Molecular characterization of cryptic and sympatric lymnaeid species from the Galba/Fossaria group in Mendoza Province, Northern Patagonia, Argentina

Abstract

BackgroundFreshwater lymnaeid snails can act as the intermediate hosts for trematode parasites such as the liver fluke Fasciola hepatica, that cause significant economic and biomedical burden worldwide, particularly through bovine fascioliasis. Transmission potential is tightly coupled to local compatibility with snail hosts, so accurate identification of lymnaeid species is crucial for understanding disease risk, especially when invasive species are encountered. Mendoza Province, in Argentina, is a center of livestock production and also an area of endemic fascioliasis transmission. However, the distribution of lymnaeid species in the region is not well known.MethodsThis study examined lymnaeid snails from seven localities in the Department of Malarguë, Mendoza Province, using morphological and molecular analyses and also describing ecological variables associated with snail presence.ResultsWhile morphological characters identified two species of lymnaeid, Galba truncatula and G. viatrix, molecular data revealed a third, cryptic species, G. neotropica, which was sympatric with G. viatrix. G. truncatula was exclusively found in high altitude (>1900 meters above sea level [masl]) sites, whereas mixed G. neotropica/G. viatrix localities were at middle elevations (1300–1900 masl), and G. viatrix was found alone at the lowest altitude sites (<1300 masl). Phylogenetic analysis using two mitochondrial markers revealed G. neotropica and G. viatrix to be closely related, and given their morphological similarities, their validities as separate taxonomic entities should be questioned.ConclusionsThis study highlights the need of a robust taxonomic framework for the identification of lymnaeid snails, incorporating molecular, morphological and ecological variables while avoiding nomenclature redundancy. As the three species observed here, including one alien invasive species, are considered hosts of varying susceptibility to Fasciola parasites, and given the economic importance of fascioliasis for livestock production, this research has critical importance for the ultimate aim of controlling disease transmission.

The first record of Galba cubensis (L. Pfeiffer, 1839) (Mollusca: Gastropoda: Lymnaeidae) from open fields of Europe

“…Our trees confirm the results of correa et al (2010,2011) and Standley et al (2013), in which G. cubensis together with G. neotropica form a sister group to G. viator, and the topology of the monophyletic Galba clade in our ITS-2 tree is basically the same as in the combined 18S/ITS-1/ITS-2 tree in barGueS et al (2011). On the other hand, the sequences of all three species in our trees are mixed within a single cluster which can be interpreted as a species cluster.…”

“…G. viator (d'Orbigny, 1835) is one of the fascioliasis vectors in Argentina (Standley at al. 2013) and Brazil (MedeiroS et al 2014).…”

New record forGalba neotropica(d'Orbigny, 1835) in Argentina, with a detailed analysis of its morphology and molecular characteristics

“…1). In Peru it was found in Lima (type locality) and Cajamarca (Bargues et al 2007(Bargues et al , 2012; in Venezuela it was found in Carabobo and Falcón (Bargues et al 2011) and in Argentina it was found in Mendoza, northern Patagonia (Mera y Sierra et al 2009;Standley et al 2013) and Buenos Aires, Central region (Sanabria et al 2012). Identities of all these records were achieved by molecular markers.…”

“…Email: jpujadas@ege.fcen.uba.ar Until recently, the specific identification of lymnaeid snails has been based exclusively on morphological characteristics of the shell, radula, and renal and reproductive organs (Hubendick 1951;Paraense 1976;Pointier et al 2004). However, reliance on these features failed to distinguish species with similar morphology (cryptic species) or variants within a single species (Pointier et al 2006;Standley et al 2013).…”

“…Galba viatrix, G. cubensis and G. neotropica differ only by the DNA sequences of different molecular markers, such as ITS-1, ITS-2 and cytochrome oxidase subunit I (COI) (Pointier et al 2006;Bargues et al 2007;Standley et al 2013).…”