scholarly journals Convergent responses of fish belonging to different feeding guilds to sewage pollution

2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Marina Rodrigues do Prado ◽  
Débora Reis de Carvalho ◽  
Carlos Bernardo Mascarenhas Alves ◽  
Marcelo Zacharias Moreira ◽  
Paulo Santos Pompeu
Keyword(s):  
Feeding Habits ◽  
Fish Tissue ◽  
Metropolitan Region ◽  
Feeding Guilds ◽  
Isotopic Niche ◽  
Trophic Guilds ◽  
Trophic Plasticity ◽  
Polluted Sites ◽  
Belo Horizonte ◽  
Industrial Sewage

ABSTRACT This study aimed to evaluate if the presence of pollutants promotes changes in feeding habits of fish species from different trophic guilds: the detritivorous species, Hypostomus francisci, and the piscivorous, Hoplias intermedius. Both species were sampled at 12 sites (with different degrees of pollution) in the Rio das Velhas basin, which is heavily polluted by domestic and industrial sewage from the Metropolitan Region of Belo Horizonte (MRBH). Stable isotope analyses of carbon (δ13C) and nitrogen (δ15N) of fish tissue and the main food resources were performed. Fishes from both trophic guilds altered their diets in degraded environments, but the detritivorous species showed greater trophic plasticity. The isotopic niche of both trophic guilds was broadest in unpolluted sites and more δ15N enriched in polluted regions. The detritivorous species presented high niche-breadth in unpolluted sites, probably due to the greater variety of resources consumed. In addition, the δ15N of the detritivorous was more enriched than the piscivorous species in polluted sites. In conclusion, fishes from both trophic guilds presented similar isotopic responses to environmental pollution. However, the detritivorous species was more sensitive to these alterations and therefore, is likely a better indicator of environmental condition than the piscivorous.

scholarly journals Changes in trophic characteristics of two fish species of Astyanax (Teleostei: Characidae) in response to aquatic pollution

2019 ◽  
Vol 36 ◽  
pp. 1-12 ◽  
Author(s):  
Mirella B. Alonso ◽  
Débora R. de Carvalho ◽  
Carlos B. M. Alves ◽  
Marcelo Z. Moreira ◽  
Paulo S. Pompeu
Keyword(s):  
Isotopic Composition ◽  
Fish Species ◽  
Environmental Changes ◽  
Stomach Contents ◽  
Niche Overlap ◽  
Trophic Niche ◽  
Metropolitan Region ◽  
Trophic Plasticity ◽  
Polluted Sites ◽  
Belo Horizonte

The trophic plasticity of most fish species of Astyanax Baird & Girard, 1854 in response to environmental changes and resource availability is high. This work evaluates the differences in the trophic characteristics of two congeneric species, Astyanaxtaeniatus (Jenyns, 1842) and Astyanaxlacustris (Lütken, 1875), in Rio das Velhas Basin, which is highly impacted by the discharge of sewage from the Metropolitan Region of Belo Horizonte (MRBH). Eight sites were sampled and grouped into three regions: upper course (two sites upstream of the MRBH); middle course (three sites located in the middle portion of the Rio das Velhas, region with greater influence of the MRBH), and lower course (three sites downstream of the MRBH). Samples of fish and food resources were collected from all sites to obtain the isotopic composition of nitrogen (δ15N) and carbon (δ13C), and the stomach contents of the two species was analized. The most common items in the stomach of A.lacustris and A.taeniatus, respectively, were from plants and insects, followed by algae/periphyton (especially at the low course of Rio das Velhas). In contrast, stable isotope analyses indicated that algae (in polluted sites) and periphyton (in least-disturbed sites) were best assimilated both species. Both analyses indicated that the trophic niches of the two species overlap more in more polluted sites relative to less polluted sites. Astyanaxtaeniatus and A.lacustris only presented different isotopic composition of carbon and nitrogen in the upper course of the Rio das Velhas, probably in response to the greater diversity of food items consumed by each species. In the other regions, the species presented similar isotopic signatures, with δ15N and δ13C notably enriched in the most polluted regions (middle and low course). Our results suggest that pollution acts by increasing trophic niche overlap of these species, altering the type of resources most assimilated, and promoting a greater enrichment of δ15N in fish and resources.

