scholarly journals Using long-term data to predict fish abundance: the case of Prochilodus lineatus (Characiformes, Prochilodontidae) in the intensely regulated upper Paraná River

2017 ◽  
Vol 15 (3) ◽  
Author(s):  
Pitágoras A. Piana ◽  
Bárbara F. Cardoso ◽  
Joilson Dias ◽  
Luiz C. Gomes ◽  
Angelo A. Agostinho ◽  
...  
Keyword(s):  
Data Analysis ◽  
Panel Data ◽  
Panel Data Analysis ◽  
Paraná River ◽  
Population Variation ◽  
Life Strategy ◽  
Spawning Period ◽  
Prochilodus Lineatus ◽  
Parana River ◽  
Upper Paraná River

ABSTRACT Populations show spatial-temporal fluctuations in abundance, partly due to random processes and partly due to self-regulatory processes. We evaluated the effects of various external factors on the population numerical abundance of curimba Prochilodus lineatus in the upper Paraná River floodplain, Brazil, over a 19-year period. Panel data analysis was applied to examine the structure of temporal and spatial abundance while controlling auto-regressive processes and spatial non-homogeneity variances that often obscure relationships. As sources of population variation, we considered predation, competition, selected abiotic variables, construction of a dam upstream of the study area, water level and flood intensity during the spawning period. We found that biological interactions (predation and competition) were not significantly related to variations in curimba abundance; specific conductance was a space indicator of abundance, apparently linked to the biology of the species; intensity of floods determined inter-annual variation in abundances; Porto Primavera Dam negatively impacted the abundances at sites in the floodplain directly affected by discharges from the dam. Panel data analysis was a powerful tool that identified the need for intense flooding to maintain high abundances of curimba in the upper Paraná River. We believe our results apply to other species with similar life strategy.

scholarly journals Trophic position of bottom-feeding fish in the Upper Paraná River floodplain

2009 ◽  
Vol 69 (2 suppl) ◽  
pp. 573-581 ◽  
Author(s):  
CA. Lopes ◽  
E. Benedito ◽  
LA. Martinelli
Keyword(s):  
Trophic Position ◽  
Paraná River ◽  
Food Sources ◽  
Prochilodus Lineatus ◽  
River Floodplain ◽  
Parana River ◽  
Spatial Differences ◽  
Upper Paraná River Floodplain ◽  
Upper Paraná River ◽  
Paraná River Floodplain

The δ15N composition of bottom-feeding fish (iliophagous = Apareiodon affinis, Cyphocharax nagelii, Prochilodus lineatus, Steindachnerina brevipinna and S. insculpta; detritivorous = Loricariichthys platymetopon and Liposarcus anisitsi; benthophagous = Satanoperca pappaterra and Hoplosternum littorale) and their primary food sources were investigated in the upper Paraná River floodplain during rainy seasons in different environments (lotic and lentic). Two hypotheses were tested: i) that the trophic position and isotopic values of the investigated organisms (fish and food resources) vary spatially; and ii) that trophic position and isotopic compositions differ among iliophagous, detritivorous and benthophagous fish. C4 macrophytes, periphyton and phytoplankton were isotopically different in sites analyzed. Significant isotopic differences occurred in the species of each trophic category. Spatial differences were observed in the isotopic composition of P. lineatus and L. platymetopon, whose values were more enriched in the Paraná River and Pau Véio Lake. Significant spatial differences in trophic position were observed for L. platymetopon and H. littorale, which presented the highest values in the Paraná and Baía rivers, respectively. Trophic positions were significantly different among the species that composed each trophic category. These findings demonstrate that in energy-flow studies in detrital food chains generalizations concerning the grouping of fish into trophic categories and/or habitats should only be carried out after careful investigations of the local/specific trophic dynamics of the organisms.

scholarly journals Investigating the diversity of fish parasites in the floodplain of the upper Paraná River: a long-term ecological monitoring

2021 ◽  
Vol 33 ◽  
Author(s):  
João Otávio Santos Silva ◽  
Atsler Luana Lehun ◽  
Aparecida de Fátima Cracco Rodrigues ◽  
Lidiany Doreto Cavalcanti ◽  
Danilo Nunes Nicola ◽  
...  
Keyword(s):  
New Species ◽  
Ecological Monitoring ◽  
Parasite Fauna ◽  
Paraná River ◽  
Fish Parasites ◽  
Prochilodus Lineatus ◽  
Host Interactions ◽  
Parana River ◽  
Upper Paraná River Floodplain ◽  
Upper Paraná River

