scholarly journals The abundance and biomass of mesozooplankton and ichthyoplankton in the confluence boundary of the Negro and the Amazon Rivers

2017 ◽  
Author(s):  
Ryota Nakajima ◽  
Elvis V Rimachi ◽  
Edinaldo N Santos-Silva ◽  
Adi Khen ◽  
Tetsuo Yamane ◽  
...  
Keyword(s):  
Juvenile Fish ◽  
Boundary Spanning ◽  
Amazon River ◽  
Black And White ◽  
Black Water ◽  
Negro River ◽  
Feeding Habitat ◽  
White Water ◽  
Black Water River ◽  
Planktonic Communities

The boundary zone between two different hydrological regimes is often a biologically enriched environment with distinct planktonic communities. In the center of the Amazon River basin, muddy white water of the Amazon River meets with black water of the Negro River, creating a conspicuous visible boundary spanning over 10 km along the Amazon River. Here, we tested the hypothesis that the confluence boundary between the white and black water rivers concentrates prey and is used as a feeding habitat for juvenile fish by investigating the abundance, biomass and distribution of mesozooplankton and ichthyoplankton communities across the two rivers. Our results show that mesozooplankton abundance and biomass were higher in the black-water river compared to the white-water river; however an exceptionally high mesozooplankton abundance was not observed in the confluence boundary. Nonetheless we found the highest abundance of ichthyoplankton in the confluence boundary, being up to 9-fold higher than in adjacent rivers. The confluence boundary between black and white water rivers may function as a boundary layer that offers benefits of both high zooplankton prey concentrations (black-water) and low predation risk (white-water). This forms a plausible explanation for the high abundance of ichthyoplankton in the confluence zone of black and white water rivers.

scholarly journals The abundance and biomass of mesozooplankton and ichthyoplankton in the confluence boundary of the Negro and the Amazon Rivers

2017 ◽  
Author(s):  
Ryota Nakajima ◽  
Elvis V Rimachi ◽  
Edinaldo N Santos-Silva ◽  
Adi Khen ◽  
Tetsuo Yamane ◽  
...  
Keyword(s):  
Juvenile Fish ◽  
Boundary Spanning ◽  
Amazon River ◽  
Black And White ◽  
Black Water ◽  
Negro River ◽  
Feeding Habitat ◽  
White Water ◽  
Black Water River ◽  
Planktonic Communities

The boundary zone between two different hydrological regimes is often a biologically enriched environment with distinct planktonic communities. In the center of the Amazon River basin, muddy white water of the Amazon River meets with black water of the Negro River, creating a conspicuous visible boundary spanning over 10 km along the Amazon River. Here, we tested the hypothesis that the confluence boundary between the white and black water rivers concentrates prey and is used as a feeding habitat for juvenile fish by investigating the abundance, biomass and distribution of mesozooplankton and ichthyoplankton communities across the two rivers. Our results show that mesozooplankton abundance and biomass were higher in the black-water river compared to the white-water river; however an exceptionally high mesozooplankton abundance was not observed in the confluence boundary. Nonetheless we found the highest abundance of ichthyoplankton in the confluence boundary, being up to 9-fold higher than in adjacent rivers. The confluence boundary between black and white water rivers may function as a boundary layer that offers benefits of both high zooplankton prey concentrations (black-water) and low predation risk (white-water). This forms a plausible explanation for the high abundance of ichthyoplankton in the confluence zone of black and white water rivers.

scholarly journals The density and biomass of mesozooplankton and ichthyoplankton in the Negro and the Amazon Rivers during the rainy season: the ecological importance of the confluence boundary

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3308 ◽  
Author(s):  
Ryota Nakajima ◽  
Elvis V. Rimachi ◽  
Edinaldo N. Santos-Silva ◽  
Laura S.F. Calixto ◽  
Rosseval G. Leite ◽  
...  
Keyword(s):  
Rainy Season ◽  
Fish Larvae ◽  
Amazon River ◽  
Black And White ◽  
Black Water ◽  
Negro River ◽  
Feeding Habitat ◽  
White Water ◽  
Ecological Importance ◽  
Density And Biomass

