Abstracts (first author)
Habitat choice in the flat periwinkle (Littorina fabalis) Iberian ecotypes: an experimental approachPDF
Although it is widely recognized that habitat choice can facilitate local adaptation, its contribution to speciation has been poorly studied. Littorina species (marine gastropods) offer unique models to study the mechanisms underlying ecotype differentiation. In the flat periwinkle L. fabalis, three ecotypes have been described in the Iberian Peninsula, each associated with different host algae/seagrass (Fucus sp., Mastocarpus sp., and Zostera marina). Whether this association results from consistent habitat preference/avoidance, represents the outcome of environmental selective pressures like predation and/or results simply from stochastic processes, has never been investigated. Here we conducted two series of laboratory experiments where we measured L. fabalis immediate habitat choice within a 30 minutes interval and long-term choice within a six days interval. Results were similar: while two of the ecotypes (living in Fucus sp. and Mastocarpus sp.) tend to choose their host algae more frequently than by chance, the opposite trend was observed for the third ecotype (living in Zostera marina). The implications of these results will be discussed within the context of ecological speciation.