scholarly journals Length-weight relationships of ornamental fish from floodplain lakes in the Solimões River basin (Iranduba, Amazonas, Brazil)

2019 ◽  
Vol 11 (2) ◽  
pp. 733 ◽  
Author(s):  
André Sampaio ◽  
Jamerson Aguiar-Santos ◽  
Hélio Anjos ◽  
Carlos Freitas ◽  
Flávia Siqueira-Souza

This research reports the LWR of ornamental fish from floodplain lakes of the Solimões River basin. The fish were caught in the Paciência island (a fluvial island) in two lakes Sacambú and Cacau using purse seine 7 m × 4 m and mesh size = 3 mm, once during the flood in June 2017 and dry in January 2018. The specimens captured were anesthetized using eugenol 15 mg · L–1, fixed formalin 10% and stored ethanol 70% after 10 days. This study provides the LWR parameters for the species Anablepsoides micropus, Anchoviella jamesi, Cichlasoma amazonarum, Heros efasciatus, Ctenobrycon hauxwellianus, Copella nattereri and Hemigrammus levis. The parameter a ranged from 0.0092 to 0.0229, b ranged from 2.78 to 3.50 and the R2 ranged from 0.985 to 0.998. The results represent new information about ornamental fish from floodplain lakes, with new LWR for five species that are not present in FishBase data set and probably are new for science. This study is preliminary and much work needs to be done especially in the Solimões River floodplain areas and with our research we hope to encourage new studies in the region.

2017 ◽  
Vol 16 (2) ◽  
Author(s):  
D. Toyama ◽  
C.D. Santos-Júnior ◽  
L.T. Kishi ◽  
T.C.S. Oliveira ◽  
J.W. Garcia ◽  
...  

2005 ◽  
Vol 2 (3) ◽  
pp. 639-690 ◽  
Author(s):  
G. P. Zhang ◽  
H. H. G. Savenije

Abstract. Based on the Representative Elementary Watershed (REW) approach, the modelling tool REWASH (Representative Elementary WAterShed Hydrology) has been developed and applied to the Geer river basin. REWASH is deterministic, semi-distributed, physically based and can be directly applied to the watershed scale. In applying REWASH, the river basin is divided into a number of sub-watersheds, so called REWs, according to the Strahler order of the river network. REWASH describes the dominant hydrological processes, i.e. subsurface flow in the unsaturated and saturated domains, and overland flow by the saturation-excess and infiltration-excess mechanisms. Through flux exchanges among the different spatial domains of the REW, surface and subsurface water interactions are fully coupled. REWASH is a parsimonious tool for modelling watershed hydrological response. However, it can be modified to include more components to simulate specific processes when applied to a specific river basin where such processes are observed or considered to be dominant. In this study, we have added a new component to simulate interception using a simple parametric approach. Interception plays an important role in the water balance of a watershed although it is often disregarded. In addition, a refinement for the transpiration in the unsaturated zone has been made. Finally, an improved approach for simulating saturation overland flow by relating the variable source area to both the topography and the groundwater level is presented. The model has been calibrated and verified using a 4-year data set, which has been split into two for calibration and validation. The model performance has been assessed by multi-criteria evaluation. This work is the first full application of the REW approach to watershed rainfall-runoff modelling in a real watershed. The results demonstrate that the REW approach provides an alternative blueprint for physically based hydrological modelling.


Purpose. Assess the current state of the Southern Bug River basin and the degree of anthropogenic impact on it (transformation) Methods. The methodology of complex field geographic research (according to S. Kurlov) was chosen for the research. On its basis, water samples were taken at the appropriate points of the river basin, which directly covered the Southern Bug River itself, as well as its tributaries, and the composition of coastal soils was analyzed. Laboratory experiments were performed on the basis of a licensed laboratory of the Uman National University of Horticulture Results. Based on the analysis of the data set of the main hydrochemical indicators of the surface water quality of the Southern Bug river basin and the analysis of the soil, it was found at some experimental points that the MPC content of the studied indicators was exceeded. The content is exceeded at all sampling points, due to the high content of complexes with humic acid salts, secondary waterlogging of reclaimed lands. The nitrite content is exceeded in the following places: r. Southern Bug (Vinnitsa and Ladyzhin), r. Ustya (Nemyriv), r. Udych litskiy district) and r. Dohna (Bershad district). The main reason for the intake of nitrates into the water is the washout of fertilizers from fields and vegetable gardens. All surface water bodies have increased water hardness, its acidity is within normal limits. The soils adjacent to the streams under consideration bear clear signs of hydrogenic accumulation of substances (carbonates, gypsum, salts) and deltaic conditions of formation (horizontal stratification, horizons buried, remnants of freshwater fauna). Conclusions. The concentration of pollutants increases with the approach of the tributaries of the Southern Bug River and the relief formed by them to their base of erosion. Excess concentrations of alkaline hydrolyzed nitrogen, as well as phosphorus and potassium compounds at the sampling points indicate a high level of intensity of the farming system, in which the use of agrochemicals is given priority. However, long-term ingress of these compounds into the water body will accelerate the process of eutrophication in the near future. The loss of humus in the soils of agricultural lands adjacent to the rivers Sob, Dokhna, Ustya was revealed. In general, the geosystem of the Southern Bug River suffers from a complex anthropogenic impact, the main source of which is agricultural production.