The boundary zone between two different hydrological regimes is often a biologically enriched environment with distinct planktonic communities. In the center of the Amazon River basin, muddy white water of the Amazon River meets with black water of the Negro River, creating a conspicuous visible boundary spanning over 10 km along the Amazon River. Here, we tested the hypothesis that the confluence boundary between the white and black water rivers concentrates prey and is used as a feeding habitat for consumers by investigating the density, biomass and distribution of mesozooplankton and ichthyoplankton communities across the two rivers during the rainy season. Our results show that mean mesozooplankton density (2,730 inds. m−3) and biomass (4.8 mg m−3) were higher in the black-water river compared to the white-water river (959 inds. m−3; 2.4 mg m−3); however an exceptionally high mesozooplankton density was not observed in the confluence boundary. Nonetheless we found the highest density of ichthyoplankton in the confluence boundary (9.7 inds. m−3), being up to 9-fold higher than in adjacent rivers. The confluence between white and black waters is sandwiched by both environments with low (white water) and high (black water) zooplankton concentrations and by both environments with low (white water) and high (black water) predation pressures for fish larvae, and may function as a boundary layer that offers benefits of both high prey concentrations and low predation risk. This forms a plausible explanation for the high density of ichthyoplankton in the confluence zone of black and white water rivers.

A classification of the major habitats of Amazonian black-water river floodplains and a comparison with their white-water counterparts

2015 ◽  
Vol 23 (4) ◽  
pp. 677-693 ◽  
Author(s):  
Wolfgang J. Junk ◽  
Florian Wittmann ◽  
Jochen Schöngart ◽  
Maria T. F. Piedade
Keyword(s):  
Black Water ◽  
River Floodplains ◽  
White Water ◽  
Black Water River

Black and white waters and their possible relationship to the podzolization process

Soil Research ◽  
1983 ◽  
Vol 21 (1) ◽  
pp. 59 ◽  
Author(s):  
R Reeve ◽  
IF Fergus
Keyword(s):  
Storage System ◽  
Residual Liquid ◽  
Chemical Analyses ◽  
Black And White ◽  
Black Water ◽  
Field Evidence ◽  
Close Proximity ◽  
Leaching Experiment ◽  
Water Field ◽  
White Water

Highly coloured, organic-stained water (black water) occurs as springs, seeps and perched lakes in the Cooloola area of south-eastern Queensland (latitude 26� S.). Springs of clear, colourless water (white water) sometimes occur in close proximity to the black water. Field evidence suggests that black waters move laterally along semipermeable B horizons of humus podzols, whereas white waters are part of a much larger storage system in which the water has been decolorized by contact with the C horizons. Thus it appears that black waters are the active eluviating agent and white waters are the residual liquid phase of the podzolization process. Chemical analyses of black and white waters, and the results of a laboratory leaching experiment, support this view. Possible mechanisms and some implications for the genesis of podzol B horizons are discussed.

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 Calcium fluxes in Hoplosternum littorale (tamoatá) exposed to different types of Amazonian waters

2009 ◽  
Vol 7 (3) ◽  
pp. 465-470 ◽  
Author(s):  
Bernardo Baldisserotto ◽  
Carlos Eduardo Copatti ◽  
Levy Carvalho Gomes ◽  
Edsandra Campos Chagas ◽  
Richard Philip Brinn ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Water Transfer ◽  
Well Water ◽  
Acidic Ph ◽  
Clear Water ◽  
Black Water ◽  
Neutral Ph ◽  
Different Types ◽  
White Water ◽  
Hoplosternum Littorale

Fishes that live in the Amazonian environment may be exposed to several kinds of waters: "black waters", containing high dissolved organic carbon and acidic pH, "white waters", with ten fold higher Ca2+ concentrations than black waters and neutral pH, and "clear waters", with two fold higher Ca2+ concentrations than black waters and also neutral pH. Therefore, the aim of the present study was to analyze Ca2+ fluxes in the facultative air-breather Hoplosternum littorale (tamoatá) exposed to different Amazonian waters. Fishes were acclimated in well water (similar to clear water) and later placed in individual chambers for Ca2+ fluxes measurements. After 4 h, water from the chambers was replaced by a different type of water. Transfer of tamoatás to ion-poor black or acidic black water resulted in net Ca2+ loss only in the first 2 h of experiment. However, transfer from black or acidic black water to white water led to only net Ca2+ influxes. The results obtained allowed us to conclude that transfer of tamoatás to ion-poor waters (black and acidic black water) led to transient net Ca2+ loss, while the amount of Ca2+ in the ion-rich white water seems adequate to prevent Ca2+ loss after transfer. Therefore, transfer of tamoatás between these Amazonian waters does not seem to result in serious Ca2+ disturbance.

