scholarly journals Functional trophic composition of the ichthyofauna of forest streams in eastern Brazilian Amazon

2013 ◽  
Vol 11 (2) ◽  
pp. 361-373 ◽  
Author(s):  
Gabriel Lourenco Brejao ◽  
Pedro Gerhard ◽  
Jansen Zuanon
Keyword(s):  
Functional Organization ◽  
Brazilian Amazon ◽  
Behavioral Observation ◽  
Main Channel ◽  
Taxonomic Structure ◽  
Trophic Groups ◽  
Ecological Studies ◽  
Alternative Approach ◽  
Ad Libitum ◽  
Forest Streams

This study aimed to describe the functional organization of the ichthyofauna of forest streams from northeastern Pará State, Brazil, based on behavioral observation of species' feeding tactics. Seven streams were sampled between June and November, 2010, during snorkeling sessions, totaling 91h 51min of visual censuses at day, dusk, and night periods. Seventy three species distributed in six orders, 26 families and 63 genera were observed, with dominance of Characiformes, followed by Siluriformes. From information gathered by ad libitum observations, each species was included in one of 18 functional trophic groups (FTGs), according to two main characteristics: (1) its most frequently observed feeding tactic; and (2) its spatial distribution in the stream environment, considering their horizontal (margins or main channel) and vertical (water column) dimensions. The most frequent FTGs observed were Nocturnal invertebrate pickers (9 species), Diurnal channel drift feeders (8 spp.), Diurnal surface pickers (7 spp.), and Ambush and stalking predators (6 spp.). The FTGs herein defined enable a comparative analysis of the structure and composition of ichthyofauna in different basins and environmental conditions, which presents an alternative approach to the use of taxonomic structure in ecological studies. The ichthyofauna classification based in FTGs proposed in this study is compared to three other classifications, proposed by Sazima (1986), Sabino & Zuanon (1998) and Casatti et al. (2001).

scholarly journals Using reliable predator identification to investigate feeding habits of Neotropical carnivores (Mammalia, Carnivora) in a deforestation frontier of the Brazilian Amazon

Mammalia ◽  
2019 ◽  
Vol 83 (5) ◽  
pp. 415-427 ◽  
Author(s):  
Flávia P. Tirelli ◽  
Thales R.O. de Freitas ◽  
Fernanda Michalski ◽  
Alexandre R. Percequillo ◽  
Eduardo Eizirik
Keyword(s):  
Feeding Habits ◽  
Brazilian Amazon ◽  
Ecological Studies ◽  
Accurate Identification ◽  
Predator Species ◽  
Non Invasive ◽  
Carnivore Species ◽  
Faecal Samples ◽  
Critical Requirement ◽  
Better Than

Abstract Accurate identification of predator species is a critical requirement to investigate their diet using faecal samples. We used non-invasive sampling and two methods of predator identification to investigate the diets of sympatric carnivores in a highly deforested region of the Brazilian Amazon. Of 108 scats, 81 could be identified at the species level using DNA sequencing and/or trichology. The former performed better than the latter (81.5% vs. 54.3% of the identified samples), and results were quite congruent (89.7% concordance in the 29 samples that could be assessed with both approaches). Nine species were identified, out of which four (crab-eating fox, ocelot, puma and jaguar) presented a sufficient number of samples to allow dietary analyses. The crab-eating fox was the most generalist (BA=0.92); ocelots focused on small- to medium-sized prey; pumas fed mostly on medium-sized items; and jaguars mostly targeted large-sized prey. A considerable overlap was observed between ocelots and pumas in all estimations (O=0.47–0.83). The presence of jaguars in the same region could be driving pumas to select medium- and small-sized prey. The results of this study highlight the importance of reliable predator identification and the need for in-depth ecological studies in areas where carnivore species are sympatric.

scholarly journals Landscape and soil regionalization in southern Brazilian Amazon and contiguous areas: methodology and relevance for ecological studies

2012 ◽  
Vol 69 (3) ◽  
pp. 217-225 ◽  
Author(s):  
Boris Volkoff ◽  
Francisco Fujita de Castro Mello ◽  
Stoécio Malta Ferreira Maia ◽  
Carlos Eduardo Pellegrino Cerri
Keyword(s):  
Brazilian Amazon ◽  
Ecological Studies

scholarly journals Chironomidae from Eastern Amazon: Understanding the differences of land-use on functional feeding groups

