The most abundant little fish in my local creek appear to be mosquito fish. My understanding is that these guys have been introduced just about everywhere around the U.S. to control mosquito populations. They are clearly top feeders (mouth up high) and are (prolific) live breeders. I have a growing population in my tank. Anyone have a feel for them? Again I suspect they are diet for the native population around here. I'll post a picture in a bit.