Biological characteristics of sperm in European flat oyster (Ostrea edulis) Marc Suquet, Stéphane Pouvreau, Isabelle Queau, Myrina Boulais, Jacqueline Le Grand, Dominique Ratiskol and Jacky Cosson Aquat. Living Resour., 31 (2018) 20 Published online: 20 August 2018 DOI: 10.1051/alr/2018008