scholarly journals External ultrastructure of Manayunkia speciosa (Fabriciidae) from Uruguay River, Argentina

2013 ◽  
Vol 84 (2) ◽  
pp. 521-529 ◽  
Author(s):  
Analía Paola ◽  
Laura Armendáriz ◽  
Alberto Rodrigues-Capítulo
Keyword(s):  
Manayunkia Speciosa ◽  
Uruguay River

A new freshwater fabriciid species (Sabellida, Fabriciidae) from the Uruguay River, Argentina, with some remarks on the relationships of Monroika Hartman, 1951, Manayunkia Bourne, 1884 and Brandtika Jones, 1974

Zootaxa ◽  
2021 ◽  
Vol 4966 (2) ◽  
pp. 187-201
Author(s):  
ANDREAS BICK ◽  
LAURA ARMENDÁRIZ
Keyword(s):  
Systematic Position ◽  
West African ◽  
South American ◽  
Freshwater Species ◽  
South American Species ◽  
The West ◽  
African Species ◽  
Thoracic And Abdominal ◽  
Manayunkia Speciosa ◽  
Uruguay River

Between the years 2007 and 2009 a hitherto unknown fabriciid species was found in the Lower Uruguay River, Argentina. Initially, it was assumed that this species could represent Manayunkia speciosa, a freshwater species originally described from North America. However, re-examinations have revealed that these specimens are clearly different from M. speciosa but they resemble Monroika africana. However, differences were also found that clearly distinguish this South American species from the African species so that it is described here as M. clarae sp. nov. The characters found in Monroika clarae sp. nov. make it also possible to compare and discuss these characters with those from the West African species Monroika africana, the Southeast Asian species Brandtika asiatica as well as Manayunkia species in terms of their systematic position. This mainly concerns the structure of the radiolar crown, the number of abdominal chaetigers, the presence of transitional chaetae as well as the structure of the thoracic and abdominal uncini. Potential origins of the freshwater Fabriciidae are also discussed. 

scholarly journals Interdisciplinary research networks and science-policy-society interactions in the Uruguay River Basin

2020 ◽  
pp. 100601
Author(s):  
Marcelo Saguier ◽  
Andrea K. Gerlak ◽  
Pilar Carolina Villar ◽  
Claudio Baigún ◽  
Virginia Venturini ◽  
...  
Keyword(s):  
River Basin ◽  
Science Policy ◽  
Interdisciplinary Research ◽  
Research Networks ◽  
Uruguay River

A reply to “Relevant factors in the eutrophication of the Uruguay River and the Río Negro”

2021 ◽  
pp. 151854
Author(s):  
I. Alcántara ◽  
A. Somma ◽  
G. Chalar ◽  
A. Fabre ◽  
A. Segura ◽  
...  
Keyword(s):  
Rio Negro ◽  
Uruguay River ◽  
Relevant Factors

Manayunkia speciosa (Leidy) in the Duluth Harbor

Science ◽  
1929 ◽  
Vol 70 (1820) ◽  
pp. 479-480
Author(s):  
O. Lloyd Meehean
Keyword(s):  
Manayunkia Speciosa

Environmental Impact Assessment as a Duty under International Law: The International Court of Justice Judgment on Pulp Mills on the River Uruguay

2010 ◽  
Vol 1 (3) ◽  
pp. 317-324 ◽  
Author(s):  
Cymie R. Payne
Keyword(s):  
Environmental Impact ◽  
International Law ◽  
Pulp Mills ◽  
High Stakes ◽  
International Court Of Justice ◽  
Court Of Justice ◽  
International Court ◽  
Environmental Dispute ◽  
International Boundary ◽  
Uruguay River

On April 20, 2010, the International Court of Justice (ICJ) announced its judgment in a high-stakes environmental dispute between Argentina and Uruguay, concerning Uruguay's authorization for pulp mills on the banks of the Uruguay River, which forms the international boundary between the two countries.

scholarly journals Population structure of Uncancylus concentricus (d'Orbigny, 1835) (Ancylidae, Pulmonata, Basommatophora) in the Multiple Use Reserve Martín García Island, Upper Río de la Plata, Argentina

2012 ◽  
Vol 72 (1) ◽  
pp. 65-70 ◽  
Author(s):  
SM Martín ◽  
AC Díaz
Keyword(s):  
Size Range ◽  
Sampling Period ◽  
Rio De La Plata ◽  
Multiple Use ◽  
Río De La Plata ◽  
La Plata ◽  
Natural Reserve ◽  
Variable Distribution ◽  
In The Wild ◽  
Uruguay River