2018 ◽  
Author(s):  
Kathia C. Sonoda ◽  
Josinete S. Monteles ◽  
Anderson Ferreira ◽  
Pedro Gerhard
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Land Development ◽  
Brazilian Amazon ◽  
Human Action ◽  
Taxonomic Resolution ◽  
Functional Feeding Groups ◽  
Amazon Forest ◽  
Group Data ◽  
Forest Streams

Deforestation for agricultural purposes is the most dangerous human action against the conservation of the Brazilian Amazon Forest; its rates reached almost 20% of the original forested area. Many studies have been conducted on Chironomidae systematics and ecology over the Amazon biome, but most concerned the Central Amazon, while little is known about Chironomidae diversity and the effects of land development and agriculture intensification on the aquatic biota from Eastern Brazilian Amazon. The present study analyzed the effects of different land-use and land-cover on Chironomidae assemblages. Land-Use and Land-Cover (LULC) at the riparian zone were assessed from satellite imagery and three categories were defined: Forest, Secondary (Capoeira) and Agriculture. Ten catchments were selected: two for Forest, five for Agriculture and three for Secondary. For each catchment we characterized habitat and sampled insects. We hypothesized that i) the assemblage taxonomic richness will change across different land uses on riparian zones and ii) feeding functionality is a better information than taxonomic resolution to show the importance of LULC upon stream. A total of 20,884 individuals were sampled from the streams, abundance was higher in Agriculture streams. Corynoneura (18.4%), Pentaneura (14.6%) and Rheotanytarus (14.0%) were the most abundant genera in Agriculture streams; Corynoneura (17.8%), Caladomyia (13.6%), Paratanytarsus (13.1%) and Beardius (10.9%) dominated Forest streams; Goeldichironomus (25.9%), Rheotanytarus (17.6%) and Polypedilum (13.2%) dominated Capoeira streams. Regarding FFG, gatherers were the most numeric abundant in Forest (50.3%), followed by filterers (38.7%), predators (6.6%) and shredders (4.2%). In Capoeira, filterers were the main FFG (61.1%), gatherers (27.9%), predators (7.7%) and shredders (3.3%). In Agriculture streams, predators, filterers and gatherers had close numeric participation, 34.9%, 32.4% and 32.2%, respectively. Shredders performed a smaller fraction (0.4%). In Forest and Agriculture, scrapers participation was under 0.2%, while it was absent at Capoeira. Permutation tests showed significant differences among assemblages, based on numerical abundance of genera and on functional feeding group data. Even though, shredders showed a discrete participation in all three LULC, it was statistically significant higher at Forest streams when compared to Agriculture ones. Our study was able to demonstrate taxonomic differences of all LULC analyzed and it also showed the importance in considering the feeding behavior to understand the effects of land-use and land-covers changes.

scholarly journals Structure of benthic macroinvertebrate assemblages on a gradient of environmental integrity in Neotropical streams

2013 ◽  
Vol 25 (4) ◽  
pp. 418-428 ◽  
Author(s):  
Marcia Thais Suriano ◽  
Alaide Aparecida Fonseca-Gessner
Keyword(s):  
Multidimensional Scaling ◽  
Atlantic Forest ◽  
Deciduous Forest ◽  
Riparian Forest ◽  
Taxonomic Composition ◽  
Taxonomic Structure ◽  
Scaling Analysis ◽  
Taxon Richness ◽  
Numerical Abundance ◽  
Forest Streams

AIM: This study investigated the taxonomic composition of the benthic macroinvertebrates in streams to evaluate how this fauna reflects the various uses of the soil and to identify which groups of macroinvertebrates might be taken as characterizing each situation under study. METHODS: To achieve these objectives, 29 streams were collected and inserted in regions with different conservation using Surber sampler. Analyzes were performed of environmental variables (Principal Components Analysis - PCA) and taxonomic structure of the community (taxon richness, numerical abundance and Multidimensional scaling - MDS). RESULTS: EPT group (orders Ephemeroptera, Plecoptera and Trichoptera) and the Coleoptera exhibited greater numerical abundance and taxon richness in streams located in reference areas. In contrast, dipteran larvae, especially the chironomids, along with immature odonates, were more abundant in streams in areas suffering from a lack of riparian forest. Multidimensional scaling analysis (MDS) revealed an environmental gradient, on which the streams within the Atlantic forest formed a tightly clustered group, as did those in semideciduous forests. However, the latter group occupied an intermediate position between the Atlantic forest streams and those in areas disturbed by human activity. Among these areas there were no specific clusters by monoculture. CONCLUSIONS: Among the groups of streams defined by the types of land use in the adjacent areas, the state of integrity was found to decline from Atlantic rainforest, through semi-deciduous forest and then pasture, to the monocultures of eucalypts and sugarcane.

