1. Instituto de Ciencias Naturales Alexander von Humbold, Universidad de Antofagasta, Antofagasta 1240003, Chile
2. Millenium Institute of Oceanography, Universidad de Concepción, Concepción 4030136, Chile
3. Animal Parasitology Department, Federal Rural University of Rio de Janeiro, Seropedica 17560-015, RJ, Brazil