1. Department of Life and Environmental Sciences, Polytechnic University of Marche, Via Brecce Bianche, 60131 Ancona, Italy.
2. Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy.
3. HGF MPG Joint Research for Deep-Sea Ecology and Technology, Max Planck Institute for Marine Microbiology, 28359 Bremen, Germany.