scholarly journals Histology and gametogenesis inHeleobia piscium(Cochliopidae) from the Multiple Use Reserve “Isla Martín García,” Buenos Aires, Argentina

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2548 ◽  
Author(s):  
Stella Maris Martin ◽  
Ana C. Díaz
Keyword(s):  
South America ◽  
Reproductive Cycle ◽  
Buenos Aires ◽  
Rio De La Plata ◽  
Multiple Use ◽  
Río De La Plata ◽  
Early Maturation ◽  
La Plata ◽  
Natural Reserve ◽  
Entre Rios

Heleobia piscium(d’Orbigny, 1835), a member of the Cochliopidae family found only in South America, is distributed from Entre Ríos, Delta del Paraná, and the littoral of the Río de la Plata down as far as to Punta Indio (Buenos Aires), the southernmost limit of the snail’s geographical distribution. To date, little information is available regarding the reproductive cycle of species within this family either in Argentina or throughout South America. The present work analyzed the histology of the reproductive system of the gonochoric speciesH. pisciumand determined the stages oogenesis and spermatogenesis under natural conditions. Specimens ofH. pisciumwere collected in the Multiple-Use Natural Reserve Isla Martín García, located in the Upper Río de la Plata estuary to the south of the mouth of the Uruguay River. The gametogenic cycle in both sexes was found to consist of the following stages: early maturation, maturation, and evacuation. The maturation period was found to extend from January to October and evacuation of the gametes to start in November and end in February (summer in the Southern Hemisphere). The results indicated theH. pisciumexhibit a reproductive cycle without a resting period.

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.

Argentina

2021 ◽  
Keyword(s):  
South America ◽  
19Th Century ◽  
Buenos Aires ◽  
Colonial Period ◽  
Rio De La Plata ◽  
Río De La Plata ◽  
Rapid Urbanization ◽  
Early 19Th Century ◽  
La Plata ◽  
The 19Th Century

Argentina emerged as a nation-state in the latter half of the 19th century. However, both popular culture and the official history generally agree that Argentina’s origins lay in the break with Spain in 1810 or even earlier, during the colonial period. The Hispanic monarchy’s dominions in South America were governed by a viceroy based in Lima until the 18th century, when two new divisions were created: the viceroy of New Granada governed the northern half of the continent, and the viceroy of Río de la Plata governed the south. The latter, whose capital was Buenos Aires, included most of what would become Argentina, Brazil, Chile, Bolivia, Paraguay, and Peru. The early-19th-century crisis of the Spanish monarchy created the conditions for the establishment of various nation-states in South America. The viceroyalty of Río de la Plata disintegrated into small power units, and a series of civil wars broke out. Paraguay would be the first independent entity to emerge (1811), followed by Bolivia (1824) and Uruguay (1828). The rest of the fourteen states-provinces of the old viceroyalty continued fighting until 1862, at which point the Argentine Republic was created. The period starting in 1862 is referred to in Argentine national historiography as the period of “national organization,” during which the state gave substance to its sovereignty and institutions. Since the colonial period, agriculture had been the principal productive sector. Toward the end of the 19th century, cattle and grains became the principal and essentially the only exports, and the engine of its growth. Some areas of the country, most especially the city of Buenos Aires and the areas under its influence, underwent rapid demographic and economic growth, which gave Buenos Aires, the country’s major port, a disproportionate role in the territory as a whole, making it the country’s critical center. In the late 19th century, state construction coincided with an important series of transformations, including the forcible incorporation of Patagonia and Gran Chaco, which until then had been under the control of indigenous peoples (“Desert Campaign,” 1878–1885), the takeoff of agricultural exports, infrastructure construction (ports, railways, etc.), rapid urbanization, and, especially, the massive arrival of immigrants, most of them from Europe, who would play an active role throughout this transformative process.

scholarly journals Actinopterygii, Siluriformes, Loricariidae, Hypostomus aspilogaster (Cope, 1894). Distribution extension and first record for Argentina

