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 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.

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 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 Freshwater gastropods diversity hotspots: three new species from the Uruguay River (South America)

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2138 ◽  
Author(s):  
Diego E. Gutiérrez Gregoric ◽  
Micaela de Lucía
Keyword(s):  
New Species ◽  
Endemic Species ◽  
Phylogenetic Analyses ◽  
Rio De La Plata ◽  
Reproductive Systems ◽  
Río De La Plata ◽  
Freshwater Gastropods ◽  
La Plata ◽  
Three New Species ◽  
Uruguay River

Background:The Atlantic Forest is globally one of the priority ecoregions for biodiversity conservation. In Argentina, it is represented by the Paranense Forest, which covers a vast area of Misiones Province between the Paraná and Uruguay rivers. The Uruguay River is a global hotspot of freshwater gastropod diversity, here mainly represented by Tateidae (genusPotamolithus) and to a lesser extent Chilinidae. The family Chilinidae (Gastropoda, Hygrophila) includes 21 species currently recorded in Argentina, and three species in the Uruguay River. The species of Chilinidae occur in quite different types of habitats, but generally in clean oxygenated water recording variable temperature ranges. Highly oxygenated freshwater environments (waterfalls and rapids) are the most vulnerable continental environments. We provide here novel information on three new species of Chilinidae from environments containing waterfalls and rapids in the Uruguay River malacological province of Argentina.Materials and Methods:The specimens were collected in 2010. We analyzed shell, radula, and nervous and reproductive systems, and determined the molecular genetics. The genetic distance was calculated for two mitochondrial markers (cytochromecoxidase subunit I–COI- and cytochrome b -Cyt b-) for these three new species and the species recorded from the Misionerean, Uruguay River and Lower Paraná-Río de la Plata malacological provinces. In addition, the COI data were analyzed phylogenetically by the neighbor-joining and Bayesian inference techniques.Results:The species described here are different in terms of shell, radula and nervous and reproductive systems, mostly based on the sculpture of the penis sheath. Phylogenetic analyses grouped the three new species with those present in the Lower Paraná-Río de la Plata and Uruguay River malacological provinces.Discussion:Phylogenetic analyses confirm the separation between the Uruguay River and the Misionerean malacological provinces in northeast Argentina. These new endemic species from the Uruguay River add further support to the suggestion that this river is a diversity hotspot of freshwater gastropods (with 54 species present in this basin, 15 of them endemic). These endemic species from environments with rapids and waterfalls should be taken into account by government agencies before the construction of dams that modify those ecologic niches in the Uruguay River.

scholarly journals Biodiversity and ecology of Hirudinea (Annelida) from the Natural Reserve of Isla Martín García, Río de la Plata, Argentina

2009 ◽  
Vol 69 (4) ◽  
pp. 1107-1113 ◽  
Author(s):  
II. César ◽  
SM. Martín ◽  
BS. Gullo ◽  
R. Liberto
Keyword(s):  
Dissolved Oxygen ◽  
Water Temperature ◽  
Environmental Variables ◽  
Rio De La Plata ◽  
Río De La Plata ◽  
La Plata ◽  
Natural Reserve ◽  
Species Groups ◽  
Floating Macrophytes ◽  
Measured Water

The Island of Martin Garcia lies at the confluence of the Uruguay and Paraná Rivers (upper Río de la Plata). This island is an outcrop of the crystalline basement. Due to basalt exploitation the island exhibits several ponds covered by carpets of free-floating macrophytes. Seven major environmental variables were measured: water and air temperature, percentage of oxygen saturation, dissolved oxygen, electrical conductivity, total dissolved solids and pH. Eleven leech species were found, Helobdella striata, H. diploides, H. adiastola and H. hyalina were new records. UPGMA clustering of species based on their occurrence in different ecological conditions revealed three main species groups. Canonical Correspondence Analysis (CCA) explained 97.2% of the correlation between species and environmental variables. H. triserialis shows the widest range of tolerance, H. hyalina shows positive relationships to conductivity; H. diploides shows a high correlation with dissolved oxygen, H. striata, H. lineata, and S. similis are negatively correlated with water temperature, and H. simplex is positively correlated with pH. Relationships between the species richness (S) and the sampling sites were negatively correlated with water temperature and positively correlated with dissolved oxygen. Leech biodiversity from the water bodies of Martín García Island, shows a great diversity of species and a wide plasticity regarding the characteristics of the environmental factors considered.

scholarly journals Annelida (Oligochaeta and Aphanoneura) from the Natural Reserve of Isla Martín García (upper Río de la Plata estuary, Argentina): biodiversity and response to environmental variables

2014 ◽  
Vol 74 (1) ◽  
pp. 128-136 ◽  
Author(s):  
II César
Keyword(s):  
Electrical Conductivity ◽  
Dissolved Oxygen ◽  
Water Temperature ◽  
Environmental Variables ◽  
Sampling Period ◽  
Abundant Species ◽  
Rio De La Plata ◽  
Río De La Plata ◽  
Oxygen Conductivity ◽  
La Plata

