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Vol. 53, 2014
Genetic,
morphological, and life history traits variation in freshwater snails
from extremely high environments of the Andean Altiplano
Gonzalo A Collado1*, Hugo F Salinas2 and Marco A Méndez2
1Departamento de Ciencias Básicas, Facultad de Ciencias, Universidad del Bío-Bío, Casilla 447, Chillán, Chile
2Laboratorio de Genética y Evolución, Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, Ñuñoa, Chile
Abstract
Background: The
isolated watersheds of the southwestern Andean Altiplano constitute a
natural laboratory to study the evolutionary divergence of freshwater
biota. Field observations showed that Biomphalaria
snails from Parinacota, Colpa, and Caquena have different shell sizes.
We performed morphometric analysis and common garden experiment to
evaluate whether the observed shell variation has a genetic base and if
this variation ismanifested in other morphological characters and life history traits.
Results: Network
analysis revealed that the snails of Parinacota form a lineage
genetically distinct from Caquena and Colpa. The morphometric analysis
of the shell showed that the Parinacota snails were larger than Caquena
and Colpa, both in nature and laboratory conditions, but there was no
evidence of difference in the shape of the shell when compared using
multivariate analyses. The number of eggs per ovicapsule was the only
life history trait that was significantly different between lineages,
although this difference may be also attributed to size of the
progenitor; the oviposition rate did not differ between lineages or
localities, and the hatching size and growth rate differed only at
the locality level, not lineages.
Conclusions: The
results suggest that shell size of the snails has a genetic basis
associated to the phenotype, while the expression and evolution of life
history traits in extreme high environments are highly influenced by
proximal causes.
Key words: Planorbidae; Biomphalaria; Haplotype network; Shell morphology; Local adaptation; Chilean Altiplano.
*Correspondence: E-mail: collado.gonzalo@gmail.com
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