scholarly journals Potential biosurfactant producing endophytic and epiphytic fungi, isolated from macrophytes in the Negro River in Manaus, Amazonas, Brazil

2016 ◽  
Vol 15 (24) ◽  
pp. 1217-1223 ◽  
Author(s):  
Marcelo Silva Lima Jo atilde o ◽  
Odair Pereira Jos eacute ◽  
Hort ecirc ncio Batista Ieda ◽  
de Queiroz Costa Neto Pedro ◽  
Concei ccedil atilde o dos Santos Jucileuza ◽  
...  
Keyword(s):  
Epiphytic Fungi ◽  
Negro River

scholarly journals Ichthyological ethnoknowledge of the “piabeiros” from the Amazon region, Brazil

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Daniel da Silva Ladislau ◽  
Maiko Willas Soares Ribeiro ◽  
Philip Dalbert da Silva Castro ◽  
Jackson Pantoja-Lima ◽  
Paulo Henrique Rocha Aride ◽  
...  
Keyword(s):  
Fish Species ◽  
Local Ecological Knowledge ◽  
Middle Part ◽  
Ornamental Fish ◽  
Ecological Knowledge ◽  
Structured Interviews ◽  
Economic Activities ◽  
Negro River ◽  
Artisanal Fishers ◽  
Ecological Aspects

Abstract Background The capture of ornamental fish is one of the main economic activities of riverine families in the Amazon. However, studies regarding the local ecological knowledge of workers in this activity are still incipient. In view of this, we have studied and explored the local ecological knowledge of artisanal fishers who specialize in the capture of fish for the aquarium trade in the middle part of the Negro River basin and investigated issues related to the ecological aspects of the fish species that are targeted by this trade in the region. Methods Therefore, we conducted semi-structured interviews and applied questionnaires to artisanal fishers of ornamental fish (N = 89), from the municipality of Barcelos, from January to April 2016. Results In total, 41 popular names were cited, which correspond to four ethnocategories and 10 families. The main species were Paracheirodon axelrodi (12.5%), Hemigrammus bleheri (8.3%), Ancistrus dolichopterus (6.4%), Symphysodon discus (5.3%), and Potamotrygon motoro (3.8%). According to the fishers, the species of fish known in the region as “piabas” have a preference for living in clusters (28.9%) and carry out migratory movements (26.1%). The diet of local fish species reported by fisheries is diverse, though mainly based on periphyton (42.2%), and the reproductive cycle directly influenced by the period of flooding of rivers in the region (37.6%) Conclusion Our study revealed that the fishers possess information on the ecological aspects of local ornamental fish species, many of which are consistent with scientific literature. The information presented may assist in the decision-making process for the management of local fishery resources and contribute to the resumption of growth and sustainability in the capture of ornamental fish.

Floristic variation across 600 km of inundation forests (Igapó) along the Negro River, Central Amazonia

Hydrobiologia ◽  
2012 ◽  
Vol 729 (1) ◽  
pp. 229-246 ◽  
Author(s):  
Juan Carlos Montero ◽  
Maria Teresa Fernandez Piedade ◽  
Florian Wittmann
Keyword(s):  
Negro River ◽  
Inundation Forests ◽  
Central Amazonia ◽  
Floristic Variation

Hydrochemical aspects of the negro river, patagonia, argentina

1980 ◽  
Vol 5 (2) ◽  
pp. 181-186 ◽  
Author(s):  
Pedro J. Depetris
Keyword(s):  
Negro River

scholarly journals The effect of seasonality on the structure of rotifers in a black-water shallow lake in Central Amazonia

2014 ◽  
Vol 86 (3) ◽  
pp. 1359-1372 ◽  
Author(s):  
CLARICE C. NOVA ◽  
VANESSA G. LOPES ◽  
LEONARDO COIMBRA E SOUZA ◽  
BETINA KOZLOWSKY-SUZUKI ◽  
TALITA A.A. PEREIRA ◽  
...  
Keyword(s):  
Species Composition ◽  
Driving Force ◽  
Community Dynamics ◽  
Flood Pulse ◽  
Small Lakes ◽  
Black Water ◽  
Negro River ◽  
Rotifer Community ◽  
Central Amazonia ◽  
Physical And Chemical

