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Based on literature review and malacological collections, 168 native freshwater bivalve and five invasive species have been recorded for 52 hydrographic regions in South America. The higher species richness has been detected in the South Atlantic, Uruguay, Paraguay, and Amazon Brazilian hydrographic regions. Presence or absence data were analysed by Principal Coordinate for Phylogeny-Weighted. The lineage Veneroida was more representative in hydrographic regions that are poorer in species and located West of South America. The Mycetopodidae and Hyriidae lineages were predominant in regions that are richest in species toward the East of the continent. The distribution of invasive species Limnoperna fortunei is not related to species richness in different hydrographic regions there. The species richness and its distribution patterns are closely associated with the geological history of the continent. The hydrographic regions present distinct phylogenetic and species composition regardless of the level of richness. Therefore, not only should the richness be considered to be a criterion for prioritizing areas for conservation, but also the phylogenetic diversity of communities engaged in services and functional aspects relevant to ecosystem maintenance.

Non-native species have been introduced at escalating rates during the last decades, mainly due to the dispersion generated by the increasing trade and transport worldwide. Mollusks, the second largest metazoan phylum in terms of species richness, are no exception to this pattern, but, to date, a comprehensive synthesis of non-native mollusk species (NNMS) in South America was not available. For this purpose, an e-discussion group was formed with malacologists and taxonomists from South America, where we exchanged and analyzed bibliography, databases and information about NNMS, providing expert opinion to this assessment. The first list of non-native mollusk species for South America, considering terrestrial, freshwater and marine environments, includes 86 NNMS distributed in 152 ecoregions (terrestrial, freshwater and marine) of the 189 recognized for the South American continent. Information on their native region, vectors, first record for South America and distribution, are also provided. In the analysis of the distribution of the NNMS and the entry points of each species (e.g., ports, cargo and passenger airports, cities) and status of conservation of the ecoregions, four hot spots were recognized: Subtropical-Atlantic,

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Desde o final de 1998, um pequeno bivalve invasor, o "mexilhão dourado", Limnoperna fortunei (Dunker, 1857), oriundo do sudeste asiático, está presente no sul do Brasil. Foi provavelmente transportado, não intencionalmente, através de água de lastro para a Bacia do Guaíba, Rio Grande do Sul, Brasil. Em nosso meio, este molusco vem causando problemas de "macrofouling" com grandes prejuízos econômicos e danos à fauna e flora. As coletas foram qualitativas e quantitativas quinzenais no período de um ano, no lago Guaíba, Praia do Veludo (30°12'35"S, 51°11'68"W), ao sul do município de Porto Alegre. Utilizou-se rede de plâncton com abertura de malha equivalente a 36 mm, filtrando-se a quantidade de 30 litros de água. Descrevem-se brevemente as diferentes fases larvais com parâmetros do comprimento. Primeiramente reconhece-se um estágio ciliado, desenvolvendo-se em trocófora (comprimento de 80 µm a 125 µm) com quatro fases distintas, e valvadas com a larva "D" (120 µm a 150 µm), o veliger de charneira reta (150 µm a 190 µm), o veliger umbonado (190 µm a 220 µm) e o pediveliger (220 µm a 250 µm). Quando pós-larvas ou plantígradas (comprimento em torno de 300 µm), começam a secretar o fio de bisso, permitindo a fixação ao substrato. Constatou-se a presença de larvas durante todos os meses amostrados, com picos nos meses de outubro a dezembro.

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