[1] Univ Chile, Fac Ciencias, Dept Ciencias Ecol, Santiago, Chile
[2] Univ Chile, Fac Ciencias, Dept Biol, Santiago, Chile
[3] Univ Barcelona, Fac Biol, Dept Ecol, Barcelona, Spain
[4] Univ Chile, Fac Med, Inst Ciencias Biomed, Santiago, Chile
[5] Max Planck Inst Limnol, D-2320 Plon, Germany
[6] McGill Univ, Montreal Neurol Inst, Montreal, PQ H3A 2T5, Canada
[7] Harvard Univ, Sch Med, Dept Neurosci, Cambridge, MA 02138 USA
[8] Univ Calif Irvine, Dept Ecol & Evolutionary Biol, Irvine, CA USA
[9] CNRS, LENA, F-75700 Paris, France