I dug a small 30' x 30' "vernal pool" about 5-8' depth with some shallows, for the frogs and amphibians. Due to mosquito issues I put 2 dozen feeder goldfish in just for fun. Within two years I had approximately 3-400 goldfish. 5 years out they were to numerous to count and some were over 9 inches long. I found it cool to see the genetic variation that occurred, with color from white through gold and all black with every combination in between, along with fan tails and regular tails. One major drawback is that they keep the bottom stirred up all the time so the water stays really muddy. This is a little different though since the only predator pressure on the goldfish is from bullfrogs and herons.
