I used feeder goldfish last year, but only 1 survived after a week of 100 degree temps. Some floated rather than simply vanishing, so I know they didn't get fished out by raccoons. Maybe I'll try again...
I was thinking that labyrinth fish (gouramis, bettas) should do better because they naturally occur in warm, slow-moving streams that are often not much more than puddles... the "labyrinth organs" in their heads allow them to gulp air and absorb oxygen from it... not quite lungs, but better than relying on gills alone.
Meanwhile, I'm keeping up the mosquito bits!
