A report and an updated list with comments on the species of freshwater molluscs of Argentina which covers an area of 2 777 815 km2is presented. Distributions of Gastropoda and Bivalvia families, endemic, exotic, invasive as well as entities of sanitary importance are also studied and recommendations on their conservation are provided. Molluscs related to the Del Plata Basin have been thoroughly studied in comparison to others areas of the country. This fauna exhibits relatively the biggest specific richness and keeps its affinity with the fauna of other regions of the basin in areas of Paraguay and Brasil. The 4 500 records of molluscs considered in this paper arise from the study of the collections of Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”, Buenos Aires; Museo de La Plata, La Plata and Fundación “Miguel Lillo”, Tucumán. These institutions keep very important collections of molluscs in southern South America. Field information has recently been obtained and localities cited by other authors are also included in the data base. Until today, 166 species have been described, 101 belonging to 10 families of Gastropoda and 65 to 7 of Bivalvia. Families with highest specific richness are Lithoglyphidae (22) and Sphaeriidae (25), respectively. The number of endemic species (those present only in Argentina) by family is: Gastropoda: Ampullariidae (1), Cochliopidae (10), Lithoglyphidae (11), Thiariidae (3), Chilinidae (11), Lymnaeidae (2) and Physidae (2?); Bivalvia: Hyriidae (1?); Etheriidae (1?) and Sphaeriidae (10). Families with a distribution that comprise almost the whole country are: the Sphaeriidae and the gastropods Cochliopidae, Chilinidae and Lymnaeidae. Families Erodonidae and Solecurtidae (Bivalvia) were registered in mixohaline environments from Buenos Aires province. Gastropod families Thiaridae and Glacidorbiidae show a very restricted distribution. The rest of the families are present mainly in the center and north of the country. Species of sanitary interest are the propagators of: schistosomiasis -Biomphalaria peregrina, B. straminea y B. tenagophila, Planorbidae-, fasciolasis -Lymnaea viatrix and L. columnella, Lymnaeidae- and dermatitis -Chilina gibbosa and C. fluminea, Chilinidae. Invasive species are: Corbicula fluminea (Corbiculidae) and Limnoperna fortunei (Mytilidae).The construction of new areas for the protection and conservation of the high risk endemic species of freshwater molluscs is a priority. It is necessary to give special attention to the species of the patagonic mountain range and of the mesopotamic area of the Del Plata Basin. | Se presenta un estado de situación y una lista actualizada y comentada sobre las especies de moluscos de agua dulce de la República Argentina. Se aborda en Gastropoda y Bivalvia la distribución a nivel de familias; las entidades endémicas, exóticas, invasoras y de importancia sanitaria. Los moluscos relacionados a la cuenca del Plata presentan la mayor riqueza específica. Base de datos: 4 500 registros relevados de las tres colecciones más importantes de la Argentina: MLP, MACN y FML. Además, se incluye información de recolecciones actuales y localidades citadas por otros autores. Hasta el presente han sido descritas 166 especies. De ellas 101 pertenecen a 10 familias de Gastropoda y 65 a 7 de Bivalvia. Las familias que presentan mayor riqueza específica son Lithoglyphidae (22) y Sphaeriidae (25), respectivamente. Sphaeriidae, Cochliopidae, Chilinidae y Lymnaeidae se distribuyen prácticamente en todo el país. Erodonidae y Solecurtidae se registran en ambientes mixohalinos de la provincia de Buenos Aires. Thiaridae y Glacidorbiidae presentan una distribución muy restringida. Especies endémicas de la Argentina: Gastropoda: Ampullariidae (1), Cochliopidae (10), Lithoglyphidae (11), Thiariidae (3), Chilinidae (11), Lymnaeidae (2) y Physidae (2?); Bivalvia: Hyriidae (1?); Etheriidae (1?) y Sphaeriidae (10). Especies de interés sanitario: propagadoras de: Esquistosomiasis, Biomphalaria peregrina, B. straminea y B. tenagophila (Planorbidae); Fasciolasis, Lymnaea viatrix y L. columnella (Lymnaeidae); y dermatitis esquistosómicas, Chilina gibbosa y C. fluminea (Chilinidae). Especies de origen asiático: Corbicula fluminea (Corbiculidae) y Limnoperna fortunei (Mytilidae). Es prioritaria la formación de áreas protegidas para la conservación de especies endémicas, especialmente de la Mesopotamia Argentina.

