For what its worth (if anything at all that is!!)Heres my understanding of the names/classification of the Zander like species.
As far as I can remember there are four very similar species, our Zander (Stizstedion lucioperca), the Zingel (can?t remember the Latin name but they are found, although quite rare in Eastern Europe. I?ve caught a small on in Czechoslovakia), and the US?s Walleye (Stizostedion vitreum vitreum I seem to remember this name has been changed recently but cant remember what too or why! Sander something or other!) and Sauger (Sander candensis). All four have that piece of skin that covers their eyes (the tapetum lucidum I think) which gives their eyes that pearlescent ?dead? look and if I remember correctly aids the night/coloured water vision.
I cant remember the exact sizes but think I?m right in saying Zingel are the smallest at up to a pound or so maximum, next are Sauger at up to 5 or 6lb, walleye up to 17-18lb (but very rarely. They seem to average around 4lb) and then our Zander which are touching it here but often exceed 20lb on the Continent.