Check List ◽  
2011 ◽  
Vol 7 (5) ◽  
pp. 596 ◽  
Author(s):  
Yamila P. Cardoso ◽  
Florencia Brancolini ◽  
Lucila Protogino ◽  
Marta Lizarralde
Keyword(s):  
Buenos Aires ◽  
First Record ◽  
Buenos Aires Province ◽  
Rio De La Plata ◽  
Southern Brazil ◽  
Río De La Plata ◽  
La Plata ◽  
La Plata Basin ◽  
Entre Rios ◽  
Uruguay River

The present work extends to Argentina the distribution of Hypostomus aspilogaster originally described from Uruguay River in southern Brazil. The examined specimens were sampled in the stream Mandisoví Grande, affluent of Uruguay River in Entre Ríos province, and in Punta Lara, from Río de la Plata basin, in Buenos Aires province, Argentina. This represents the first country record for this species. 

scholarly journals A 200 años de la Constitución de 1819. Breve comentario de su historia

2019 ◽  
Vol 11 (11) ◽  
pp. 280
Author(s):  
Diego Gabriel Presa
Keyword(s):  
Buenos Aires ◽  
Rio De La Plata ◽  
Santa Fe ◽  
Río De La Plata ◽  
La Plata ◽  
Del Rio ◽  
Entre Rios

El 22 de abril de 1819 el Congreso de Tucumán, sesionaba en Buenos Aires y sanciona el primer texto constitucional orgánico para las Provincias Unidas del Rio de La Plata  el Estado; texto que no van a aceptar las provincias litorales de la Banda Oriental del Uruguay –no solo por no coincidir con el mismo, sino por estar ocupada por los portugueses desde 1816 a instancias de Buenos Aires-  y las provincias de Corrientes, Entre Ríos y Santa Fe. No obstante este texto constitucional, que es el primero en su estilo,   llevara al camino a la Constitución de 1853. Hoy doscientos años después podemos recorrer su articulado y ver dicho texto en profundidad, donde muchas de las atribuciones de los poderes del estado, se fueron manteniendo en los textos constitucionales que le sucedieron, hasta terminar en artículos vigentes en la Constitución Nacional de 1853 y sus reformas.  

Acido delta-aminolevulínico dehidrasa (ALA-D) como biomarcador de exposición a plomo en peces

2008 ◽  
Author(s):  
◽  
Paula Edith Lombardi
Keyword(s):  
Cyprinus Carpio ◽  
Buenos Aires ◽  
Rio De La Plata ◽  
Río De La Plata ◽  
Prochilodus Lineatus ◽  
La Plata ◽  
Del Rio

La actividad de la enzima ácido δ-aminolevulínico dehidrasa (ALA-D) es un reconocido biomarcador específico de exposición a plomo. Debido a sus características ha sido utilizado en estudios de monitoreo ambiental para evaluar la exposición a plomo en diversos organismos, entre ellos peces. El principal objetivo del presente trabajo de tesis fue validar un método de evaluación general de riesgo ecotoxicológico por exposición a plomo en poblaciones naturales de peces. Para tal fin se seleccionaron tres especies recolectadas del río de la Plata: Prochilodus lineatus (sábalo), Leporinus obtusidens (boga) y Cyprinus carpio (carpa). Las zonas de muestreo elegidas fueron: Berazategui y Berisso ubicadas cerca de las emisiones de residuos cloacales provenientes de las ciudades de Buenos Aires y La Plata. La tercera, Atalaya, libre de emisiones cloacales, pero sujeta a emisiones diversas, todas ellas, de origen antropogénico. Los muestreos se realizaron entre junio de 2002 y mayo de 2004. En primera instancia se caracterizaron diversos parámetros de la enzima ALA-D en muestras de sangre y de tejido hepático. Los resultados obtenidos mostraron características similares en la enzima sanguínea de todas las especies estudiadas. Lo mismo se observó para la enzima hepática. La comparación entre tejidos mostró diferencias en el valor de Km, siendo menor para la enzima hepática. Posteriormente, se procedió a validar el uso de la enzima como parámetro biomarcador de exposición a plomo en estudios de campo.

