Any "guppy" living in local streams in Palmie. I would venture to say, are definately gambusia.
A very hardy, noxious fish.
It will wipe out native species and even frogs from any area that they get established in.
If you find any that live down there in the streams, catch and photograph them, for a little bit of confirmation.
By the way, it is illegal to keep, breed, sell, give away, or spread in any way, gambusia.
In fact, if you catch them in a waterway, it is illegal to replace it alive back into the water.
Alan 104