The ultrastructural characters of the mature spermatozoon of Opechona bacillaris (Molin, 1859) (Digenea, Lepocreadiidae) a parasite of Scomber colias Gmelin, 1789 (Scombridae) off the coast of Dakar (Senegal) - Ndiaye, P. I.; Bakhoum, A. J. S.; Sène, A.; Diagne, P. M.; Miquel, J. (Acta Zoologica, 2013)