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Morphological and molecular studies of the taxa of the Biomphalaria tenagophila complex were conducted on specimens from Argentina, Brazil, Paraguay, Peru, Uruguay and Venezuela. The morphological analysis included aspects of the shell, mantle, excretory organs and reproductive system. DNA barcode, ABGD and mPTP were used to group specimens into Operational Taxonomic Units (OTUs) and in attempt to solve species boundary delimitation problems within the Biomphalaria tenagophila complex. Population analyzes were also performed based on the cytochrome C oxidase I (COI) and 16S genes. The seminal vesicle, extension of the oviduct in relation to the distal ovispermioduct, vaginal pouch, aspect of the penial complex, aspect of the prepuce diaphragm, diaphragm papilla, extension of the penial sheath in relation to the prepuce and prepuce dimensions are essential for the determination of the taxa of the Biomphalaria tenagophila complex. An updated molecular phylogeny for Biomphalaria based on COI, 16S and ITS2 genes is presented and recover Biomphalaria tenagophila complex as monophyletic. The morphological, population and phylogenetic data observed in an integrated way define taxonomic questions, such as the proposition of a new status for B. guaibensis, which integrates into the Biomphalaria tenagophila complex. [ABSTRACT FROM AUTHOR]

A protocol combining acute toxicity, developmental toxicity and mutagenicity analysis in freshwater snail Biomphalaria glabrata for application in ecotoxicological studies is described. For acute toxicity testing, LC 50 and EC 50 values were determined; dominant lethal mutations induction was the endpoint for mutagenicity analysis. Reference toxicant potassium dichromate (K2Cr2O7 ) was used to characterize B. glabrata sensitivity for toxicity and cyclophosphamide to mutagenicity testing purposes. Compared to other relevant freshwater species, B. glabrata showed high sensitivity: the lowest EC 50 value was obtained with embryos at veliger stage (5.76 mg/L). To assess the model applicability for environmental studies, influent and effluent water samples from a wastewater treatment plant were evaluated. Gastropod sensitivity was assessed in comparison to the standardized bioassay with Daphnia similis exposed to the same water samples. Sampling sites identified as toxic to daphnids were also detected by snails, showing a qualitatively similar sensitivity suggesting that B. glabrata is a suitable test species for freshwater monitoring. Holding procedures and protocols implemented for toxicity and developmental bioassays showed to be in compliance with international standards for intra-laboratory precision. Thereby, we are proposing this system for application in ecotoxicological studies. [ABSTRACT FROM AUTHOR]