1. Department of Anatomy, Animal Production and Clinical Veterinary Sciences, Faculty of Veterinary Science, University of Santiago de Compostela, Campus Universitario S/N, 27002 Lugo, Spain.
2. Evolutionary Developmental Biology Research Group, Biology Department, Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium.
3. Skretting Aquaculture Research Centre, Sjøhagen 3, 4016 Stavanger, Norway.
4. Dipartimento di Scienze Mediche Veterinarie, Università di Bologna, Via Tolara di Sopra 50, 40064 Ozzano Emilia, Italy.