Rotifers have often been used as indicators of sudden changes in physical and chemical features of the aquatic environment. Such features vary greatly during flood pulse events in small lakes connected to major floodplains. However, few are the studies that investigate the consequences of the flood pulse in rotifer species composition, abundance, richness and diversity, especially in Amazonian lakes. We analyzed samples from a small blackwater lake of an “igarapé” connected permanently to the Negro river, in Central Amazonia. Samples were taken twice a year for two years, comprising flooding and receding periods of the flood pulse. Rotifer abundance increased significantly after draught events, and electrical conductivity and turbidity were intrinsically related to such variation. Species composition also changed from flooding to receding periods. Some taxa, such as Brachionus zahniseri reductus and Lecane remanei were restricted to receding periods, while Brachionus zahniseri, Brachionus gillardi and Lecane proiecta were only present during flooding. A shift in the composition of rotifer families was observed from one period to another, showing the effect of renewing waters of the flood pulse. These results suggest that the flood pulse acts as a driving force and stressing condition, considerably altering rotifer community dynamics, either changing species composition or decreasing abundance.

scholarly journals Morphology of lateral line canals in Neotropical freshwater stingrays (Chondrichthyes: Potamotrygonidae) from Negro River, Brazilian Amazon

2010 ◽  
Vol 8 (4) ◽  
pp. 867-876 ◽  
Author(s):  
Akemi Shibuya ◽  
Jansen Zuanon ◽  
Maria Lúcia G. de Araújo ◽  
Sho Tanaka
Keyword(s):  
Lateral Line ◽  
The Body ◽  
Mechanical Stimuli ◽  
High Concentration ◽  
Ventral Region ◽  
Negro River ◽  
Accurate Localization ◽  
Posterior Lateral Line ◽  
The Family ◽  
The Relationship

The relationship between the distribution of the lateral line canals and their functionality has not been well examined in elasmobranchs, especially among Neotropical freshwater stingrays of the family Potamotrygonidae. The spatial distribution of the canals and their tubules and the quantification of the neuromasts were analyzed in preserved specimens of Potamotrygon motoro, P. orbignyi, Potamotrygon sp. "cururu", and Paratrygon aiereba from the middle Negro River, Amazonas, Brazil. The hyomandibular, infraorbital, posterior lateral line, mandibular, nasal and supraorbital canals were characterized and their pores and neuromasts quantified. The ventral canals are known to facilitate the accurate localization of prey items under the body, and our results indicate that the dorsal canals may be employed in identifying the presence of predators or potential prey positioned above the stingray's body. The presence of non-pored canals in the ventral region may be compensated by the high concentration of neuromasts found in the same area, which possibly allow the accurate detection of mechanical stimuli. The concentration of non-pored canals near the mouth indicates their importance in locating and capturing prey buried in the bottom substrate, possibly aided by the presence of vesicles of Savi.

scholarly journals Morphobiological aspects of Rhodnius brethesi Matta, 1919 (Hemiptera:Reduviidae) from the Upper and Middle Negro River, Amazon region of Brazil: I - scanning electron microscopy

2005 ◽  
Vol 100 (8) ◽  
pp. 915-923 ◽  
Author(s):  
Jacenir Reis dos Santos-Mallet ◽  
Angela Cristina Verissimo Junqueira ◽  
Carlos José de Carvalho Moreira ◽  
Zelia Andrade ◽  
José Rodrigues Coura ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Amazon Region ◽  
Negro River ◽  
Scanning Electron

scholarly journals Epiphytic fungi induced pathogen resistance of invasive plant Ipomoea cairica against Colletotrichum gloeosporioides

2019 ◽  
Author(s):  
Hua Xu ◽  
Minjie Zhu ◽  
Shaoshan Li ◽  
Weibin Ruan ◽  
Can Xie
Keyword(s):  
Colletotrichum Gloeosporioides ◽  
Pathogen Resistance ◽  
Artificial Inoculation ◽  
Stem Length ◽  
Systemic Resistance ◽  
Fusarium Fujikuroi ◽  
Natural Habitats ◽  
Glucanase Activity ◽  
Epiphytic Fungi ◽  
Leaf Surfaces

