Bivalve distribution in hydrographic regions in South America: historical overview and conservation

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 PhylogenyWeighted. 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 speciesLimnoperna fortuneiis 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. A plan to the management of this fauna according to particular ecological characteristics and human uses of hydrographic regions is neededFil: Pereira, Daniel . Universidade Federal Do Rio Grande Do Sul; BrasilFil: Dreher Mansur, Maria Cristina . Universidade Federal Do Rio Grande Do Sul; BrasilFil: Duarte, Leandro D. S. . Universidade Federal Do Rio Grande Do Sul; BrasilFil: Schramm de Oliveira, Arthur . Universidade Federal Do Rio Grande Do Sul; BrasilFil: Mansur Pimpao, Daniel . Universidade Federal Do Rio Grande Do Sul; BrasilFil: Tasso Callil, Claudia . Universidade Federal Do Mato Grosso Do Sul; BrasilFil: Ituarte, Cristian Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales; ArgentinaFil: Parada, Esperanza . Plataforma de Investigación en Ecohidrología y Ecohidráulica (ECOHYD); ChileFil: Peredo, Santiago . Plataforma de Investigación en Ecohidrología y Ecohidráulica (ECOHYD); ChileFil: Darrigran, Gustavo Alberto. Universidad Nacional de la Plata. Facultad de Cs.naturales y Museo. Div.zoologia Invertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Scarabino, Fabrizio . Museo Nacional de Historia Natural; UruguayFil: Clavijo, Cristhian. Museo Nacional de Historia Natural; UruguayFil: Lara, Gladys . Universidad Católica de Temuco; ChileFil: Miyahira, Igor Christo . Universidade do Estado do Rio de Janeiro; BrasilFil: Raya Rodriguez, Maria Teresa . Universidade Federal Do Rio Grande Do Sul; BrasilFil: Lasso, Carlos . Instituto de Investigacion de Recursos Biologicos Alexander von Humboldt; Colombi

Bivalves in a bottleneck: taxonomy, phylogeography and conservation of freshwater mussels (Bivalvia: Unionoida) in Australasia

The conservation biology of Australasian freshwater mussels is hindered by lack of a taxonomic framework that employs molecular data as a complement to shell characters, larval forms and internal anatomy. The fauna includes more than 32 known species (30+ Hyriidae, 2 Unionidae), but has not been revised for 55 years, despite minor amendments. The hyriids are relics of Gondwana, represented in Australia and New Guinea by the ancestral Velesunioninae and in Australia and New Zealand by the Hyriinae (Tribe Hyridellini). Many taxonomic and phylogeographic issues await resolution, including the relationships between Australasian and South American species, and between Australian and New Zealand species, and the status of species in New Guinea (including uncertain reports of Unionidae) and the Solomon Islands. Once these are clarified, it will be easier to identify threatened species and evaluate the conservation status of the fauna. At present, only seven taxa are named in the IUCN Red List or under national/state legislation, and these are not representative. Threatening processes include altered flow regimes, catchment disturbances, salinisation, pollution and invasive species. While the need for a taxonomic revision is paramount, progress in conservation may depend also upon involving the wider community