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

Abstract

Background: The Chilean Altiplano and the Atacama Desert in northern Chile harbor isolated hydrological systems or oases where it is possible to find minute aquatic snails of the genus Heleobia whose taxonomy is uncertain and where many populations remain unknown. Here, we obtained samples from 30 localities distributed in the region and used molecular (12S and 16S mitochondrial genes) and morphological (penis) characters to investigate diversity of this poorly known fauna. Results: Molecular phylogenetic analysis consistently recovered five clades, one of which constitutes a cryptic species previously assigned to a species recognized in the area. Four other clades contained sequences of one nominal species consistent with its type locality and at least two additional candidate species, which were corroborated by a particular penis morphology. Furthermore, some morphological differences in penis morphology were observed in two Altiplano populations not resolved by the DNA sequences, providing support for two additional candidate species in the genus. A molecular clock analysis allowed tracing the origin of lineages back to the Early Pleistocene.

Geographical isolation and genetic differentiation: the case ofOrestias ascotanensis(Teleostei: Cyprinodontidae), an Andean killifish inhabiting a highland salt pan

“…These marked modifications of the landscape appear to have made the biodiversity in the Altiplano unique in the world. Examples of this biodiversity are the endemic lineages of snails of the genus Biomphalaria (Collado, Vila & Méndez, ; Collado & Méndez, ) and Heleobia (Collado, Valladares & Méndez, ), frogs of the genus Telmatobius (De La Riva, García‐París & Parra‐Olea, ; Sáez et al ., ), and fish of the genus Orestias (Parenti, ; Esquer‐Garrigos, ; Esquer‐Garrigos et al ., ; Vila et al ., ), all of which exhibit high species richness and high genetic diversity in this geographical region. Particularly, the high speciation rate in the genus Orestias has been associated with lacustrine level variations, which apparently facilitated the allopatric speciation process, especially in the southern part of the distributional range of this genus (Parker & Kornfield, ; Lüssen, Falk & Villwock, ).…”

A new freshwater snail (Caenogastropoda: Cochliopidae) from the Atacama Desert, northern Chile

“…All these characters as a whole differentiate this species from other species of the group whose penis morphology is known (e.g. Hubendick 1955;Gaillard & de Castellanos 1976;Hershler & Thompson 1992;Ovando & De Francesco 2011;Collado 2012;Collado et al 2013). The sister group of this species is an undescribed population from Carrera Pinto, northern Chile (Collado et al 2013), a spring separated from Aguada de Chorrillos by over 100 km of arid desert.…”

“…The snails from Aguada de Chorrillos and Carrera Pinto belong to the clade including Heleobia transitoria (Biese, 1947), and a population from Quebrada El León in the Atacama Desert. These snails are not very close to Heleobia opachensis (Biese, 1947), Heleobia loaensis (Biese, 1947), Heleobia chimbaensis (Biese, 1944), Heleobia ascotanensis (Courty, 1907) and Heleobia atacamensis (Philippi, 1860) (Collado et al 2013) described from northern Chile.…”

“…Hubendick 1955;Gaillard & de Castellanos 1976;Hershler & Thompson 1992;Ovando & De Francesco 2011;Collado 2012;Collado et al 2013). The sister group of this species is an undescribed population from Carrera Pinto, northern Chile (Collado et al 2013), a spring separated from Aguada de Chorrillos by over 100 km of arid desert. I did not treat these populations as conspecific because of differences in shell and penis morphology (Fig.…”

Insights into the Evolutionary History of an Extinct South American Freshwater Snail Based on Historical DNA

“…Consequently, the mitochondrial 12S rRNA gene (hereafter 12S) was selected for further characterization based on previous research showing its potential utility in other gastropods (e.g. [23–25]). Partial sequences of the 12S gene were amplified with the 12SF () and 12SR () primers [24].…”