Bivalves are among the main groups of invasive freshwater species, with the Asian clam genus Corbicula in particular being widely distributed. While global studies have focused on Corbicula fluminea (Müller, 1774), the invasive potential of Corbicula largillierti (Philippi, 1844) and Corbicula fluminalis (Müller, 1774) is still unknown. The spread of invasive species may be intensified by climate change. We estimated and compared environmentally suitable areas for these species under hypothetical climate scenarios, generating global maps of invasion risk. We found large climatically suitable areas for C. largillierti and C. fluminalis (under species distribution models) and that their invasive potential is currently underestimated. The analysis revealed many areas in which changing climate may favour the invasion of Corbicula spp.

The winter of 2009/2010 was particularly severe in Northern Portugal resulting in higher river flow levels. A study was undertaken to assess the impact of this situation on several populations of freshwater bivalves (e.g., Anodonta anatina, Corbicula fluminea, Margaritifera margaritifera, Potomida littoralis and Unio delphinus) in the catchments of the Rivers Minho, Douro, Tâmega, Tua and Sabor. Massive die-offs occurred for all species in all rivers, resulting in the removal of great numbers and biomass from the riverbed to the adjacent riverbanks, reaching maximum values of 2280 individuals.m−2 and 10 225 g wet weight.m−2, respectively. The invasive Asian clam C. fluminea had both highest density and biomass (however, this invasive bivalve is not dominant in several surveyed sites, and some rivers are still not colonized by this species). Results show that the quantitative and qualitative importance of this carrion transfer to the riverbank should be incorporated in future studies on the assessment of ecosystem function, contributing to a better understanding of the role of freshwater bivalves as resource pulses in adjacent terrestrial habitats. Some of the affected species have conservational importance and these extreme climatic events are predicted to increase in the future. These massive die-off events should be incorporated into management plans and selected restoration measures such as rapid relocation of endangered native mussels back to the riverbed can be easily applied to lessen possible impacts.

The Asian clam Corbicula fluminea is one of the most invasive species in freshwater aquatic ecosystems. The rapid growth,earlier sexual maturity, short life span, high fecundity and its association with human activities makes C. fluminea anon-indigenous invasive species likely to colonize new environments. This species, originally distributed in Asiatic ecosystems,is now a common inhabitant of American and European freshwater habitats. The present paper reviews the information related tothe life cycle, ecology and potential ecological and economic impacts caused by C. fluminea in the invaded habitats.Furthermore, this paper also proposed future works that may be implemented in order to increase our general knowledge aboutthe ecology of this bivalve.

This study evaluated the status of the Asian clam Corbicula fluminea (Müller, 1774) in the River Lima estuary (Portugal),which it first invaded in 2002. During the summers of 2004 and 2005, spatial and temporal variations in the abundance, biomassand population structure of C. fluminea were investigated in this estuary. This species was present in a limited intertidal area ofthe estuary and was rarely found in the subtidal zone. Its abundance and biomass were considerably lower than those found inother estuarine systems. Based on these studies it appears that salinity fluctuations and possibly other factors such as nutrientsand environmental contaminants are keeping this invasive species from reaching its full potential. Given the lower abundanceand biomass recorded and the restrict distribution of the species in this estuary, the eradication of this nonindigenous invasivespecies is still possible. The findings of this study may be useful for the management of this species not only in the River Limaestuary but also in other locations it may invade.

Corbicula fluminea populations were sampled annually from 1997 to 2000 at the beginning of the autumn, i.e. at the end of the reproduction period, at 14 sites along the Saône and Rhône rivers. Recruitment in the upper reach of these rivers was generally high. Conversely, the observation of other sectors revealed generally low or no production of juveniles, missing cohorts and major year to year variations in population structure. Nevertheless, no dramatic fall in population density was observed during the surveyed four years. This suggests that the longevity of the Corbicula populations of the Saône and Rhône rivers is ensured to a great extent by the drifting of individuals from the upper course of these rivers and their tributaries. Two possible causes are put forward to explain the low recruitment observed : low production of phytoplankton that prevents adults from constituting sufficient energy reserves to ensure the full development of larvae, and/or toxic contamination, which inhibits the development of phytoplankton and it is lethal for pediveligers.

The epithelia of the main organs likely to be involved in contaminant uptake, viz. mantle and gill were studied in the Asiaticclam Corbicula fluminea as a base for future ecotoxicological studies. On its margin, the mantle epithelium displays three foldsseparated by two grooves. The outer epithelium made of cubic cells, and the periostracal groove are involved in the formation iscomposed of the shell, secreting crystals and the periostracal lamella respectively. In the median area, the inner epithelium iscomposed of three cell types: ordinary epithelial cells, ciliated cells and mucocytes. The gill epithelium displays two structurallyand functionally different areas: a respiratory area in the interlamellar chamber and, on the opposite side, a ciliated epithelium.The respiratory epithelium is composed of thin pavement epithelial cells. The ciliated epithelium is made of different cell types:lateral ciliated epithelial cells, secretory cells, latero-frontal ciliated cells and ciliated frontal cells. The role of the secretory cellsis particularly discussed in relation to their structural similarity with lower vertebrate chloride cells (ionocytes) involved in iono- andosmoregulation processes.