Rainfall Prediction by Artificial Neural Networks Trained using Different Climate Variables

2021 ◽  
Author(s):  
Mateus Alexandre da Silva ◽  
Marina Neves Merlo ◽  
Michael Silveira Thebaldi ◽  
Danton Diego Ferreira ◽  
Felipe Schwerz ◽  
...  
Keyword(s):  
Neural Networks ◽  
Artificial Neural Networks ◽  
Input Data ◽  
Back Propagation ◽  
Metropolitan Region ◽  
Climate Variables ◽  
Back Propagation Algorithm ◽  
Rainfall Prediction ◽  
Artificial Neural ◽  
Belo Horizonte

Abstract Predicting rainfall can prevent and mitigate damages caused by its deficit or excess, besides providing necessary tools for adequate planning for the use of water. This research aimed to predict the monthly rainfall, one month in advance, in four municipalities in the metropolitan region of Belo Horizonte, using artificial neural networks (ANN) trained with different climate variables, and to indicate the suitability of such variables as inputs to these models. The models were developed through the MATLAB® software version R2011a, using the NNTOOL toolbox. The ANN’s were trained by the multilayer perceptron architecture and the Feedforward and Back propagation algorithm, using two combinations of input data were used, with 2 and 6 variables, and one combination of input data with 3 of the 6 variables most correlated to observed rainfall from 1970 to 1999, to predict the rainfall from 2000 to 2009. The most correlated variables to the rainfall of the following month are the sequential number corresponding to the month, total rainfall and average compensated temperature, and the best performance was obtained with these variables. Furthermore, it was concluded that the performance of the models was satisfactory; however, they presented limitations for predicting months with high rainfall.

scholarly journals Study of Phlebotomine Sand Flies (Diptera: Psychodidae) Collected in a Leishmania-Endemic Area of the Metropolitan Region of Belo Horizonte, Brazil

2010 ◽  
Vol 47 (6) ◽  
pp. 972-976 ◽  
Author(s):  
Gustavo M. L. Carvalho ◽  
Célia M. F. Gontijo ◽  
Alda L. Falcão ◽  
José D. Andrade Filho
Keyword(s):  
Endemic Area ◽  
Metropolitan Region ◽  
Sand Flies ◽  
Phlebotomine Sand Flies ◽  
Belo Horizonte

scholarly journals Hábitos alimentarios de quironómidos (Diptera: Chironomidae) en lagos del páramo de Chingaza, Colombia

2017 ◽  
Vol 66 (1) ◽  
pp. 136 ◽  
Author(s):  
Yulibey Caleño Ruiz ◽  
Carlos Alberto Rivera Rondon ◽  
Hernando Ovalle
Keyword(s):  
Dietary Habits ◽  
Feeding Habits ◽  
Diet Overlap ◽  
Gut Contents ◽  
High Mountain ◽  
Trophic Guilds ◽  
Use Of Resources ◽  
Fine Particulate ◽  
Chironomidae Larvae ◽  
Well Differentiated

Tropical high mountain lakes show unique environmental conditions where chironomids play an important role in ecosystem functioning. The characteristics of these environments could favor diet overlap and therefore a high interspecific competition. This study described the dietary habits of chironomid genera, identified whether the dietary habits were specialized or generalist, and analyzed the diet overlap in the genera. Chironomidae larvae were collected from four lakes of the Chingaza paramo during the dry season, between April and May of 2 016. The feeding habits of larvae were evaluated by analyzing gut contents following standard methods. Each genus was assigned to trophic guilds (carnivore, detritivore and algivore) and the diet overlap was estimated using the Pinka's index. A total of 1 003 individuals were collected and nine genera were identified. Larvae consumed mainly fine particulate organic matter (FPOM), algae, macrophyte fragments, macroinvertebrates, and animal tissues. FPOM was the main feeding resource of detritivores. The analysis of diets showed a high affinity of each genus for a single trophic guild and most of the genera were generalist in the use of resources. For all lakes, high levels of diet overlap were observed among genera and trophic guilds, mainly among detritivores. Our results suggested that Chironomidae larvae of these lakes presented well differentiated trophic habits, and showed a moderate diet overlap within detritivores and carnivores.

