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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,

BackgroundCell-cell interactions are a basic principle for the organization of tissues and organs allowing them to perform integrated functions and to organize themselves spatially and temporally. Peptidic molecules secreted by neurons and epithelial cells play fundamental roles in cell-cell interactions, acting as local neuromodulators, neurohormones, as well as endocrine and paracrine messengers. Allatotropin (AT) is a neuropeptide originally described as a regulator of Juvenile Hormone synthesis, which plays multiple neural, endocrine and myoactive roles in insects and other organisms.MethodsA combination of immunohistochemistry using AT-antibodies and AT-Qdot nanocrystal conjugates was used to identify immunoreactive nerve cells containing the peptide and epithelial-muscular cells targeted by AT in Hydra plagiodesmica. Physiological assays using AT and AT- antibodies revealed that while AT stimulated the extrusion of the hypostome in a dose-response fashion in starved hydroids, the activity of hypostome in hydroids challenged with food was blocked by treatments with different doses of AT-antibodies.ConclusionsAT antibodies immunolabeled nerve cells in the stalk, pedal disc, tentacles and hypostome. AT-Qdot conjugates recognized epithelial-muscular cell in the same tissues, suggesting the existence of anatomical and functional relationships between these two cell populations. Physiological assays indicated that the AT-like peptide is facilitating food ingestion.SignificanceImmunochemical, physiological and bioinformatics evidence advocates that AT is an ancestral neuropeptide involved in myoregulatory activities associated with meal ingestion and digestion.

The effects of global change and globalization of trade on the biosphere spur an increase in bioinvasions and their subsequent impact on ecosystems. Continental invading bivalves are important because of their impact on artificially-constructed structures. Limnoperna fortunei was first found in the Neotropical region in 1991. Since then it has dispersed upstream in the Plata and Guaíba basins at a rate of 240 km y(-1). This species causes macrofouling in a manner similar to that caused by Dreissena polymorpha. This paper describes the biology of L. fortunei larvae from a hydroelectric power plant in South America. We suggest the importance of knowing the biology of the invading species and the need to consider the settlement patterns and densities of larvae in each of the sectors of the facility in order to achieve a sustainable prevention/control of macrofouling. This study acquires a global significance under the assumption that L. fortunei will eventually invade North America and Europe.