performance. Thus, long-term experiments considering these endemic tree species into agroforestry systems may exploit interesting results in tropical conditions.
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