Abstract: Aim The aim of this study was to present the description of new species of fish parasites in native and non-native hosts and the parasite interaction / host, available in studies for 37 years in the upper Paraná River floodplain. Methods The sampling described in this study is part of a scientometric methodology, in which specific query expressions were used, together with the database available in the Nupelia Sector Library, through Theses and Dissertations. Results A total of 44 species of parasites belonging to different groups were described for 27 species of fish of different orders. In these 37 years of studies, an increase 68% was observed in the number of parasite species, presenting a richness of 201 species in the floodplain, being: Monogenea, Digenea, Nematoda and Cestoda are the groups that present the largest records of species. More than 80 hosts have their parasite fauna registered and most studies are carried out with species of native hosts in the floodplain, being Prochilodus lineatus the host with the highest number of records. Conclusions Parasitological studies are an important scientific tool for understanding the dynamics of ecological interactions in the natural environment, and knowledge of this diversity of organisms is continuous and necessary, and the results of the monitoring carried out in the floodplain during the last 37 years only reinforce this with a constant increase in the description of new species and new records of parasite-host interactions. In times of constant environmental loss and habitat fragmentation, it is of utmost importance to care for and preserve floodplains to maintain biodiversity.

scholarly journals Otolith morphometry provides length and weight predictions and insights about capture sites of Prochilodus lineatus (Characiformes: Prochilodontidae)

2018 ◽  
Vol 16 (4) ◽  
Author(s):  
Herick Soares de Santana ◽  
Amanda Cantarute Rodrigues ◽  
Carolina Viviana Minte-Vera
Keyword(s):  
Paraná River ◽  
Variance Analysis ◽  
Predictive Equations ◽  
Prochilodus Lineatus ◽  
River Floodplain ◽  
Parana River ◽  
Upper Paraná River Floodplain ◽  
Upper Paraná River ◽  
Paraná River Floodplain ◽  
Linear Regressions

ABSTRACT Here we choose the sábalo Prochilodus lineatus, to answer the following questions: How the otolith length and weight are correlated to fish measurements (length and weight)? How reliable are the otoliths measurements to predict the length and age of P. lineatus? Finally, we propose predictive equations of the length and weight of the fish using length and weight of the otolith. The otoliths were sampled from individuals collected in the Upper Paraná River floodplain during 2012 and 2013 years. The relationships among the otolith measurements and both length and weight of the fish were performed using linear regressions. To test whether the length and weight of the otolith differ between the sampled sites, Variance Analysis was performed. Finally, we made analysis of Kruskal-Wallis to verify if the measurements obtained through the otoliths could be used to distinguish the age of the fish. We demonstrate that the length and weight of the otolith are good proxies to predict the length and weight of the fish. Although some ages were statistically different, this result does not support the idea that the age of the fish can be accurately inferred only using otolith measures.

scholarly journals Genetic variability of Prochilodus lineatus (Characiformes, Prochilodontidae) in the upper Paraná river

1997 ◽  
Vol 20 (3) ◽  
pp. 381-388 ◽  
Author(s):  
Eloísa Revaldaves ◽  
Erasmo Renesto ◽  
Maria F.P.S. Machado
Keyword(s):  
Genetic Variability ◽  
Fishery Management ◽  
Paraná River ◽  
Starch Gel Electrophoresis ◽  
Prochilodus Lineatus ◽  
Parana River ◽  
Electrophoretic Patterns ◽  
High Gene ◽  
Starch Gel ◽  
Upper Paraná River

The genetic variability of the "curimba", Prochilodus lineatus, from three locations in the Paraná river basin, was investigated by starch gel electrophoresis. A total of 160 specimens were analyzed for 19 enzymes, 12 of which permitted successful interpretation of electrophoretic patterns. Eighteen loci were identified and six of them proved to be polymorphic (EST-1*, EST-2*, IDH-1*, PGM-1*, PGM-2*, LDH-2*). Mean heterozygosity was considered high (13%) by comparison with the literature. A low level of differentiation was found among subpopulations, with mean F ST = 0.018. Values of genetic distance and genetic identity suggest that, at least along this stretch of the river, P. lineatus comprises a single breed with high gene flow. This analysis has important implications for fishery management, aquaculture, and conservation of the stocks

scholarly journals Biology and population features of a rare species of Pseudopimelodidae from the Upper Paraná River Basin

