check this out : Fishes of Minnesota-Brook silverside
Here's a better picture of a Brook Silverside (better than the pic in the link) -
These little guys are one of the best Crappie baits there is !! And with your unique situation, of having them be the primary baitfish of this body of water, you should really take advantage of that. Catch them and use them
I've caught Crappie on Silversides .... alive, dead, whole, or cut in half ... night or day.
Now ... being as you're in Oklahoma --- you may have the Inland Silversides in your waters. Here's a picture of an Inland Silverside ... note the difference in how the mouth looks :
In either case ... I'd bet that they'd be excellent bait for Crappie or White Bass (Sand Bass, as you call them). They're not too hard to catch, but they are a bit of trouble to keep alive for any length of time ... which is why I know that Crappie will still bite them, even when dead (whole or cut).
... cp