Distribution of the Unionida (Bivalvia, Paleoheterodonta) from Argentina and its conservation in the Southern Neotropical Region.

Bivalves are one of the most representative groups in the Phylum Mollusca, with over 1,100 freshwater species around the world except Antarctica. About 900 of these species belong to the Order Unionida Gray, 1854. In South America, the distributional range of the Unionida includes all countries in the region and extends as far south as the lakes and rivers of Argentinean-Chilean Patagonia. With the aim of generating distribution maps for the different genera of Unionida in Argentina, we consulted the databases of the nation's main official malacological collections. The data were analyzed and georeferenced using the point-radius method. Spatial analyses were performed with the software Q-GIS 2.16.3 Nødebo using vector layers under the 2007 Argentinean Geodesic Positions reference system. A total 1,833 lots were analyzed, of which it was possible to georeference 1,503. The distribution of Unionida in Argentinean territory was analyzed according to political provinces, Surface Drainage Basins and the Argentinean Protected Areas. Species richness was analyzed using the surface drainage basins of Argentina. We generate distribution maps for each genus and discuss the species threat status and conservation degree in the region. Only six (18%) of the Unionida present in Argentina have been classified by the IUCN, four are Least Concern and two are Data Deficient. This pattern is also valid for all of South America. More than 95% of the distributional range of the Unionida has no protected area. Conservation management is necessary for the preservation of Unionida diversity in southern South America.

Redescripción de Potamolithus supersulcatus Pilsbry, 1896 (Gastropoda, Tateidae) del sur de la cuenca Del Plata

The genus Potamolithus Pilsbry, 1896 (Gastropoda; Tateidae), has 31 species, 22 of which are distributed in Argentina in Del Plata basin, defining the Uruguay River and the Rيo de la Plata as a hotspot of diversity in freshwater gastropods. However, most of its species has been described only by conchology characters and a few has anatomical data, leading to the description of subspecies or morphs that overlap each other. Potamolithus lapidum some authors attribute four subspecies (with conchology data and anatomical partial data), but others include eight morphs. We give a start the study of Potamolithus lapidum elevating to Potamolithus lapidum supersulcatus Pilsbry, 1896 to the category of species, of which only known partially conchology and radular characters. We provide data of: shell, pallial organs, head, foot, penis, radula, female and male reproductive system, nervous system and partial sequence of mitochondrial gene cytochrome c oxidase subunit I. A good description of species of the genus Potamolithus is necessary, because some species have been listed as vulnerable species and they inhabit rivers that are being modified by human activity and the presence of invasive bivalve Limnoperna fortunei.

El género Potamolithus Pilsbry, 1896 (Gastropoda; Tateidae), posee 31 especies, 22 de las cuales se hayan en la Argentina distribuidas principalmente en la cuenca Del Plata, definiendo al río Uruguay y al Río de la Plata como una zona caliente de diversidad en gasterópodos dulceacuícolas. Sin embargo, la mayoría de sus especies han sido descriptas solo por caracteres conquilógicos y, unas pocas tienen datos anatómicos, conllevando a la descripción de subespecies o morfos que se superponen unos a otros. A Potamolithus lapidum algunos autores le atribuyen cuatro subespecies (con datos conquiológicos, y una con datos parciales de anatomía blanda), sin embargo otros incluyen ocho “morfos”. Aquí nosotros damos un comienzo en el estudio de Potamolithus lapidum elevando a Potamolithus lapidum supersulcatus Pilsbry, 1896 a la categoría de especie, de la cual solo se conocen caracteres conquiológicos y radulares parcialmente. Aportamos datos de: concha, órganos paleales, cabeza, pie, pene, rádula, sistemas reproductor femenino y masculino, sistema nervioso y, secuencia parcial del gen mitocondrial citocromo c oxidasa subunidad I. Es necesario realizar una buena descripción de las especies del género Potamolithus debido a que algunas de las especies ya han sido citadas como especies vulnerables y que habitan ríos que están siendo modificados por la actividad humana y por la presencia del bivalvo invasor Limnoperna fortunei.

Redescripción de Potamolithus supersulcatus Pilsbry, 1896 (Gastropoda, Tateidae) del sur de la cuenca Del Plata

The genus Potamolithus Pilsbry, 1896 (Gastropoda; Tateidae), has 31 species, 22 of which are distributed in Argentina in Del Plata basin, defining the Uruguay River and the Rيo de la Plata as a hotspot of diversity in freshwater gastropods. However, most of its species has been described only by conchology characters and a few has anatomical data, leading to the description of subspecies or morphs that overlap each other. Potamolithus lapidum some authors attribute four subspecies (with conchology data and anatomical partial data), but others include eight morphs. We give a start the study of Potamolithus lapidum elevating to Potamolithus lapidum supersulcatus Pilsbry, 1896 to the category of species, of which only known partially conchology and radular characters. We provide data of: shell, pallial organs, head, foot, penis, radula, female and male reproductive system, nervous system and partial sequence of mitochondrial gene cytochrome c oxidase subunit I. A good description of species of the genus Potamolithus is necessary, because some species have been listed as vulnerable species and they inhabit rivers that are being modified by human activity and the presence of invasive bivalve Limnoperna fortunei.(AU)