Poe and His Global Advocates

2018 ◽  
pp. 596-617
Author(s):  
Emron Esplin
Keyword(s):  
Twentieth Century ◽  
South America ◽  
Rio De La Plata ◽  
Río De La Plata ◽  
Literary Traditions ◽  
La Plata ◽  
Original Works ◽  
Definition Of ◽  
Global Reputation

This essay explores Edgar Allan Poe’s extraordinary relationships with various literary traditions across the globe, posits that Poe is the most influential US writer on the global literary scene, and argues that Poe’s current global reputation relies at least as much on the radiance of the work of Poe’s literary advocates—many of whom are literary stars in their own right—as it does on the brilliance of Poe’s original works. The article briefly examines Poe’s most famous French advocates (Baudelaire, Mallarmé, Valéry); glosses the work of his advocates throughout Europe, Asia, and the Americas; and offers a concise case study of Poe’s influence on and advocacy from three twentieth-century writers from the Río de la Plata region of South America (Quiroga, Borges, and Cortázar). The essay concludes by reading the relationships between Poe and his advocates through the ancient definition of astral or stellar influence.

scholarly journals Mollusks (Gastropoda and Bivalvia) of the Multiple-Use Reserve Martín García Island, Río de la Plata River: biodiversity and ecology

2012 ◽  
Vol 72 (1) ◽  
pp. 121-130 ◽  
Author(s):  
II César ◽  
SM Martín ◽  
A Rumi ◽  
M Tassara
Keyword(s):  
Dissolved Oxygen ◽  
Water Temperature ◽  
Environmental Variables ◽  
Sampling Period ◽  
Pomacea Canaliculata ◽  
Rio De La Plata ◽  
Multiple Use ◽  
Río De La Plata ◽  
Oxygen Conductivity ◽  
La Plata

The Island of Martin Garcia is located in the Upper Río de la Plata, to the south of mouth the Uruguay River. The aim of the present study was to analyse the biodiversity of the island freshwater mollusks and their relationships to environmental variables. Twelve sampling sites were selected, five were along the littoral section of the island and seven were Inland ponds. Seven major environmental variables were measured: water and air temperature, percentage of oxygen saturation, dissolved oxygen, electrical conductivity, total dissolved solids and pH. Twenty-seven mollusk species were found, Antillorbis nordestensis, Biomphalaria tenagophila tenagophila , B. t. guaibensis, B. straminea, B. peregrina, Drepanotrema kermatoides, D. cimex, D. depressissimum, Chilina fluminea, C. rushii, C. megastoma, Uncancylus concentricus, Hebetancylus moricandi, Stenophysa marmorata, Heleobia piscium, H. parchappii, Potamolithus agapetus, P. buschii, P. lapidum, Pomacea canaliculata, P. megastoma, Asolene platae, Corbicula fluminea, Eupera platensis, Pisidium sterkianum, P. taraguyense and Limnoperna fortunei. UPGMA clustering of species based on their occurrence in different ecological conditions revealed two main species groups. The Canonical Correspondence Analysis suggests that the species distribution is related to the physico-chemical condition of water. Axis two of the ordination diagram displayed the approximately 95.6% of the correlation between species and environmental variables. Dissolved oxygen, conductivity, water temperature and pH showed the highest fluctuations during the sampling period. The species richness (S) showed relationships mainly with water temperature and conductivity. The biodiversity of the gastropods and bivalves from Martín García Island amounts to up to 26 species. Among the Gastropoda, the Planorbidae family made the most sizeable contribution. The Lithogliphidae P. agapetus (26.28%) and P. buschii (9.50%) showed the highest relative frequencies of occurrence within the littoral environments, while the Planorbidae D. cimex (23.83%) and D. kermatoides (11.59%) likewise did so in the inland ponds.

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