I’ve been to Ginny and seen snails and fish and freshwater flounder (but they’re 2in long and well-camoflaged).
Catfish Hotel at Manatee Springs State park pretty much a catfish nursery. You’ll see lots of fish at all stages of growth. It looks like pea soup from all the duckweed but is actually a very nice dive.
Vortex has a lot of fish during the day time. If you want to see eels and crawfish, it’s best to go at night. Like Barry says, they’re shy.