scholarly journals SPATIAL EVALUATION OF THE WATER QUALITY FROM THE VELHAS RIVER CHANNEL, IN THE STATE OF MINAS GERAIS

2018 ◽  
Vol 15 (30) ◽  
pp. 75-86
Author(s):  
C. C. PINTO ◽  
K. B. ALMEIDA ◽  
S. C. OLIVEIRA
Keyword(s):  
Water Quality ◽  
Principal Component ◽  
Industrial Effluents ◽  
Metropolitan Region ◽  
Multivariate Statistical ◽  
Pollution Levels ◽  
Group 3 ◽  
Group 2 ◽  
Belo Horizonte ◽  
Monitoring Stations

This study presents an evaluation of the water quality variability of 19 monitoring stations located in the channel of the Velhas river, using multivariate statistical techniques - Cluster Analysis (CA) and Principal Component Analysis/Factor Analysis (PCA/FA). Sixteen physical-chemical parameters were evaluated between January 2009 and June 2016, totalizing 27,232 valid observations. The CA grouped the nineteen monitoring stations into three groups based on the pollution levels. The PCA/FA resulted in six latent factors for group 1, four for group 2 and five for group 3, accounting for 71.44%, 65.32% and 61.69% of the total variance in the respective water quality. The factors indicated that the parameters responsible for the variations in water quality are mainly related to the release of sanitary sewage and industrial effluents and also to agriculture and livestock activities. These results reflect different water quality conditions of the Velhas River in its extension but, in fact, it is verified a greater variability of the water in the Metropolitan Region of Belo Horizonte and its downstream, justified by the different loads of pollutants received in this region, mainly the releases of domestic sewage and industrial effluents.

scholarly journals Malacological assessment and natural infestation of Biomphalaria straminea (Dunker, 1848) by Schistosoma mansoni (Sambon, 1907) and Chaetogaster limnaei (K. von Baer, 1827) in an urban eutrophic watershed

2005 ◽  
Vol 65 (2) ◽  
pp. 217-228 ◽  
Author(s):  
M. Callisto ◽  
P. Moreno ◽  
J. F. Jr. Gonçalves ◽  
W. R. Ferreira ◽  
C. L. Z. Gomes
Keyword(s):  
Schistosoma Mansoni ◽  
Local Population ◽  
Minas Gerais ◽  
Metropolitan Region ◽  
Infestation Rate ◽  
Close Attention ◽  
Biomphalaria Straminea ◽  
Natural Infestation ◽  
Reservoir Watershed ◽  
Belo Horizonte

The objective of this study was to perform a malacological assessment at the Ibirité reservoir watershed in the metropolitan region of Belo Horizonte (Minas Gerais) and to evaluate the natural infestation rate of Biomphalaria straminea (Gastropoda: Planorbidae)by Schistosoma mansoni (Platyhelminthes: Trematoda) and Chaetogaster limnaei (Oligochaeta: Naididae). The samples were collected from July to August 2002. The B. straminea individuals collected were kept in the laboratory; the natural infestation rate by S. mansoni and C. limnaei was assessed weekly. The malacological assessment identified fivemollusk species present in the Ibirité reservoir watershed: B. straminea, Physa marmorata, Lymnea sp., Melanoides tuberculatus,and Pomacea austrum. Laboratory observations showed that the B. straminea individuals were infected by C. limnaei rather than S. mansoni. Although there was no infection of B. straminea by S. mansoni,presence of B. straminea in itself merits close attention due to possible risk of human schistosomiasis by the local population.

scholarly journals Characterization of the consumer market and motivations for the consumption of craft beer

2018 ◽  
Vol 120 (2) ◽  
pp. 378-391 ◽  
Author(s):  
Naiara Barbosa Carvalho ◽  
Luis Antonio Minim ◽  
Moysés Nascimento ◽  
Gustavo Henrique de Castro Ferreira ◽  
Valéria Paula Rodrigues Minim
Keyword(s):  
Design Methodology ◽  
Metropolitan Region ◽  
Competitive Advantages ◽  
Market Segment ◽  
Consumer Market ◽  
Content Type ◽  
Craft Beer ◽  
Belo Horizonte ◽  
Practical Implications