El género Potamolithus Pilsbry, 1896 (Gastropoda; Tateidae), posee 31 especies, 22 de las cuales se hayan en la Argentina distribuidas principalmente en la cuenca Del Plata, definiendo al río Uruguay y al Río de la Plata como una zona caliente de diversidad en gasterópodos dulceacuícolas. Sin embargo, la mayoría de sus especies han sido descriptas solo por caracteres conquilógicos y, unas pocas tienen datos anatómicos, conllevando a la descripción de subespecies o morfos que se superponen unos a otros. A Potamolithus lapidum algunos autores le atribuyen cuatro subespecies (con datos conquiológicos, y una con datos parciales de anatomía blanda), sin embargo otros incluyen ocho “morfos”. Aquí nosotros damos un comienzo en el estudio de Potamolithus lapidum elevando a Potamolithus lapidum supersulcatus Pilsbry, 1896 a la categoría de especie, de la cual solo se conocen caracteres conquiológicos y radulares parcialmente. Aportamos datos de: concha, órganos paleales, cabeza, pie, pene, rádula, sistemas reproductor femenino y masculino, sistema nervioso y, secuencia parcial del gen mitocondrial citocromo c oxidasa subunidad I. Es necesario realizar una buena descripción de las especies del género Potamolithus debido a que algunas de las especies ya han sido citadas como especies vulnerables y que habitan ríos que están siendo modificados por la actividad humana y por la presencia del bivalvo invasor Limnoperna fortunei.(AU)

Gasterópodos terrestres de la provincia de Misiones, Argentina / Terrestrial gastropods from Misiones Province, Argentina

The Atlantic Forest represents one of the global priority eco-regions for biodiversity conservation. In Argentina, this is represented by the Paranense Forest, which occupies much of the Misiones Province. In this paper, an updated list of land mollusks from Misiones Province is presented, and its species richness was evaluated comparing protected and unprotected areas. For this, we reviewed La Plata Museum Mollusk Collection, updated the literature review, and developed some field work between 2009 and 2010. For the areographic work, a grid (50x50km) was applied to a Misiones province map. In this region, large areas of native vegetation constituting the Paranaense Forest still persist, and include protected areas such as the Iguazú National Park and Puerto Península Provincial Park. These areas have been the most explored at the malacological level (both terrestrial and aquatic environments), a fact that is consistent with the greater number of records found, which may also be the explanation for the highest number of species recorded in the region. A database containing 497 records was compiled. The number of species occurring in this Province was increased from 28 to 56; 11 of which were exotic species. A total of 38 of the species occurred in protected areas and 53 in unprotected areas; and 25 species were micro-mollusks. Orthalicidae was the family with the highest species number (10) and the widest distribution, occupying 16/20 sampling units. Megalobulimus was the genus found in a greater number of sampling units (14/20). The highest values of specific richness of land gastropods were found in Northern Misiones (R=32). This richness was similar to that previously reported for the Tucumán Province, although species occurring in both provinces were mostly different. The richness in Misiones Province border areas, as the Republic of Paraguay and the state of Santa Catarina (Brazil), was about twice that found in the province. The present study showed the existence of poorly explored areas at malacological level, especially in Central and Eastern Misiones. Data presented here will allow focus future sampling efforts on such areas, so patterns of species distribution can be better defined. Rev. Biol. Trop. 61 (4): 1759-1768. Epub 2013 December 01.

El Bosque Atlántico es una de las eco-regiones prioritarias para la conservación global de la diversidad biológica. En territorio argentino se encuentra representado por la Selva Paranense que ocupa gran parte de la provincia de Misiones. Aquí se presenta una lista actualizada de los moluscos terrestres de la provincia de Misiones, se evalúa su riqueza y se las compara entre áreas protegidas y no protegidas. Se elaboró una base de datos de 497 registros. Se utilizó una grilla de 50x50km sobre el mapa de la provincia de Misiones. Se amplió el número de especies presentes en esta provincia de 28 a 56 (11 exóticas y 25 micromoluscos). En áreas no protegidas se registraron 53 especies y 38 en áreas protegidas. Orthalicidae presentó el mayor número de especies (diez) y la distribución más amplia. Megalobulimus spp. se registró en 14 unidades de muestreo. Los mayores valores de riqueza específica se encontraron en el extremo norte de la provincia (R=32), donde a su vez se registra la mayor cantidad de muestreos. En esta región se mantienen grandes extensiones de vegetación autóctona que conforman la Selva Paranaense y zonas protegidas como el Parque Nacional Iguazú y el Parque Provincial Puerto Península.