Author(s):  
Lucie Straková ◽  
Radovan Kopp ◽  
Eliška Maršálková ◽  
Blahoslav Maršálek

Our paper brings new information about long-term changes of the phytoplankton communities in the Brno reservoir with the focus on the Microcystis abundance using the semi-monthly monitoring data covering the period 2006–2012. The main aim is to extract from this long-term data set differences in number of Microcystis cells depending on environmental factors. The development of cyanobacteria in Brno reservoir is caused by excessive phosphate loading from wastewater treatment facilities upstream and from non–point sources along the Svratka river. It focuses management effort on upstream controls of reservoir condition. High abundance in millions of cyanobacteria cells in 1ml observed in Brno reservoir before was reduced to values in the order of thousands cells in 1ml in last two years through a combination of measures (liming, precipitation of phosphorus on inflow, aeration and destratification). Phytoplankton composition was also changed and at the expense of cyanobacteria promoted the development of green algae and diatoms.


Author(s):  
Mohd Saiful Samsudin ◽  
Saiful Iskandar Khalit ◽  
Azman Azid ◽  
Hafizan Juahir ◽  
Ahmad Shakir Mohd Saudi ◽  
...  

This study presents the application of selected environmetric in the Perlis River Basin. The results show PCA extracted nine principal components (PCs) with eigenvalues greater than one, which equates to about 77.15% of the total variance in the water-quality data set. The absolute principal component scores (APCS)-MLR model discovered BOD and COD as the main parameters, which indicates the measure of the agricultural pollution in the Perlis River Basin, the hierarchical agglomerative cluster analysis (HACA) shows 11 monitoring stations assembled into two clusters in accordance with similarities in the concentration of BOD and COD, which are grouped in P4. The X ̅ control chart shows that the mean concentration of BOD and COD in P4 is in the control process. The capability ratio (Cp) was applied to measure the risk of the concentration in terms of the river pollution in a subsequent period of time using the limit NWQS.


2004 ◽  
Vol 64 (3a) ◽  
pp. 501-510 ◽  
Author(s):  
F. K. Siqueira-Souza ◽  
C. E. C. Freitas

The fish community of the Solimões floodplain lakes was studied by bimonthly samples taken from May 2001 to April 2002. These were carried out at lakes Maracá (03º51'33"S, 62º35'08,6"W), Samaúma (03º50'42,1"S, 61º39'49,3"W), and Sumaúma and Sacambú (03º17'11,6"S and 60º04'31,4"W), located between the town of Coari and the confluence of the Solimões and Negro rivers. Collections were done with 15 gillnets of standardized dimensions with several mesh sizes. We collected 1,313 animals distributed in 77 species, belonging to 55 genera of 20 families and 5 orders. Characiformes was the most abundant Order, with a larger number of representatives in the Serrasalmidae and Curimatidae. The most abundant species in the samplings were Psectrogaster rutiloides (132 individuals), Pigocentrus nattereri (115 individuals), and Serrasalmus elongatus (109 individuals). Lakes Samaúma, Sacambú, and Sumaúma were adjusted to logarithmic and lognormal series. The diversity exhibited an inverse gradient to the river flow, showing the highest diversity at Lake Sumaúma, followed by Samaúma, Sacambú, and Maracá. Species richness estimated through the jackknife technique ranged from 78 to 107 species.


1984 ◽  
Vol 28 (04) ◽  
pp. 282-289
Author(s):  
James H. Ma

A finite-element code to account for thermal expansion in a solid was developed for the Independent Research and Independent Exploratory Development project "Tribology of Sliding Surface Bearings." The program is based on a two-dimensional model using a second or higher-order interpolation function in the element space that will allow a diverse temperature field, such as a steep nonlinear temperature gradient, to be prescribed in a solid body. The computer code has a definite advantage over certain finite-element systems that are commercially available. Many accept only a constant, or averaged, temperature input into their element space. With the new capabilities, complex thermal mechanical responses under severe temperature gradients can be readily analyzed. For instance, the hot spot in a ship's landing deck due to the concentrated heat load, such as those generated by high-temperature jet exhaust, can be more realistically represented by the elements of current development. The element mesh size and the input data set are more manageable.


Sign in / Sign up

Export Citation Format

Share Document