Great news ozark on the grass shrimp. I have spotted some of mine at night with a strong light but during the day I'm sure they hang out in the FA or leaves. I've seined my shallows lately trying to capture the fast moving goldfish and have been surprised when a large shrimp, or some other critter shows up when I didn't know they were there.

Setter, I'm sure you have shrimp they are pretty resilient. Crayfish, not sure... They like rock piles to hide in.