scholarly journals Population structure, reproductive biology and feeding of Astyanax fasciatus (Cuvier, 1819) in an Upper Paraná River tributary, Misiones, Argentina

2011 ◽  
Vol 23 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Lourdes María Hirt ◽  
Patricia Raquel Araya ◽  
Silvia Alicia Flores
Keyword(s):  
Population Structure ◽  
Reproductive Biology ◽  
Paraná River ◽  
Parana River ◽  
Astyanax Fasciatus ◽  
Upper Paraná River

Interpopulational comparative cytogenetics analysis among three Astyanax (Characiformes: Incertae Sedis) species of two streams of upper Paraná River basin, Brazil

Biologia ◽  
2014 ◽  
Vol 69 (6) ◽  
Author(s):  
Cassia Yano ◽  
Orlando Moreira Filho ◽  
Vladimir Margarido
Keyword(s):  
River Basin ◽  
Paraná River ◽  
Evolutionary Trend ◽  
Comparative Cytogenetics ◽  
Parana River ◽  
Astyanax Fasciatus ◽  
Upper Paraná River ◽  
Upper Paraná River Basin ◽  
Interpopulational Differences ◽  
Paraná River Basin

AbstractPopulations of Astyanax paranae, Astyanax fasciatus and Astyanax altiparanae collected from the Pindorama and Lopei streams (upper Paraná river basin, Brazil) were cytogenetically studied, checking for chromosomal differentiation and the evolutionary trend in the three species. Forty-eight chromosomes (8m + 20sm + 10st + 10a) were observed in both populations of Astyanax paranae. Astyanax fasciatus exhibited 50 chromosomes (8m + 18sm + 10st + 14a, Pindorama stream; 8m + 14sm + 12st + 16a, Lopei stream). The diploid number for A. altiparanae was 50 chromosomes in both populations (6m + 30sm + 4st + 10a). The three studied species exhibited multiple AgNORs with differences among the populations of A. paranae and A. fasciatus. Regarding the heterochromatin distribution, interpopulational differences were observed in the three species. The data of the present study demonstrate that both A. paranae and A. fasciatus exhibit karyotypical interpopulational differences more conspicuous than A. altiparanae populations, probably due to the characteristics that restricted both the A. paranae and the A. fasciatus to the upper portion of the streams, leading to the fixation of different chromosomal rearrangements in the populations. However, the absence of conspicuos interpopulational karyotypical differences in A. altiparanae suggests a gene flow between both populations. In the present study, the role of the streams as an environment which maintains the diversity of fish with different genetic pools became evident.

scholarly journals Evaluation of the Upper Paraná River discharge controlled by reservoirs

2009 ◽  
Vol 69 (2 suppl) ◽  
pp. 707-716 ◽  
Author(s):  
EE. Souza Filho
Keyword(s):  
Paraná River ◽  
River Level ◽  
Parana River ◽  
River Damming ◽  
Discharge Rates ◽  
Historical Series ◽  
Discharge Regime ◽  
Upper Paraná River ◽  
The Relationship ◽  
Different Levels

The building of large dams in the Upper Paraná River basin altered the discharge regime at the Porto São José River section. The discharge regime has been altered since 1972, but the changes intensified after the Porto Primavera damming, in late 1998. Considering that discharge control affects the relationship between channel and floodplain, this work aimed to evaluate the intensity of the discharge control that resulted from the operation of the Porto Primavera Dam. To achieve this objective, statistical analyses were carried out based on the Porto São José Fluviometric Station historical series of river level readings and discharge, between 1964 and 2007. Results showed that the average discharge increased from 1964 to 1981 and diminished after river damming. The increase of average discharge rates was followed by an increase of the duration of higher discharges at different levels of geomorphologic and limnological importance, and the reduction of average discharge during the last observed period was followed by a disproportionate decrease in the duration of the abovementioned discharges. Moreover, it is clear that the relationship between fluviometric level and fluvial discharge changed, which implies that a certain river level reading represents a higher discharge than necessary before river damming.

scholarly journals Genetic variability of brycon orbignyanus (valenciennes, 1850) (characiformes: characidae) in cultivated and natural populations of the upper paraná river, and implications for the conservation of the species

2011 ◽  
Vol 54 (4) ◽  
pp. 839-848 ◽  
Author(s):  
Renata de Souza Panarari-Antunes ◽  
Alberto José Prioli ◽  
Sônia Maria Alves Pinto Prioli ◽  
Alexsandro Sobreira Galdino ◽  
Horácio Ferreira Julio Junior ◽  
...  
Keyword(s):  
Genetic Variability ◽  
Natural Populations ◽  
Paraná River ◽  
Parana River ◽  
Upper Paraná River

scholarly journals Comparison of the diet of Alouatta caraya (Primates: Atelidae) between a riparian island and mainland on the Upper Parana River, southern Brazil

2008 ◽  
Vol 25 (3) ◽  
pp. 419-426 ◽  
Author(s):  
Gabriela Ludwig ◽  
Lucas M. Aguiar ◽  
Walfrido K. Svoboda ◽  
Carmen L. S. Hilst ◽  
Italmar T. Navarro ◽  
...  
Keyword(s):  
Sampling Method ◽  
Riparian Forest ◽  
Diet Breadth ◽  
Paraná River ◽  
Food Type ◽  
Left Bank ◽  
Southern Brazil ◽  
Alouatta Caraya ◽  
Parana River ◽  
Upper Paraná River

Howler monkeys (Alouatta Lacèpéde, 1799) are folivores-frugivores with flexible diets depending on conditions. Here, we compare the diets of Alouatta caraya (Humboldt, 1812) in two riparian forests (island and mainland), in Porto Rico region, Upper Paraná River, Southern Brazil. Howlers were followed from October 2004 to September 2005 in the riparian forest of a 1,050 ha island and in the continuous riparian forest on the mainland (left bank of the river). The "scan sampling" method with instantaneous samples every 15 minutes was used. Besides vines, diet breadth was similar: 17 species consumed on the island versus 16 species on the mainland. Both consumed leaves followed by fruits more than any other food type (leaves: island - 65%, mainland - 49%, fruits: island - 24%, mainland - 46%). Even though the plant Cecropia pachystachya Trécul is less abundant in the mainland it was the item most consumed in both locations all year long, which suggests its importance for the howlers. Diet also varied both seasonally and between the island and mainland, apparently following changes in local abundance of each item and due to plant phenologies.

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