The Island of Martín García – located in the Upper Río de la Plata, to the south of the Uruguay River – is an outcropping of the crystalline basement. Fourteen sampling sites were selected, five along the littoral section of the island and nine in inland ponds. Four major environmental variables were measured: water temperature, dissolved oxygen, electrical conductivity, and pH. A total of 34 species of Oligochaeta and Aphanoneura were found, 30 belonging to Naididae plus one species each of the Narapidae, Lumbricidae, Enchytraeidae, and Aeolosomatidae. The thirteen most frequent species were: A. leydigi (30%), N. bonettoi (13%), L. hoffmeisteri (11%), N. variabilis(10%), S. trivandrana (6.5%), A. pigueti (5.6%), D. sawayai (4.5%), D. digitata(3.5%), C. diastrophus (2.7%), A. costatus (2.5%), P. longiseta (2.0%), Enchytraeidae (1.5%), and A. p. paraguayensis(1.4%). UPGMA clustering of species based on their occurrence in different ecological conditions revealed two main species groups. Canonic-correspondence analysis (CCA) was conducted with the 15 most frequent and abundant species in the 9 sampling sites and the 4 environmental variables. Results from the CCA revealed that the order of fluctuation of the environmental variables during the sampling period was, from the greatest to the least: dissolved oxygen, conductivity, pH, and water temperature. Approximately 97.6% of the correlations between species and environmental variables were expressed on axis 1 of the ordination diagram. Species richness correlated with the four environmental variables in the following order, from the weakest to the strongest: water temperature, pH, electrical conductivity, and dissolved oxygen.

scholarly journals Geographic variation of Moenkhausia bonita (Characiformes: Characidae) in the rio de la Plata basin, with distributional comments on M. intermedia

2019 ◽  
Vol 17 (1) ◽  
Author(s):  
James Anyelo Vanegas-Ríos ◽  
Ricardo Britzke ◽  
Juan Marcos Mirande
Keyword(s):  
Distinct Group ◽  
Multivariate Methods ◽  
Rio De La Plata ◽  
Meristic Characters ◽  
Río De La Plata ◽  
La Plata ◽  
La Plata Basin ◽  
Bermejo Basin ◽  
Uruguay River ◽  
Canonical Analyses

ABSTRACT Moenkhausia bonita occurs in numerous additional localities from the Bermejo, Paraná, Paraguay, and Uruguay river basins. Given that this finding greatly expands the distributional range of M. bonita, we carried out an intraspecific comparison, using multivariate methods for 18 morphometric and eight meristic characters taken from a comprehensive sample of 536 specimens. All localities were distributed in four major geographic groups as follows: Bermejo, Paraná, Paraguay, and Uruguay. Results of the morphometric comparisons showed significant differences among the studied groups except between the Paraguay and Uruguay groups. Statistical differences in meristic values were found for most between-group comparisons, especially in those resulting from discriminant canonical analyses (DCA). Specimens from the Bermejo basin were the most distinct group in most morphological comparisons. However, the overall subtle differences found in body morphology likely reflect intraspecific variation within M. bonita and seem to be mainly influenced by spatial and environmental features of drainages. As M. bonita was previously identified as M. intermedia in the río de La Plata basin, distributional comments on the latter species in that basin are provided.

scholarly journals Mixed-stock and discriminant models use for assessing recruitment sources of estuarine fish populations in La Plata Basin (South America)

2019 ◽  
Vol 99 (06) ◽  
pp. 1429-1433
Author(s):  
Esteban Avigliano ◽  
Jorge Pisonero ◽  
Nerea Bordel ◽  
Alejandro Dománico ◽  
Alejandra Vanina Volpedo
Keyword(s):  
South America ◽  
Estuarine Fish ◽  
Rio De La Plata ◽  
Río De La Plata ◽  
Data Set ◽  
Prochilodus Lineatus ◽  
La Plata ◽  
La Plata Basin ◽  
Recruitment Sources ◽  
Uruguay River

AbstractThe objective of this study was to identify potential recruitment sources of Prochilodus lineatus from freshwater areas (Paraná and Uruguay rivers) to estuarine population of the Río de la Plata Estuary (La Plata Basin, South America), considering young (age-1) and adult (age-7) fish. LA-ICP-MS chemical analysis of the otolith core (nine element:Ca ratios) of an unknown mixed sample from Río de la Plata Estuary (2011 and 2017) was compared with a young-of-year baseline data set (same cohort) and classified into freshwater nurseries (Paraná or Uruguay river) by using maximum classification-likelihood models (MLE and MCL) and quadratic discriminant analysis (QDA). Considering the three models used, the Uruguay River was the most important contributor for both young and adult populations. The young population (2011) was highly mixed with contributions between 31.7 to 68.3%, while the degree of mixing was found to decrease in 2017 (adult fish) from 97.1 to 100% contributions. The three employed methods showed comparable estimates, however, the QDA showed a high similarity with the MCL model, suggesting sensitivity to evaluate small contributions, unlike the MLE method. Our results show the potential application of maximum likelihood mixture models and QDA for determining the relative importance of recruitment sources of fish in estuarine waters of the La Plata Basin.

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