Composition and community structure of mangroves distributed on the east coast of Marajó Island, Brazil

2022 ◽  
Author(s):  
Barbara Luzia Santos de Oliveira Faro ◽  
Priscila Sanjuan de Medeiros-Sarmento ◽  
Norma Ely Santos Beltrão ◽  
Paulo Weslem Portal Gomes ◽  
Ana Cláudia Caldeira Tavares-Martins
Keyword(s):  
Floristic Composition ◽  
Distribution Patterns ◽  
Major Influence ◽  
Structural Development ◽  
Black Water ◽  
Composition And Structure ◽  
Marine System ◽  
Marajó Island ◽  
White Water ◽  
Degree Of Similarity

Abstract Mangroves in the Amazon are influenced by several environmental conditions that determine the composition and structural development of the arboreal flora, which results in different distribution patterns. In this study, we sought to answer two questions: (1) what is the composition and structure of the mangroves near the mouth of the Amazon River in Marajó Island? (2) Are the fringe and inland mangroves more similar or dissimilar in terms of floristic composition? For this, we delimited a fringe zone and an inland zone about 1 km apart from each other. In each zone, we distributed five 400-m2 plots. The individuals were grouped into diameter and height classes and structural and phytosociological parameters were calculated. Ten species were recorded in the mangroves, of which seven are typical of white-water (várzea) and black-water (igapó) flooded forest ecosystems. We believed the adjacent ecosystems and the hydrological network are inducing the establishment of such species. The composition and structure of mangroves did not differ statistically between zones, and the degree of similarity may be a result of similar environmental factors in these zones such as low relief and high frequency of macrotides. We conclude that the vegetation of the studied mangroves has a major influence of the fluvial-marine system of the great rivers of the Amazon associated with a diversity of ecosystems that, together, generate greater floristic richness when compared to mangroves in other regions.

scholarly journals Catfishes of the genus Auchenipterichthys (Osteichthyes: Siluriformes: Auchenipteridae): a revisionary study

2005 ◽  
Vol 3 (1) ◽  
pp. 89-106 ◽  
Author(s):  
Carl J. Ferraris Jr. ◽  
Richard P. Vari ◽  
Sandra J. Raredon
Keyword(s):  
River Basin ◽  
River Basins ◽  
Junior Synonym ◽  
Amazon River ◽  
Amazon River Basin ◽  
Orinoco River ◽  
Negro River ◽  
Madeira River ◽  
Fourth Species ◽  
Madeira River Basin

The Neotropical auchenipterid catfish genus Auchenipterichthys is reviewed and found to include four species. Auchenipterichthys thoracatus, formerly considered to be widely distributed throughout the Amazon River basin, is found to be restricted to the upper Madeira River basin. The widespread Amazonian species that had been misidentified as A. thoracatus is, instead, A. coracoideus; a species that also occurs in the upper Essequibo River. Auchenipterichthys longimanus, the most widely distributed species of the genus, is found through much of the Amazon and Orinoco River basins. The fourth species of the genus, A. punctatus (and its junior synonym A. dantei), is found in the upper portions of the Orinoco and Negro River basins in Venezuela and the central portions of the Amazon River basin in Brazil. All four species of Auchenipterichthys are redescribed and illustrated, and a key to the species is provided.

scholarly journals Pinnularia caprichosa sp. nov.: a diatom from a black water Brazilian Amazon system

Phytotaxa ◽  
2015 ◽  
Vol 239 (3) ◽  
pp. 280 ◽  
Author(s):  
Andreia Cavalcante Pereira ◽  
Lezilda Carvalho Torgan ◽  
Ana Luiza Burliga ◽  
John Patrick Kociolek ◽  
Carlos E. Wetzel ◽  
...  
Keyword(s):  
New Species ◽  
River Basin ◽  
Amazon Basin ◽  
Brazilian Amazon ◽  
New Taxon ◽  
Middle Portion ◽  
Black Water ◽  
Negro River ◽  
Electron Microscopical ◽  
Scanning Electron

While possessing a remarkable diversity in the acidic and oligotrophic waters of the Amazon basin, the genus Pinnularia appears underdescribed in the region. In this study, we present light and scanning electron microscopical observations on Pinnularia caprichosa sp. nov. from Tupé Lake, a dendritic lake located on the floodplain of the Negro River basin. This new taxon has a large axial area and transapical striae that are slightly radiate to parallel and longer in the middle portion of the valve. The species was compared with Pinnularia elliptica, P. instabilis, P. lacunarum, P. montana, P. permontana and P. subflexuosa, all of which closely resemble P. caprichosa but differ from the new species in specific details of size, striae density and valve shape.

Sign in / Sign up

Export Citation Format

Share Document