2010 ◽  
Vol 10 (3) ◽  
pp. 161-167 ◽  
Author(s):  
André Luiz Henríques Esguícero ◽  
Marlene Sofia Arcifa
Keyword(s):  
River Basin ◽  
Rare Species ◽  
Paraná River ◽  
Small Rivers ◽  
High Fecundity ◽  
Spawning Period ◽  
Parana River ◽  
Upper Paraná River ◽  
Upper Paraná River Basin ◽  
Paraná River Basin

Streams contain an expressive fraction of the South American fish diversity, mostly composed of small-sized, endemic, and rare species. Populational, reproductive, and diet aspects of Microglanis garavelloi were studied, aiming to make a wide characterization of this species of bumblebee catfish. This is an endemic species of the Upper Paraná River Basin, and the only representative of the genus in the watershed. It is a littoral-dweller of small rivers, with asymptotic length of 34.1 mm and a population mostly composed of individuals with 20-30 mm of standard length. This species presents high fecundity and mortality rate, and low longevity and growth rate. It is a total spawner, October to February being the spawning period, and probably has brood care behavior, as has been already observed for some Heptapteridae species. The species can be considered an active predator, probably presenting benthic life like most siluriforms, having a diet uniquely composed of aquatic insect larvae. This species occurs as small populations patchily distributed in the Upper Paraná River Basin. This population characteristic, combined with the progressive environmental degradation of its habitats, points to a situation of constant threat that could lead to an irreversible extinction process.

Credit Market Depth and Income Inequality in Vietnam: A Panel-Data Analysis

2016 ◽  
pp. 5-18
Author(s):  
Hoi Le Quoc ◽  
Hoi Chu Minh
Keyword(s):  
Data Analysis ◽  
Panel Data ◽  
Income Inequality ◽  
Financial Development ◽  
Inflection Point ◽  
Panel Data Analysis ◽  
Credit Market ◽  
Method Of Moment ◽  
Market Depth ◽  
Generalized Method Of Moment

Financial development could exert various effects on income distribution of a country. By employing Generalized Method of Moment, this paper aims at examining the impacts of credit market depth, one of most used financial development barometers, on income inequality in Vietnam. The empirical findings show that expanding credit market in the country could lead to higher income inequality. We have not found evidence that supports the hypothesis of an inverted U-shaped relation ever introduced by Greenwood and Jovanovich, although this hypothesis may still hold in a sense that Vietnam has not reached to the inflection point to generate such a curve alike.

ÖRGÜTLERDE ÖRGÜTSEL BOLLUĞUN GİRİŞİMSEL ORYANTASYON ÜZERİNDEKİ ETKİSİ

2016 ◽  
Vol 4 (3) ◽  
Author(s):  
Nurdan Gürkan ◽  
Ahmet Ferda Çakmak
Keyword(s):  
Corporate Governance ◽  
Data Analysis ◽  
Panel Data ◽  
Strategic Management ◽  
Significant Relationship ◽  
Entrepreneurial Orientation ◽  
Panel Data Analysis ◽  
Organizational Slack ◽  
Analysis Method ◽  
The Relationship

The concept of entrepreneurial orientation, which emerges with the development of strategic management, refers to entrepreneurship orientations of businesses. The businesses need resources in other words organizational slack in order to develop their entrepreneurial trends. The organizational slack consists of three slack type. These slack types are available slack, recoverable slack and potential slack. The purpose of this study is to examine whether organizational slack in the businesses has an effect on entrepreneurial orientation. The relationship between organizational slack and entrepreneurial orientation was investigated through 20 companies that were traded in Borsa Istanbul Corporate Governance Index for 2010-2014 period using panel data analysis method. The results of the study indicate the existence of a statistically significant relationship between and the available slack and the recoverable slack with the entrepreneurial orientation in the businesses. According to findings; there was no statistically significant relationship between potential slack and entrepreneurial orientation.

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