Se presenta un estado de situación y una lista actualizada y comentada sobre las especies de moluscos de agua dulce de la República Argentina. Se aborda en Gastropoda y Bivalvia la distribución a nivel de familias; las entidades endémicas, exóticas, invasoras y de importancia sanitaria. Los moluscos relacionados a la cuenca del Plata presentan la mayor riqueza específica. Base de datos: 4 500 registros relevados de las tres colecciones más importantes de la Argentina: MLP, MACN y FML. Además, se incluye información de recolecciones actuales y localidades citadas por otros autores. Hasta el presente han sido descritas 166 especies. De ellas 101 pertenecen a 10 familias de Gastropoda y 65 a 7 de Bivalvia. Las familias que presentan mayor riqueza específica son Lithoglyphidae (22) y Sphaeriidae (25), respectivamente. Sphaeriidae, Cochliopidae, Chilinidae y Lymnaeidae se distribuyen prácticamente en todo el país. Erodonidae y Solecurtidae se registran en ambientes mixohalinos de la provincia de Buenos Aires. Thiaridae y Glacidorbiidae presentan una distribución muy restringida. Especies endémicas de la Argentina: Gastropoda: Ampullariidae (1), Cochliopidae (10), Lithoglyphidae (11), Thiariidae (3), Chilinidae (11), Lymnaeidae (2) y Physidae (2?); Bivalvia: Hyriidae (1?); Etheriidae (1?) y Sphaeriidae (10). Especies de interés sanitario: propagadoras de: Esquistosomiasis, Biomphalaria peregrina, B. straminea y B. tenagophila (Planorbidae); Fasciolasis, Lymnaea viatrix y L. columnella (Lymnaeidae); y dermatitis esquistosómicas, Chilina gibbosa y C. fluminea (Chilinidae). Especies de origen asiático: Corbicula fluminea (Corbiculidae) y Limnoperna fortunei (Mytilidae). Es prioritaria la formación de áreas protegidas para la conservación de especies endémicas, especialmente de la Mesopotamia Argentina.<br>Latin American Malacology. Freshwater Mollusks from Argentina. A report and an updated list with comments on the species of freshwater molluscs of Argentina which covers an area of 2 777 815 km² is presented. Distributions of Gastropoda and Bivalvia families, endemic, exotic, invasive as well as entities of sanitary importance are also studied and recommendations on their conservation are provided. Molluscs related to the Del Plata Basin have been thoroughly studied in comparison to others areas of the country. This fauna exhibits relatively the biggest specific richness and keeps its affinity with the fauna of other regions of the basin in areas of Paraguay and Brasil. The 4 500 records of molluscs considered in this paper arise from the study of the collections of Museo Argentino de Ciencias Naturales "Bernardino Rivadavia", Buenos Aires; Museo de La Plata, La Plata and Fundación "Miguel Lillo", Tucumán. These institutions keep very important collections of molluscs in southern South America. Field information has recently been obtained and localities cited by other authors are also included in the data base. Until today, 166 species have been described, 101 belonging to 10 families of Gastropoda and 65 to 7 of Bivalvia. Families with highest specific richness are Lithoglyphidae (22) and Sphaeriidae (25), respectively. The number of endemic species (those present only in Argentina) by family is: Gastropoda: Ampullariidae (1), Cochliopidae (10), Lithoglyphidae (11), Thiariidae (3), Chilinidae (11), Lymnaeidae (2) and Physidae (2?); Bivalvia: Hyriidae (1?); Etheriidae (1?) and Sphaeriidae (10). Families with a distribution that comprise almost the whole country are: the Sphaeriidae and the gastropods Cochliopidae, Chilinidae and Lymnaeidae. Families Erodonidae and Solecurtidae (Bivalvia) were registered in mixohaline environments from Buenos Aires province. Gastropod families Thiaridae and Glacidorbiidae show a very restricted distribution. The rest of the families are present mainly in the center and north of the country. Species of sanitary interest are the propagators of: schistosomiasis -Biomphalaria peregrina, B. straminea y B. tenagophila, Planorbidae-, fasciolasis -Lymnaea viatrix and L. columnella, Lymnaeidae- and dermatitis -Chilina gibbosa and C. fluminea, Chilinidae. Invasive species are: Corbicula fluminea (Corbiculidae) and Limnoperna fortunei (Mytilidae). The construction of new areas for the protection and conservation of the high risk endemic species of freshwater molluscs is a priority. It is necessary to give special attention to the species of the patagonic mountain range and of the mesopotamic area of the Del Plata Basin. Rev. Biol. Trop. 56 (1): 77-111. Epub 2008 March 31.

