Are you looking for Gambusia Affinis</em>, or any type of Gambusia? You can find Gambusia in nearly any body of freshwater in the US, or around the world, and all of them will eat mosquito larvae. I read that this fish is the most widespread species in the world, and I believe it. We added about 20 to our pond a few years ago, and I am pretty sure we now have about one kazillion. You're welcome to some of ours.
Wow, at 25 for $30 - my kazillion minnows are worth a fortune!