Animals 6 Argentina 6 Cestoda 6 Microscopy, Electron, Scanning 6 Skates (Fish) 6 Tetraphyllidea 6 article 6 cestode 6 electric fish 6 parasitology 6 Female 4 Intestines 4 Male 4 Potamotrygon 4 Potamotrygon motoro 4 Potamotrygoninae 4 animal 4 animal disease 4 histology 4 morphology 4 nonhuman 4 scanning electron microscopy 4 taxonomy 4 ultrastructure 4 Agonistic behavior 2 Animalia 2 Arhynchobatinae 2 Atlantoraja castelnaui 2 Bathyraja eatonii 2 Bathyraja maccaini 2