In 1996 and 1998, a collection of gasteropods was made in the Agua Blanca State Park in order to establish their taxonomic identity and geographic distribution. From this collection, 23 species (1 freshwater and 22 terrestrial) were found to be Prosobranchia (26.1%) and Pulmonata (73.9%). For the Prosobranchia specie, half of them were observed to be Mesogastropoda and the other half Archaeogastropoda; while the Pulmonata specie was encountered to have 100 % of Stylommatophora. The specie´s richness was 23. The geographic distribution of the species, restricted to the Mesoamerican Neotropical region, was the main zoographic component with 78.3% (43.5% Mesoamerican Neotropical species with the addition of 34.8 % Mexican Neotropical endemics). The endemic species of Mexico represented 40%, from which 8 % were endemic to Tabasco. | Con el objetivo de establecer la identidad taxonómica y la distribución geográfica de los gasterópodos del Parque Estatal Agua Blanca, durante 1996 y 1998 se recolectaron estos organismos. Se registraron 23 especies, de estas una es dulceacuícola y 22 terrestres, el 26.1% fueron Prosobranchia y de estos la mitad fueron Mesogastropoda y la otra Archaeogastropoda. Del 73.9% correspondiente a los Pulmonata, el 100% fueron Stylommatophora. La riqueza de especies fue de 23. La distribución geográfica de las especies fue de estirpe Neotropical Mesoamericana (especies neotropicales mesoamericanas (43.5%) mas las neotropicales endémicas a México (34.8%)) representó el principal componente zoogeográfico con un 78.3%. Las especies endémicas de México representaron 40% y de estas el 8% fueron endémicas para Tabasco.

The marine biota from the middle Pennsylvanian outcrops of the Sierra Agua Verde, located in mid-eastern Sonora, consists of phylloid algae of the genera Komia and Eugonophyllum and a number of invertebrates. These species include bioaccumulations of chaetetids; brachiopods of the genera Dielasma sp., Reticulariina sp., Anthracospirifer sp., Antiquatonia sp.; bryozoans of the genus Thamniscus; tabulate corals such as Syringopora and solitary corals such as Zaphrentis; fusulinid foraminifera such as Pseudostaffella, Eoshubertella texana, Fusulinella llanoensis, and Zellerella; gastropods of the genus Euomphalus and Donaldina; and the crinoid genera Cyclocaudex, Cyclocrista, Heterosteleschus, Lamprosterigma, Mooreanteris, Pentagonopternix, Preptopremium, Cycloscaspus, and Pentaridica. The material was collected from outcrops in the first 512m of the La Joya Formation, and their sediments have a total thickness of 780m and consist of limestone interbedded with calcareous mudstone and sandstone lenses. The age of the middle Pennsylvanian strata corresponds to that of the Atokan stage (311 million years). The species assemblages are typical of a shallow tropical marine benthos. The analysis of the distribution of the species allowed for the determination of their paleogeographic relationships with the components of the biota of the Carboniferous strata of Texas and Kansas in the United States of America, which belong to the province of the North American Craton.

In 1996 and 1998, a collection of gasteropods was made in the Agua Blanca State Park in order to establish their taxonomic identity and geographic distribution. From this collection, 23 species (1 freshwater and 22 terrestrial) were found to be Prosobranchia (26.1%) and Pulmonata (73.9%). For the Prosobranchia specie, half of them were observed to be Mesogastropoda and the other half Archaeogastropoda; while the Pulmonata specie was encountered to have 100 % of Stylommatophora. The specie's richness was 23. The geographic distribution of the species, restricted to the Mesoamerican Neotropical region, was the main zoographic component with 78.3% (43.5% Mesoamerican Neotropical species with the addition of 34.8 % Mexican Neotropical endemics). The endemic species of Mexico represented 40%, from which 8 % were endemic to Tabasco. | Con el objetivo de establecer la identidad taxonómica y la distribución geográfica de los gasterópodos del Parque Estatal Agua Blanca, durante 1996 y 1998 se recolectaron estos organismos. Se registraron 23 especies, de estas una es dulceacuícola y 22 terrestres, el 26.1% fueron Prosobranchia y de estos la mitad fueron Mesogastropoda y la otra Archaeogastropoda. Del 73.9% correspondiente a los Pulmonata, el 100% fueron Stylommatophora. La riqueza de especies fue de 23. La distribución geográfica de las especies fue de estirpe Neotropical Mesoamericana (especies neotropicales mesoamericanas (43.5%) mas las neotropicales endémicas a México (34.8%)) representó el principal componente zoogeográfico con un 78.3%. Las especies endémicas de México representaron 40% y de estas el 8% fueron endémicas para Tabasco.

