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

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.

2012 ◽  
Vol 72 (1) ◽  
pp. 65-70 ◽  
Author(s):  
SM Martín ◽  
AC Díaz

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.


Nauplius ◽  
2015 ◽  
Vol 23 (1) ◽  
pp. 21-30 ◽  
Author(s):  
José Roberto Debastiani-Júnior ◽  
Lourdes Maria Abdu Elmoor-Loureiro ◽  
Marcos Gomes Nogueira

2000 ◽  
Vol 86 (6) ◽  
pp. 1318 ◽  
Author(s):  
Juliana Notarnicola ◽  
Odile Bain ◽  
Graciela T. Navone

Author(s):  
Nicolás Vidal ◽  
Alejandro D'Anatro ◽  
Iván González‐Bergonzoni ◽  
Ivana Silva ◽  
Patricia Correa ◽  
...  

Phytotaxa ◽  
2016 ◽  
Vol 253 (1) ◽  
pp. 81
Author(s):  
LEONARDO PAZ DEBLE ◽  
FABIANO DA SILVA ALVES ◽  
ANABELA S. DE OLIVEIRA-DEBLE

A new species of Calydorea is described and illustrated for northern Uruguay and southwest Rio Grande do Sul State, Brazil. This new species is closely related to C. nuda however, differs by its dark-blue or dark violet-blue flowers, stamens with white-cream filaments and bigger anthers, and style branches free towards the top. Data on phenology, geographic distribution, conservation, and habitat are provided. Moreover, a table to segregate this new species from its related species, and an identification key for the Calydorea species occurring in the sub-region of “Northern Campos” of Río de La Plata Grasslands are supplied.


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