My favorite kind of fishing is for trout, and after having studied the stomach contents of quite a few trout, particularly those caught in deep lakes, I have seen that a large portion of what trout eat are freshwater shrimp of the Gammarus genus, generally called scuds. I have studied gammarids quite a bit, and while some of them can get as big as a single salmon egg, they are not a very practical organism to use for live or dead bait.
I have used scud and egg imitation dry flies to great effect (the orange-colored egg imitations seemed to be indistinguishable to the fish from the scud imitations) in some deep lakes with wild Rainbows in western Alberta when I was working in Canada a few years ago. I have also seen scud imitation lures like the Widowmaker Scud Missile, but I was wondering whether there is a kind of live or natural bait that imitates these well.
I was thinking that perhaps an orange salmon egg or small ball of orange power bait might do the trick, or perhaps actual crayfish or shrimp meat. Another possibility might be to buy the dried gammarus people feed to newts and turtles, soak them, and put a few on the hook.
Thanks for your input, and I am hoping others have thought about the best way to take advantage of the weakness trout have for freshwater shrimp.