Distribution extension of Ateles chamek (Humboldt 1812) in the southwestern Brazilian Amazon: identification by visual evidence and fecal DNA

Mammalia ◽  
2018 ◽  
Vol 82 (2) ◽  
pp. 173-177
Author(s):  
André Valle Nunes ◽  
Ricardo Koroiva ◽  
Gabrielle Nóbrega Gomes Vanessa ◽  
Vinícius Santana Orsini
Keyword(s):  
Species Identification ◽  
Brazilian Amazon ◽  
Hair Color ◽  
Fecal Dna ◽  
Ecological Studies ◽  
Mato Grosso ◽  
Facial Hair ◽  
Visual Evidence ◽  
Molecular Sequencing ◽  
Threatened Status

Abstract One group of Ateles chamek (Humboldt 1812) was observed during 12 days in the Vila Bela da Santíssima Trindade municipality, in the state of Mato Grosso. During that time fecal samples (n=10) were collected and molecular sequencing was used to confirm species identification. The results suggest that the particular pattern of facial hair color observed in this group may be used for differentiation from other sub-populations; however, a deeper study is required for confirmation of these results. This record represents the most southwestern observation of this species, and increases the geographic distribution of A. chamek for about 16 km into the southern Brazilian Amazon. Taking into consideration the threatened status of this species of monkey, and that this region is under constant intensive deforestation, it is important to highlight that ecological studies and conservation activities require urgent development.

scholarly journals Characteristic of phytoplankton and water quality assessment in the Amur River at Khabarovsk in the ice-free period of 2018–2019

2021 ◽  
Vol 201 (3) ◽  
pp. 640-661
Author(s):  
T. V. Nikulina ◽  
S. E. Kulbachnyi
Keyword(s):  
Water Quality ◽  
Water Quality Assessment ◽  
Main Channel ◽  
Species Number ◽  
Taxonomic Structure ◽  
Algal Flora ◽  
Amur River ◽  
Phytoplankton Communities ◽  
The Amur River ◽  
Total Species

Species composition and taxonomic structure of phytoplankton communities in the main channel of the Amur at Khabarovsk (Russia) were monitored from spring to autumn of 2018–2019. In total, 187 species, varieties and forms of algae and cyanobacteria were found belonged to 8 phyla (Cyanobacteria, Bacillariophyta, Charophyta, Chlorophyta, Heterokontophyta, Rhodophyta, Euglenozoa, and Miozoa) and 75 genera. Diatoms formed the basis of the algal flora (94.7 % of the total species number). Mass vegetations of the diatoms and charophytes were observed with dominance of Asterionella formosa, Aulacoseira islandica, A. ambigua, A. granulata var. granulata, A. granulata var. angustissima, Ulnaria ulna, Diatoma tenue, Nitzschia acicularis, Stephanodiscus sp., Tabellaria flocculosa, Hannaea arcus var. rectus, Melosira varians, Fragilaria capucina var. vaucheriae, F. crotonensis, and Mougeotia sp. ster. Total number and biomass of plankton algae and cyanobacteria varied in the ranges of 1.74–5724.39 million cells/L and 2.5–2648.5 mg/L in spring-summer and 0.07–0.62 million cells/L and 0.2–1.4 mg/L in autumn. The water quality was evaluated by Pantle-Buck method modified by Sládeček as the betamezosaprobic III class (slightly polluted).

scholarly journals A Novel Audiovisual Brain-Computer Interface and Its Application in Awareness Detection