Background. Ipomoea cairica (L.) Sweet is a destructive invasive weed in South China but rarely infected with pathogens in nature. Its pathogen resistance mechanism is largely unknown at present. Some non-pathogenic isolates of Fusarium oxysporum and Fusarium fujikuroi are prevalent on many plant species and function as pathogen resistance inducers of host plants. The objective of the present research is to investigate whether the symbiosis between the both fungi and I. cairica is present, and thereby induce pathogen resistance of I. cairica. Methods. Through field investigation, we explored the occurrence rates of F. oxysporum and F. fujikuroi on leaf surfaces of I. cairica plants in natural habitats and compared their abundance between healthy leaves and leaves infected with Colletotrichum gloeosporioides, a natural pathogen. With artificial inoculation, we assessed their pathogencity to I. cairica and study their contribution of pathogen resistance to I. cairica against C. gloeosporioides. Results. We found that F. oxysporum and F. fujikuroi were widely epiphytic on healthy leaf surfaces of I. cairica in sunny non-saline, shady non-saline and sunny saline habitats. Their occurrence rates reached up to 100%. Moreover, we found that the abundance of F. oxysporum and F. fujikuroi on leaves infected with C. gloeosporioides were significantly lower than that of healthy leaves. With artificial inoculation, we empirically confirmed that F. oxysporum and F. fujikuroi were non-pathogenic to I. cairica. It was interesting that colonization by F. fujikuroi, F. oxysporum alone and a mixture of both fungi resulted in a reduction of C. gloeosporioides infection to I. cairica accompanied by lower lesion area to leaf surface area ratio, increased H2O2 concentration and salicylic acid (SA) level relative to the control. However, NPR1 expression, chitinase and β -1,3-glucanase activities as well as stem length and biomass of I. cairica plant only could be significantly improved by F. oxysporum and a mixture of both fungi but not by F. fujikuroi. In addition, as compared to colonization by F. oxysporum and a mixture of both fungi, F. fujikuroi induced significantly higher jasmonic acid (JA) level but significantly lower β -1,3-glucanase activity in leaves of I. cairica plants. Thus, our findings indicated the symbiosis of epiphytic fungi F. fujikuroi and F. oxysporum facilitated the fitness of I. cairica via the induced systemic resistance of host plant against C. gloeosporioides. F. oxysporum played a dominant role in inducing pathogen resistance of I. cairica. Its presence alleviated the antagonism of the JA signaling on SA-dependent β -1,3-glucanase activity and enabled I. cairica plants to maintain relatively higher level of resistance against C. gloeosporioides.

scholarly journals Amaranth irrigation frequency in northeast Patagonia, Argentina

2021 ◽  
pp. 247-258
Author(s):  
Maria Fany Zubillaga ◽  
Roberto Simon Martínez ◽  
Ricardo Camina ◽  
Gustavo Adolfo Orioli ◽  
Mauricio Failla ◽  
...  
Keyword(s):  
Water Use ◽  
Irrigation Frequency ◽  
Production Potential ◽  
Amaranthus Cruentus ◽  
Negro River ◽  
Rio Negro ◽  
Grain Crop ◽  
Number Of Leaves ◽  
Use Efficiency ◽  
Plant Stand

Introduction. The production potential of grain amaranth has recently been demonstrated in northeastern Patagonia, Argentina. This crop under irrigation and in a temperate semi-arid climate showed an adequate development of the plants in their different phenological stages with high economic performance. Objectives. This study explored the response of Amaranthus cruentus cv Mexicano to different irrigation frequencies in the lower valley of Río Negro river, Patagonia, Argentina. Method. The experimental design was of three blocks with randomized treatments (subplots), each one corresponding to a different irrigation frequency. The first six irrigations were performed every 7 days for all the treatments, to ensure the establishment of the crop. Then the following treatments were applied: irrigation every 7 days (FI), every 14 days (FII), and every 21 days (FIII). The following biometric variables and their components were measured: height of plant, number of leaves, biomass and economic yield. Results. The results suggest that the optimum irrigation frequency was FII (14 days), resulting in an adequate plant stand at panicle initiation and allows a proper development of plant with optimal biological and economical yields and the highest efficiency of water use (4.02 kg·m-3). Conclusions. The contributions of this study demonstrated the production potential of A. cruentus crop in the lower valley of the Río Negro river under irrigation, representing the southernmost study on irrigation frequency made for this grain crop in the world. A management of irrigation water of 7 days for the establishment of the crop and then with a frequency of 14 days showed the highest yield and the best water use efficiency.

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