The present work analyzes the population dynamics of Uncancylus concentricus in natural conditions in the northeastern coastal area of the Multiple Use Natural Reserve Isla Martín García (Beach of Basural), Buenos Aires, Argentina. Martín García Island is located in the Upper Río de La Plata, to the south of the mouth of the Uruguay River (34° 11' 25" S and 58° 15'38" W). Monthly collections were made from August 2005 to December 2006. The size frequency of the U. concentricus population throughout the sampling period ranges from 1.2 to 8.3 m. The changes in the size frequencies throughout the months surveyed indicate a variable distribution pattern because of the increase and decrease in water flow, but we observed a peak in the frequency of individuals within the size range 3.5 to 4.5 mm in the population. It can be concluded that this species lives for at least a year in the wild since the juveniles are highly abundant in spring and summer.

scholarly journals Influence of net-cage fish farming on zooplankton biomass in the Itá reservoir, SC, Brazil

2012 ◽  
Vol 23 (4) ◽  
pp. 357-367 ◽  
Author(s):  
Bruna Roque Loureiro ◽  
Christina Wyss Castelo Branco ◽  
Evoy Zaniboni Filho
Keyword(s):  
Fish Farming ◽  
Dry Weight ◽  
Control Area ◽  
Zooplankton Biomass ◽  
Total Density ◽  
Total Zooplankton ◽  
Net Cage ◽  
Uruguay River ◽  
Cage Fish ◽  
Total Zooplankton Biomass

OBJECTIVES: This study aimed to verify the influence of net-cage fish farming on zooplankton biomass in the Itá reservoir (Uruguay River, Brazil). METHODS: Samples were collected monthly from October/2009 to May/2010 at the surface and at the bottom in two sampling stations, the net-cage area and in a control area using a Van Dorn bottle and a plankton net (68 µm). RESULTS: The Cladocera and Copepoda biomass was estimated by dry weight using a micro-analytical balance, and the Rotifera biomass by Biovolume. Total zooplankton biomass varied between 6.47 and 131.56 mgDW.m-3 Calanoida copepod presented the highest value of biomass (127.56 mgDW.m-3) and rotifers, despite having an important contribution to total density, showed a maximum biomass of 2.01 mgDW.m-3. Zooplankton biomass at the net-cage area surface was higher when compared with the control area during the months of October to January. However, the zooplankton biomass was similar at the bottom of the two areas throughout the studied period. From February until May, zooplankton biomass decreased in both sampling stations, a fact probably associated with the flushing of the reservoir, followed by an increase in water transparency and a decrease in chlorophyll-a concentration in the following months (February to May). CONCLUSIONS: The influence of fish farming on zooplankton biomass was detected at the surface of the net-cage area only from October to January. From February to May this influence was not found, probably by the influence of the flushing of the reservoir.

scholarly journals Frugivory and seed dispersal of Solanum granuloso-leprosum Dunal (Solanaceae) by birds in deciduous seasonal forest

2016 ◽  
Vol 76 (4) ◽  
pp. 818-823 ◽  
Author(s):  
F. A. F. Jacomassa
Keyword(s):  
Deciduous Forest ◽  
Bird Species ◽  
Rio Grande ◽  
Rio Grande Do Sul ◽  
Forest Fragment ◽  
Fruit Removal ◽  
Feeding Behaviors ◽  
River Region ◽  
Strong Competition ◽  
Uruguay River

Abstract The goal of this study was to identify which bird species consume Solanum granuloso-leprosum fruits and disperse its seeds. 60 hours of focal observations were carried out between April and May 2006 on the edge of a deciduous forest fragment in the Uruguay River region, Rio Grande do Sul state, Brazil. Ten species were observed in total removing 443 fruits. Saltator similis removed 61.8% of the fruits, followed by Tangara sayaca (17.1%), Pipraeidea bonariensis (11.7%), and T. preciosa (6.8%), while the remaining six species accounted for only 2.5% of the fruits removed. Most fruit removal occurred early in the day or mid-afternoon. The most common feeding behaviors were picking (60.7%), followed by stalling (23%) and hovering (16%). Birds flew more than 10 m from the fruit plant in 62% of the removal events. All bird species observed here may be considered potential dispersers of S. granuloso-leprosum, as they moved the seeds away from the mother plant where strong competition and predation are likely to occur. Results also suggest that S. granuloso-leprosum may be useful in ecological restoration programs.

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