INVESTIGADORES
BELTRAMINO Ariel Anibal
congresos y reuniones científicas
Título:
Concerning genetic lineages and conservation units in Aylacostoma snails from High Paraná River (Argentina-Paraguay)
Autor/es:
VOGLER, R.E.; BELTRAMINO, A.A.; PESO, J.G.; ARGÜELLES, C.F.; RUMI, A.
Lugar:
Rio de Janeiro
Reunión:
Congreso; XI International Congress on Medical and Applied Malacology; 2012
Institución organizadora:
Sociedade Brasileira de Malacologia - SBMa
Resumen:
We provide a genetic analysis of Aylacostoma snails (Thiaridae) from Argentina-Paraguay focused on setting conservation priorities. This group is listed by IUCN as extinct in the wild as the result of filling the Reservoir of Yacyretá. Three endemic species were described by mid-1950s along a short reach of the High Paraná River. Two of them can presently be considered as extinct; however, Aylacostoma chloroticum is still found in nature, but critically endangered. Recently, few specimens of a new uncharacterized morphotype (hereafter NM) were recorded from the same area. We use cytochrome oxidase subunit 1 (COI) sequences to identify genetic lineages both for A. chloroticum and NM. We analyzed 37 specimens from six localities spanning the narrow geographical range of A. chloroticum, and 6 specimens from the only two sites where NM is known to occur. We obtained 43 sequences of 658 bp in length from which we identified three haplotypes (H): two for A. chloroticum differing in 1 substitution i.e. H1 (n=33) and H2 (n=4); the third (H3) was exclusive to NM, differing in 28 substitutions from A. chloroticum (H1). From a phylogenetic perspective, two subclades were recognized within A. chloroticum, one including all the geographic records, and a minor one containing specimens only from a single location. Phylogenetic reconstructions also suggest that NM might be a new species, rather than a lineage of A. chloroticum. Finally, we used genetic data to define evolutionarily significant units (ESUs) for conservation purposes. Our data suggest that A. chloroticum presents, at least, two ESUs. Since both ESUs converge in a single location, and given that the new morphotype occur at the same site, the location referred as Rio Beach, Paraguay (27º24´29.83"S; 55º49´32.94"W), is highlighted as a key source of genetic diversity to optimize ex situ conservation of these snails.