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Fei Wang ◽  
Yanbin He ◽  
Jiahui Pan ◽  
Qiuyou Xie ◽  
Ronghao Yu ◽  
...  
Keyword(s):  
Behavioral Observation ◽  
Event Related Potential ◽  
Audiovisual Integration ◽  
Computer Interfaces ◽  
Brain Responses ◽  
Alternative Approach ◽  
Number Recognition ◽  
Audiovisual Stimuli ◽  
Command Following ◽  
Bci System

Abstract Currently, detecting awareness in patients with disorders of consciousness (DOC) is a challenging task, which is commonly addressed through behavioral observation scales such as the JFK Coma Recovery Scale-Revised. Brain-computer interfaces (BCIs) provide an alternative approach to detect awareness in patients with DOC. However, these patients have a much lower capability of using BCIs compared to healthy individuals. This study proposed a novel BCI using temporally, spatially and semantically congruent audiovisual stimuli involving numbers (i.e., visual and spoken numbers). Subjects were instructed to selectively attend to the target stimuli cued by instruction. Ten healthy subjects first participated in the experiment to evaluate the system. The results indicated that the audiovisual BCI system outperformed auditory-only and visual-only systems. Through event-related potential analysis, we observed audiovisual integration effects for target stimuli, which enhanced the discriminability between brain responses for target and nontarget stimuli and thus improved the performance of the audiovisual BCI. This system was then applied to detect the awareness of seven DOC patients, five of whom exhibited command following as well as number recognition. Thus, this audiovisual BCI system may be used as a supportive bedside tool for awareness detection in patients with DOC.

scholarly journals Range extension of a small livebearer fish, Poecilia scalpridens (Garman, 1895) (Cyprinodontiformes, Poeciliidae): a new record for the Jari river drainage, Amapá, Brazilian Amazon

Check List ◽  
2021 ◽  
Vol 17 (4) ◽  
pp. 1081-1087
Author(s):  
Pedro Henrique Negreiros de Bragança ◽  
Felipe Polivanov Ottoni ◽  
Cecile de Souza Gama ◽  
Elisabeth Henschel
Keyword(s):  
New Record ◽  
Brazilian Amazon ◽  
Main Channel ◽  
Range Extension ◽  
Amazon River ◽  
Field Surveys ◽  
Diagnostic Characters ◽  
River Drainage

Recent field expeditions in the Jari river drainage, in addition to examination of uncatalogued poeciliids, allowed the identification of specimens as Poecilia (Pamphorichthys) scalpridens (Garman, 1895). The known range of this species includes lakes and igarapés in the lower reaches of tributaries near the main channel of the Amazon River between Parintins and the mouth of the Tapajós River. Here, we expand the range of P. scalpridens by about 300 km. We provide the main diagnostic characters of P. scalpridens to facilitate identification of specimens collected in future field surveys.

Light and electron microscopic investigation of adenohypophyses of germfree, food-restricted, and germfree-food restricted aging, male lobund-wistar rats

1988 ◽  
Vol 46 ◽  
pp. 352-353
Author(s):  
G. Ilse ◽  
K. Kovacs ◽  
N. Ryan ◽  
T. Sano ◽  
L. Stefaneanu ◽  
...  
Keyword(s):  
Wistar Rats ◽  
Microscopic Investigation ◽  
Electron Microscopic Investigation ◽  
Aging Male ◽  
Sprague Dawley ◽  
Electron Microscopic ◽  
Sprague Dawley Rats ◽  
Old Rats ◽  
Ad Libitum ◽  
Microscopic Findings

Germfree state and food restriction have been shown to increase life span and delay tumor occurrence in rats. We report here the histologic, immunocytochemical and electron microscopic findings of adenohypophyses of aging, male Lobund-Wistar rats raised at Lobund Laboratories. In our previous study, the morphologic changes in the adenohypophyses of old rats have been extensively investigated by histology, immunocytochemistry and electron microscopy. Lactotroph adenomas were frequent in Long-Evans and Sprague-Dawley rats, whereas gonadotroph adenomas were frequent in Sprague-Dawley and Wistar rats.Male Lobund-Wistar rats were divided into four groups: 1) conventional, which were raised under normal non-germfree environment and received food ad libitum; 2) germfree-food ad libitum; 3) conventional environment-food restricted and 4) germfree-food restricted. The adenohypophyses were removed from 6-month-, 18-month- and 30-month-old rats. For light microscopy, adenohypophyses were fixed in formalin and embedded in paraffin.

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