Feeding behavior of the invasive bivalve Limnoperna fortunei (Dunker, 1857) under exposure to toxic cyanobacteria Microcystis aeruginosa

The aim of this study was to test the effects of cyanobacteria toxicity on feeding behavior of the golden mussel Limnoperna fortunei. First, it was tested the hypothesis that L. fortunei preferentially graze on non-toxic phytoplankton and reject toxic cyanobacteria. Second, it was tested the hypothesis that toxic cyanobacteria negatively affect feeding and survival of L. fortunei. The present study is the first to evaluate the effects of toxic cyanobacteria on L. fortunei feeding and survival. In the short-term grazing, golden mussel filtration rates were evaluated in the presence of toxic and non-toxic strains of cyanobacteria Microcystis aeruginosa, and non-toxic phytoplankton Nitzschia palea. Highest filtration rates were registered when mussels fed on Nitzschia. Despite that, golden mussel expelled Nitzschia cells in large quantities and preferentially ingested Microcystis cells, both toxic and non-toxic strains. In the long-term grazing, mussels were exposed to toxic and non-toxic strains of Microcystis during 5 days. Filtration rates were not significantly different for toxic and non-toxic Microcystis throughout exposure period. The results have demonstrated cyanobacteria toxicity is not the main factor influencing L. fortunei feeding behavior. Survival of L. fortunei feeding on toxic cyanobacteria shows the potential of this invasive bivalve as a vector to the transference of cyanotoxins to higher trophic levels

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