Crappie is a Perch, same as a Walleye is, but I don't mind if you have a preference.
The same electric knife you carve the turkey with will also do well on fish. Assuming you have power of coarse.
About 14 bucks at WalMart, only complaint i have is the cord is a little short.
You are correct, walleye, perch, and crappie are all in the same scientific classification kingdom, phylum, class, and order but we all know that is not how "we" commonly describe them.
My wife would kill me if I used the same electric knife to carve the turkey and fillet fish.
I actually prefer a carving knife over electric carving knife, and yes a fillet knife will do just fine, as well as my cleaver, ulu, or bolo knife.
Life is all about choices, what "we" do with them is entirely up to us. That's the beauty of having plenty of choices and preferences.
There are lots of things we can do without or make do of what "we" have but don't. "Our" rifle/gun inventory is a prime example. I have one electric carving knife and one cordless fillet knife but my rifle/gun inventory is many folds.
Choices, choices, choices ....................... personal preferences/individualism.
Cheers!