Purpose The purpose of this paper is to determine the demographic characteristics and habits of craft beer consumers, as well as to identify the motivational factors for consumption. Design/methodology/approach Data were collected through questionnaires applied to 316 Brazilian craft beer consumers, and results were evaluated descriptively and by multivariate statistics. Findings The results of the survey revealed that there is a growing market segment with different buying habits and behaviors compared to traditional beer consumers. Demographically, it was found that these consumers are an attractive part of the beer market in terms of age, schooling and, more importantly, in terms of income, factors that indicate the probability of continued growth in the sector. Research limitations/implications The research was limited to craft beer consumers in the metropolitan region of Belo Horizonte/MG, Brazil. Practical implications The results obtained are important, as they can help new craft breweries, as well as help established industry managers to create strategies related to marketing four Ps in order to increase the consumption of its products, with competitive advantages to the market. Originality/value This research presents the characteristics of the consumers of craft beer, a market segment in evident rise in Brazil, about which there are few studies. In addition, it provides valuable information to both the new beverage manufacturers as well as to the already established entrepreneurs in the market so that they can increase the consumption of their products in a strategic way.

scholarly journals Taxonomy-based differences in feeding guilds of fish

2019 ◽  
Vol 66 (1) ◽  
pp. 51-56
Author(s):  
Javier Sánchez-Hernández
Keyword(s):  
Trophic Ecology ◽  
Feeding Habits ◽  
Empirical Support ◽  
Taxonomic Resolution ◽  
Feeding Guilds ◽  
Generic Level ◽  
Taxonomic Relatedness ◽  
Genus Level ◽  
Marine Vs Freshwater ◽  
And Behavior

Abstract It has been taken for granted that feeding guilds and behavior in animals are linked to the taxonomic relatedness of species, but empirical evidence supporting such relationship is virtually missing. To examine the importance of taxonomy on trophic ecology, I here present the first well-resolved dietary taxonomy analysis based on feeding guilds (predation, herbivory, and filtering) among families and genera within the fish order Perciformes. Taxonomic relatedness in feeding did not vary with ecosystem dimension (marine vs. freshwater). Although predation dominates among Perciformes fishes, this study shows that in most cases taxonomic units (family or genus) are composed by species with several feeding guilds. Related species are more similar in feeding compared with species that are taxonomically more distant, demonstrating that there is a greater variation of feeding guilds within families than genera. Thus, there is no consistency in feeding guilds between family- and genus-level taxonomy. This study provides empirical support for the notion that genera are more informative than families, underlining that family-level taxonomy should be avoided to infer feeding habits of fish species at finer taxonomic resolution. Thus, the choice of taxonomic resolution (family or genus level) in ecological studies is key to avoid information loss and misleading results. I conclude that high-rank taxonomic units (i.e., above the generic level) are not appropriate to test research hypotheses about the feeding of fish.

scholarly journals Where do penguins go during the inter-breeding period? Using geolocation to track the winter dispersion of the macaroni penguin

2009 ◽  
Vol 5 (4) ◽  
pp. 473-476 ◽  
Author(s):  
C. A. Bost ◽  
J. B. Thiebot ◽  
D. Pinaud ◽  
Y. Cherel ◽  
P. N. Trathan
Keyword(s):  
Southern Ocean ◽  
Feeding Habits ◽  
Euphausia Superba ◽  
Integrative Approach ◽  
Breeding Period ◽  
World Population ◽  
Isotopic Niche ◽  
Marine Predators ◽  
Central Indian Ocean ◽  
Macaroni Penguin

Although penguins are key marine predators from the Southern Ocean, their migratory behaviour during the inter-nesting period remains widely unknown. Here, we report for the first time, to our knowledge, the winter foraging movements and feeding habits of a penguin species by using geolocation sensors fitted on penguins with a new attachment method. We focused on the macaroni penguin Eudyptes chrysolophus at Kerguelen, the single largest consumer of marine prey among all seabirds. Overall, macaroni penguins performed very long winter trips, remaining at sea during approximately six months within the limits of the Southern Ocean. They departed from Kerguelen in an eastward direction and distributed widely, over more than 3.10 6 km 2 . The penguins spent most of their time in a previously unrecognized foraging area, i.e. a narrow latitudinal band (47–49° S) within the central Indian Ocean (70–110° E), corresponding oceanographically to the Polar Frontal Zone. There, their blood isotopic niche indicated that macaroni penguins preyed mainly upon crustaceans, but not on Antarctic krill Euphausia superba , which does not occur at these northern latitudes. Such winter information is a crucial step for a better integrative approach for the conservation of this species whose world population is known to be declining.

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