Phylogenetic relationships and taxonomy of Altiplano populations of Biomphalaria (Gastropoda: Planorbidae): inference from a multilocus approach

Abstract

Isolated closed basins provide a natural laboratory to study the differentiation among wild populations. Here we examined the phylogenetic relationships of the Southern Altiplano populations of Biomphalaria, a genus with medical importance, using nuclear (ITS1, ITS2) and mitochondrial (16S) ribosomal gene markers and a species of Helisoma as outgroup. Phylogenetic trees based on separate and combined analyses show that these populations form a particular lineage within Biomphalaria along with Biomphalaria peregrina (d'Orbigny, 1835) and Biomphalaria oligoza Paraense, 1974. The origin of this clade was estimated to have occurred in the middle Pleistocene. Molecular analyses showed that the nominal species Biomphalaria crequii (Courty, 1907) from the Salar de Ascotán and Biomphalaria costata (Biese, 1951) from the Salar de Carcote, previously synonymized with Biomphalaria andecola (d'Orbigny, 1835) and B. peregrina, respectively, are distinct taxa. Molecular data did not resolve the relationship of Biomphalaria aymara Valdovinos & Stuardo, 1991 from the Isluga swamps to other Biomphalaria species, but confirm that the populations from the Lauca and Huasco basins may represent a distinct undescribed species of Biomphalaria from the Southern Altiplano. Snails examined for trematodes were found to be positive in some Altiplano localities. © 2012 The Linnean Society of London, Zoological Journal of the Linnean Society, 2012, 165, 795–808.

Hidden diversity in spring snails from the Andean Altiplano, the second highest plateau on Earth, and the Atacama Desert, the driest place in the world

“…The matrix used in the combined analysis included taxa for which we did not have sequences for some of the two loci; in this case, the taxa were coded as "missing data", which has shown not to unduly influence the phylogenetic resolution (Wiens and Reeder 1995;Wiens 1998;Collado and Méndez 2012b).…”

“…The mitochondrial 16S rRNA gene was amplified by polymerase chain reaction (PCR) using the primers 16Sar-L (5′-CGCCTGTTTATCAAAAACAT-3′) and 16Sbr-H (5′-CCGGTCTGAACTCAGATCACGT-3′) (see Palumbi 1996). PCR conditions were described in Collado and Méndez (2012b) for this molecular marker. The mitochondrial 12S rRNA gene was amplified by PCR using the primers L1091 (5′-AAAAAGCTTCAAACTGGGATTAGATACCCCACT AT-3′) and H1478 (5′-TGACTGCAGAGGGTGACGGG CGGTGTGT-3′) (Kocher et al 1989).…”

“…Divergence times were estimated using the BEAST program (version 1.5.3, GNU Lesser General Public License, Boston, MA, USA) . We used a nucleotide substitution rate of 1.9% per million years for the 16S gene, the average divergence rate of this gene estimated for invertebrates (Cunningham et al 1992;Patarnello et al 1996) and previously used in gastropods (DeJong et al 2001;Collado and Méndez 2012b). The analysis was performed using a lognormal molecular clock, the general time reversible (GTR) substitution model plus the gamma distribution and the Yule process of speciation.…”

Microgeographic differentiation among closely related species ofBiomphalaria(Gastropoda: Planorbidae) from the Andean Altiplano

“…Freshwater snails of the genus Biomphalaria Preston, 1910 are widely distributed in the south‐western Altiplano (Courty, ; Biese, ; Valdovinos & Stuardo, ; Collado et al ., ; Collado & Méndez, 2012a, b). Phylogenetic analyses performed using ribosomal DNA sequences of the ITS1 and ITS2 nuclear regions and 16S mitochondrial gene recovered the populations of Biomphalaria of the region in a strongly supported clade, together with the Neotropical species Biomphalaria peregrina (Orbigny, 1835) and Biomphalaria oligoza (Orbigny, 1835) (Collado & Méndez, 2012a). Phylogenetic analyses using the cytochrome c oxidase subunit I gene ( COI ) locus allowed us to infer a ‘southern Altiplano species complex’ of Biomphalaria whose sister group is B. peregrina (Collado et al ., 2011).…”

Genetic, morphological, and life history traits variation in freshwater snails from extremely high environments of the Andean Altiplano

“…One lineage was composed of populations from the Lauca basin, among which is the Parinacota wetland, while a second lineage was composed of populations from the Caquena basin, which included snails from the Colpa and Caquena wetlands. The two lineages belong to different taxa, as yet undescribed, which were recently inferred by phylogenetic analysis (Collado et al 2011;Collado and Méndez 2012). The percentage of sequence divergence between lineages (1.9%) is within the range of nucleotide variation estimated between closely related species of Biomphalaria (0.5% to 3.3%, Jørgensen et al 2007;Collado et al 2011).…”