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Vol. 52, 2013
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
Gonzalo
A Collado1*, Moisés A Valladares2 and Marco A
Méndez2
1Departamento
de Biología y Ciencias Ambientales, Facultad de Ciencias, Universidad
de Valparaíso, Gran Bretaña, 1111 Valparaíso, Chile
2Laboratorio de Genética y Evolución, Facultad de
Ciencias, Universidad de Chile, Las Palmeras, 3425 Santiago, Chile
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.
Conclusions: We found support for
recognizing four nominal species, one undescribed species and at least
other four candidate species of the genus Heleobia in northern Chile. We also
suggest that the current level of species diversity of Heleobia in the region is
underestimated by the use of conchological criteria to recognize
species and by the limited sampling conducted to date.
Key words: Cochliopidae; Distribution
patterns; Semisalsinae; Spring snails; Taxonomy.
*Correspondence: E-mail: collado.gonzalo@gmail.com
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