In this note we introduce a taxonomic study of three freshwater Mollusc species of S. Tome and Principe Islands (Gulf of Guinea, West Africa), Neritina afra Sowerby, 1841, Neritilia manoeli (Dohrn, 1866) (Prosobranchia: Neritidae) and Bulinus (Bulinus) forskalii (Ehrenberg, 1831) (Pulmonata: Planorbidae). Along with study we present a briefly freshwater malacological history in S. Tome and Principe Islands and we mention the freshwater species signalized for those islands for several authors. | PORTUGUES: Na presente nota apresentamos o estudo taxonomico de 3 especies de Gastropodes de agua doce das ilhas de S. Tome e Principe (golfo da Guine, costa ocidental de Africa), Neritina afra Sowerby, 1841, Neritilia manoeli (Dohrn, 1866) (Prosobranchia: Neritidae) e Bulinus (Bulinus) forskalii (Ehrenberg, 1831) (Pulmonata: Planorbidae). A par deste estudo elaboramos um breve resumo historico da Malacologia de agua doce nas ilhas de S. Tome e do Principe e mencionamos as especies de agua doce, assinaladas para aquelas ilhas pelos varios autores.

Mollusks can be a very frequent feeding item in the diet of many species of fishes inhabiting the Neotropical region. However, the possibility of malacofagous fishes act as important passive dispersors for native and exotic mollusks in rivers of this region is poorly documented. In this study, mollusks ability to survive of passing through the digestive system of Pimelodus pintado, Iheringichthys labrosus, Leporinus obtusidens and Rhinodoras dorbignyi, four species common in Southern Brazilian rivers, was evaluated. Three study methods, namely, intestinal content analysis, faecal content analysis and a laboratorial experiment, in which different mollusk taxa/morphotypes were offered to fishes, were used. Results obtained showed that the studied fish species apparently predate especially thinshelled morphotypes, although generally feeding on a variety of mollusk taxa/morphotypes. However, only thick-shelled morphotypes (Heleobia spp., Potamolithus spp., and Corbicula fluminea) were found alive in the fish rectum or feces. Individuals found alive not always survived more than 12 hours after having been placed on recipients containing water and oxygen. This result suggests that other factors should be involved in mollusks ability to survive. The absence of strong incisiform oral teeth in fish digestive tract is important for the survival of many mollusks, because their presence, such as in L. obtusidens, determinate the fragmentation of many shells. Thus, only P. pintado, I. labrosus and R. dorbignyi, which do not show this tooth type, could be considered as passive dispersers of some mollusk taxa, and of some Hidropsyche larvae and leeches in rivers of the Neotropical region. Possibly, these fish species were also involved in the invasion of many non-navigable streams in southern Brazil, by the Asiatic bivalve C. fluminea. | Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES | Na região Neotropical, moluscos podem ser um item alimentar frequente na dieta de muitos peixes. Contudo, a possibilidade de peixes malacófagos atuarem como importantes dispersores passivos de moluscos nos rios da região não está bem documentada. Neste estudo, a capacidade de moluscos sobreviverem à passagem pelo trato digestório de Pimelodus pintado, Iheringichthys labrosus, Leporinus obtusidens e Rhinodoras dorbignyi, quatro espécies comuns nos rios da região sul do Brasil, foi avaliada. Três métodos de estudo foram utilizados: análise de conteúdo intestinal, análise de conteúdo fecal e experimento de oferta de diferentes táxons/morfotipos de moluscos em laboratório. Os resultados obtidos mostraram que, apesar de as espécies estudadas se alimentarem de grande variedade de moluscos, aparentemente, preferem predar moluscos com conchas finas. Contudo, apenas moluscos com concha espessa (Heleobia spp, Potamolithus spp e Corbicula fluminea) foram encontrados vivos no reto ou nas fezes. Destes, nem todos foram capazes de sobreviver por mais de 12 horas, após serem removidos do reto ou das fezes, e condicionados em recipientes contendo água e oxigênio. Isto sugere que outros fatores devem estar envolvidos na capacidade de sobrevivência dos moluscos. Adicionalmente, observou-se que a presença de fortes dentes orais incisivos em peixes como L. obtusidens, determinou a fragmentação de muitas conchas. Dessa forma, a ausência desse tipo de dente no trato digestório dos peixes é um fator importante para a sobrevivência de muitos moluscos. Na região Neotropical, apenas peixes sem dentes orais incisivos, como P. pintado, I. labrosus e R. dorbignyi podem ser considerados dispersores passivos de alguns táxons de moluscos e, ainda, de larvas de Hidropsyche e de sanguessugas. Possivelmente, estas três espécies também estão envolvidas na disseminação do bivalve asiático invasor, C. fluminea, em diversos riachos não navegáveis do sul do Brasil.