Is Pickeral a different fish then a Walleye?

[yamaha 1]

I was brought up in Saskatchewan for the better part of my life and we allways called Walleye, Pickeral. Now a co worker told me this morrning that a pickeral is a different fish then a Walleye. He said there was no Pickeral in Alberta, just Walleye. Pickeral was only found in Saskatchewan, it looks like a Walleye but it was a different fish. I said you must be thinking of a Sauger and I called bull *****. He said he knew what a Sauger was and that was different. Does any one know if he is telling the truth?