Structure and morphometrics of Ancyrocephalus paradoxus (Monogenea: Ancyrocephalidae) from Sander lucioperca (Percidae) in Czechia

New morphometric data, including details of the copulatory system and attachment structures, as well as inner organs are provided for Ancyrocephalus paradoxus Creplin, 1839. Scanning electron microscopy reveals new information of the body shape, position of the cephalic organs’ openings, and structure of anchors, as well as differences in the in anchors’ structure in adults and sub-adults of A. paradoxus. Energy dispersive analysis for X-ray was conducted for the first time for anchors in Monogenea and revealed structural differences between different parts of the anchors in two age groups.